Compare regions, not four loose numbers

`PixelRegion` derives `PartialEq`, `Clone` and `Copy`, so `assert_corners!` compares one against another instead of flattening both to a tuple whose order there was nothing to check. A failure now prints two regions.
Say what these do without naming what they lean on
2026-09-13 21:42:21 -04:00 · 2026-09-13 21:37:44 -04:00 · 2026-09-13 21:29:38 -04:00 · 2026-09-13 21:04:29 -04:00 · 2026-09-13 20:44:01 -04:00 · 2026-09-13 20:16:17 -04:00
42 changed files with 2056 additions and 1238 deletions
@@ -234,18 +234,18 @@ dependencies = [
 [[package]]
 name = "bit-set"
-version = "0.8.0"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "08807e080ed7f9d5433fa9b275196cfc35414f66a0c79d864dc51a0d825231a3"
+checksum = "09ec2f926cc3060f09db9ebc5b52823d85268d24bb917e472c0c4bea35780a7d"
 dependencies = [
 "bit-vec",
 ]
 [[package]]
 name = "bit-vec"
-version = "0.8.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"
+checksum = "b71798fca2c1fe1086445a7258a4bc81e6e49dcd24c8d0dd9a1e57395b603f51"
 [[package]]
 name = "bit_field"
@@ -274,12 +274,6 @@ dependencies = [
 "core2",
 ]
 [[package]]
 name = "block"
 version = "0.1.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d8c1fef690941d3e7788d328517591fecc684c084084702d6ff1641e993699a"
 [[package]]
 name = "block2"
 version = "0.5.1"
@@ -289,6 +283,15 @@ dependencies = [
 "objc2 0.5.2",
 ]
 [[package]]
 name = "block2"
 version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cdeb9d870516001442e364c5220d3574d2da8dc765554b4a617230d33fa58ef5"
 dependencies = [
 "objc2 0.6.4",
 ]
 [[package]]
 name = "built"
 version = "0.8.0"
@@ -391,9 +394,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"
 [[package]]
 name = "cfg_aliases"
-version = "0.2.1"
+version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"
+checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
 [[package]]
 name = "clipboard-win"
@@ -406,9 +409,9 @@ dependencies = [
 [[package]]
 name = "codespan-reporting"
-version = "0.12.0"
+version = "0.13.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe6d2e5af09e8c8ad56c969f2157a3d4238cebc7c55f0a517728c38f7b200f81"
+checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
 dependencies = [
 "serde",
 "termcolor",
@@ -450,16 +453,6 @@ dependencies = [
 "libc",
 ]
 [[package]]
 name = "core-foundation"
 version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b2a6cd9ae233e7f62ba4e9353e81a88df7fc8a5987b8d445b4d90c879bd156f6"
 dependencies = [
 "core-foundation-sys",
 "libc",
 ]
 [[package]]
 name = "core-foundation-sys"
 version = "0.8.7"
@@ -473,8 +466,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c07782be35f9e1140080c6b96f0d44b739e2278479f64e02fdab4e32dfd8b081"
 dependencies = [
 "bitflags 1.3.2",
- "core-foundation 0.9.4",
+ "core-foundation",
- "core-graphics-types 0.1.3",
+ "core-graphics-types",
 "foreign-types",
 "libc",
 ]
@@ -486,18 +479,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "45390e6114f68f718cc7a830514a96f903cccd70d02a8f6d9f643ac4ba45afaf"
 dependencies = [
 "bitflags 1.3.2",
- "core-foundation 0.9.4",
+ "core-foundation",
 "libc",
 ]
 [[package]]
 name = "core-graphics-types"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3d44a101f213f6c4cdc1853d4b78aef6db6bdfa3468798cc1d9912f4735013eb"
 dependencies = [
 "bitflags 2.10.0",
 "core-foundation 0.10.1",
 "libc",
 ]
@@ -739,15 +721,6 @@ version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "77ce24cb58228fbb8aa041425bb1050850ac19177686ea6e0f41a70416f56fdb"
 [[package]]
 name = "font-types"
 version = "0.10.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39a654f404bbcbd48ea58c617c2993ee91d1cb63727a37bf2323a4edeed1b8c5"
 dependencies = [
 "bytemuck",
 ]
 [[package]]
 name = "font-types"
 version = "0.12.4"
@@ -771,7 +744,7 @@ dependencies = [
 "objc2-core-text",
 "objc2-foundation 0.3.2",
 "parlance",
- "read-fonts 0.41.0",
+ "read-fonts",
 "roxmltree",
 "smallvec",
 "windows",
@@ -806,6 +779,30 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "aa9a19cbb55df58761df49b23516a86d432839add4af60fc256da840f66ed35b"
 [[package]]
 name = "futures-core"
 version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "92d699e522242e69e3003b94ecc1f960f3a5e015aa7c5d7486e65ad01dd94f5e"
 [[package]]
 name = "futures-task"
 version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd417de3d1d015fc3bfd2b1ea46dfc7bab72ef86f1cc7cc9c78e728b34a6d1fd"
 [[package]]
 name = "futures-util"
 version = "0.3.34"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0d50a92467f8ba5dd6e3ee5d4bd04d73ab2e4e1c44474a0674821dfce14b79bc"
 dependencies = [
 "futures-core",
 "futures-task",
 "pin-project-lite",
 "slab",
 ]
 [[package]]
 name = "fxhash"
 version = "0.2.1"
@@ -860,9 +857,9 @@ dependencies = [
 [[package]]
 name = "glow"
-version = "0.16.0"
+version = "0.17.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5e5ea60d70410161c8bf5da3fdfeaa1c72ed2c15f8bbb9d19fe3a4fad085f08"
+checksum = "29038e1c483364cc6bb3cf78feee1816002e127c331a1eec55a4d202b9e1adb5"
 dependencies = [
 "js-sys",
 "slotmap",
@@ -893,26 +890,6 @@ dependencies = [
 "windows",
 ]
 [[package]]
 name = "gpu-descriptor"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b89c83349105e3732062a895becfc71a8f921bb71ecbbdd8ff99263e3b53a0ca"
 dependencies = [
 "bitflags 2.10.0",
 "gpu-descriptor-types",
 "hashbrown 0.15.5",
 ]
 [[package]]
 name = "gpu-descriptor-types"
 version = "0.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fdf242682df893b86f33a73828fb09ca4b2d3bb6cc95249707fc684d27484b91"
 dependencies = [
 "bitflags 2.10.0",
 ]
 [[package]]
 name = "half"
 version = "2.7.1"
@@ -933,7 +910,7 @@ checksum = "c03d949a14aa089bbb282f7dd76a498a7f684428e4257202efc119ec010376f9"
 dependencies = [
 "bitflags 2.10.0",
 "bytemuck",
- "read-fonts 0.41.0",
+ "read-fonts",
 "smallvec",
 ]
@@ -972,12 +949,6 @@ version = "0.5.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
 [[package]]
 name = "hexf-parse"
 version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dfa686283ad6dd069f105e5ab091b04c62850d3e4cf5d67debad1933f55023df"
 [[package]]
 name = "icu_collections"
 version = "2.3.0"
@@ -1108,9 +1079,9 @@ checksum = "ae293c039020f9ec10710af98d29ce6aa2051486638b49c9a6409f3b4a9e98ad"
 [[package]]
 name = "image"
-version = "0.25.9"
+version = "0.25.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6506c6c10786659413faa717ceebcb8f70731c0a60cbae39795fdf114519c1a"
+checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
 dependencies = [
 "bytemuck",
 "byteorder-lite",
@@ -1126,8 +1097,8 @@ dependencies = [
 "rayon",
 "rgb",
 "tiff",
- "zune-core 0.5.0",
+ "zune-core",
- "zune-jpeg 0.5.8",
+ "zune-jpeg",
 ]
 [[package]]
@@ -1247,11 +1218,12 @@ dependencies = [
 [[package]]
 name = "js-sys"
-version = "0.3.83"
+version = "0.3.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "464a3709c7f55f1f721e5389aa6ea4e3bc6aba669353300af094b29ffbdde1d8"
+checksum = "ce57d20d1ea864ce2ac172ab472d409214f4fd359f0b2a2775abdf522e2af99e"
 dependencies = [
- "once_cell",
+ "cfg-if",
 "futures-util",
 "wasm-bindgen",
 ]
@@ -1280,9 +1252,9 @@ checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"
 [[package]]
 name = "libc"
-version = "0.2.179"
+version = "0.2.189"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c5a2d376baa530d1238d133232d15e239abad80d05838b4b59354e5268af431f"
+checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"
 [[package]]
 name = "libfuzzer-sys"
@@ -1375,15 +1347,6 @@ dependencies = [
 "imgref",
 ]
 [[package]]
 name = "malloc_buf"
 version = "0.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "62bb907fe88d54d8d9ce32a3cceab4218ed2f6b7d35617cafe9adf84e43919cb"
 dependencies = [
 "libc",
 ]
 [[package]]
 name = "maybe-rayon"
 version = "0.1.1"
@@ -1409,21 +1372,6 @@ dependencies = [
 "libc",
 ]
 [[package]]
 name = "metal"
 version = "0.33.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c7047791b5bc903b8cd963014b355f71dc9864a9a0b727057676c1dcae5cbc15"
 dependencies = [
 "bitflags 2.10.0",
 "block",
 "core-graphics-types 0.2.0",
 "foreign-types",
 "log",
 "objc",
 "paste",
 ]
 [[package]]
 name = "miniz_oxide"
 version = "0.8.9"
@@ -1436,9 +1384,9 @@ dependencies = [
 [[package]]
 name = "moxcms"
-version = "0.7.11"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ac9557c559cd6fc9867e122e20d2cbefc9ca29d80d027a8e39310920ed2f0a97"
+checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
 dependencies = [
 "num-traits",
 "pxfm",
@@ -1446,9 +1394,9 @@ dependencies = [
 [[package]]
 name = "naga"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "618f667225063219ddfc61251087db8a9aec3c3f0950c916b614e403486f1135"
+checksum = "a616d2fb8c89516ac2723a581f69d6c18576046bed761bd6b305e5618e6ae130"
 dependencies = [
 "arrayvec",
 "bit-set",
@@ -1457,11 +1405,11 @@ dependencies = [
 "cfg_aliases",
 "codespan-reporting",
 "half",
- "hashbrown 0.16.1",
+ "hashbrown 0.17.1",
 "hexf-parse",
 "indexmap",
 "libm",
 "log",
 "naga-types",
 "num-traits",
 "once_cell",
 "rustc-hash",
@@ -1470,6 +1418,18 @@ dependencies = [
 "unicode-ident",
 ]
 [[package]]
 name = "naga-types"
 version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "590afbf58a6f4f62873cd5cff4468061844bafa1cdf399cc954537c22d768d49"
 dependencies = [
 "hashbrown 0.17.1",
 "indexmap",
 "rustc-hash",
 "thiserror 2.0.17",
 ]
 [[package]]
 name = "ndk"
 version = "0.9.0"
@@ -1594,15 +1554,6 @@ dependencies = [
 "syn 2.0.113",
 ]
 [[package]]
 name = "objc"
 version = "0.2.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "915b1b472bc21c53464d6c8461c9d3af805ba1ef837e1cac254428f4a77177b1"
 dependencies = [
 "malloc_buf",
 ]
 [[package]]
 name = "objc-sys"
 version = "0.3.5"
@@ -1635,13 +1586,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e4e89ad9e3d7d297152b17d39ed92cd50ca8063a89a9fa569046d41568891eff"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "libc",
 "objc2 0.5.2",
 "objc2-core-data",
 "objc2-core-image",
 "objc2-foundation 0.2.2",
- "objc2-quartz-core",
+ "objc2-quartz-core 0.2.2",
 ]
 [[package]]
@@ -1663,7 +1614,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "74dd3b56391c7a0596a295029734d3c1c5e7e510a4cb30245f8221ccea96b009"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-core-location",
 "objc2-foundation 0.2.2",
@@ -1675,7 +1626,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a5ff520e9c33812fd374d8deecef01d4a840e7b41862d849513de77e44aa4889"
 dependencies = [
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1687,7 +1638,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "617fbf49e071c178c0b24c080767db52958f716d9eabdf0890523aeae54773ef"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1722,10 +1673,10 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55260963a527c99f1819c4f8e3b47fe04f9650694ef348ffd2227e8196d34c80"
 dependencies = [
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
- "objc2-metal",
+ "objc2-metal 0.2.2",
 ]
 [[package]]
@@ -1734,7 +1685,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "000cfee34e683244f284252ee206a27953279d370e309649dc3ee317b37e5781"
 dependencies = [
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-contacts",
 "objc2-foundation 0.2.2",
@@ -1763,7 +1714,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0ee638a5da3799329310ad4cfa62fbf045d5f56e3ef5ba4149e7452dcf89d5a8"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "dispatch",
 "libc",
 "objc2 0.5.2",
@@ -1797,7 +1748,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a1a1ae721c5e35be65f01a03b6d2ac13a54cb4fa70d8a5da293d7b0020261398"
 dependencies = [
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-app-kit 0.2.2",
 "objc2-foundation 0.2.2",
@@ -1810,11 +1761,23 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "dd0cba1276f6023976a406a14ffa85e1fdd19df6b0f737b063b95f6c8c7aadd6"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
 [[package]]
 name = "objc2-metal"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a0125f776a10d00af4152d74616409f0d4a2053a6f57fa5b7d6aa2854ac04794"
 dependencies = [
 "bitflags 2.10.0",
 "block2 0.6.2",
 "objc2 0.6.4",
 "objc2-foundation 0.3.2",
 ]
 [[package]]
 name = "objc2-quartz-core"
 version = "0.2.2"
@@ -1822,10 +1785,24 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e42bee7bff906b14b167da2bac5efe6b6a07e6f7c0a21a7308d40c960242dc7a"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
- "objc2-metal",
+ "objc2-metal 0.2.2",
 ]
 [[package]]
 name = "objc2-quartz-core"
 version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "96c1358452b371bf9f104e21ec536d37a650eb10f7ee379fff67d2e08d537f1f"
 dependencies = [
 "bitflags 2.10.0",
 "objc2 0.6.4",
 "objc2-core-foundation",
 "objc2-core-graphics",
 "objc2-foundation 0.3.2",
 "objc2-metal 0.3.2",
 ]
 [[package]]
@@ -1845,7 +1822,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8bb46798b20cd6b91cbd113524c490f1686f4c4e8f49502431415f3512e2b6f"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-cloud-kit",
 "objc2-core-data",
@@ -1853,7 +1830,7 @@ dependencies = [
 "objc2-core-location",
 "objc2-foundation 0.2.2",
 "objc2-link-presentation",
- "objc2-quartz-core",
+ "objc2-quartz-core 0.2.2",
 "objc2-symbols",
 "objc2-uniform-type-identifiers",
 "objc2-user-notifications",
@@ -1865,7 +1842,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "44fa5f9748dbfe1ca6c0b79ad20725a11eca7c2218bceb4b005cb1be26273bfe"
 dependencies = [
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1877,7 +1854,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "76cfcbf642358e8689af64cee815d139339f3ed8ad05103ed5eaf73db8d84cb3"
 dependencies = [
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "objc2 0.5.2",
 "objc2-core-location",
 "objc2-foundation 0.2.2",
@@ -1971,7 +1948,7 @@ dependencies = [
 "linebender_resource_handle",
 "parlance",
 "parley_data",
- "skrifa 0.44.0",
+ "skrifa",
 ]
 [[package]]
@@ -2275,9 +2252,9 @@ dependencies = [
 [[package]]
 name = "ravif"
-version = "0.12.0"
+version = "0.13.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ef69c1990ceef18a116855938e74793a5f7496ee907562bd0857b6ac734ab285"
+checksum = "e52310197d971b0f5be7fe6b57530dcd27beb35c1b013f29d66c1ad73fbbcc45"
 dependencies = [
 "avif-serialize",
 "imgref",
@@ -2294,6 +2271,18 @@ version = "0.6.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "20675572f6f24e9e76ef639bc5552774ed45f1c30e2951e1e99c59888861c539"
 [[package]]
 name = "raw-window-metal"
 version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "40d213455a5f1dc59214213c7330e074ddf8114c9a42411eb890c767357ce135"
 dependencies = [
 "objc2 0.6.4",
 "objc2-core-foundation",
 "objc2-foundation 0.3.2",
 "objc2-quartz-core 0.3.2",
 ]
 [[package]]
 name = "rayon"
 version = "1.11.0"
@@ -2314,16 +2303,6 @@ dependencies = [
 "crossbeam-utils",
 ]
 [[package]]
 name = "read-fonts"
 version = "0.36.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5eaa2941a4c05443ee3a7b26ab076a553c343ad5995230cc2b1d3e993bdc6345"
 dependencies = [
 "bytemuck",
 "font-types 0.10.1",
 ]
 [[package]]
 name = "read-fonts"
 version = "0.41.0"
@@ -2331,7 +2310,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "046a7d674daf459825b32f5062056d6882db0d2f5a479fbd76ccfc870ac18709"
 dependencies = [
 "bytemuck",
- "font-types 0.12.4",
+ "font-types",
 "once_cell",
 ]
@@ -2506,16 +2485,6 @@ dependencies = [
 "quote",
 ]
 [[package]]
 name = "skrifa"
 version = "0.39.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c9eb0b904a04d09bd68c65d946617b8ff733009999050f3b851c32fb3cfb60e"
 dependencies = [
 "bytemuck",
 "read-fonts 0.36.0",
 ]
 [[package]]
 name = "skrifa"
 version = "0.44.0"
@@ -2523,7 +2492,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "819ab7d62b1d3e72d9d9dea5650bac30424f9111364bb94928dbf5ecad1baa68"
 dependencies = [
 "bytemuck",
- "read-fonts 0.41.0",
+ "read-fonts",
 ]
 [[package]]
@@ -2583,9 +2552,9 @@ dependencies = [
 [[package]]
 name = "spirv"
-version = "0.3.0+sdk-1.3.268.0"
+version = "0.4.0+sdk-1.4.341.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "eda41003dc44290527a59b13432d4a0379379fa074b70174882adfbdfd917844"
+checksum = "d9571ea910ebd84c86af4b3ed27f9dbdc6ad06f17c5f96146b2b671e2976744f"
 dependencies = [
 "bitflags 2.10.0",
 ]
@@ -2614,7 +2583,7 @@ version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c2499c2d826531388872b2268718aed907a39bd785ab0dcfe57fab26283f92e"
 dependencies = [
- "skrifa 0.39.0",
+ "skrifa",
 "yazi",
 "zeno",
 ]
@@ -2703,16 +2672,16 @@ dependencies = [
 [[package]]
 name = "tiff"
-version = "0.10.3"
+version = "0.11.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af9605de7fee8d9551863fd692cce7637f548dbd9db9180fcc07ccc6d26c336f"
+checksum = "b63feaf3343d35b6ca4d50483f94843803b0f51634937cc2ec519fc32232bc52"
 dependencies = [
 "fax",
 "flate2",
 "half",
 "quick-error",
 "weezl",
- "zune-jpeg 0.4.21",
+ "zune-jpeg",
 ]
 [[package]]
@@ -2885,9 +2854,9 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.106"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0d759f433fa64a2d763d1340820e46e111a7a5ab75f993d1852d70b03dbb80fd"
+checksum = "aecb87a33d3b0c5e3b7aa46336eaf486cffafbd281b195e4c8b80d50df2351bf"
 dependencies = [
 "cfg-if",
 "once_cell",
@@ -2898,22 +2867,19 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.56"
+version = "0.4.78"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "836d9622d604feee9e5de25ac10e3ea5f2d65b41eac0d9ce72eb5deae707ce7c"
+checksum = "6ef4c5d3d2cdf5c54f4231181768f5510842e350db025faf1f7163b1030ed928"
 dependencies = [
 "cfg-if",
 "js-sys",
 "once_cell",
 "wasm-bindgen",
 "web-sys",
 ]
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.106"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "48cb0d2638f8baedbc542ed444afc0644a29166f1595371af4fecf8ce1e7eeb3"
+checksum = "a690d511e3c1a8b3a55e33511e3c2c00c78415cd23650f32b808627f5696b9ed"
 dependencies = [
 "quote",
 "wasm-bindgen-macro-support",
@@ -2921,22 +2887,22 @@ dependencies = [
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.106"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cefb59d5cd5f92d9dcf80e4683949f15ca4b511f4ac0a6e14d4e1ac60c6ecd40"
+checksum = "411e4887f0071ef2d2164a9d5fdf2d20efbef78fccd3a78b0c10a1dc5295e48a"
 dependencies = [
 "bumpalo",
 "proc-macro2",
 "quote",
- "syn 2.0.113",
+ "syn 3.0.5",
 "wasm-bindgen-shared",
 ]
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.106"
+version = "0.2.128"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cbc538057e648b67f72a982e708d485b2efa771e1ac05fec311f9f63e5800db4"
+checksum = "81941cd78d0c92026c33e5e01312845a4cb1e9af3407f9134b100dd03144103e"
 dependencies = [
 "unicode-ident",
 ]
@@ -3052,9 +3018,9 @@ dependencies = [
 [[package]]
 name = "web-sys"
-version = "0.3.83"
+version = "0.3.105"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9b32828d774c412041098d182a8b38b16ea816958e07cf40eec2bc080ae137ac"
+checksum = "9fbddc4a036f00ec4f18c83445bd3115cb306a91da554919a099d9222fe4a7f8"
 dependencies = [
 "js-sys",
 "wasm-bindgen",
@@ -3078,9 +3044,9 @@ checksum = "a28ac98ddc8b9274cb41bb4d9d4d5c425b6020c50c46f25559911905610b4a88"
 [[package]]
 name = "wgpu"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9cb534d5ffd109c7d1135f34cdae29e60eab94855a625dcfe1705f8bc7ad79f"
+checksum = "527ccdf43dd5b2e8676eed9984ce00e2bbb0a1b85b70c1969dcb6cd2eb55ab9e"
 dependencies = [
 "arrayvec",
 "bitflags 2.10.0",
@@ -3088,7 +3054,7 @@ dependencies = [
 "cfg-if",
 "cfg_aliases",
 "document-features",
- "hashbrown 0.16.1",
+ "hashbrown 0.17.1",
 "js-sys",
 "log",
 "naga",
@@ -3108,9 +3074,9 @@ dependencies = [
 [[package]]
 name = "wgpu-core"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8bb4c8b5db5f00e56f1f08869d870a0dff7c8bc7ebc01091fec140b0cf0211a9"
+checksum = "14c018fce9b6270aa203c2fdd56f3cce996713534bd757e4ea58c8560b121f14"
 dependencies = [
 "arrayvec",
 "bit-set",
@@ -3119,10 +3085,11 @@ dependencies = [
 "bytemuck",
 "cfg_aliases",
 "document-features",
- "hashbrown 0.16.1",
+ "hashbrown 0.17.1",
 "indexmap",
 "log",
 "naga",
 "naga-types",
 "once_cell",
 "parking_lot",
 "portable-atomic",
@@ -3135,66 +3102,70 @@ dependencies = [
 "wgpu-core-deps-emscripten",
 "wgpu-core-deps-windows-linux-android",
 "wgpu-hal",
 "wgpu-naga-bridge",
 "wgpu-types",
 ]
 [[package]]
 name = "wgpu-core-deps-apple"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "87b7b696b918f337c486bf93142454080a32a37832ba8a31e4f48221890047da"
+checksum = "061f3d319a40d39d00b1ecc2c33b89fe21d4e6fe01859df3500a3a8ecccd6b68"
 dependencies = [
 "wgpu-hal",
 ]
 [[package]]
 name = "wgpu-core-deps-emscripten"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34b251c331f84feac147de3c4aa3aa45112622a95dd7ee1b74384fa0458dbd79"
+checksum = "d98b86cf4abf524a902dd35f18ca6a3f08fc2ae9847c8f10b48e30491b1f0b86"
 dependencies = [
 "wgpu-hal",
 ]
 [[package]]
 name = "wgpu-core-deps-windows-linux-android"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "68ca976e72b2c9964eb243e281f6ce7f14a514e409920920dcda12ae40febaae"
+checksum = "7586165fd5f6d881cb9ce4bb71f40d6caab2c0f1837e3fc1d9788a197fb6004f"
 dependencies = [
 "wgpu-hal",
 ]
 [[package]]
 name = "wgpu-hal"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "293080d77fdd14d6b08a67c5487dfddbf874534bb7921526db56a7b75d7e3bef"
+checksum = "b6b7fb58561a792bc237628ba0792e332de418fefe145f13b5ed8201e6d52f58"
 dependencies = [
 "android_system_properties",
 "arrayvec",
 "ash",
 "bit-set",
 "bitflags 2.10.0",
- "block",
+ "block2 0.6.2",
 "bytemuck",
 "cfg-if",
 "cfg_aliases",
 "core-graphics-types 0.2.0",
 "glow",
 "glutin_wgl_sys",
 "gpu-allocator",
- "gpu-descriptor",
+ "hashbrown 0.17.1",
 "hashbrown 0.16.1",
 "js-sys",
 "khronos-egl",
 "libc",
 "libloading",
 "log",
 "metal",
 "naga",
 "naga-types",
 "ndk-sys",
- "objc",
+ "objc2 0.6.4",
 "objc2-core-foundation",
 "objc2-core-graphics",
 "objc2-foundation 0.3.2",
 "objc2-metal 0.3.2",
 "objc2-quartz-core 0.3.2",
 "once_cell",
 "ordered-float",
 "parking_lot",
@@ -3203,26 +3174,44 @@ dependencies = [
 "profiling",
 "range-alloc",
 "raw-window-handle",
 "raw-window-metal",
 "renderdoc-sys",
 "smallvec",
 "static_assertions",
 "thiserror 2.0.17",
 "wasm-bindgen",
 "wayland-sys",
 "web-sys",
 "wgpu-naga-bridge",
 "wgpu-types",
 "windows",
 "windows-core",
 "windows-result",
 ]
 [[package]]
 name = "wgpu-naga-bridge"
 version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "d2f62e73117bb7a62bfd9c5a5841438a823f6566c6442a808ee269d2d055c081"
 dependencies = [
 "naga",
 "wgpu-types",
 ]
 [[package]]
 name = "wgpu-types"
-version = "28.0.0"
+version = "30.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e18308757e594ed2cd27dddbb16a139c42a683819d32a2e0b1b0167552f5840c"
+checksum = "99dad6f1fbdbbdb4c278a6508b059d44688f5cebddf78d005a46a31340269286"
 dependencies = [
 "bitflags 2.10.0",
 "bytemuck",
 "js-sys",
 "log",
 "naga-types",
 "raw-window-handle",
 "static_assertions",
 "web-sys",
 ]
@@ -3586,12 +3575,12 @@ dependencies = [
 "android-activity",
 "atomic-waker",
 "bitflags 2.10.0",
- "block2",
+ "block2 0.5.1",
 "bytemuck",
 "calloop",
 "cfg_aliases",
 "concurrent-queue",
- "core-foundation 0.9.4",
+ "core-foundation",
 "core-graphics",
 "cursor-icon",
 "dpi",
@@ -3858,12 +3847,6 @@ dependencies = [
 "syn 3.0.5",
 ]
 [[package]]
 name = "zune-core"
 version = "0.4.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "3f423a2c17029964870cfaabb1f13dfab7d092a62a29a89264f4d36990ca414a"
 [[package]]
 name = "zune-core"
 version = "0.5.0"
@@ -3879,20 +3862,11 @@ dependencies = [
 "simd-adler32",
 ]
 [[package]]
 name = "zune-jpeg"
 version = "0.4.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "29ce2c8a9384ad323cf564b67da86e21d3cfdff87908bc1223ed5c99bc792713"
 dependencies = [
 "zune-core 0.4.12",
 ]
 [[package]]
 name = "zune-jpeg"
 version = "0.5.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e35aee689668bf9bd6f6f3a6c60bb29ba1244b3b43adfd50edd554a371da37d5"
 dependencies = [
- "zune-core 0.5.0",
+ "zune-core",
 ]
@@ -29,9 +29,9 @@ edition = "2024"
 [workspace.dependencies]
 pollster = "0.4.0"
 winit = "0.30.12"
-wgpu = "28.0.0"
+wgpu = "30.0.1"
 bytemuck = "1.23.1"
-image = "0.25.6"
+image = "0.25.10"
 parley = "0.11.1"
 swash = "0.2.10"
 fxhash = "0.2.1"
@@ -421,7 +421,7 @@ impl Display for UiRegion {
    }
 }
-#[derive(Debug)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub struct PixelRegion {
    pub top_left: Vec2,
    pub bot_right: Vec2,
@@ -1,7 +1,7 @@
 use std::ops::{Index, IndexMut};
 use crate::{
-    render::{MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst, Primitives},
+    render::{LayerDraws, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
    util::to_mut,
 };
@@ -39,7 +39,7 @@ struct Child {
    tail: usize,
 }
-pub type PrimitiveLayers = Layers<Primitives>;
+pub type DrawLayers = Layers<LayerDraws>;
 impl<T: Default> Layers<T> {
    pub fn new() -> Layers<T> {
@@ -119,7 +119,7 @@ impl<T: Default> Layers<T> {
    }
 }
-impl PrimitiveLayers {
+impl DrawLayers {
    pub fn write<P: Primitive>(
        &mut self,
        layer: LayerId,
@@ -1,6 +1,5 @@
 use crate::{
-    Align, GlyphAtlas, GlyphEntry, GlyphKey, PlacedGlyph, RegionAlign, Textures, UiColor,
+    Align, GlyphAtlas, GlyphEntry, GlyphKey, PlacedGlyph, RegionAlign, UiColor, util::Vec2,
    util::Vec2,
 };
 use parley::{
    Alignment, AlignmentOptions, FontContext, FontFamily, FontFamilyName, GenericFamily, Layout,
@@ -159,7 +158,7 @@ impl TextBuffer {
 }
 impl TextData {
-    pub fn place(&mut self, buffer: &TextBuffer, textures: &mut Textures) -> Vec<PlacedGlyph> {
+    pub fn place(&mut self, buffer: &TextBuffer) -> Vec<PlacedGlyph> {
        let mut placed = Vec::new();
        for line in buffer.layout.lines() {
            for item in line.items() {
@@ -185,17 +184,14 @@ impl TextData {
                        subpixel,
                        coords: coords_hash,
                    };
-                    let Some(entry) = self.glyph_entry(
+                    let Some(entry) = self.glyph_entry(GlyphRaster {
-                        GlyphRaster {
+                        key,
-                            key,
+                        font: font_ref,
-                            font: font_ref,
+                        font_size,
-                            font_size,
+                        coords,
-                            coords,
+                        subpixel,
-                            subpixel,
+                        glyph_id: glyph.id,
-                            glyph_id: glyph.id,
+                    }) else {
                        },
                        textures,
                    ) else {
                        continue;
                    };
                    placed.push(PlacedGlyph {
@@ -211,11 +207,7 @@ impl TextData {
        placed
    }
-    fn glyph_entry(
+    fn glyph_entry(&mut self, glyph: GlyphRaster<'_>) -> Option<GlyphEntry> {
        &mut self,
        glyph: GlyphRaster<'_>,
        textures: &mut Textures,
    ) -> Option<GlyphEntry> {
        if let Some(entry) = self.atlas.get(&glyph.key) {
            return entry;
        }
@@ -237,7 +229,7 @@ impl TextData {
        .render(&mut scaler, glyph.glyph_id as u16);
        if let Some(image) = image {
-            self.atlas.insert(glyph.key, &image, textures)
+            self.atlas.insert(glyph.key, &image)
        } else {
            self.atlas.insert_empty(glyph.key);
            None
@@ -278,10 +270,9 @@ impl TextData {
        buffer: &mut TextBuffer,
        attrs: &TextAttrs,
        width: Option<f32>,
        textures: &mut Textures,
    ) -> RenderedText {
        buffer.shape(self, attrs, width);
-        let glyphs = self.place(buffer, textures);
+        let glyphs = self.place(buffer);
        RenderedText {
            glyphs,
            size: buffer.size(),
@@ -1,7 +1,4 @@
-use crate::{
+use crate::util::{RefCounter, Vec2};
    render::TexturePrimitive,
    util::{RefCounter, Vec2},
 };
 use image::{DynamicImage, GenericImageView};
 use std::{
    ops::Index,
@@ -10,7 +7,7 @@ use std::{
 #[derive(Debug, Clone)]
 pub struct TextureHandle {
-    inner: TexturePrimitive,
+    slot: u32,
    size: Vec2,
    counter: RefCounter,
    send: Sender<u32>,
@@ -31,6 +28,8 @@ pub enum TextureUpdate<'a> {
    Set(u32, &'a DynamicImage),
    Patch(u32, PatchRect, &'a DynamicImage),
    Free(u32),
    /// Added and freed before the renderer drained either update. It still has
    /// to push a slot to stay lined up with `images`; `Free` then empties it.
    PushFree,
    SetFree,
 }
@@ -64,14 +63,8 @@ impl Textures {
    pub fn add(&mut self, image: impl Into<DynamicImage>) -> TextureHandle {
        let image = image.into();
        let size = image.dimensions().into();
        let view_idx = self.push(image);
        // 0 == default in renderer; TODO: actually create samplers here
        let sampler_idx = 0;
        TextureHandle {
-            inner: TexturePrimitive {
+            slot: self.push(image),
                view_idx,
                sampler_idx,
            },
            size,
            counter: RefCounter::new(),
            send: self.send.clone(),
@@ -92,15 +85,20 @@ impl Textures {
    }
    pub fn image_mut(&mut self, handle: &TextureHandle) -> &mut DynamicImage {
-        self.images[handle.inner.view_idx as usize]
+        self.images[handle.slot as usize]
            .as_mut()
            .expect("texture was freed while still held")
    }
    /// Queue an upload of just `rect`, after writing it with `image_mut`.
    pub fn patch(&mut self, handle: &TextureHandle, rect: PatchRect) {
-        self.updates
+        self.updates.push(Update::Patch(handle.slot, rect));
-            .push(Update::Patch(handle.inner.view_idx, rect));
+    }
    /// How many textures are live, which is what a ui can ask; the renderer's
    /// copies follow from the updates it drains.
    pub fn count(&self) -> usize {
        self.images.iter().flatten().count()
    }
    pub fn free(&mut self) {
@@ -131,8 +129,9 @@ impl Textures {
 }
 impl TextureHandle {
-    pub fn primitive(&self) -> TexturePrimitive {
+    /// Index into `Textures`, and into the renderer's parallel slots.
-        self.inner
+    pub fn slot(&self) -> u32 {
        self.slot
    }
    pub fn size(&self) -> Vec2 {
        self.size
@@ -142,7 +141,7 @@ impl TextureHandle {
 impl Drop for TextureHandle {
    fn drop(&mut self) {
        if self.counter.drop() {
-            let _ = self.send.send(self.inner.view_idx);
+            let _ = self.send.send(self.slot);
        }
    }
 }
@@ -151,7 +150,7 @@ impl Index<&TextureHandle> for Textures {
    type Output = DynamicImage;
    fn index(&self, index: &TextureHandle) -> &Self::Output {
-        self.images[index.inner.view_idx as usize].as_ref().unwrap()
+        self.images[index.slot as usize].as_ref().unwrap()
    }
 }
@@ -1,11 +1,12 @@
 use crate::{
-    PatchRect, TextureHandle, Textures,
+    PatchRect,
    util::{HashMap, Vec2},
 };
 use image::RgbaImage;
 use swash::scale::image::{Content, Image};
-const PAGE: u32 = 1024;
+/// Side of one page, and so of every layer of `render::page`'s array texture.
 pub(crate) const PAGE: u32 = 1024;
 /// Transparent margin kept around every glyph, so that sampling one cannot
 /// pick up its neighbour along a shared edge.
@@ -35,8 +36,8 @@ pub struct GlyphEntry {
    pub width: u32,
    pub height: u32,
    pub is_colored: bool,
-    pub view_idx: u32,
+    /// Which atlas array layer this glyph is on.
-    pub sampler_idx: u32,
+    pub layer: u32,
 }
 impl GlyphEntry {
@@ -48,18 +49,26 @@ impl GlyphEntry {
 }
 struct Page {
-    handle: TextureHandle,
+    image: RgbaImage,
    x: u32,
    y: u32,
    shelf_height: u32,
 }
 /// A rectangle of one page the renderer has not uploaded yet.
 #[derive(Clone, Copy)]
 pub struct PageUpload {
    pub layer: u32,
    pub rect: PatchRect,
 }
 #[derive(Default)]
 pub struct GlyphAtlas {
    pages: Vec<Page>,
    /// `None` for a glyph that rasterised to nothing -- a space, say. Cached
    /// too, so it is not re-rasterised on every layout.
    entries: HashMap<GlyphKey, Option<GlyphEntry>>,
    uploads: Vec<PageUpload>,
 }
 impl GlyphAtlas {
@@ -67,12 +76,7 @@ impl GlyphAtlas {
        self.entries.get(key).copied()
    }
-    pub fn insert(
+    pub fn insert(&mut self, key: GlyphKey, image: &Image) -> Option<GlyphEntry> {
        &mut self,
        key: GlyphKey,
        image: &Image,
        textures: &mut Textures,
    ) -> Option<GlyphEntry> {
        let w = image.placement.width;
        let h = image.placement.height;
        if w == 0 || h == 0 {
@@ -94,23 +98,11 @@ impl GlyphAtlas {
            return None;
        }
-        let (page_idx, x, y) = self.allocate(w, h, textures);
+        let upload = self.allocate(w, h);
-        let page = &self.pages[page_idx];
+        let PatchRect { x, y, .. } = upload.rect;
        write_glyph(&mut self.pages[upload.layer as usize].image, image, x, y);
        self.uploads.push(upload);
        let img = textures.image_mut(&page.handle);
        let rgba = img.as_mut_rgba8().expect("atlas page is rgba8");
        write_glyph(rgba, image, x, y);
        let handle = page.handle.clone();
        let rect = PatchRect {
            x,
            y,
            width: w,
            height: h,
        };
        textures.patch(&handle, rect);
        let page = &self.pages[page_idx];
        let scale = 1.0 / PAGE as f32;
        let entry = GlyphEntry {
            uv_min: Vec2::new(x as f32 * scale, y as f32 * scale),
@@ -120,39 +112,60 @@ impl GlyphAtlas {
            width: w,
            height: h,
            is_colored: matches!(image.content, Content::Color),
-            view_idx: page.handle.primitive().view_idx,
+            layer: upload.layer,
            sampler_idx: page.handle.primitive().sampler_idx,
        };
        self.entries.insert(key, Some(entry));
        Some(entry)
    }
-    fn allocate(&mut self, w: u32, h: u32, textures: &mut Textures) -> (usize, u32, u32) {
+    /// Reserves room for a `w` by `h` glyph, adding a page if none has it.
    fn allocate(&mut self, w: u32, h: u32) -> PageUpload {
        let rect = |x, y| PatchRect {
            x,
            y,
            width: w,
            height: h,
        };
        if let Some((i, (x, y))) = self
            .pages
            .iter_mut()
            .enumerate()
            .find_map(|(i, page)| page.allocate(w, h).map(|position| (i, position)))
        {
-            return (i, x, y);
+            return PageUpload {
                layer: i as u32,
                rect: rect(x, y),
            };
        }
        let handle = textures.add(RgbaImage::new(PAGE, PAGE));
        self.pages.push(Page {
-            handle,
+            image: RgbaImage::new(PAGE, PAGE),
            x: PAD + w + PAD,
            y: PAD,
            shelf_height: h + PAD,
        });
-        (self.pages.len() - 1, PAD, PAD)
+        PageUpload {
            layer: self.pages.len() as u32 - 1,
            rect: rect(PAD, PAD),
        }
    }
    /// Drains what has been written since the last call, for the renderer to
    /// upload. A new page needs nothing more: wgpu leaves the rest of a fresh
    /// layer transparent, which is what an atlas wants.
    pub fn uploads(&mut self) -> impl Iterator<Item = (PageUpload, &RgbaImage)> {
        let pages = &self.pages;
        self.uploads
            .drain(..)
            .map(|upload| (upload, &pages[upload.layer as usize].image))
    }
    pub fn insert_empty(&mut self, key: GlyphKey) {
        self.entries.insert(key, None);
    }
-    pub fn page_count(&self) -> usize {
+    pub fn page_count(&self) -> u32 {
-        self.pages.len()
+        self.pages.len() as u32
    }
    pub fn glyph_count(&self) -> usize {
@@ -12,20 +12,16 @@ pub struct WindowUniform {
 #[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
 pub struct PrimitiveInstance {
    pub region: UiRegion,
    pub binding: u32,
    pub idx: u32,
    pub mask_idx: MaskIdx,
 }
 impl PrimitiveInstance {
-    const ATTRIBS: [VertexAttribute; 7] = vertex_attr_array![
+    const ATTRIBS: [VertexAttribute; 5] = vertex_attr_array![
        0 => Float32x2,
        1 => Float32x2,
        2 => Float32x2,
        3 => Float32x2,
        4 => Uint32,
        5 => Uint32,
        6 => Uint32,
    ];
    pub fn desc() -> VertexBufferLayout<'static> {
@@ -1,8 +1,6 @@
 use std::num::NonZero;
 use crate::{
    UiData, UiRenderState,
-    render::{data::PrimitiveInstance, texture::GpuTextures, util::ArrBuf},
+    render::{data::PrimitiveInstance, util::ArrBuf},
    util::{HashMap, Vec2},
 };
 use data::WindowUniform;
@@ -13,6 +11,7 @@ use wgpu::{
 mod atlas;
 mod data;
 mod page;
 mod primitive;
 mod texture;
 mod util;
@@ -21,42 +20,63 @@ pub use atlas::*;
 pub use data::{Mask, MaskIdx};
 pub use primitive::*;
-const SHAPE_SHADER: &str = include_str!("./shader.wgsl");
+const PRELUDE: &str = include_str!("./shader/prelude.wgsl");
 pub struct UiRenderNode {
-    uniform_group: BindGroup,
+    shared_layout: BindGroupLayout,
-    primitive_layout: BindGroupLayout,
+    shared_group: BindGroup,
-    rsc_layout: BindGroupLayout,
+    format: TextureFormat,
    rsc_group: BindGroup,
-    pipeline: RenderPipeline,
+    /// One per registered primitive, in id order.
    primitives: Vec<PrimitivePipeline>,
    layers: HashMap<usize, RenderLayer>,
    active: Vec<usize>,
    window_buffer: Buffer,
    textures: GpuTextures,
    masks: ArrBuf<Mask>,
 }
 struct RenderLayer {
    /// One per registered primitive, `None` where this layer draws none.
    primitives: Vec<Option<ListBuffers>>,
 }
 /// What draws one registered primitive.
 struct PrimitivePipeline {
    data_layout: BindGroupLayout,
    pipeline: RenderPipeline,
    render: Box<dyn PrimitiveRender>,
 }
 /// One list's vertex buffer and the data its shader reads.
 struct ListBuffers {
    instance: ArrBuf<PrimitiveInstance>,
-    primitives: PrimitiveBuffers,
+    data: ArrBuf<u8>,
-    primitive_group: BindGroup,
+    group: Option<BindGroup>,
    /// What the primitive asked to keep per instance, if anything.
    bindings: Vec<u32>,
 }
 impl UiRenderNode {
    pub fn draw<'a>(&'a self, pass: &mut RenderPass<'a>) {
-        pass.set_pipeline(&self.pipeline);
+        pass.set_bind_group(0, &self.shared_group, &[]);
        pass.set_bind_group(0, &self.uniform_group, &[]);
        pass.set_bind_group(2, &self.rsc_group, &[]);
        for i in &self.active {
            let layer = &self.layers[i];
-            if layer.instance.len() == 0 {
+            for (id, list) in layer.primitives.iter().enumerate() {
-                continue;
+                let Some(list) = list else { continue };
                let Some(group) = &list.group else { continue };
                let primitive = &self.primitives[id];
                pass.set_pipeline(&primitive.pipeline);
                pass.set_bind_group(1, group, &[]);
                pass.set_vertex_buffer(0, list.instance.buffer.slice(..));
                primitive.render.draw(
                    pass,
                    ListDraw {
                        instances: list.instance.len() as u32,
                        bindings: &list.bindings,
                    },
                );
            }
            pass.set_bind_group(1, &layer.primitive_group, &[]);
            pass.set_vertex_buffer(0, layer.instance.buffer.slice(..));
            pass.draw(0..4, 0..layer.instance.len() as u32);
        }
    }
@@ -67,55 +87,56 @@ impl UiRenderNode {
        ui: &mut UiData,
        ui_render: &mut UiRenderState,
    ) {
        // Before the layers: each list is given its pipeline's data layout.
        self.build_pipelines(device, queue, &ui.primitives);
        self.active.clear();
-        for (i, primitives) in ui_render.layers.iter_mut() {
+        for (i, draws) in ui_render.layers.iter_mut() {
            self.active.push(i);
-            for change in primitives.apply_free() {
+            for change in draws.apply_free() {
                if let Some(inst) = ui_render.active.get_mut(&change.id) {
                    for h in &mut inst.primitives {
-                        if h.layer == i && h.inst_idx == change.old {
+                        if h.layer == i && h.kind == change.kind && h.inst_idx == change.old {
                            h.inst_idx = change.new;
                            break;
                        }
                    }
                }
            }
-            let rlayer = self.layers.entry(i).or_insert_with(|| {
+            let rlayer = self.layers.entry(i).or_insert_with(RenderLayer::new);
-                let primitives = PrimitiveBuffers::new(device);
+            if draws.updated {
-                let primitive_group =
+                let lists = draws.primitives();
-                    Self::primitive_group(device, &self.primitive_layout, primitives.buffers());
+                // The zip would otherwise skip a list with no pipeline.
-                RenderLayer {
+                assert!(lists.len() <= self.primitives.len());
-                    instance: ArrBuf::new(
+                rlayer.primitives.resize_with(lists.len(), || None);
-                        device,
+                for ((buffers, list), primitive) in rlayer
-                        BufferUsages::VERTEX | BufferUsages::COPY_DST,
+                    .primitives
-                        "instance",
+                    .iter_mut()
-                    ),
+                    .zip(lists)
-                    primitives,
+                    .zip(&self.primitives)
-                    primitive_group,
+                {
                    let Some(list) = list else {
                        continue;
                    };
                    buffers
                        .get_or_insert_with(|| ListBuffers::new(device))
                        .update(device, queue, primitive, list);
                }
-            });
+                draws.updated = false;
            if primitives.updated {
                rlayer
                    .instance
                    .update(device, queue, primitives.instances());
                rlayer.primitives.update(device, queue, primitives.data());
                rlayer.primitive_group = Self::primitive_group(
                    device,
                    &self.primitive_layout,
                    rlayer.primitives.buffers(),
                );
                primitives.updated = false;
            }
        }
-        let mut changed = false;
+        for primitive in &mut self.primitives {
-        changed |= self.textures.update(&mut ui.textures);
+            primitive.render.update(ui);
        }
        if ui.masks.changed {
            ui.masks.changed = false;
-            self.masks.update(device, queue, &ui.masks[..]);
+            if self.masks.update(device, queue, &ui.masks[..]) {
-            changed = true;
+                self.shared_group = Self::shared_group(
-        }
+                    device,
-        if changed {
+                    &self.shared_layout,
-            self.rsc_group = Self::rsc_group(device, &self.rsc_layout, &self.textures, &self.masks);
+                    &self.window_buffer,
                    &self.masks,
                );
            }
        }
    }
@@ -128,17 +149,7 @@ impl UiRenderNode {
        queue.write_buffer(&self.window_buffer, 0, bytemuck::cast_slice(slice));
    }
-    pub fn new(
+    pub fn new(device: &Device, config: &SurfaceConfiguration) -> Self {
        device: &Device,
        queue: &Queue,
        config: &SurfaceConfiguration,
        limits: UiLimits,
    ) -> Self {
        let shader = device.create_shader_module(ShaderModuleDescriptor {
            label: Some("UI Shape Shader"),
            source: ShaderSource::Wgsl(SHAPE_SHADER.into()),
        });
        let window_uniform = WindowUniform {
            width: config.width as f32,
            height: config.height as f32,
@@ -149,67 +160,73 @@ impl UiRenderNode {
            usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
        });
-        let uniform_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
+        let shared_layout = Self::shared_layout(device);
            entries: &[BindGroupLayoutEntry {
                binding: 0,
                visibility: ShaderStages::VERTEX | ShaderStages::FRAGMENT,
                ty: BindingType::Buffer {
                    ty: BufferBindingType::Uniform,
                    has_dynamic_offset: false,
                    min_binding_size: None,
                },
                count: None,
            }],
            label: Some("window"),
        });
        let uniform_group = Self::bind_group_0(device, &uniform_layout, &window_buffer);
        let primitive_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
            entries: &core::array::from_fn::<_, { PrimitiveBuffers::LEN }, _>(|i| {
                BindGroupLayoutEntry {
                    binding: i as u32,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Buffer {
                        ty: BufferBindingType::Storage { read_only: true },
                        has_dynamic_offset: false,
                        min_binding_size: None,
                    },
                    count: None,
                }
            }),
            label: Some("primitive"),
        });
        let tex_manager = GpuTextures::new(device, queue);
        let masks = ArrBuf::new(
            device,
            BufferUsages::STORAGE | BufferUsages::COPY_DST,
            "ui masks",
        );
        let shared_group = Self::shared_group(device, &shared_layout, &window_buffer, &masks);
-        let rsc_layout = Self::rsc_layout(device, &limits);
+        Self {
-        let rsc_group = Self::rsc_group(device, &rsc_layout, &tex_manager, &masks);
+            shared_layout,
            shared_group,
            format: config.format,
            primitives: Vec::new(),
            window_buffer,
            layers: HashMap::default(),
            active: Vec::new(),
            masks,
        }
    }
-        let pipeline_layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
+    /// Compiles a pipeline for every primitive registered since the last call.
-            label: Some("UI Shape Pipeline Layout"),
+    /// Sources only ever arrive at the end, so an id keeps its pipeline.
-            bind_group_layouts: &[&uniform_layout, &primitive_layout, &rsc_layout],
+    fn build_pipelines(&mut self, device: &Device, queue: &Queue, registry: &PrimitiveRegistry) {
-            immediate_size: 0,
+        for source in &registry.sources()[self.primitives.len()..] {
            let render = (source.render)(device, queue);
            let data_layout = Self::data_layout(device, source.stride);
            let mut groups = vec![Some(&self.shared_layout), Some(&data_layout)];
            groups.extend(render.layout().map(Some));
            let layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
                label: Some(source.label),
                bind_group_layouts: &groups,
                immediate_size: 0,
            });
            let pipeline = Self::pipeline(device, &layout, self.format, source.wgsl, source.label);
            self.primitives.push(PrimitivePipeline {
                data_layout,
                pipeline,
                render,
            });
        }
    }
    fn pipeline(
        device: &Device,
        layout: &PipelineLayout,
        format: TextureFormat,
        wgsl: &str,
        label: &str,
    ) -> RenderPipeline {
        let module = device.create_shader_module(ShaderModuleDescriptor {
            label: Some(label),
            source: ShaderSource::Wgsl(format!("{PRELUDE}\n{wgsl}").into()),
        });
-        let pipeline = device.create_render_pipeline(&RenderPipelineDescriptor {
+        device.create_render_pipeline(&RenderPipelineDescriptor {
-            label: Some("UI Shape Pipeline"),
+            label: Some(label),
-            layout: Some(&pipeline_layout),
+            layout: Some(layout),
            vertex: VertexState {
-                module: &shader,
+                module: &module,
                entry_point: Some("vs_main"),
-                buffers: &[PrimitiveInstance::desc()],
+                buffers: &[Some(PrimitiveInstance::desc())],
                compilation_options: Default::default(),
            },
            fragment: Some(FragmentState {
-                module: &shader,
+                module: &module,
                entry_point: Some("fs_main"),
                targets: &[Some(ColorTargetState {
-                    format: config.format,
+                    format,
                    blend: Some(BlendState::ALPHA_BLENDING),
                    write_mask: ColorWrites::ALL,
                })],
@@ -232,90 +249,42 @@ impl UiRenderNode {
            },
            multiview_mask: None,
            cache: None,
        });
        Self {
            uniform_group,
            primitive_layout,
            rsc_layout,
            rsc_group,
            pipeline,
            window_buffer,
            layers: HashMap::default(),
            active: Vec::new(),
            textures: tex_manager,
            masks,
        }
    }
    fn bind_group_0(
        device: &Device,
        layout: &BindGroupLayout,
        window_buffer: &Buffer,
    ) -> BindGroup {
        device.create_bind_group(&BindGroupDescriptor {
            layout,
            entries: &[BindGroupEntry {
                binding: 0,
                resource: window_buffer.as_entire_binding(),
            }],
            label: Some("ui window"),
        })
    }
-    fn primitive_group(
+    /// What every draw in the ui is given: the window and the masks.
-        device: &Device,
+    fn shared_layout(device: &Device) -> BindGroupLayout {
        layout: &BindGroupLayout,
        buffers: [(u32, &Buffer); PrimitiveBuffers::LEN],
    ) -> BindGroup {
        device.create_bind_group(&BindGroupDescriptor {
            layout,
            entries: &buffers.map(|(binding, buf)| BindGroupEntry {
                binding,
                resource: buf.as_entire_binding(),
            }),
            label: Some("ui primitives"),
        })
    }
    fn rsc_layout(device: &Device, limits: &UiLimits) -> BindGroupLayout {
        device.create_bind_group_layout(&BindGroupLayoutDescriptor {
            entries: &[
                BindGroupLayoutEntry {
                    binding: 0,
-                    visibility: ShaderStages::FRAGMENT,
+                    visibility: ShaderStages::VERTEX | ShaderStages::FRAGMENT,
-                    ty: BindingType::Texture {
+                    ty: BindingType::Buffer {
-                        sample_type: TextureSampleType::Float { filterable: false },
+                        ty: BufferBindingType::Uniform,
-                        view_dimension: TextureViewDimension::D2,
+                        has_dynamic_offset: false,
-                        multisampled: false,
+                        min_binding_size: BufferSize::new(size_of::<WindowUniform>() as u64),
                    },
-                    count: Some(NonZero::new(limits.max_textures).unwrap()),
+                    count: None,
                },
                BindGroupLayoutEntry {
                    binding: 1,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Sampler(SamplerBindingType::NonFiltering),
                    count: Some(NonZero::new(limits.max_samplers).unwrap()),
                },
                BindGroupLayoutEntry {
                    binding: 2,
                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Buffer {
                        ty: BufferBindingType::Storage { read_only: true },
                        has_dynamic_offset: false,
-                        min_binding_size: None,
+                        min_binding_size: BufferSize::new(size_of::<Mask>() as u64),
                    },
                    count: None,
                },
            ],
-            label: Some("ui rsc"),
+            label: Some("ui shared"),
        })
    }
-    fn rsc_group(
+    fn shared_group(
        device: &Device,
        layout: &BindGroupLayout,
-        tex_manager: &GpuTextures,
+        window: &Buffer,
        masks: &ArrBuf<Mask>,
    ) -> BindGroup {
        device.create_bind_group(&BindGroupDescriptor {
@@ -323,45 +292,85 @@ impl UiRenderNode {
            entries: &[
                BindGroupEntry {
                    binding: 0,
-                    resource: BindingResource::TextureViewArray(&tex_manager.views()),
+                    resource: window.as_entire_binding(),
                },
                BindGroupEntry {
                    binding: 1,
                    resource: BindingResource::SamplerArray(&tex_manager.samplers()),
                },
                BindGroupEntry {
                    binding: 2,
                    resource: masks.buffer.as_entire_binding(),
                },
            ],
-            label: Some("ui rsc"),
+            label: Some("ui shared"),
        })
    }
-    pub fn view_count(&self) -> usize {
+    /// Layout for a list of one primitive's data. Every size in the ui is
-        self.textures.view_count()
+    /// stated, so "is the buffer big enough for one entry?" is answered when
    /// the bind group is made; a `None` size is wgpu's to check on every draw.
    fn data_layout(device: &Device, stride: u64) -> BindGroupLayout {
        device.create_bind_group_layout(&BindGroupLayoutDescriptor {
            entries: &[BindGroupLayoutEntry {
                binding: 0,
                visibility: ShaderStages::FRAGMENT,
                ty: BindingType::Buffer {
                    ty: BufferBindingType::Storage { read_only: true },
                    has_dynamic_offset: false,
                    min_binding_size: BufferSize::new(stride),
                },
                count: None,
            }],
            label: Some("ui primitive data"),
        })
    }
 }
-pub struct UiLimits {
+impl RenderLayer {
-    max_textures: u32,
+    fn new() -> Self {
    max_samplers: u32,
 }
 impl Default for UiLimits {
    fn default() -> Self {
        Self {
-            max_textures: 100000,
+            primitives: Vec::new(),
            max_samplers: 1000,
        }
    }
 }
-impl UiLimits {
+impl ListBuffers {
-    pub fn max_binding_array_elements_per_shader_stage(&self) -> u32 {
+    fn new(device: &Device) -> Self {
-        self.max_textures + self.max_samplers
+        Self {
            instance: ArrBuf::new(
                device,
                BufferUsages::VERTEX | BufferUsages::COPY_DST,
                "instance",
            ),
            data: ArrBuf::new(
                device,
                BufferUsages::STORAGE | BufferUsages::COPY_DST,
                "primitive data",
            ),
            group: None,
            bindings: Vec::new(),
        }
    }
-    pub fn max_binding_array_sampler_elements_per_shader_stage(&self) -> u32 {
+
-        self.max_samplers
+    fn update(
        &mut self,
        device: &Device,
        queue: &Queue,
        primitive: &PrimitivePipeline,
        list: &InstanceList,
    ) {
        self.bindings.clear();
        primitive.render.instance_bindings(list, &mut self.bindings);
        self.instance.update(device, queue, list.instances());
        let resized = self.data.update(device, queue, list.data());
        if list.instances().is_empty() {
            self.group = None;
        } else if resized || self.group.is_none() {
            self.group = Some(device.create_bind_group(&BindGroupDescriptor {
                layout: &primitive.data_layout,
                entries: &[BindGroupEntry {
                    binding: 0,
                    resource: self.data.buffer.as_entire_binding(),
                }],
                label: Some("ui primitive data"),
            }));
        }
    }
 }
@@ -0,0 +1,156 @@
 use wgpu::*;
 use crate::{GlyphAtlas, UiData};
 use super::{
    atlas::PAGE,
    primitive::{ListDraw, PrimitiveRender},
    texture::{default_sampler, sampled_group, sampled_layout, write_region},
 };
 /// Draws glyphs from the atlas, which it owns: one array texture bound once
 /// for a whole list, since every glyph in it reads the same pages.
 pub struct GlyphRender {
    pages: GpuPages,
    layout: BindGroupLayout,
    sampler: Sampler,
 }
 impl GlyphRender {
    pub fn new(device: &Device, queue: &Queue) -> Self {
        let layout = sampled_layout(device, TextureViewDimension::D2Array, "ui atlas");
        let sampler = default_sampler(device);
        Self {
            pages: GpuPages::new(device, queue, &layout, &sampler),
            layout,
            sampler,
        }
    }
 }
 impl PrimitiveRender for GlyphRender {
    fn layout(&self) -> Option<&BindGroupLayout> {
        Some(&self.layout)
    }
    fn update(&mut self, ui: &mut UiData) {
        self.pages
            .update(&mut ui.text.atlas, &self.layout, &self.sampler);
    }
    fn draw<'a>(&'a self, pass: &mut RenderPass<'a>, list: ListDraw<'a>) {
        pass.set_bind_group(2, self.pages.group(), &[]);
        pass.draw(0..4, 0..list.instances);
    }
 }
 /// The glyph atlas on the GPU: one array texture whose layers are the pages
 /// `GlyphAtlas` packs.
 ///
 /// One array rather than a texture per page because a layer index is ordinary
 /// Vulkan 1.0 / GLES sampling, where a `binding_array` would need
 /// `VK_EXT_descriptor_indexing`, which a real share of Android GPUs lack.
 pub struct GpuPages {
    device: Device,
    queue: Queue,
    texture: Texture,
    group: BindGroup,
 }
 impl GpuPages {
    pub fn new(
        device: &Device,
        queue: &Queue,
        layout: &BindGroupLayout,
        sampler: &Sampler,
    ) -> Self {
        let texture = create_array(device, 1);
        Self {
            device: device.clone(),
            queue: queue.clone(),
            group: atlas_group(device, layout, &texture, sampler),
            texture,
        }
    }
    pub fn update(&mut self, atlas: &mut GlyphAtlas, layout: &BindGroupLayout, sampler: &Sampler) {
        if atlas.page_count() > self.texture.depth_or_array_layers() {
            self.grow(atlas.page_count(), layout, sampler);
        }
        for (upload, page) in atlas.uploads() {
            let dst = TexelCopyTextureInfo {
                texture: &self.texture,
                mip_level: 0,
                origin: Origin3d {
                    x: upload.rect.x,
                    y: upload.rect.y,
                    z: upload.layer,
                },
                aspect: TextureAspect::All,
            };
            write_region(&self.queue, dst, page, upload.rect);
        }
    }
    pub fn group(&self) -> &BindGroup {
        &self.group
    }
    /// Doubles until `needed` fits and copies the old layers across GPU side.
    /// The new texture stales the group, so that is rebuilt here.
    fn grow(&mut self, needed: u32, layout: &BindGroupLayout, sampler: &Sampler) {
        let old = self.texture.depth_or_array_layers();
        let mut layers = old;
        while layers < needed {
            layers *= 2;
        }
        let texture = create_array(&self.device, layers);
        let mut encoder = self
            .device
            .create_command_encoder(&CommandEncoderDescriptor {
                label: Some("atlas grow"),
            });
        encoder.copy_texture_to_texture(
            self.texture.as_image_copy(),
            texture.as_image_copy(),
            Extent3d {
                width: PAGE,
                height: PAGE,
                depth_or_array_layers: old,
            },
        );
        self.queue.submit(std::iter::once(encoder.finish()));
        self.group = atlas_group(&self.device, layout, &texture, sampler);
        self.texture = texture;
    }
 }
 fn atlas_group(
    device: &Device,
    layout: &BindGroupLayout,
    texture: &Texture,
    sampler: &Sampler,
 ) -> BindGroup {
    let view = texture.create_view(&TextureViewDescriptor {
        dimension: Some(TextureViewDimension::D2Array),
        ..Default::default()
    });
    sampled_group(device, layout, &view, sampler, "ui atlas")
 }
 fn create_array(device: &Device, layers: u32) -> Texture {
    device.create_texture(&TextureDescriptor {
        label: Some("glyph atlas"),
        size: Extent3d {
            width: PAGE,
            height: PAGE,
            depth_or_array_layers: layers,
        },
        mip_level_count: 1,
        sample_count: 1,
        dimension: TextureDimension::D2,
        format: TextureFormat::Rgba8Unorm,
        usage: TextureUsages::TEXTURE_BINDING | TextureUsages::COPY_DST | TextureUsages::COPY_SRC,
        view_formats: &[],
    })
 }
@@ -1,115 +1,247 @@
-use std::ops::{Deref, DerefMut};
+use std::{any::TypeId, marker::PhantomData};
 use crate::{
-    Color, UiRegion, WidgetId,
+    Color, TextureHandle, UiData, UiRegion, WidgetId,
    render::{
        ArrBuf,
        data::{MaskIdx, PrimitiveInstance},
        page::GlyphRender,
        texture::ImageRender,
    },
-    util::Vec2,
+    util::{HashMap, Vec2},
 };
 use bytemuck::Pod;
-use wgpu::*;
+use wgpu::{BindGroupLayout, Device, Queue, RenderPass};
-pub struct Primitives {
+/// One instance of a primitive, laid out as the struct its shader reads.
 ///
 /// The type carries its own shader, so drawing one is all the wiring it needs:
 /// its list, free list, buffers and pipeline follow from being registered.
 pub trait Primitive: Pod + 'static {
    /// Compiled after `prelude.wgsl`, which states what it declares and what
    /// it is given.
    const WGSL: &'static str;
    /// Made once, the first time the renderer sees this primitive. It owns
    /// whatever the shader samples and records the primitive's own draws; the
    /// default owns nothing and draws every instance in one call.
    fn render(device: &Device, queue: &Queue) -> Box<dyn PrimitiveRender>
    where
        Self: Sized,
    {
        let _ = (device, queue);
        Box::new(Instanced)
    }
 }
 /// The renderer's half of a primitive: what it samples, what it uploads, and
 /// what draws it records.
 ///
 /// Everything a draw shares -- the pipeline, the window and masks, the list's
 /// own data and instance buffer -- is set before this is called. What is left
 /// is what only this primitive knows: its group 2, and how many draws its
 /// instances are.
 pub trait PrimitiveRender {
    /// The layout its shader reads at group 2. `None` for a primitive whose
    /// shader samples nothing, whose pipeline then has no group 2 at all.
    fn layout(&self) -> Option<&BindGroupLayout> {
        None
    }
    /// Uploads whatever this primitive owns, once a frame, before any draw.
    fn update(&mut self, ui: &mut UiData) {
        let _ = ui;
    }
    /// Keeps what the primitive needs per instance at draw time, read from
    /// the list's own data. A primitive that binds nothing per instance --
    /// most of them -- leaves this empty and draws in one call.
    fn instance_bindings(&self, list: &InstanceList, out: &mut Vec<u32>) {
        let _ = (list, out);
    }
    fn draw<'a>(&'a self, pass: &mut RenderPass<'a>, list: ListDraw<'a>);
 }
 /// What a `PrimitiveRender` draws: this list's instances, and whatever
 /// `instance_bindings` kept for them.
 pub struct ListDraw<'a> {
    pub instances: u32,
    pub bindings: &'a [u32],
 }
 /// The default: nothing sampled, every instance in one call.
 pub struct Instanced;
 impl PrimitiveRender for Instanced {
    fn draw<'a>(&'a self, pass: &mut RenderPass<'a>, list: ListDraw<'a>) {
        pass.draw(0..4, 0..list.instances);
    }
 }
 /// Which registered primitive an instance is.
 pub struct PrimitiveKind<P> {
    id: u32,
    _p: PhantomData<fn(P)>,
 }
 impl<P> PrimitiveKind<P> {
    fn new(id: u32) -> Self {
        Self {
            id,
            _p: PhantomData,
        }
    }
 }
 impl<P> Clone for PrimitiveKind<P> {
    fn clone(&self) -> Self {
        *self
    }
 }
 impl<P> Copy for PrimitiveKind<P> {}
 /// Every primitive a ui can draw, in the order they were first drawn.
 #[derive(Default)]
 pub struct PrimitiveRegistry {
    kinds: Vec<PrimitiveSource>,
    ids: HashMap<TypeId, u32>,
 }
 pub struct PrimitiveSource {
    pub wgsl: &'static str,
    pub label: &'static str,
    /// Size of one instance's entry, stated as the data binding's minimum.
    pub stride: u64,
    pub render: fn(&Device, &Queue) -> Box<dyn PrimitiveRender>,
 }
 impl PrimitiveRegistry {
    /// Registers `P` if this is the first time it has been drawn.
    pub fn kind<P: Primitive>(&mut self) -> PrimitiveKind<P> {
        let Self { kinds, ids } = self;
        let id = *ids.entry(TypeId::of::<P>()).or_insert_with(|| {
            kinds.push(PrimitiveSource {
                wgsl: P::WGSL,
                label: std::any::type_name::<P>(),
                stride: size_of::<P>() as u64,
                render: P::render,
            });
            kinds.len() as u32 - 1
        });
        PrimitiveKind::new(id)
    }
    pub fn sources(&self) -> &[PrimitiveSource] {
        &self.kinds
    }
 }
 /// One registered primitive's instances in one layer. Everything per-instance
 /// rides here, so it stays in step through a `swap_remove`.
 pub struct InstanceList {
    instances: Vec<PrimitiveInstance>,
    /// The widget each instance belongs to, for renumbering its handles.
    assoc: Vec<WidgetId>,
    data: PrimitiveData,
    free: Vec<usize>,
    /// `stride` bytes of the primitive's own data per instance.
    data: Vec<u8>,
    /// From the type the list was made for, so a write is never checked.
    stride: usize,
 }
 impl InstanceList {
    fn new<P: Primitive>() -> Self {
        Self {
            instances: Vec::new(),
            assoc: Vec::new(),
            free: Vec::new(),
            data: Vec::new(),
            stride: size_of::<P>(),
        }
    }
    pub fn instances(&self) -> &[PrimitiveInstance] {
        &self.instances
    }
    pub fn data(&self) -> &[u8] {
        &self.data
    }
    pub fn stride(&self) -> usize {
        self.stride
    }
    fn push(&mut self, id: WidgetId, inst: PrimitiveInstance, data: &[u8]) -> usize {
        if let Some(i) = self.free.pop() {
            self.instances[i] = inst;
            self.assoc[i] = id;
            self.data[i * self.stride..][..self.stride].copy_from_slice(data);
            i
        } else {
            let i = self.instances.len();
            self.instances.push(inst);
            self.assoc.push(id);
            self.data.extend_from_slice(data);
            i
        }
    }
    fn free(&mut self, i: usize) -> MaskIdx {
        self.free.push(i);
        self.instances[i].mask_idx
    }
    fn apply_free(&mut self, kind: u32) -> impl Iterator<Item = PrimitiveChange> {
        self.free.sort_by(|a, b| b.cmp(a));
        let instances = &mut self.instances;
        let assoc = &mut self.assoc;
        let data = &mut self.data;
        let stride = self.stride;
        self.free.drain(..).filter_map(move |i| {
            instances.swap_remove(i);
            assoc.swap_remove(i);
            let last = instances.len();
            data.copy_within(last * stride..(last + 1) * stride, i * stride);
            data.truncate(last * stride);
            if i == last {
                return None;
            }
            let id = assoc[i];
            Some(PrimitiveChange {
                id,
                kind,
                old: last,
                new: i,
            })
        })
    }
 }
 /// Everything one layer draws, one list per registered primitive.
 pub struct LayerDraws {
    /// `None` until this layer draws that primitive, because only the write
    /// knows the type the list is for.
    primitives: Vec<Option<InstanceList>>,
    pub updated: bool,
 }
-impl Default for Primitives {
+impl Default for LayerDraws {
    fn default() -> Self {
        Self {
-            instances: Default::default(),
+            primitives: Vec::new(),
            assoc: Default::default(),
            data: Default::default(),
            free: Vec::new(),
            updated: true,
        }
    }
 }
-pub trait Primitive: Pod {
+impl LayerDraws {
    const BINDING: u32;
    fn vec(data: &mut PrimitiveData) -> &mut PrimitiveVec<Self>;
 }
 macro_rules! primitives {
    ($($name:ident: $ty:ty => $binding:expr,)*) => {
        #[derive(Default)]
        pub struct PrimitiveData {
            $(pub(crate) $name: PrimitiveVec<$ty>,)*
        }
        pub struct PrimitiveBuffers {
            $($name: ArrBuf<$ty>,)*
        }
        impl PrimitiveBuffers {
            pub fn update(&mut self, device: &Device, queue: &Queue, data: &PrimitiveData) {
                $(self.$name.update(device, queue, &data.$name);)*
            }
        }
        impl PrimitiveBuffers {
            pub const LEN: usize = primitives!(@count $($name)*);
            pub fn buffers(&self) -> [(u32, &Buffer); Self::LEN] {
                [
                    $((<$ty>::BINDING, &self.$name.buffer),)*
                ]
            }
            pub fn new(device: &Device) -> Self {
                Self {
                    $($name: ArrBuf::new(
                        device,
                        BufferUsages::STORAGE | BufferUsages::COPY_DST,
                        stringify!($name),
                    ),)*
                }
            }
        }
        impl PrimitiveData {
            pub fn clear(&mut self) {
                $(self.$name.clear();)*
            }
            pub fn free(&mut self, binding: u32, idx: usize) {
                match binding {
                    $(<$ty>::BINDING => self.$name.free(idx),)*
                    _ => unreachable!()
                }
            }
        }
        $(
            unsafe impl bytemuck::Pod for $ty {}
            unsafe impl bytemuck::Zeroable for $ty {}
            impl Primitive for $ty {
                const BINDING: u32 = $binding;
                fn vec(data: &mut PrimitiveData) -> &mut PrimitiveVec<Self> {
                    &mut data.$name
                }
            }
        )*
    };
    (@count $t1:tt $($t:tt)+) => { 1 + primitives!(@count $($t)+) };
    (@count $t:tt) => { 1 };
 }
 pub struct PrimitiveInst<P> {
    pub id: WidgetId,
    pub primitive: P,
    pub region: UiRegion,
    pub mask_idx: MaskIdx,
 }
 impl Primitives {
    pub fn write<P: Primitive>(
        &mut self,
        layer: usize,
        PrimitiveInst {
            kind,
            id,
            primitive,
            region,
@@ -117,65 +249,67 @@ impl Primitives {
        }: PrimitiveInst<P>,
    ) -> PrimitiveHandle {
        self.updated = true;
-        let vec = P::vec(&mut self.data);
+        // Grown on first use rather than sized from the registry, which a
-        let i = vec.add(primitive);
+        // layer cannot see.
-        let inst = PrimitiveInstance {
+        if self.primitives.len() <= kind.id as usize {
-            region,
+            self.primitives.resize_with(kind.id as usize + 1, || None);
-            idx: i as u32,
+        }
-            mask_idx,
+        let inst_idx = self.primitives[kind.id as usize]
-            binding: P::BINDING,
+            .get_or_insert_with(InstanceList::new::<P>)
-        };
+            .push(
-        let inst_i = if let Some(i) = self.free.pop() {
+                id,
-            self.instances[i] = inst;
+                PrimitiveInstance { region, mask_idx },
-            self.assoc[i] = id;
+                bytemuck::bytes_of(&primitive),
-            i
+            );
-        } else {
+        PrimitiveHandle {
-            let i = self.instances.len();
+            layer,
-            self.instances.push(inst);
+            kind: kind.id,
-            self.assoc.push(id);
+            inst_idx,
-            i
+        }
-        };
+    }
-        PrimitiveHandle::new::<P>(layer, inst_i, i)
+
    pub fn primitives(&self) -> &[Option<InstanceList>] {
        &self.primitives
    }
    /// returns (old index, new index)
    pub fn apply_free(&mut self) -> impl Iterator<Item = PrimitiveChange> {
-        self.free.sort_by(|a, b| b.cmp(a));
+        self.primitives
-        self.free.drain(..).filter_map(|i| {
+            .iter_mut()
-            self.instances.swap_remove(i);
+            .enumerate()
-            self.assoc.swap_remove(i);
+            .filter_map(|(kind, list)| Some((kind as u32, list.as_mut()?)))
-            if i == self.instances.len() {
+            .flat_map(|(kind, list)| list.apply_free(kind))
                return None;
            }
            let id = self.assoc[i];
            let old = self.instances.len();
            Some(PrimitiveChange { id, old, new: i })
        })
    }
    pub fn free(&mut self, h: &PrimitiveHandle) -> MaskIdx {
        self.updated = true;
-        self.data.free(h.binding, h.data_idx);
+        self.list(h).free(h.inst_idx)
        self.free.push(h.inst_idx);
        self.instances[h.inst_idx].mask_idx
    }
    pub fn data(&self) -> &PrimitiveData {
        &self.data
    }
    pub fn instances(&self) -> &Vec<PrimitiveInstance> {
        &self.instances
    }
    pub fn region_mut(&mut self, h: &PrimitiveHandle) -> &mut UiRegion {
        self.updated = true;
-        &mut self.instances[h.inst_idx].region
+        &mut self.list(h).instances[h.inst_idx].region
    }
    /// A handle is only ever made by `write`, which is what created the list.
    fn list(&mut self, h: &PrimitiveHandle) -> &mut InstanceList {
        self.primitives[h.kind as usize]
            .as_mut()
            .expect("handle names a primitive this layer never drew")
    }
 }
 pub struct PrimitiveInst<P> {
    pub kind: PrimitiveKind<P>,
    pub id: WidgetId,
    pub primitive: P,
    pub region: UiRegion,
    pub mask_idx: MaskIdx,
 }
 pub struct PrimitiveChange {
    pub id: WidgetId,
    /// Which registered primitive's list moved, since they index separately.
    pub kind: u32,
    pub old: usize,
    pub new: usize,
 }
@@ -183,30 +317,12 @@ pub struct PrimitiveChange {
 #[derive(Debug)]
 pub struct PrimitiveHandle {
    pub layer: usize,
    pub kind: u32,
    pub inst_idx: usize,
    pub data_idx: usize,
    pub binding: u32,
 }
 impl PrimitiveHandle {
    fn new<P: Primitive>(layer: usize, inst_idx: usize, data_idx: usize) -> Self {
        Self {
            layer,
            inst_idx,
            data_idx,
            binding: P::BINDING,
        }
    }
 }
 primitives!(
    rects: RectPrimitive => 0,
    textures: TexturePrimitive => 1,
    glyphs: GlyphPrimitive => 2,
 );
 #[repr(C)]
-#[derive(Copy, Clone)]
+#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
 pub struct RectPrimitive {
    pub color: Color<u8>,
    pub radius: f32,
@@ -214,6 +330,10 @@ pub struct RectPrimitive {
    pub inner_radius: f32,
 }
 impl Primitive for RectPrimitive {
    const WGSL: &'static str = include_str!("shader/rect.wgsl");
 }
 impl RectPrimitive {
    pub fn color(color: Color<u8>) -> Self {
        Self {
@@ -225,71 +345,51 @@ impl RectPrimitive {
    }
 }
-#[repr(C)]
+/// `color` is multiplied by the atlas alpha for a mask glyph; a colour glyph
-#[derive(Debug, Copy, Clone)]
+/// takes the texel unchanged, which `GlyphEntry::IS_COLORED` selects.
-pub struct TexturePrimitive {
+#[repr(C, align(8))]
    pub view_idx: u32,
    pub sampler_idx: u32,
 }
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
 pub struct GlyphPrimitive {
    pub uv_min: Vec2,
    pub uv_max: Vec2,
-    pub view_idx: u32,
+    /// Which atlas array layer this glyph is on.
-    pub sampler_idx: u32,
+    pub layer: u32,
    pub color: Color<u8>,
    pub flags: u32,
 }
-pub struct PrimitiveVec<T> {
+// Manual rather than derived: the align(8) leaves four bytes of padding, which
-    vec: Vec<T>,
+// is how WGSL lays the struct out.
-    free: Vec<usize>,
+unsafe impl bytemuck::Pod for GlyphPrimitive {}
 unsafe impl bytemuck::Zeroable for GlyphPrimitive {}
 impl Primitive for GlyphPrimitive {
    const WGSL: &'static str = include_str!("shader/glyph.wgsl");
    fn render(device: &Device, queue: &Queue) -> Box<dyn PrimitiveRender> {
        Box::new(GlyphRender::new(device, queue))
    }
 }
-impl<T> PrimitiveVec<T> {
+/// One drawn image. Its shader reads nothing per instance; the slot names the
-    pub fn new() -> Self {
+/// texture to bind for it.
 #[repr(C)]
 #[derive(Debug, Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
 pub struct TexturePrimitive {
    pub slot: u32,
 }
 impl Primitive for TexturePrimitive {
    const WGSL: &'static str = include_str!("shader/texture.wgsl");
    fn render(device: &Device, queue: &Queue) -> Box<dyn PrimitiveRender> {
        Box::new(ImageRender::new(device, queue))
    }
 }
 impl From<&TextureHandle> for TexturePrimitive {
    fn from(handle: &TextureHandle) -> Self {
        Self {
-            vec: Vec::new(),
+            slot: handle.slot(),
            free: Vec::new(),
        }
    }
    pub fn add(&mut self, t: T) -> usize {
        if let Some(i) = self.free.pop() {
            self.vec[i] = t;
            i
        } else {
            let i = self.vec.len();
            self.vec.push(t);
            i
        }
    }
    pub fn free(&mut self, i: usize) {
        self.free.push(i);
    }
    pub fn clear(&mut self) {
        self.free.clear();
        self.vec.clear();
    }
 }
 impl<T> Default for PrimitiveVec<T> {
    fn default() -> Self {
        Self::new()
    }
 }
 impl<T> Deref for PrimitiveVec<T> {
    type Target = Vec<T>;
    fn deref(&self) -> &Self::Target {
        &self.vec
    }
 }
 impl<T> DerefMut for PrimitiveVec<T> {
    fn deref_mut(&mut self) -> &mut Self::Target {
        &mut self.vec
    }
 }
@@ -1,204 +0,0 @@
 const RECT: u32 = 0u;
 const TEXTURE: u32 = 1u;
 const GLYPH: u32 = 2u;
@group(0) @binding(0)
 var<uniform> window: WindowUniform;
@group(1) @binding(RECT)
 var<storage> rects: array<Rect>;
@group(1) @binding(TEXTURE)
 var<storage> textures: array<TextureInfo>;
@group(1) @binding(GLYPH)
 var<storage> glyphs: array<GlyphInfo>;
 struct Rect {
    color: u32,
    radius: f32,
    thickness: f32,
    inner_radius: f32,
 }
 struct TextureInfo {
    view_idx: u32,
    sampler_idx: u32,
 }
 struct GlyphInfo {
    uv_min: vec2<f32>,
    uv_max: vec2<f32>,
    view_idx: u32,
    sampler_idx: u32,
    color: u32,
    flags: u32,
 }
 struct Mask {
    x: UiSpan,
    y: UiSpan,
 }
 struct UiSpan {
    start: UiScalar,
    end: UiScalar,
 }
 struct UiScalar {
    rel: f32,
    abs: f32,
 }
 struct UiVec2 {
    rel: vec2<f32>,
    abs: vec2<f32>,
 }
@group(2) @binding(0)
 var views: binding_array<texture_2d<f32>>;
@group(2) @binding(1)
 var samplers: binding_array<sampler>;
@group(2) @binding(2)
 var<storage> masks: array<Mask>;
 struct WindowUniform {
    dim: vec2<f32>,
 };
 struct InstanceInput {
    @location(0) x_start: vec2<f32>,
    @location(1) x_end: vec2<f32>,
    @location(2) y_start: vec2<f32>,
    @location(3) y_end: vec2<f32>,
    @location(4) binding: u32,
    @location(5) idx: u32,
    @location(6) mask_idx: u32,
 }
 struct VertexOutput {
    @location(0) top_left: vec2<f32>,
    @location(1) bot_right: vec2<f32>,
    @location(2) uv: vec2<f32>,
    @location(3) binding: u32,
    @location(4) idx: u32,
    @location(5) mask_idx: u32,
    @builtin(position) clip_position: vec4<f32>,
 };
 struct Region {
    pos: vec2<f32>,
    uv: vec2<f32>,
    top_left: vec2<f32>,
    bot_right: vec2<f32>,
 }
@vertex
 fn vs_main(
    @builtin(vertex_index) vi: u32,
    in: InstanceInput,
 ) -> VertexOutput {
    var out: VertexOutput;
    let top_left_rel = vec2(in.x_start.x, in.y_start.x);
    let top_left_abs = vec2(in.x_start.y, in.y_start.y);
    let bot_right_rel = vec2(in.x_end.x, in.y_end.x);
    let bot_right_abs = vec2(in.x_end.y, in.y_end.y);
    let top_left = floor(top_left_rel * window.dim) + floor(top_left_abs);
    let bot_right = floor(bot_right_rel * window.dim) + floor(bot_right_abs);
    let size = bot_right - top_left;
    let uv = vec2<f32>(
        f32(vi % 2u),
        f32(vi / 2u)
    );
    let pos = (top_left + uv * size) / window.dim * 2.0 - 1.0;
    out.clip_position = vec4<f32>(pos.x, -pos.y, 0.0, 1.0);
    out.uv = uv;
    out.binding = in.binding;
    out.idx = in.idx;
    out.top_left = top_left;
    out.bot_right = bot_right;
    out.mask_idx = in.mask_idx;
    return out;
 }
@fragment
 fn fs_main(
    in: VertexOutput
 ) -> @location(0) vec4<f32> {
    let pos = in.clip_position.xy;
    let region = Region(pos, in.uv, in.top_left, in.bot_right);
    let i = in.idx;
    var color: vec4<f32>;
    switch in.binding {
        case RECT: {
            color = draw_rounded_rect(region, rects[i]);
        }
        case TEXTURE: {
            color = draw_texture(region, textures[i]);
        }
        case GLYPH: {
            color = draw_glyph(region, glyphs[i]);
        }
        default: {
            color = vec4(1.0, 0.0, 1.0, 1.0);
        }
    }
    if in.mask_idx != 4294967295u {
        let mask = masks[in.mask_idx];
        let tl = UiVec2(vec2(mask.x.start.rel, mask.y.start.rel), vec2(mask.x.start.abs, mask.y.start.abs));
        let br = UiVec2(vec2(mask.x.end.rel, mask.y.end.rel), vec2(mask.x.end.abs, mask.y.end.abs));
        let top_left = floor(tl.rel * window.dim) + floor(tl.abs);
        let bot_right = floor(br.rel * window.dim) + floor(br.abs);
        if pos.x < top_left.x || pos.x > bot_right.x || pos.y < top_left.y || pos.y > bot_right.y {
            color *= 0.0;
        }
    }
    return color;
 }
 // TODO: this seems really inefficient (per frag indexing)?
 fn draw_texture(region: Region, info: TextureInfo) -> vec4<f32> {
    return textureSample(views[info.view_idx], samplers[info.sampler_idx], region.uv);
 }
 fn draw_glyph(region: Region, g: GlyphInfo) -> vec4<f32> {
    let uv = mix(g.uv_min, g.uv_max, region.uv);
    let texel = textureSample(views[g.view_idx], samplers[g.sampler_idx], uv);
    if (g.flags & 1u) != 0u {
        return texel;
    }
    var color = unpack4x8unorm(g.color);
    color.a *= texel.a;
    return color;
 }
 fn draw_rounded_rect(region: Region, rect: Rect) -> vec4<f32> {
    var color = unpack4x8unorm(rect.color);
    let edge = 0.5;
    let size = region.bot_right - region.top_left;
    let corner = size / 2.0;
    let center = region.top_left + corner;
    let dist = distance_from_rect(region.pos, center, corner, rect.radius);
    color.a *= 1.0 - smoothstep(-min(edge, rect.radius), edge, dist);
    if rect.thickness > 0.0 {
        let dist2 = distance_from_rect(region.pos, center, corner - rect.thickness, rect.inner_radius);
        color.a *= smoothstep(-min(edge, rect.inner_radius), edge, dist2);
    }
    return color;
 }
 fn distance_from_rect(pixel_pos: vec2<f32>, rect_center: vec2<f32>, rect_corner: vec2<f32>, radius: f32) -> f32 {
    // vec from center to pixel
    let p = pixel_pos - rect_center;
    // vec from inner rect corner to pixel
    let q = abs(p) - (rect_corner - radius);
    return length(max(q, vec2(0.0))) - radius;
 }
@@ -0,0 +1,33 @@
 // Matches `GlyphEntry::IS_COLORED`.
 const COLORED: u32 = 1u;
 // The glyph atlas, whose array layers are its pages.
@group(2) @binding(0)
 var atlas: texture_2d_array<f32>;
@group(2) @binding(1)
 var samp: sampler;
 struct GlyphInfo {
    uv_min: vec2<f32>,
    uv_max: vec2<f32>,
    // Which layer of the atlas array this glyph's page is.
    layer: u32,
    color: u32,
    flags: u32,
 }
@group(1) @binding(0)
 var<storage> glyphs: array<GlyphInfo>;
@fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    let g = glyphs[in.idx];
    let uv = mix(g.uv_min, g.uv_max, in.uv);
    let texel = textureSample(atlas, samp, uv, i32(g.layer));
    if (g.flags & COLORED) != 0u {
        return masked(in, texel);
    }
    var color = unpack4x8unorm(g.color);
    color.a *= texel.a;
    return masked(in, color);
 }
@@ -0,0 +1,96 @@
 // Prepended to every primitive's shader, which declares its own instance data
 // as `var<storage> <name>: array<T>` at group 1 binding 0, and an `fs_main`
 // shading one instance of it. What it samples, if anything, is bound at group
 // 2: the texture at binding 0 and the sampler at binding 1.
@group(0) @binding(0)
 var<uniform> window: WindowUniform;
@group(0) @binding(1)
 var<storage> masks: array<Mask>;
 struct WindowUniform {
    dim: vec2<f32>,
 };
 struct Mask {
    x: UiSpan,
    y: UiSpan,
 }
 struct UiSpan {
    start: UiScalar,
    end: UiScalar,
 }
 struct UiScalar {
    rel: f32,
    abs: f32,
 }
 struct InstanceInput {
    @location(0) x_start: vec2<f32>,
    @location(1) x_end: vec2<f32>,
    @location(2) y_start: vec2<f32>,
    @location(3) y_end: vec2<f32>,
    @location(4) mask_idx: u32,
 }
 struct VertexOutput {
    @location(0) top_left: vec2<f32>,
    @location(1) bot_right: vec2<f32>,
    @location(2) uv: vec2<f32>,
    @location(3) @interpolate(flat) mask_idx: u32,
    @location(4) @interpolate(flat) idx: u32,
    @builtin(position) clip_position: vec4<f32>,
 };
@vertex
 fn vs_main(
    @builtin(vertex_index) vi: u32,
    @builtin(instance_index) ii: u32,
    in: InstanceInput,
 ) -> VertexOutput {
    var out: VertexOutput;
    let top_left_rel = vec2(in.x_start.x, in.y_start.x);
    let top_left_abs = vec2(in.x_start.y, in.y_start.y);
    let bot_right_rel = vec2(in.x_end.x, in.y_end.x);
    let bot_right_abs = vec2(in.x_end.y, in.y_end.y);
    let top_left = floor(top_left_rel * window.dim) + floor(top_left_abs);
    let bot_right = floor(bot_right_rel * window.dim) + floor(bot_right_abs);
    let size = bot_right - top_left;
    let uv = vec2<f32>(
        f32(vi % 2u),
        f32(vi / 2u)
    );
    let pos = (top_left + uv * size) / window.dim * 2.0 - 1.0;
    out.clip_position = vec4<f32>(pos.x, -pos.y, 0.0, 1.0);
    out.uv = uv;
    out.top_left = top_left;
    out.bot_right = bot_right;
    out.mask_idx = in.mask_idx;
    out.idx = ii;
    return out;
 }
 fn masked(in: VertexOutput, color: vec4<f32>) -> vec4<f32> {
    if in.mask_idx == 4294967295u {
        return color;
    }
    let mask = masks[in.mask_idx];
    let tl = vec2(mask.x.start.rel, mask.y.start.rel);
    let tl_abs = vec2(mask.x.start.abs, mask.y.start.abs);
    let br = vec2(mask.x.end.rel, mask.y.end.rel);
    let br_abs = vec2(mask.x.end.abs, mask.y.end.abs);
    let top_left = floor(tl * window.dim) + floor(tl_abs);
    let bot_right = floor(br * window.dim) + floor(br_abs);
    let pos = in.clip_position.xy;
    if pos.x < top_left.x || pos.x > bot_right.x || pos.y < top_left.y || pos.y > bot_right.y {
        return color * 0.0;
    }
    return color;
 }
@@ -0,0 +1,39 @@
 struct Rect {
    color: u32,
    radius: f32,
    thickness: f32,
    inner_radius: f32,
 }
@group(1) @binding(0)
 var<storage> rects: array<Rect>;
@fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    let rect = rects[in.idx];
    var color = unpack4x8unorm(rect.color);
    let edge = 0.5;
    let size = in.bot_right - in.top_left;
    let corner = size / 2.0;
    let center = in.top_left + corner;
    let pos = in.clip_position.xy;
    let dist = distance_from_rect(pos, center, corner, rect.radius);
    color.a *= 1.0 - smoothstep(-min(edge, rect.radius), edge, dist);
    if rect.thickness > 0.0 {
        let dist2 = distance_from_rect(pos, center, corner - rect.thickness, rect.inner_radius);
        color.a *= smoothstep(-min(edge, rect.inner_radius), edge, dist2);
    }
    return masked(in, color);
 }
 fn distance_from_rect(pixel_pos: vec2<f32>, rect_center: vec2<f32>, rect_corner: vec2<f32>, radius: f32) -> f32 {
    // vec from center to pixel
    let p = pixel_pos - rect_center;
    // vec from inner rect corner to pixel
    let q = abs(p) - (rect_corner - radius);
    return length(max(q, vec2(0.0))) - radius;
 }
@@ -0,0 +1,10 @@
 // The image this instance draws, bound for it alone.
@group(2) @binding(0)
 var image: texture_2d<f32>;
@group(2) @binding(1)
 var samp: sampler;
@fragment
 fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    return masked(in, textureSample(image, samp, in.uv));
 }
@@ -1,119 +1,119 @@
-use image::{DynamicImage, EncodableLayout, GenericImageView};
+use image::{DynamicImage, EncodableLayout, GenericImageView, RgbaImage};
 use wgpu::{util::DeviceExt, *};
-use crate::{PatchRect, TextureUpdate, Textures};
+use crate::{
    PatchRect, TextureUpdate, Textures, UiData,
    render::{
        TexturePrimitive,
        primitive::{ListDraw, PrimitiveRender},
    },
 };
 /// Draws standalone images, which it owns. Each is its own texture, so each
 /// instance binds its own and is a draw of its own.
 pub struct ImageRender {
    textures: GpuTextures,
    layout: BindGroupLayout,
    sampler: Sampler,
 }
 impl ImageRender {
    pub fn new(device: &Device, queue: &Queue) -> Self {
        Self {
            textures: GpuTextures::new(device, queue),
            layout: sampled_layout(device, TextureViewDimension::D2, "ui image"),
            sampler: default_sampler(device),
        }
    }
 }
 impl PrimitiveRender for ImageRender {
    fn layout(&self) -> Option<&BindGroupLayout> {
        Some(&self.layout)
    }
    fn update(&mut self, ui: &mut UiData) {
        self.textures
            .update(&mut ui.textures, &self.layout, &self.sampler);
    }
    fn instance_bindings(&self, list: &super::InstanceList, out: &mut Vec<u32>) {
        let slots = list
            .data()
            .chunks_exact(list.stride())
            .map(|data| bytemuck::pod_read_unaligned::<TexturePrimitive>(data).slot);
        out.extend(slots);
    }
    fn draw<'a>(&'a self, pass: &mut RenderPass<'a>, list: ListDraw<'a>) {
        for (i, &slot) in list.bindings.iter().enumerate() {
            let Some(image) = self.textures.group(slot) else {
                continue;
            };
            pass.set_bind_group(2, image, &[]);
            pass.draw(0..4, i as u32..i as u32 + 1);
        }
    }
 }
 /// The standalone images a ui draws, each its own texture and bind group --
 /// unlike the glyph atlas in `super::page`, which is one array they share.
 pub struct GpuTextures {
    device: Device,
    queue: Queue,
-    /// Parallel to `views`; patches require textures rather than views.
+    slots: Vec<Option<ImageGpu>>,
-    textures: Vec<Option<Texture>>,
+}
-    views: Vec<TextureView>,
+
-    view_count: usize,
+struct ImageGpu {
-    samplers: Vec<Sampler>,
+    /// Kept for `patch`, which needs the texture rather than the view.
-    null_view: TextureView,
+    texture: Texture,
-    no_views: Vec<TextureView>,
+    group: BindGroup,
 }
 impl GpuTextures {
-    pub fn update(&mut self, textures: &mut Textures) -> bool {
+    pub fn new(device: &Device, queue: &Queue) -> Self {
-        let mut bindings_changed = false;
+        Self {
            device: device.clone(),
            queue: queue.clone(),
            slots: Vec::new(),
        }
    }
    pub fn update(&mut self, textures: &mut Textures, layout: &BindGroupLayout, sampler: &Sampler) {
        for update in textures.updates() {
-            bindings_changed |= match update {
+            match update {
                TextureUpdate::Push(image) => {
-                    self.push(image);
+                    let image = self.create(image, layout, sampler);
-                    true
+                    self.slots.push(Some(image));
                }
                TextureUpdate::Set(i, image) => {
-                    self.set(i, image);
+                    let image = self.create(image, layout, sampler);
-                    true
+                    self.slots[i as usize] = Some(image);
                }
-                TextureUpdate::Patch(i, rect, image) => {
+                TextureUpdate::Patch(i, rect, image) => self.patch(i, rect, image),
-                    self.patch(i, rect, image);
+                TextureUpdate::PushFree => self.slots.push(None),
-                    false
+                TextureUpdate::SetFree => {}
-                }
+                TextureUpdate::Free(i) => self.slots[i as usize] = None,
-                TextureUpdate::SetFree => {
+            }
                    self.view_count += 1;
                    true
                }
                TextureUpdate::Free(i) => {
                    self.free(i);
                    true
                }
                TextureUpdate::PushFree => {
                    self.push_free();
                    true
                }
            };
        }
        bindings_changed
    }
    fn set(&mut self, i: u32, image: &DynamicImage) {
        self.view_count += 1;
        let (texture, view) = self.create(image);
        self.textures[i as usize] = Some(texture);
        self.views[i as usize] = view;
    }
    fn free(&mut self, i: u32) {
        self.view_count -= 1;
        self.textures[i as usize] = None;
        self.views[i as usize] = self.null_view.clone();
    }
    fn push(&mut self, image: &DynamicImage) {
        self.view_count += 1;
        let (texture, view) = self.create(image);
        self.textures.push(Some(texture));
        self.views.push(view);
    }
    fn push_free(&mut self) {
        self.view_count += 1;
        self.textures.push(None);
        self.views.push(self.null_view.clone());
    }
-    fn patch(&mut self, i: u32, rect: PatchRect, image: &DynamicImage) {
+    pub fn group(&self, slot: u32) -> Option<&BindGroup> {
-        let Some(texture) = &self.textures[i as usize] else {
+        self.slots.get(slot as usize)?.as_ref().map(|i| &i.group)
            return;
        };
        if rect.width == 0 || rect.height == 0 {
            return;
        }
        // `write_texture` requires tightly packed rows, unlike the atlas image.
        let sub = image
            .view(rect.x, rect.y, rect.width, rect.height)
            .to_image();
        self.queue.write_texture(
            TexelCopyTextureInfo {
                texture,
                mip_level: 0,
                origin: Origin3d {
                    x: rect.x,
                    y: rect.y,
                    z: 0,
                },
                aspect: TextureAspect::All,
            },
            sub.as_bytes(),
            TexelCopyBufferLayout {
                offset: 0,
                bytes_per_row: Some(rect.width * 4),
                rows_per_image: Some(rect.height),
            },
            Extent3d {
                width: rect.width,
                height: rect.height,
                depth_or_array_layers: 1,
            },
        );
    }
-    fn create(&self, image: &DynamicImage) -> (Texture, TextureView) {
+    fn create(
-        let image = image.to_rgba8();
+        &self,
-        let (width, height) = image.dimensions();
+        image: &DynamicImage,
        layout: &BindGroupLayout,
        sampler: &Sampler,
    ) -> ImageGpu {
        let rgba = image.to_rgba8();
        let (width, height) = rgba.dimensions();
        let texture = self.device.create_texture_with_data(
            &self.queue,
            &TextureDescriptor {
-                label: None,
+                label: Some("image"),
                size: Extent3d {
                    width,
                    height,
@@ -127,63 +127,115 @@ impl GpuTextures {
                view_formats: &[],
            },
            wgt::TextureDataOrder::MipMajor,
-            image.as_bytes(),
+            rgba.as_bytes(),
        );
        let view = texture.create_view(&TextureViewDescriptor::default());
-        (texture, view)
+        let group = sampled_group(&self.device, layout, &view, sampler, "ui image");
        ImageGpu { texture, group }
    }
-    pub fn new(device: &Device, queue: &Queue) -> Self {
+    fn patch(&mut self, i: u32, rect: PatchRect, image: &DynamicImage) {
-        let null_view = null_texture_view(device);
+        let Some(Some(slot)) = self.slots.get(i as usize) else {
-        Self {
+            return;
-            device: device.clone(),
+        };
-            queue: queue.clone(),
+        let dst = TexelCopyTextureInfo {
-            textures: Vec::new(),
+            texture: &slot.texture,
-            views: Vec::new(),
+            mip_level: 0,
-            samplers: vec![default_sampler(device)],
+            origin: Origin3d {
-            no_views: vec![null_view.clone()],
+                x: rect.x,
-            null_view,
+                y: rect.y,
-            view_count: 0,
+                z: 0,
            },
            aspect: TextureAspect::All,
        };
        match image.as_rgba8() {
            Some(rgba) => write_region(&self.queue, dst, rgba, rect),
            // The texture is rgba8, so any other layout has to be converted --
            // and converting the rectangle is cheaper than the whole image.
            None => {
                let sub = image
                    .view(rect.x, rect.y, rect.width, rect.height)
                    .to_image();
                write_region(&self.queue, dst, &sub, PatchRect { x: 0, y: 0, ..rect });
            }
        }
    }
    pub fn views(&self) -> Vec<&TextureView> {
        if self.views.is_empty() {
            &self.no_views
        } else {
            &self.views
        }
        .iter()
        .by_ref()
        .collect()
    }
    pub fn samplers(&self) -> Vec<&Sampler> {
        self.samplers.iter().by_ref().collect()
    }
    pub fn view_count(&self) -> usize {
        self.view_count
    }
 }
-pub fn null_texture_view(device: &Device) -> TextureView {
+pub fn write_region(queue: &Queue, dst: TexelCopyTextureInfo, src: &RgbaImage, rect: PatchRect) {
-    device
+    if rect.width == 0 || rect.height == 0 {
-        .create_texture(&TextureDescriptor {
+        return;
-            label: Some("null"),
+    }
-            size: Extent3d {
+    let stride = src.width() * 4;
-                width: 1,
+    queue.write_texture(
-                height: 1,
+        dst,
-                depth_or_array_layers: 1,
+        src.as_bytes(),
        TexelCopyBufferLayout {
            offset: (rect.y * stride + rect.x * 4) as u64,
            bytes_per_row: Some(stride),
            rows_per_image: Some(rect.height),
        },
        Extent3d {
            width: rect.width,
            height: rect.height,
            depth_or_array_layers: 1,
        },
    );
 }
 /// What a primitive that samples binds: a texture, and the sampler that reads
 /// it.
 pub fn sampled_group(
    device: &Device,
    layout: &BindGroupLayout,
    view: &TextureView,
    sampler: &Sampler,
    label: &'static str,
 ) -> BindGroup {
    device.create_bind_group(&BindGroupDescriptor {
        layout,
        entries: &[
            BindGroupEntry {
                binding: 0,
                resource: BindingResource::TextureView(view),
            },
-            mip_level_count: 1,
+            BindGroupEntry {
-            sample_count: 1,
+                binding: 1,
-            dimension: TextureDimension::D2,
+                resource: BindingResource::Sampler(sampler),
-            format: TextureFormat::Rgba8Unorm,
+            },
-            usage: TextureUsages::TEXTURE_BINDING,
+        ],
-            view_formats: &[],
+        label: Some(label),
-        })
+    })
-        .create_view(&TextureViewDescriptor::default())
+}
 /// The layout for one of those. The dimension differs -- the atlas is an
 /// array of pages and an image is not -- and nothing else does.
 pub fn sampled_layout(
    device: &Device,
    dimension: TextureViewDimension,
    label: &'static str,
 ) -> BindGroupLayout {
    device.create_bind_group_layout(&BindGroupLayoutDescriptor {
        entries: &[
            BindGroupLayoutEntry {
                binding: 0,
                visibility: ShaderStages::FRAGMENT,
                ty: BindingType::Texture {
                    sample_type: TextureSampleType::Float { filterable: false },
                    view_dimension: dimension,
                    multisampled: false,
                },
                count: None,
            },
            BindGroupLayoutEntry {
                binding: 1,
                visibility: ShaderStages::FRAGMENT,
                ty: BindingType::Sampler(SamplerBindingType::NonFiltering),
                count: None,
            },
        ],
        label: Some(label),
    })
 }
 pub fn default_sampler(device: &Device) -> Sampler {
@@ -21,17 +21,25 @@ impl<T: Pod> ArrBuf<T> {
            _pd: PhantomData,
        }
    }
-    pub fn update(&mut self, device: &Device, queue: &Queue, data: &[T]) {
+    /// Returns whether the `Buffer` was recreated, which stales any cached
-        if self.len != data.len() {
+    /// `BindGroup` holding it.
    pub fn update(&mut self, device: &Device, queue: &Queue, data: &[T]) -> bool {
        let resized = self.len != data.len();
        if resized {
            self.len = data.len();
            self.buffer =
                Self::init_buf(device, std::mem::size_of_val(data), self.usage, self.label);
        }
        queue.write_buffer(&self.buffer, 0, bytemuck::cast_slice(data));
        resized
    }
    pub fn len(&self) -> usize {
        self.len
    }
    fn init_buf(device: &Device, size: usize, usage: BufferUsages, label: &'static str) -> Buffer {
        let mut size = size as u64;
        if usage.contains(BufferUsages::STORAGE) {
            // A binding cannot be empty or under the layout's minimum.
            size = size.max(std::mem::size_of::<T>() as u64);
        }
        device.create_buffer(&BufferDescriptor {
@@ -41,8 +49,4 @@ impl<T: Pod> ArrBuf<T> {
            usage,
        })
    }
    #[allow(clippy::len_without_is_empty)]
    pub fn len(&self) -> usize {
        self.len
    }
 }
@@ -1,4 +1,6 @@
-use crate::{Mask, TextData, Textures, WeakWidget, WidgetId, Widgets, util::TrackedArena};
+use crate::{
    Mask, PrimitiveRegistry, TextData, Textures, WeakWidget, WidgetId, Widgets, util::TrackedArena,
 };
 mod active;
 mod cache;
@@ -7,13 +9,15 @@ mod render_state;
 mod size;
 pub use active::*;
-pub use painter::Painter;
+pub use painter::{Painter, PrimitiveLike};
 pub use render_state::*;
 pub use size::*;
 #[derive(Default)]
 pub struct UiData {
    pub widgets: Widgets,
    /// Every primitive this ui can draw.
    pub primitives: PrimitiveRegistry,
    pub textures: Textures,
    pub text: TextData,
    pub masks: TrackedArena<Mask, u32>,
@@ -1,7 +1,10 @@
 use crate::{
    Axis, Len, RenderedText, Size, SizeCtx, StrongWidget, TextAttrs, TextBuffer, TextData,
    TextureHandle, UiRegion, UiRenderState, UiRsc, UiScalar, UiVec2, Widget, WidgetId,
-    render::{GlyphPrimitive, Mask, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
+    render::{
        GlyphPrimitive, Mask, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst, PrimitiveKind,
        TexturePrimitive,
    },
    util::Vec2,
 };
@@ -21,15 +24,26 @@ pub struct Painter<'a> {
 impl<'a> Painter<'a> {
    fn primitive_at<P: Primitive>(&mut self, primitive: P, region: UiRegion) {
        let kind = self.rsc.ui_mut().primitives.kind::<P>();
        self.write(kind, primitive, region);
    }
    /// Takes the kind, for a caller writing many of one primitive.
    fn write<P: Primitive>(&mut self, kind: PrimitiveKind<P>, primitive: P, region: UiRegion) {
        let h = self.state.layers.write(
            self.layer,
            PrimitiveInst {
                kind,
                id: self.id,
                primitive,
                region,
                mask_idx: self.mask,
            },
        );
        self.push_primitive(h);
    }
    fn push_primitive(&mut self, h: PrimitiveHandle) {
        if self.mask != MaskIdx::NONE {
            // TODO: I have no clue if this works at all :joy:
            self.rsc.ui_mut().masks.push_ref(self.mask);
@@ -38,11 +52,13 @@ impl<'a> Painter<'a> {
    }
    /// Writes a primitive to be rendered
-    pub fn primitive<P: Primitive>(&mut self, primitive: P) {
+    pub fn primitive(&mut self, primitive: impl PrimitiveLike) {
        let primitive = primitive.into_primitive(self);
        self.primitive_at(primitive, self.region)
    }
-    pub fn primitive_within<P: Primitive>(&mut self, primitive: P, region: UiRegion) {
+    pub fn primitive_within(&mut self, primitive: impl PrimitiveLike, region: UiRegion) {
        let primitive = primitive.into_primitive(self);
        self.primitive_at(primitive, region.within(&self.region));
    }
@@ -75,21 +91,6 @@ impl<'a> Painter<'a> {
        );
    }
    pub fn texture_within(&mut self, handle: &TextureHandle, region: UiRegion) {
        self.textures.push(handle.clone());
        self.primitive_at(handle.primitive(), region.within(&self.region));
    }
    pub fn texture(&mut self, handle: &TextureHandle) {
        self.textures.push(handle.clone());
        self.primitive(handle.primitive());
    }
    pub fn texture_at(&mut self, handle: &TextureHandle, region: UiRegion) {
        self.textures.push(handle.clone());
        self.primitive_at(handle.primitive(), region);
    }
    pub fn render_text(
        &mut self,
        buffer: &mut TextBuffer,
@@ -97,10 +98,12 @@ impl<'a> Painter<'a> {
        width: Option<f32>,
    ) -> RenderedText {
        let ui = self.rsc.ui_mut();
-        ui.text.render(buffer, attrs, width, &mut ui.textures)
+        ui.text.render(buffer, attrs, width)
    }
    // TODO: merge the text methods into the primitive ones.
    pub fn glyphs(&mut self, text: &RenderedText, origin: UiRegion) {
        let kind = self.rsc.ui_mut().primitives.kind::<GlyphPrimitive>();
        for glyph in text.glyphs.iter() {
            let mut region = origin;
            region.x.end = region.x.start;
@@ -108,12 +111,12 @@ impl<'a> Painter<'a> {
            let mut region = region.offset(UiVec2::abs(glyph.offset));
            region.x.end = region.x.start + UiScalar::abs(glyph.entry.width as f32);
            region.y.end = region.y.start + UiScalar::abs(glyph.entry.height as f32);
-            self.primitive_at(
+            self.write(
                kind,
                GlyphPrimitive {
                    uv_min: glyph.entry.uv_min,
                    uv_max: glyph.entry.uv_max,
-                    view_idx: glyph.entry.view_idx,
+                    layer: glyph.entry.layer,
                    sampler_idx: glyph.entry.sampler_idx,
                    color: text.color,
                    flags: glyph.entry.flags(),
                },
@@ -169,3 +172,28 @@ impl<'a> Painter<'a> {
        self.state.size_ctx(self.id, self.region.size(), self.rsc)
    }
 }
 /// What `Painter::primitive` takes: a primitive, or something that yields one
 /// and does whatever else drawing it needs.
 pub trait PrimitiveLike {
    type Primitive: Primitive;
    fn into_primitive(self, painter: &mut Painter) -> Self::Primitive;
 }
 impl<P: Primitive> PrimitiveLike for P {
    type Primitive = P;
    fn into_primitive(self, _: &mut Painter) -> P {
        self
    }
 }
 impl PrimitiveLike for &TextureHandle {
    type Primitive = TexturePrimitive;
    /// Retains a share of the handle, so the slot the primitive names cannot
    /// be freed and reused while it is still drawn.
    fn into_primitive(self, painter: &mut Painter) -> TexturePrimitive {
        painter.textures.push(self.clone());
        self.into()
    }
 }
@@ -1,13 +1,13 @@
 use crate::{
-    ActiveData, Axis, IdLike, MaskIdx, Painter, PixelRegion, PrimitiveLayers, SizeCtx,
+    ActiveData, Axis, DrawLayers, IdLike, MaskIdx, Painter, PixelRegion, SizeCtx, StrongWidget,
-    StrongWidget, UiRegion, UiRsc, UiVec2, WidgetId, Widgets,
+    UiRegion, UiRsc, UiVec2, WidgetId, Widgets,
    ui::cache::Cache,
    util::{HashMap, HashSet, Vec2, forget_ref},
 };
 pub struct UiRenderState {
    pub active: HashMap<WidgetId, ActiveData>,
-    pub layers: PrimitiveLayers,
+    pub layers: DrawLayers,
    pub(super) output_size: Vec2,
    pub cache: Cache,
@@ -34,6 +34,10 @@ impl UiRenderState {
        self.resized = true;
    }
    pub fn output_size(&self) -> Vec2 {
        self.output_size
    }
    pub fn update<'a>(&mut self, root: impl Into<Option<&'a StrongWidget>>, rsc: &mut dyn UiRsc) {
        // safety mechanism for memory leaks; might wanna return a result instead so user can
        // decide whether to panic or not
@@ -243,14 +247,14 @@ impl UiRenderState {
    }
    pub fn debug_layers(&self) {
-        for ((idx, depth), primitives) in self.layers.iter_depth() {
+        for ((idx, depth), draws) in self.layers.iter_depth() {
            let indent = " ".repeat(depth * 2);
-            let len = primitives.instances().len();
+            let counts: Vec<String> = draws
-            print!("{indent}{idx}: {len} primitives");
+                .primitives()
-            if len >= 1 {
+                .iter()
-                print!(" ({})", primitives.instances()[0].binding);
+                .map(|l| l.as_ref().map_or(0, |l| l.instances().len()).to_string())
-            }
+                .collect();
-            println!();
+            println!("{indent}{idx}: [{}]", counts.join(", "));
        }
    }
@@ -308,7 +312,6 @@ impl UiRenderState {
            source,
            cache: &mut self.cache,
            text: &mut ui.text,
            textures: &mut ui.textures,
            widgets: &ui.widgets,
            outer,
            output_size: self.output_size,
@@ -1,11 +1,10 @@
 use crate::{
-    Axis, AxisT, IdLike, Len, RenderedText, Size, TextAttrs, TextBuffer, TextData, Textures,
+    Axis, AxisT, IdLike, Len, RenderedText, Size, TextAttrs, TextBuffer, TextData, UiVec2,
-    UiVec2, WidgetAxisFns, WidgetId, Widgets, XAxis, YAxis, ui::cache::Cache, util::Vec2,
+    WidgetAxisFns, WidgetId, Widgets, XAxis, YAxis, ui::cache::Cache, util::Vec2,
 };
 pub struct SizeCtx<'a> {
    pub text: &'a mut TextData,
    pub textures: &'a mut Textures,
    pub(super) source: WidgetId,
    pub(super) widgets: &'a Widgets,
    pub(super) cache: &'a mut Cache,
@@ -33,7 +32,6 @@ impl SizeCtx<'_> {
            .get_dyn_dynamic(id)
            .desired_len::<A>(&mut SizeCtx {
                text: self.text,
                textures: self.textures,
                source: self.source,
                widgets: self.widgets,
                cache: self.cache,
@@ -82,7 +80,7 @@ impl SizeCtx<'_> {
        attrs: &TextAttrs,
        width: Option<f32>,
    ) -> RenderedText {
-        self.text.render(buffer, attrs, width, self.textures)
+        self.text.render(buffer, attrs, width)
    }
    pub fn label(&self, id: WidgetId) -> &String {
@@ -10,11 +10,7 @@ struct State {
 }
 impl DefaultAppState for State {
-    fn new(
+    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, _: Proxy<Self>) -> Self {
        mut ui_state: DefaultUiState,
        rsc: &mut DefaultRsc<Self>,
        _: Proxy<Self::Event>,
    ) -> Self {
        rect(Color::RED).set_root(rsc, &mut ui_state);
        Self { ui_state }
    }
@@ -15,11 +15,7 @@ pub struct Client {
 }
 impl DefaultAppState for Client {
-    fn new(
+    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, _: Proxy<Self>) -> Self {
        mut ui_state: DefaultUiState,
        rsc: &mut DefaultRsc<Self>,
        _: Proxy<Self::Event>,
    ) -> Self {
        let rrect = rect(Color::WHITE).radius(20);
        let pad_test = (
            rrect.color(Color::BLUE),
@@ -212,10 +208,10 @@ impl DefaultAppState for Client {
        render: &mut UiRenderState,
    ) {
        let new = format!(
-            "widgets: {}\nactive: {}\nviews: {}",
+            "widgets: {}\nactive: {}\ntextures: {}",
            rsc.widgets().len(),
            render.active_widgets(),
-            self.ui_state.renderer.ui.view_count(),
+            rsc.ui().textures.count(),
        );
        if new != *rsc.widgets()[self.info].content {
            *rsc.widgets_mut()[self.info].content = new;
@@ -11,11 +11,7 @@ struct State {
 }
 impl DefaultAppState for State {
-    fn new(
+    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, _: Proxy<Self>) -> Self {
        mut ui_state: DefaultUiState,
        rsc: &mut DefaultRsc<Self>,
        _: Proxy<Self::Event>,
    ) -> Self {
        let rect = rect(Color::RED).add(rsc);
        rect.task_on(CursorSense::click(), async move |mut ctx| {
            tokio::time::sleep(Duration::from_secs(1)).await;
@@ -36,11 +36,7 @@ impl Test {
 }
 impl DefaultAppState for State {
-    fn new(
+    fn new(mut ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, _: Proxy<Self>) -> Self {
        mut ui_state: DefaultUiState,
        rsc: &mut DefaultRsc<Self>,
        _: Proxy<Self::Event>,
    ) -> Self {
        let test = Test::new(rsc);
        test.on(CursorSense::click(), move |_, rsc| {
@@ -1,10 +1,6 @@
 use crate::prelude::*;
 use arboard::Clipboard;
-use std::{
+use std::{marker::PhantomData, sync::Arc, time::Instant};
    marker::{PhantomData, Sized},
    sync::Arc,
    time::Instant,
 };
 use winit::{
    event::{Ime, WindowEvent},
    event_loop::{ActiveEventLoop, EventLoopProxy},
@@ -29,7 +25,35 @@ pub use sense::*;
 pub use state::*;
 pub use task::*;
-pub type Proxy<Event> = EventLoopProxy<Event>;
+/// Sends an application's own events to its event loop. It wraps the proxy
 /// rather than being one because task updates travel the same way: what an
 /// application sends is its `Event`, not the loop's whole message type.
 pub struct Proxy<State: DefaultAppState>(EventLoopProxy<DefaultEvent<State>>);
 impl<State: DefaultAppState> Clone for Proxy<State> {
    fn clone(&self) -> Self {
        Self(self.0.clone())
    }
 }
 impl<State: DefaultAppState> Proxy<State> {
    pub fn send_event(&self, event: State::Event) {
        let _ = self.0.send_event(DefaultEvent::User(event));
    }
 }
 /// What the event loop carries: the application's own events, and the
 /// updates tasks send back to the ui thread.
 pub enum DefaultEvent<State: DefaultAppState> {
    User(State::Event),
    Update(Box<dyn TaskUpdate<DefaultRsc<State>>>),
 }
 impl<State: DefaultAppState> TaskQueue<DefaultRsc<State>> for Proxy<State> {
    fn send(&self, update: Box<dyn TaskUpdate<DefaultRsc<State>>>) {
        let _ = self.0.send_event(DefaultEvent::Update(update));
    }
 }
 pub struct DefaultUiState {
    pub root: Option<StrongWidget>,
@@ -70,9 +94,8 @@ pub trait HasDefaultUiState: Sized + 'static {
 }
 pub trait DefaultAppState: HasDefaultUiState {
-    type Event = ();
+    type Event: Send = ();
-    fn new(ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, proxy: Proxy<Self::Event>)
+    fn new(ui_state: DefaultUiState, rsc: &mut DefaultRsc<Self>, proxy: Proxy<Self>) -> Self;
    -> Self;
    #[allow(unused_variables)]
    fn event(
        &mut self,
@@ -105,18 +128,14 @@ pub struct DefaultRsc<State: 'static> {
 }
 impl<State> DefaultRsc<State> {
-    fn init(window: Arc<Window>) -> (Self, TaskMsgReceiver<Self>) {
+    pub fn init(queue: Arc<dyn TaskQueue<Self>>) -> Self {
-        let (tasks, recv) = Tasks::init(window);
+        Self {
-        (
+            ui: Default::default(),
-            Self {
+            events: Default::default(),
-                ui: Default::default(),
+            tasks: Tasks::init(queue),
-                events: Default::default(),
+            state: Default::default(),
-                tasks,
+            _state: Default::default(),
-                state: Default::default(),
+        }
                _state: Default::default(),
            },
            recv,
        )
    }
    pub fn create_state<T: 'static>(&mut self, id: impl IdLike, data: T) -> WeakState<T> {
@@ -181,43 +200,32 @@ pub struct DefaultApp<State: DefaultAppState> {
    rsc: DefaultRsc<State>,
    render: UiRenderState,
    state: State,
    task_recv: TaskMsgReceiver<DefaultRsc<State>>,
 }
 impl<State: DefaultAppState> AppState for DefaultApp<State> {
-    type Event = State::Event;
+    type Event = DefaultEvent<State>;
    fn new(event_loop: &ActiveEventLoop, proxy: EventLoopProxy<Self::Event>) -> Self {
        let window = event_loop
            .create_window(State::window_attributes())
            .unwrap();
        let default_state = DefaultUiState::new(window);
-        let (mut rsc, task_recv) = DefaultRsc::init(default_state.window.clone());
+        let mut rsc = DefaultRsc::init(Arc::new(Proxy(proxy.clone())));
-        let state = State::new(default_state, &mut rsc, proxy);
+        let state = State::new(default_state, &mut rsc, Proxy(proxy));
        let render = UiRenderState::new();
-        Self {
+        Self { rsc, state, render }
            rsc,
            state,
            render,
            task_recv,
        }
    }
    fn event(&mut self, event: Self::Event, _: &ActiveEventLoop) {
-        self.state.event(event, &mut self.rsc, &mut self.render);
+        match event {
            DefaultEvent::User(event) => self.state.event(event, &mut self.rsc, &mut self.render),
            DefaultEvent::Update(update) => update(&mut self.state, &mut self.rsc),
        }
        self.request_redraw_if_needed();
    }
    fn window_event(&mut self, event: WindowEvent, event_loop: &ActiveEventLoop) {
-        let Self {
+        let Self { rsc, render, state } = self;
            rsc,
            render,
            state,
            task_recv,
        } = self;
        for update in task_recv.try_iter() {
            update(state, rsc);
        }
        let ui_state = state.default_state_mut();
        let input_changed = ui_state.input.event(&event);
@@ -297,11 +305,8 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
            _ => (),
        }
        state.window_event(event, rsc, render);
-        let ui_state = self.state.default_state_mut();
+        self.request_redraw_if_needed();
-        if render.needs_redraw(&ui_state.root, rsc.widgets()) {
+        self.state.default_state_mut().input.end_frame();
            ui_state.renderer.window().request_redraw();
        }
        ui_state.input.end_frame();
    }
    fn exit(&mut self) {
@@ -309,6 +314,15 @@ impl<State: DefaultAppState> AppState for DefaultApp<State> {
    }
 }
 impl<State: DefaultAppState> DefaultApp<State> {
    fn request_redraw_if_needed(&mut self) {
        let ui_state = self.state.default_state_mut();
        if self.render.needs_redraw(&ui_state.root, self.rsc.widgets()) {
            ui_state.renderer.window().request_redraw();
        }
    }
 }
 pub trait RscIdx<Rsc> {
    type Output;
    fn get(self, rsc: &Rsc) -> &Self::Output;
@@ -1,4 +1,4 @@
-use iris_core::{UiData, UiLimits, UiRenderNode, UiRenderState};
+use iris_core::{UiData, UiRenderNode, UiRenderState};
 use pollster::FutureExt;
 use std::sync::Arc;
 use wgpu::*;
@@ -22,7 +22,20 @@ impl UiRenderer {
    }
    pub fn draw(&mut self) {
-        let output = self.surface.get_current_texture().unwrap();
+        let output = match self.surface.get_current_texture() {
            CurrentSurfaceTexture::Success(texture) => texture,
            CurrentSurfaceTexture::Suboptimal(texture) => {
                self.surface.configure(&self.device, &self.config);
                texture
            }
            CurrentSurfaceTexture::Outdated | CurrentSurfaceTexture::Lost => {
                self.surface.configure(&self.device, &self.config);
                return;
            }
            CurrentSurfaceTexture::Timeout
            | CurrentSurfaceTexture::Occluded
            | CurrentSurfaceTexture::Validation => return,
        };
        let view = output
            .texture
            .create_view(&TextureViewDescriptor::default());
@@ -46,7 +59,7 @@ impl UiRenderer {
        self.queue.submit(std::iter::once(encoder.finish()));
        self.window.pre_present_notify();
-        output.present();
+        self.queue.present(output);
    }
    pub fn resize(&mut self, size: &PhysicalSize<u32>) {
@@ -65,9 +78,10 @@ impl UiRenderer {
    pub fn new(window: Arc<Window>) -> Self {
        let size = window.inner_size();
-        let instance = Instance::new(&InstanceDescriptor {
+        let instance = Instance::new(InstanceDescriptor {
            backends: Backends::PRIMARY,
-            ..Default::default()
+            display: Some(Box::new(window.clone())),
            ..InstanceDescriptor::new_without_display_handle()
        });
        let surface = instance
@@ -79,22 +93,14 @@ impl UiRenderer {
                power_preference: PowerPreference::default(),
                compatible_surface: Some(&surface),
                force_fallback_adapter: false,
                apply_limit_buckets: false,
            })
            .block_on()
            .expect("Could not get adapter!");
        let ui_limits = UiLimits::default();
        let (device, queue) = adapter
            .request_device(&DeviceDescriptor {
                required_features: Features::TEXTURE_BINDING_ARRAY
                    | Features::PARTIALLY_BOUND_BINDING_ARRAY
                    | Features::SAMPLED_TEXTURE_AND_STORAGE_BUFFER_ARRAY_NON_UNIFORM_INDEXING,
                required_limits: Limits {
                    max_binding_array_elements_per_shader_stage: ui_limits
                        .max_binding_array_elements_per_shader_stage(),
                    max_binding_array_sampler_elements_per_shader_stage: ui_limits
                        .max_binding_array_sampler_elements_per_shader_stage(),
                    max_buffer_size: 1 << 30,
                    ..Default::default()
                },
@@ -114,6 +120,7 @@ impl UiRenderer {
        let config = SurfaceConfiguration {
            usage: TextureUsages::RENDER_ATTACHMENT,
            format: surface_format,
            color_space: SurfaceColorSpace::Auto,
            width: size.width,
            height: size.height,
            present_mode: PresentMode::AutoVsync,
@@ -126,7 +133,7 @@ impl UiRenderer {
        let encoder = Self::create_encoder(&device);
-        let ui = UiRenderNode::new(&device, &queue, &config, ui_limits);
+        let ui = UiRenderNode::new(&device, &config);
        Self {
            surface,
@@ -1,11 +1,5 @@
 use iris_core::HasState;
-use std::{
+use std::{pin::Pin, sync::Arc};
    pin::Pin,
    sync::{
        Arc,
        mpsc::{Receiver as SyncReceiver, Sender as SyncSender, channel as sync_channel},
    },
 };
 use tokio::{
    runtime::Runtime,
    sync::mpsc::{
@@ -13,64 +7,52 @@ use tokio::{
        unbounded_channel as async_channel,
    },
 };
 use winit::window::Window;
 pub type TaskMsgSender<Rsc> = SyncSender<Box<dyn TaskUpdate<Rsc>>>;
 pub type TaskMsgReceiver<Rsc> = SyncReceiver<Box<dyn TaskUpdate<Rsc>>>;
 pub trait TaskUpdate<Rsc: HasState>: FnOnce(&mut Rsc::State, &mut Rsc) + Send {}
 impl<F: FnOnce(&mut Rsc::State, &mut Rsc) + Send, Rsc: HasState> TaskUpdate<Rsc> for F {}
 /// Hands an update from a task to the thread that owns the ui. Delivery and
 /// waking are one act: a host posts the update as a message its loop already
 /// carries, so nothing has to wake the loop separately, or claim a redraw to
 /// be looked at.
 pub trait TaskQueue<Rsc: HasState>: Send + Sync + 'static {
    fn send(&self, update: Box<dyn TaskUpdate<Rsc>>);
 }
 pub struct Tasks<Rsc: HasState> {
    start: AsyncSender<BoxTask>,
-    window: Arc<Window>,
+    queue: Arc<dyn TaskQueue<Rsc>>,
    msg_send: SyncSender<Box<dyn TaskUpdate<Rsc>>>,
 }
 pub struct TaskCtx<Rsc: HasState> {
-    send: TaskMsgSender<Rsc>,
+    queue: Arc<dyn TaskQueue<Rsc>>,
 }
 impl<Rsc: HasState> TaskCtx<Rsc> {
    pub fn update(&mut self, f: impl TaskUpdate<Rsc> + 'static) {
-        let _ = self.send.send(Box::new(f));
+        self.queue.send(Box::new(f));
    }
 }
 impl<Rsc: HasState + 'static> TaskCtx<Rsc> {
    fn new(send: TaskMsgSender<Rsc>) -> Self {
        Self { send }
    }
 }
 type BoxTask = Pin<Box<dyn Future<Output = ()> + Send>>;
 impl<Rsc: HasState> Tasks<Rsc> {
-    pub fn init(window: Arc<Window>) -> (Self, TaskMsgReceiver<Rsc>) {
+    pub fn init(queue: Arc<dyn TaskQueue<Rsc>>) -> Self {
        let (start, start_recv) = async_channel();
        let (msgs, msgs_recv) = sync_channel();
        std::thread::spawn(|| {
            let rt = Runtime::new().unwrap();
            rt.block_on(listen(start_recv))
        });
-        (
+        Self { start, queue }
            Self {
                start,
                msg_send: msgs,
                window,
            },
            msgs_recv,
        )
    }
    pub fn spawn<F: AsyncFnOnce(TaskCtx<Rsc>) + 'static + std::marker::Send>(&mut self, task: F)
    where
        F::CallOnceFuture: Send,
    {
-        let send = self.msg_send.clone();
+        let queue = self.queue.clone();
        let window = self.window.clone();
        let _ = self.start.send(Box::pin(async move {
-            task(TaskCtx::new(send)).await;
+            task(TaskCtx { queue }).await;
            window.request_redraw();
        }));
    }
 }
@@ -0,0 +1,181 @@
 //! A ui with no window: build a tree, run frames, move a pointer, and read
 //! back where widgets landed.
 //!
 //! It does not draw. A claim about pixels still needs a real surface.
 use crate::prelude::*;
 use std::{
    sync::{
        Arc,
        mpsc::{Receiver, SyncSender, sync_channel},
    },
    time::Duration,
 };
 /// There is no loop here to post to, so updates queue until the test asks
 /// for them.
 struct Queue(SyncSender<Box<dyn TaskUpdate<DefaultRsc<HarnessState>>>>);
 impl TaskQueue<DefaultRsc<HarnessState>> for Queue {
    fn send(&self, update: Box<dyn TaskUpdate<DefaultRsc<HarnessState>>>) {
        let _ = self.0.send(update);
    }
 }
 /// `assert_eq!` for where a frame put a widget, written as its two corners.
 #[macro_export]
 macro_rules! assert_corners {
    ($harness:expr, $id:expr, ($x0:expr, $y0:expr), ($x1:expr, $y1:expr)) => {
        assert_eq!(
            $harness.region(&$id).expect("widget drew nothing"),
            $crate::core::PixelRegion {
                top_left: $crate::core::util::Vec2::new($x0 as f32, $y0 as f32),
                bot_right: $crate::core::util::Vec2::new($x1 as f32, $y1 as f32),
            }
        );
    };
 }
 pub use crate::assert_corners;
 #[derive(Default)]
 pub struct HarnessState {
    pub root: Option<StrongWidget>,
 }
 impl HasRoot for HarnessState {
    fn set_root(&mut self, root: StrongWidget) {
        self.root = Some(root);
    }
 }
 pub struct Harness {
    pub rsc: DefaultRsc<HarnessState>,
    pub render: UiRenderState,
    pub state: HarnessState,
    updates: Receiver<Box<dyn TaskUpdate<DefaultRsc<HarnessState>>>>,
    cursor: CursorState,
 }
 impl Harness {
    /// `size` is the output in physical pixels.
    pub fn new(size: impl Into<Vec2>) -> Self {
        // A `TaskQueue` must be `Sync`, which `mpsc::Sender` is not; the
        // bound that comes with `SyncSender` is far past anything a test
        // leaves unread.
        let (send, updates) = sync_channel(1024);
        let rsc = DefaultRsc::init(Arc::new(Queue(send)));
        let mut render = UiRenderState::new();
        render.resize(size);
        Self {
            rsc,
            render,
            state: HarnessState::default(),
            updates,
            cursor: CursorState::default(),
        }
    }
    pub fn size(&self) -> Vec2 {
        self.render.output_size()
    }
    pub fn resize(&mut self, size: impl Into<Vec2>) {
        self.render.resize(size);
    }
    /// Sets the root and lays it out, so a pointer event has something to hit.
    pub fn set_root<T>(&mut self, widget: impl WidgetLike<DefaultRsc<HarnessState>, T>) {
        widget.set_root(&mut self.rsc, &mut self.state);
        self.frame();
    }
    pub fn needs_redraw(&self) -> bool {
        self.render
            .needs_redraw(&self.state.root, self.rsc.widgets())
    }
    pub fn apply_updates(&mut self) -> usize {
        let mut applied = 0;
        while let Ok(update) = self.updates.try_recv() {
            update(&mut self.state, &mut self.rsc);
            applied += 1;
        }
        applied
    }
    /// Waits for a task's first update, then applies everything waiting.
    /// False if none arrived in time.
    #[must_use]
    pub fn await_update(&mut self, timeout: Duration) -> bool {
        let Ok(update) = self.updates.recv_timeout(timeout) else {
            return false;
        };
        update(&mut self.state, &mut self.rsc);
        self.apply_updates();
        true
    }
    /// Lays the tree out and builds its primitives.
    pub fn frame(&mut self) {
        self.apply_updates();
        self.render.update(&self.state.root, &mut self.rsc);
    }
    /// Where the last frame put a widget, or `None` if it drew nothing.
    pub fn region(&self, id: &impl IdLike) -> Option<PixelRegion> {
        self.render.window_region(id)
    }
    pub fn move_to(&mut self, pos: impl Into<Vec2>) {
        self.cursor.pos = pos.into();
        self.cursor.exists = true;
        self.sense();
    }
    pub fn leave(&mut self) {
        self.cursor.exists = false;
        self.sense();
    }
    pub fn press(&mut self, button: CursorButton) {
        self.button(button).update(true);
        self.sense();
    }
    pub fn release(&mut self, button: CursorButton) {
        self.button(button).update(false);
        self.sense();
    }
    /// A wheel carries no position, so this goes wherever the cursor was last
    /// moved to -- nowhere, until it has been moved.
    pub fn scroll(&mut self, delta: impl Into<Vec2>) {
        self.cursor.scroll_delta = delta.into();
        self.sense();
    }
    pub fn click(&mut self, pos: impl Into<Vec2>) {
        self.move_to(pos);
        self.press(CursorButton::Left);
        self.release(CursorButton::Left);
    }
    fn button(&mut self, button: CursorButton) -> &mut ActivationState {
        let buttons = &mut self.cursor.buttons;
        match button {
            CursorButton::Left => &mut buttons.left,
            CursorButton::Middle => &mut buttons.middle,
            CursorButton::Right => &mut buttons.right,
        }
    }
    /// Dispatches against the layout of the last frame, which is what a
    /// window delivers input against too.
    fn sense(&mut self) {
        let cursor = self.cursor.clone();
        let size = self.render.output_size();
        self.render
            .run_sensors(&mut self.rsc, &mut self.state, cursor, size);
        self.cursor.end_frame();
    }
 }
@@ -7,6 +7,7 @@
 pub mod default;
 pub mod event;
 pub mod harness;
 pub mod widget;
 pub use iris_core as core;
@@ -7,7 +7,7 @@ pub struct Image {
 impl Widget for Image {
    fn draw(&mut self, painter: &mut Painter) {
-        painter.texture(&self.handle);
+        painter.primitive(&self.handle);
    }
    fn desired_width(&mut self, _: &mut SizeCtx) -> Len {
@@ -4,7 +4,7 @@ mod max_size;
 mod offset;
 mod pad;
 mod scroll;
-mod sized;
+mod set_size;
 mod span;
 mod stack;
@@ -14,6 +14,6 @@ pub use max_size::*;
 pub use offset::*;
 pub use pad::*;
 pub use scroll::*;
-pub use sized::*;
+pub use set_size::*;
 pub use span::*;
 pub use stack::*;
@@ -1,12 +1,12 @@
 use crate::prelude::*;
-pub struct Sized {
+pub struct SetSize {
    pub inner: StrongWidget,
    pub x: Option<Len>,
    pub y: Option<Len>,
 }
-impl Sized {
+impl SetSize {
    fn apply_to_outer(&self, ctx: &mut SizeCtx) {
        if let Some(x) = self.x {
            ctx.outer.x.select_len(x.apply_rest());
@@ -17,7 +17,7 @@ impl Sized {
    }
 }
-impl Widget for Sized {
+impl Widget for SetSize {
    fn draw(&mut self, painter: &mut Painter) {
        painter.widget(&self.inner);
    }
@@ -1,5 +1,5 @@
 use crate::prelude::*;
-use std::marker::{Sized, Unsize};
+use std::marker::Unsize;
 pub struct WidgetPtr {
    pub inner: Option<StrongWidget>,
@@ -1,5 +1,5 @@
 use crate::prelude::*;
-use std::marker::{PhantomData, Sized};
+use std::marker::PhantomData;
 pub struct TextBuilder<State, O = TextOutput, H: WidgetOption<State> = ()> {
    pub content: String,
@@ -31,9 +31,9 @@ widget_trait! {
        }
    }
-    fn sized(self, size: impl Into<Size>) -> impl WidgetFn<Rsc, Sized> {
+    fn sized(self, size: impl Into<Size>) -> impl WidgetFn<Rsc, SetSize> {
        let size = size.into();
-        move |state| Sized {
+        move |state| SetSize {
            inner: self.add_strong(state),
            x: Some(size.x),
            y: Some(size.y),
@@ -58,18 +58,18 @@ widget_trait! {
        }
    }
-    fn width(self, len: impl Into<Len>) -> impl WidgetFn<Rsc, Sized> {
+    fn width(self, len: impl Into<Len>) -> impl WidgetFn<Rsc, SetSize> {
        let len = len.into();
-        move |state| Sized {
+        move |state| SetSize {
            inner: self.add_strong(state),
            x: Some(len),
            y: None,
        }
    }
-    fn height(self, len: impl Into<Len>) -> impl WidgetFn<Rsc, Sized> {
+    fn height(self, len: impl Into<Len>) -> impl WidgetFn<Rsc, SetSize> {
        let len = len.into();
-        move |state| Sized {
+        move |state| SetSize {
            inner: self.add_strong(state),
            x: None,
            y: Some(len),
@@ -0,0 +1,205 @@
 //! What one frame of `UiRenderNode::draw` costs on the CPU, against the number
 //! of layers it walks. Recording only: the pass is built and dropped without
 //! being submitted, so this is the loop's cost and not the GPU's.
 //!
 //!     cargo test --release --test draw_cost -- --ignored --nocapture
 //!
 //! Wall time is the wrong number to read for anything under a few percent --
 //! it varied by 2x between runs of one unchanged binary where instructions
 //! retired varied by 0.1%. Count those instead:
 //!
 //!     perf stat -e instructions:u target/release/.../draw_cost-* --ignored
 //!
 //! That is how `PrimitiveRender` was measured against a match in the renderer:
 //! 6 instructions per list drawn, against the ~5,400 wgpu spends recording
 //! one.
 //!
 //! The instance is leaked deliberately. A Vulkan loader may unload the driver
 //! when the last one drops, which can fault as a thread that used it exits --
 //! and every test runs on a spawned thread.
 use std::time::Instant;
 use iris::prelude::*;
 use iris_core::{
    GlyphPrimitive, MaskIdx, PrimitiveInst, RectPrimitive, TextureHandle, TexturePrimitive, UiData,
    UiRegion, UiRenderNode, UiRenderState,
 };
 use wgpu::{Color as GpuColor, *};
 const SIZE: u32 = 1024;
 const FRAMES: u32 = 200;
 /// Reported as the best of this many batches, since the mean moves by more
 /// than the thing being measured.
 const BATCHES: u32 = 8;
 fn gpu() -> Option<(Device, Queue)> {
    // Probed rather than assumed: there may be no Vulkan adapter, and GL is
    // what is left when there is not.
    let all = Instance::new(InstanceDescriptor::new_without_display_handle());
    let instance = match pollster::block_on(all.request_adapter(&RequestAdapterOptions::default()))
    {
        Ok(_) => all,
        Err(_) => Instance::new(InstanceDescriptor {
            backends: Backends::GL,
            ..InstanceDescriptor::new_without_display_handle()
        }),
    };
    // Leaked rather than dropped: see the note at the top of the file.
    let instance: &'static Instance = Box::leak(Box::new(instance));
    let adapter =
        pollster::block_on(instance.request_adapter(&RequestAdapterOptions::default())).ok()?;
    println!("adapter: {:?}", adapter.get_info());
    pollster::block_on(adapter.request_device(&DeviceDescriptor::default())).ok()
 }
 fn config(format: TextureFormat) -> SurfaceConfiguration {
    SurfaceConfiguration {
        usage: TextureUsages::RENDER_ATTACHMENT,
        format,
        color_space: SurfaceColorSpace::Auto,
        width: SIZE,
        height: SIZE,
        present_mode: PresentMode::Fifo,
        desired_maximum_frame_latency: 2,
        alpha_mode: CompositeAlphaMode::Auto,
        view_formats: vec![],
    }
 }
 /// Every layer draws all three primitives, so the renderer takes a different
 /// path for each list it walks -- which is the case a single-primitive layer
 /// would never exercise. Images are bound per instance, so there are few.
 fn fill(
    ui: &mut UiData,
    render: &mut UiRenderState,
    layers: usize,
    per_layer: usize,
 ) -> Vec<TextureHandle> {
    let rect = ui.primitives.kind::<RectPrimitive>();
    let glyph = ui.primitives.kind::<GlyphPrimitive>();
    let texture = ui.primitives.kind::<TexturePrimitive>();
    let id = ui.widgets.add_strong(Rect::new(UiColor::WHITE)).id();
    let handles: Vec<_> = (0..4)
        .map(|_| ui.textures.add(image::RgbaImage::new(4, 4)))
        .collect();
    let mut layer = 0;
    for _ in 0..layers {
        for _ in 0..per_layer {
            render.layers.write(
                layer,
                PrimitiveInst {
                    kind: rect,
                    id,
                    primitive: RectPrimitive::color(UiColor::WHITE),
                    region: UiRegion::FULL,
                    mask_idx: MaskIdx::NONE,
                },
            );
            render.layers.write(
                layer,
                PrimitiveInst {
                    kind: glyph,
                    id,
                    primitive: GlyphPrimitive {
                        uv_min: vec2(0.0, 0.0),
                        uv_max: vec2(1.0, 1.0),
                        layer: 0,
                        color: UiColor::WHITE,
                        flags: 0,
                    },
                    region: UiRegion::FULL,
                    mask_idx: MaskIdx::NONE,
                },
            );
        }
        for h in &handles[..2] {
            render.layers.write(
                layer,
                PrimitiveInst {
                    kind: texture,
                    id,
                    primitive: TexturePrimitive::from(h),
                    region: UiRegion::FULL,
                    mask_idx: MaskIdx::NONE,
                },
            );
        }
        layer = render.layers.next(layer);
    }
    handles
 }
 fn frame_cost(device: &Device, queue: &Queue, layers: usize, per_layer: usize) -> f64 {
    let format = TextureFormat::Bgra8Unorm;
    let mut node = UiRenderNode::new(device, &config(format));
    let mut ui = UiData::default();
    let mut render = UiRenderState::new();
    let _handles = fill(&mut ui, &mut render, layers, per_layer);
    node.update(device, queue, &mut ui, &mut render);
    let target = device.create_texture(&TextureDescriptor {
        label: Some("draw cost"),
        size: Extent3d {
            width: SIZE,
            height: SIZE,
            depth_or_array_layers: 1,
        },
        mip_level_count: 1,
        sample_count: 1,
        dimension: TextureDimension::D2,
        format,
        usage: TextureUsages::RENDER_ATTACHMENT,
        view_formats: &[],
    });
    let view = target.create_view(&TextureViewDescriptor::default());
    let record = |frames: u32| {
        let start = Instant::now();
        for _ in 0..frames {
            let mut encoder = device.create_command_encoder(&CommandEncoderDescriptor::default());
            {
                let pass = &mut encoder.begin_render_pass(&RenderPassDescriptor {
                    color_attachments: &[Some(RenderPassColorAttachment {
                        view: &view,
                        resolve_target: None,
                        ops: Operations {
                            load: LoadOp::Clear(GpuColor::BLACK),
                            store: StoreOp::Store,
                        },
                        depth_slice: None,
                    })],
                    ..Default::default()
                });
                node.draw(pass);
            }
            drop(encoder.finish());
        }
        start.elapsed().as_secs_f64() / frames as f64
    };
    record(FRAMES / 4);
    (0..BATCHES)
        .map(|_| record(FRAMES))
        .fold(f64::MAX, f64::min)
 }
 #[test]
 #[ignore = "measurement, not a check"]
 fn draw_cost_by_layer_count() {
    let Some((device, queue)) = gpu() else {
        panic!("no wgpu device; see the this-machine-graphics notes");
    };
    println!(
        "layers, each 8 rects + 8 glyphs + 2 images: us/frame (us per layer), best of {BATCHES}"
    );
    let base = frame_cost(&device, &queue, 1, 8) * 1e6;
    for layers in [8, 64, 256, 1024] {
        let per_frame = frame_cost(&device, &queue, layers, 8) * 1e6;
        // Net of the empty pass, which is the same in any version of this.
        println!(
            "{layers:>5}: {per_frame:8.1} us ({:.3} us)",
            (per_frame - base).max(0.0) / layers as f64
        );
    }
 }
@@ -0,0 +1,34 @@
 //! Where a frame puts things, with no window to put them in.
 use iris::harness::{Harness, assert_corners};
 use iris::prelude::*;
 /// A fixed 100 wide, and the rest of the 400 to its neighbour.
 fn two_rects(h: &mut Harness) -> (WidgetId, WidgetId) {
    let left = rect(Color::RED).width(100).add(&mut h.rsc);
    let right = rect(Color::BLUE).add(&mut h.rsc);
    h.set_root((left, right).span(Dir::RIGHT));
    (left.id(), right.id())
 }
 #[test]
 fn a_span_gives_each_child_the_width_it_asked_for() {
    let mut h = Harness::new((400, 200));
    let (left, right) = two_rects(&mut h);
    assert_corners!(h, left, (0, 0), (100, 200));
    assert_corners!(h, right, (100, 0), (400, 200));
 }
 #[test]
 fn resizing_relays_out_against_the_new_output() {
    let mut h = Harness::new((400, 200));
    let (left, right) = two_rects(&mut h);
    h.resize((800, 100));
    assert!(h.needs_redraw());
    h.frame();
    assert_corners!(h, left, (0, 0), (100, 100));
    assert_corners!(h, right, (100, 0), (800, 100));
 }
@@ -0,0 +1,60 @@
 //! Which widget an input reaches.
 use std::{cell::RefCell, rc::Rc};
 use iris::harness::Harness;
 use iris::prelude::*;
 #[test]
 fn a_press_reaches_only_the_widget_under_the_cursor() {
    let mut h = Harness::new((400, 200));
    let clicks = Rc::new(RefCell::new(Vec::new()));
    let (on_left, on_right) = (clicks.clone(), clicks.clone());
    let left = rect(Color::RED)
        .width(100)
        .on(CursorSense::click(), move |_, _| {
            on_left.borrow_mut().push("left")
        })
        .add(&mut h.rsc);
    let right = rect(Color::BLUE)
        .on(CursorSense::click(), move |_, _| {
            on_right.borrow_mut().push("right")
        })
        .add(&mut h.rsc);
    h.set_root((left, right).span(Dir::RIGHT));
    h.click((50, 100));
    assert_eq!(*clicks.borrow(), ["left"]);
    h.click((300, 100));
    assert_eq!(*clicks.borrow(), ["left", "right"]);
 }
 #[test]
 fn hover_ends_when_the_cursor_leaves_the_window() {
    let mut h = Harness::new((400, 200));
    let hovered = Rc::new(RefCell::new(0));
    let ended = Rc::new(RefCell::new(0));
    let (h_count, e_count) = (hovered.clone(), ended.clone());
    let widget = rect(Color::RED)
        .on(CursorSense::HoverStart, move |_, _| {
            *h_count.borrow_mut() += 1
        })
        .on(CursorSense::HoverEnd, move |_, _| {
            *e_count.borrow_mut() += 1
        })
        .add(&mut h.rsc);
    h.set_root(widget);
    h.move_to((200, 100));
    assert_eq!((*hovered.borrow(), *ended.borrow()), (1, 0));
    // A second sample inside the same widget is not a second hover.
    h.move_to((210, 100));
    assert_eq!((*hovered.borrow(), *ended.borrow()), (1, 0));
    h.leave();
    assert_eq!((*hovered.borrow(), *ended.borrow()), (1, 1));
 }
@@ -0,0 +1,26 @@
 //! Scrolling moves content and stops at its ends.
 use iris::harness::{Harness, assert_corners};
 use iris::prelude::*;
 #[test]
 fn a_wheel_scrolls_the_content_and_stops_at_its_end() {
    let mut h = Harness::new((400, 200));
    // Twice the window's height, so there is 200 to scroll.
    let top = rect(Color::RED).height(200).add(&mut h.rsc);
    let bottom = rect(Color::BLUE).height(200).add(&mut h.rsc);
    h.set_root((top, bottom).span(Dir::DOWN).scrollable());
    h.move_to((200, 100));
    // `Scroll` starts snapped to the end.
    assert_corners!(h, top, (0, -200), (400, 0));
    // The handler scales a wheel line by 50.
    h.scroll((0, 1));
    h.frame();
    assert_corners!(h, top, (0, -150), (400, 50));
    h.scroll((0, 10));
    h.frame();
    assert_corners!(h, top, (0, 0), (400, 200));
 }
@@ -0,0 +1,23 @@
 //! What a background task can change, and how it gets back to the ui.
 use std::time::Duration;
 use iris::harness::Harness;
 use iris::prelude::*;
 #[test]
 fn a_task_update_reaches_the_tree() {
    let mut h = Harness::new((400, 200));
    let widget = rect(Color::RED).add(&mut h.rsc);
    h.set_root(widget.task_on(CursorSense::click(), async move |mut ctx| {
        ctx.update(move |_, rsc| widget(rsc).color = Color::BLUE);
    }));
    h.click((200, 100));
    assert!(
        h.await_update(Duration::from_secs(5)),
        "the task sent no update"
    );
    assert_eq!(h.rsc[widget].color, Color::BLUE);
 }
Author	SHA1	Message	Date
iris	7cefc72f97	Compare regions, not four loose numbers `PixelRegion` derives `PartialEq`, `Clone` and `Copy`, so `assert_corners!` compares one against another instead of flattening both to a tuple whose order there was nothing to check. A failure now prints two regions.	2026-09-13 21:42:21 -04:00
iris	0f9f379cec	Say what these do without naming what they lean on A doc comment that names something outside the method goes stale when that thing changes, and nobody editing it looks here.	2026-09-13 21:37:44 -04:00
iris	7eb2b85425	One proxy, and a macro instead of a shared test module `Proxy` is the task queue as well as the way an application sends its own events, so `ProxyQueue` is gone. `schedule_redraw` becomes `request_redraw_if_needed`, which says what the comment beside it was saying. `assert_corners!` replaces the region helper, so `tests/common` goes with it, and the scroll test now states both corners rather than one number.	2026-09-13 21:29:38 -04:00
iris	3a74a04a5b	Post task updates to the loop instead of waking it `WakeTaskQueue` becomes `TaskQueue`, which carries the update itself. Delivery and waking are then one act: the winit host sends it through the `EventLoopProxy` as a `DefaultEvent::Update`, so there is no channel beside the loop and nothing has to claim a redraw is needed in order to be looked at. `Window::request_redraw` is gone from this path; `event` applies the update and then asks the tree whether anything became dirty, which is the same question `window_event` already ended with -- now `schedule_redraw`, called from both. The loop's message type is `DefaultEvent<State>`, so `Proxy` becomes a wrapper that takes the application's own `Event` and requires it to be `Send`, since it now crosses to the task thread by that route. The harness supplies a channel-backed queue, which is what lets a test hold updates until it asks for them. Tests split by subject -- layout, pointer, scroll, tasks -- with the region helper in `tests/common`.	2026-09-13 21:04:29 -04:00
iris	e97aba30e0	Merge upstream/main (#14 ) into split/15-harness	2026-09-13 20:44:01 -04:00
iris-aiandiris	32b10383d8	Rename the Sized widget to SetSize (#14 ) `Sized` shadowed the marker trait, so a `?Sized` bound in any crate that imports the prelude failed to resolve -- a compile error in someone else's code that nothing here would have caught. It was already biting inside iris: `default/mod.rs`, `widget/ptr.rs` and `widget/text/build.rs` all imported `std::marker::Sized` explicitly to get out from under it, which they no longer need. `SetSize` rather than `FixedSize` because the size it sets need not be fixed -- `width(rest(2))` (a flex weight) and `width(rel(0.5))` (half the parent) build the same widget, and both are more common than `sized((100, 100))`. It also pairs with the `MaxSize` beside it in that module: one sets a length, the other caps it. The builders are unchanged. `tests/prelude_bounds.rs` is a compile-level guard -- it fails to build if the prelude shadows `Sized` again, which I checked by reverting `src/` under it: ``` error[E0404]: expected trait, found struct `Sized` --> tests/prelude_bounds.rs:8:22 \| 8 \| fn takes_unsized<T: ?Sized>(_: &T) {} \| ^^^^^ not a trait ``` The pad tab of the tabs example -- the one built out of `sized` and the flexible widths -- renders pixel-identical to before the rename. --------- Co-authored-by: iris <2+iris@noreply.localhost> Reviewed-on: iris/iris#14 Co-authored-by: AIris <4+iris-ai@noreply.localhost>	2026-09-13 20:16:17 -04:00
iris	d5efdd2b97	Run a ui without a window, and test one `Tasks` held an `Arc<Window>` only to call `request_redraw` when a task finished, which made the task queue -- and so `DefaultRsc` -- impossible to build without a window. It now takes an `Arc<dyn WakeTaskQueue>`, and `Window` implements it. Waking moves from "the task ended" to "an update was sent", which is when there is something for the host to apply: a task that keeps running after sending one no longer holds its update until it finishes, and a task that sends none no longer asks for a frame it does not need. `iris::harness` is what that buys. `UiRenderState` already does layout, hit testing and primitive building with no surface, so a test can build a tree, run frames, move a pointer and read back where widgets landed. `tests/harness.rs` does each of those; none of them could be written before, since the only entry point to layout was a window. It does not draw. A claim about pixels still needs a real surface.	2026-09-13 20:14:11 -04:00
iris-aiandiris	00d2230b84	Build on wgpu 30 (#13 ) Two majors, and the renderer is under everything else left to extract -- so it goes before the slices that would otherwise be written against wgpu 28 and then again against 30. `image` 0.25.6 -> 0.25.10 rides along. `winit` stays on 0.30.12, since 0.31 is only a prerelease and nothing here needs it; `parley` 0.11.1 is current. What the API asked for, beyond the version: - An instance takes the display it will present on, and GLES on Wayland needs it, so the window the surface is made from is handed over with it. That one matters for Android rather than for this machine. - `get_current_texture` returns a status rather than a `Result`, which replaced an `unwrap` that would have panicked on a resize or an occluded window: reconfigure when the surface is outdated, lost or suboptimal, and skip the frame when there is nothing to draw into. - Presenting moved to the queue, still after `pre_present_notify`. - Bind group and vertex buffer layouts are sparse, so each slot states `Some(layout)`. Verified the same way as #11: the tabs example with two runtime-added images, an image alone in a layer, and glyphs from a four-page atlas all render identically. `tests/draw_cost.rs` gives 33.6/167/587/2855 us per frame at 8/64/256/1024 layers, against 33.3/161/588/2903 on wgpu 28 -- no change. --------- Co-authored-by: iris <2+iris@noreply.localhost> Reviewed-on: iris/iris#13 Reviewed-by: iris <2+iris@noreply.localhost> Co-authored-by: AIris <4+iris-ai@noreply.localhost>	2026-09-13 19:07:47 -04:00
iris-aiandiris	b234497d21	Draw the glyph atlas as an array texture and images with their own bind groups + primitive rendering overhaul Replaces the bindless `binding_array<texture_2d<f32>>` the renderer bound every texture through. That array needs `VK_EXT_descriptor_indexing`, which a real share of Android GPUs lack, so the old shape did not run there at all. The two things being bound want opposite treatment, so they are now split: - Glyph atlas pages become layers of one `texture_2d_array`. A glyph primitive carries a `layer` instead of a view/sampler index pair. A layer index is an ordinary sampling operand, so this needs nothing beyond plain Vulkan 1.0 / GLES. Growing the atlas recreates the array with headroom and `copy_texture_to_texture`s the old layers across, no readback. - A standalone image gets its own texture and its own bind group, and draws in its own call. It no longer needs a per-instance entry in `PrimitiveData`: the bind group has already picked the texture. `Primitives` keeps images in a list of their own as a result, with `PrimitiveChange::is_image` naming which list a renumbering belongs to -- the two have independent index spaces, so `(layer, inst_idx)` alone would collide between them. Two notes on judgement calls, since this slice was rebuilt on top of `main` rather than transplanted: - The source version renamed `GlyphEntry::is_colored` to `is_color` and added a second `IS_COLOR` flag constant beside the existing `GlyphEntry::IS_COLORED`. Both dropped: #10's naming and its `flags()` are kept, and UVs stay `Vec2` rather than going back to `[f32; 2]`. - `ImageGpu` no longer holds the `Texture` behind its view, which removes an `#[allow(dead_code)]`. A `TextureView` keeps its own reference to the texture, checked by rendering rather than assumed -- see below. ### Verification ``` cargo fmt --all --check cargo clippy --workspace --all-targets --locked -- -D warnings cargo test --workspace --locked ``` All clean; the 4 text-edit tests pass. The only clippy output is the pre-existing future-incompatibility notice about `naga`/`wgpu`/`winit`. Because this is a rendering change, it was also run for real rather than only compiled. The `tabs` example was rendered on this machine's GPU -- Venus onto an RX 7900 XT, confirmed from the loaded ICD (`libvulkan_virtio.so` on `/dev/dri/renderD128`) rather than assumed, since a failed Vulkan init here silently falls back to llvmpipe and would make the screenshots meaningless. Screenshots before and after the change are byte-identical (same md5) in two scenes: the default tab, which exercises text (the atlas path) and rects, and the image tab with a standalone image pushed at startup, which exercises the per-image bind group. The image-tab scene needed a temporary local edit to the example to push the image without a click; that edit is not part of this branch. The same comparison, re-run after dropping the `Texture` field, is still byte-identical -- which is the check that the view alone keeps it alive. --------- Co-authored-by: iris <2+iris@noreply.localhost> Reviewed-on: iris/iris#11 Reviewed-by: iris <2+iris@noreply.localhost> Co-authored-by: AIris <4+iris-ai@noreply.localhost>	2026-09-13 18:56:59 -04:00