Draw the glyph atlas as an array texture and images with their own bind groups

The renderer bound every texture through one `binding_array<texture_2d<f32>>` indexed per primitive. That needs `VK_EXT_descriptor_indexing`, which a real share of Android GPUs do not have, so the shape did not run there at all. Split the two things being bound, since they want opposite treatment: - Glyph atlas pages become layers of one `texture_2d_array`. A glyph primitive carries a layer rather than a view/sampler index pair, and a layer index is an ordinary sampling operand -- no extension. Growing the atlas recreates the array with headroom and copies the old layers across GPU-side. - 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` at all: the bind group has already picked the texture. `Primitives` therefore keeps images in a list of their own, with `PrimitiveChange::is_image` saying which list a renumbering belongs to -- the two have independent index spaces, so `(layer, inst_idx)` alone would collide between them. Verified on this machine's real GPU (Venus onto an RX 7900 XT, confirmed by the loaded ICD rather than assumed): the `tabs` example renders byte-identical screenshots before and after, both for a text-and-rect tab and for one holding a standalone image.
2026-09-13 03:58:12 -04:00
25 changed files with 1667 additions and 1637 deletions
@@ -234,18 +234,18 @@ dependencies = [

 [[package]]
 name = "bit-set"
-version = "0.10.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09ec2f926cc3060f09db9ebc5b52823d85268d24bb917e472c0c4bea35780a7d"
+checksum = "08807e080ed7f9d5433fa9b275196cfc35414f66a0c79d864dc51a0d825231a3"
 dependencies = [
 "bit-vec",
 ]

 [[package]]
 name = "bit-vec"
-version = "0.9.1"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b71798fca2c1fe1086445a7258a4bc81e6e49dcd24c8d0dd9a1e57395b603f51"
+checksum = "5e764a1d40d510daf35e07be9eb06e75770908c27d411ee6c92109c9840eaaf7"

 [[package]]
 name = "bit_field"
@@ -274,6 +274,12 @@ 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"
@@ -283,15 +289,6 @@ 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"
@@ -394,9 +391,9 @@ checksum = "9330f8b2ff13f34540b44e946ef35111825727b38d33286ef986142615121801"

 [[package]]
 name = "cfg_aliases"
-version = "0.2.2"
+version = "0.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f079e83a288787bcd14a6aea84cee5c87a67c5a3e660c30f557a3d24761b3527"
+checksum = "613afe47fcd5fac7ccf1db93babcb082c5994d996f20b8b159f2ad1658eb5724"

 [[package]]
 name = "clipboard-win"
@@ -409,9 +406,9 @@ dependencies = [

 [[package]]
 name = "codespan-reporting"
-version = "0.13.1"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "af491d569909a7e4dee0ad7db7f5341fef5c614d5b8ec8cf765732aba3cff681"
+checksum = "fe6d2e5af09e8c8ad56c969f2157a3d4238cebc7c55f0a517728c38f7b200f81"
 dependencies = [
 "serde",
 "termcolor",
@@ -453,6 +450,16 @@ 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"
@@ -466,8 +473,8 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c07782be35f9e1140080c6b96f0d44b739e2278479f64e02fdab4e32dfd8b081"
 dependencies = [
 "bitflags 1.3.2",
- "core-foundation",
- "core-graphics-types",
+ "core-foundation 0.9.4",
+ "core-graphics-types 0.1.3",
 "foreign-types",
 "libc",
 ]
@@ -479,7 +486,18 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "45390e6114f68f718cc7a830514a96f903cccd70d02a8f6d9f643ac4ba45afaf"
 dependencies = [
 "bitflags 1.3.2",
- "core-foundation",
+ "core-foundation 0.9.4",
+ "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",
 ]

@@ -721,6 +739,15 @@ 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"
@@ -744,7 +771,7 @@ dependencies = [
 "objc2-core-text",
 "objc2-foundation 0.3.2",
 "parlance",
- "read-fonts",
+ "read-fonts 0.41.0",
 "roxmltree",
 "smallvec",
 "windows",
@@ -779,30 +806,6 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
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-[[package]]
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-checksum = "92d699e522242e69e3003b94ecc1f960f3a5e015aa7c5d7486e65ad01dd94f5e"
-
-[[package]]
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-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd417de3d1d015fc3bfd2b1ea46dfc7bab72ef86f1cc7cc9c78e728b34a6d1fd"
-
-[[package]]
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-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
- "futures-core",
- "futures-task",
- "pin-project-lite",
- "slab",
-]
-
 [[package]]
 name = "fxhash"
 version = "0.2.1"
@@ -857,9 +860,9 @@ dependencies = [

 [[package]]
 name = "glow"
-version = "0.17.0"
+version = "0.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29038e1c483364cc6bb3cf78feee1816002e127c331a1eec55a4d202b9e1adb5"
+checksum = "c5e5ea60d70410161c8bf5da3fdfeaa1c72ed2c15f8bbb9d19fe3a4fad085f08"
 dependencies = [
 "js-sys",
 "slotmap",
@@ -890,6 +893,26 @@ 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"
@@ -910,7 +933,7 @@ checksum = "c03d949a14aa089bbb282f7dd76a498a7f684428e4257202efc119ec010376f9"
 dependencies = [
 "bitflags 2.10.0",
 "bytemuck",
- "read-fonts",
+ "read-fonts 0.41.0",
 "smallvec",
 ]

@@ -949,6 +972,12 @@ 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"
@@ -1079,9 +1108,9 @@ checksum = "ae293c039020f9ec10710af98d29ce6aa2051486638b49c9a6409f3b4a9e98ad"

 [[package]]
 name = "image"
-version = "0.25.10"
+version = "0.25.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "85ab80394333c02fe689eaf900ab500fbd0c2213da414687ebf995a65d5a6104"
+checksum = "e6506c6c10786659413faa717ceebcb8f70731c0a60cbae39795fdf114519c1a"
 dependencies = [
 "bytemuck",
 "byteorder-lite",
@@ -1097,8 +1126,8 @@ dependencies = [
 "rayon",
 "rgb",
 "tiff",
- "zune-core",
- "zune-jpeg",
+ "zune-core 0.5.0",
+ "zune-jpeg 0.5.8",
 ]

 [[package]]
@@ -1218,12 +1247,11 @@ dependencies = [

 [[package]]
 name = "js-sys"
-version = "0.3.105"
+version = "0.3.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ce57d20d1ea864ce2ac172ab472d409214f4fd359f0b2a2775abdf522e2af99e"
+checksum = "464a3709c7f55f1f721e5389aa6ea4e3bc6aba669353300af094b29ffbdde1d8"
 dependencies = [
- "cfg-if",
- "futures-util",
+ "once_cell",
 "wasm-bindgen",
 ]

@@ -1252,9 +1280,9 @@ checksum = "7a79a3332a6609480d7d0c9eab957bca6b455b91bb84e66d19f5ff66294b85b8"

 [[package]]
 name = "libc"
-version = "0.2.189"
+version = "0.2.179"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3eaf3ede3fee6db1a4c2ee091bf8a8b4dccdc6d17f656fb07896ee72867612f2"
+checksum = "c5a2d376baa530d1238d133232d15e239abad80d05838b4b59354e5268af431f"

 [[package]]
 name = "libfuzzer-sys"
@@ -1347,6 +1375,15 @@ 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"
@@ -1372,6 +1409,21 @@ 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"
@@ -1384,9 +1436,9 @@ dependencies = [

 [[package]]
 name = "moxcms"
-version = "0.8.1"
+version = "0.7.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bb85c154ba489f01b25c0d36ae69a87e4a1c73a72631fc6c0eb6dde34a73e44b"
+checksum = "ac9557c559cd6fc9867e122e20d2cbefc9ca29d80d027a8e39310920ed2f0a97"
 dependencies = [
 "num-traits",
 "pxfm",
@@ -1394,9 +1446,9 @@ dependencies = [

 [[package]]
 name = "naga"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a616d2fb8c89516ac2723a581f69d6c18576046bed761bd6b305e5618e6ae130"
+checksum = "618f667225063219ddfc61251087db8a9aec3c3f0950c916b614e403486f1135"
 dependencies = [
 "arrayvec",
 "bit-set",
@@ -1405,11 +1457,11 @@ dependencies = [
 "cfg_aliases",
 "codespan-reporting",
 "half",
- "hashbrown 0.17.1",
+ "hashbrown 0.16.1",
+ "hexf-parse",
 "indexmap",
 "libm",
 "log",
- "naga-types",
 "num-traits",
 "once_cell",
 "rustc-hash",
@@ -1418,18 +1470,6 @@ dependencies = [
 "unicode-ident",
 ]

-[[package]]
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-version = "30.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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-dependencies = [
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- "indexmap",
- "rustc-hash",
- "thiserror 2.0.17",
-]
-
 [[package]]
 name = "ndk"
 version = "0.9.0"
@@ -1554,6 +1594,15 @@ 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"
@@ -1586,13 +1635,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "libc",
 "objc2 0.5.2",
 "objc2-core-data",
 "objc2-core-image",
 "objc2-foundation 0.2.2",
- "objc2-quartz-core 0.2.2",
+ "objc2-quartz-core",
 ]

 [[package]]
@@ -1614,7 +1663,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
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- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-core-location",
 "objc2-foundation 0.2.2",
@@ -1626,7 +1675,7 @@ version = "0.2.2"
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 checksum = "a5ff520e9c33812fd374d8deecef01d4a840e7b41862d849513de77e44aa4889"
 dependencies = [
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1638,7 +1687,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1673,10 +1722,10 @@ version = "0.2.2"
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 checksum = "55260963a527c99f1819c4f8e3b47fe04f9650694ef348ffd2227e8196d34c80"
 dependencies = [
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
- "objc2-metal 0.2.2",
+ "objc2-metal",
 ]

 [[package]]
@@ -1685,7 +1734,7 @@ version = "0.2.2"
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 checksum = "000cfee34e683244f284252ee206a27953279d370e309649dc3ee317b37e5781"
 dependencies = [
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-contacts",
 "objc2-foundation 0.2.2",
@@ -1714,7 +1763,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "dispatch",
 "libc",
 "objc2 0.5.2",
@@ -1748,7 +1797,7 @@ version = "0.2.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-app-kit 0.2.2",
 "objc2-foundation 0.2.2",
@@ -1761,23 +1810,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]

-[[package]]
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-version = "0.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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- "objc2-foundation 0.3.2",
-]
-
 [[package]]
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@@ -1785,24 +1822,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
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 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
- "objc2-metal 0.2.2",
-]
-
-[[package]]
-name = "objc2-quartz-core"
-version = "0.3.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
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-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",
+ "objc2-metal",
 ]

 [[package]]
@@ -1822,7 +1845,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b8bb46798b20cd6b91cbd113524c490f1686f4c4e8f49502431415f3512e2b6f"
 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-cloud-kit",
 "objc2-core-data",
@@ -1830,7 +1853,7 @@ dependencies = [
 "objc2-core-location",
 "objc2-foundation 0.2.2",
 "objc2-link-presentation",
- "objc2-quartz-core 0.2.2",
+ "objc2-quartz-core",
 "objc2-symbols",
 "objc2-uniform-type-identifiers",
 "objc2-user-notifications",
@@ -1842,7 +1865,7 @@ version = "0.2.2"
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 checksum = "44fa5f9748dbfe1ca6c0b79ad20725a11eca7c2218bceb4b005cb1be26273bfe"
 dependencies = [
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-foundation 0.2.2",
 ]
@@ -1854,7 +1877,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "76cfcbf642358e8689af64cee815d139339f3ed8ad05103ed5eaf73db8d84cb3"
 dependencies = [
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "objc2 0.5.2",
 "objc2-core-location",
 "objc2-foundation 0.2.2",
@@ -1948,7 +1971,7 @@ dependencies = [
 "linebender_resource_handle",
 "parlance",
 "parley_data",
- "skrifa",
+ "skrifa 0.44.0",
 ]

 [[package]]
@@ -2252,9 +2275,9 @@ dependencies = [

 [[package]]
 name = "ravif"
-version = "0.13.0"
+version = "0.12.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e52310197d971b0f5be7fe6b57530dcd27beb35c1b013f29d66c1ad73fbbcc45"
+checksum = "ef69c1990ceef18a116855938e74793a5f7496ee907562bd0857b6ac734ab285"
 dependencies = [
 "avif-serialize",
 "imgref",
@@ -2271,18 +2294,6 @@ 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"
@@ -2303,6 +2314,16 @@ 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"
@@ -2310,7 +2331,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "046a7d674daf459825b32f5062056d6882db0d2f5a479fbd76ccfc870ac18709"
 dependencies = [
 "bytemuck",
- "font-types",
+ "font-types 0.12.4",
 "once_cell",
 ]

@@ -2485,6 +2506,16 @@ 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"
@@ -2492,7 +2523,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "819ab7d62b1d3e72d9d9dea5650bac30424f9111364bb94928dbf5ecad1baa68"
 dependencies = [
 "bytemuck",
- "read-fonts",
+ "read-fonts 0.41.0",
 ]

 [[package]]
@@ -2552,9 +2583,9 @@ dependencies = [

 [[package]]
 name = "spirv"
-version = "0.4.0+sdk-1.4.341.0"
+version = "0.3.0+sdk-1.3.268.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d9571ea910ebd84c86af4b3ed27f9dbdc6ad06f17c5f96146b2b671e2976744f"
+checksum = "eda41003dc44290527a59b13432d4a0379379fa074b70174882adfbdfd917844"
 dependencies = [
 "bitflags 2.10.0",
 ]
@@ -2583,7 +2614,7 @@ version = "0.2.10"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6c2499c2d826531388872b2268718aed907a39bd785ab0dcfe57fab26283f92e"
 dependencies = [
- "skrifa",
+ "skrifa 0.39.0",
 "yazi",
 "zeno",
 ]
@@ -2672,16 +2703,16 @@ dependencies = [

 [[package]]
 name = "tiff"
-version = "0.11.3"
+version = "0.10.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b63feaf3343d35b6ca4d50483f94843803b0f51634937cc2ec519fc32232bc52"
+checksum = "af9605de7fee8d9551863fd692cce7637f548dbd9db9180fcc07ccc6d26c336f"
 dependencies = [
 "fax",
 "flate2",
 "half",
 "quick-error",
 "weezl",
- "zune-jpeg",
+ "zune-jpeg 0.4.21",
 ]

 [[package]]
@@ -2854,9 +2885,9 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen"
-version = "0.2.128"
+version = "0.2.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "aecb87a33d3b0c5e3b7aa46336eaf486cffafbd281b195e4c8b80d50df2351bf"
+checksum = "0d759f433fa64a2d763d1340820e46e111a7a5ab75f993d1852d70b03dbb80fd"
 dependencies = [
 "cfg-if",
 "once_cell",
@@ -2867,19 +2898,22 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.78"
+version = "0.4.56"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6ef4c5d3d2cdf5c54f4231181768f5510842e350db025faf1f7163b1030ed928"
+checksum = "836d9622d604feee9e5de25ac10e3ea5f2d65b41eac0d9ce72eb5deae707ce7c"
 dependencies = [
+ "cfg-if",
 "js-sys",
+ "once_cell",
 "wasm-bindgen",
+ "web-sys",
 ]

 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.128"
+version = "0.2.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a690d511e3c1a8b3a55e33511e3c2c00c78415cd23650f32b808627f5696b9ed"
+checksum = "48cb0d2638f8baedbc542ed444afc0644a29166f1595371af4fecf8ce1e7eeb3"
 dependencies = [
 "quote",
 "wasm-bindgen-macro-support",
@@ -2887,22 +2921,22 @@ dependencies = [

 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.128"
+version = "0.2.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "411e4887f0071ef2d2164a9d5fdf2d20efbef78fccd3a78b0c10a1dc5295e48a"
+checksum = "cefb59d5cd5f92d9dcf80e4683949f15ca4b511f4ac0a6e14d4e1ac60c6ecd40"
 dependencies = [
 "bumpalo",
 "proc-macro2",
 "quote",
- "syn 3.0.5",
+ "syn 2.0.113",
 "wasm-bindgen-shared",
 ]

 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.128"
+version = "0.2.106"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "81941cd78d0c92026c33e5e01312845a4cb1e9af3407f9134b100dd03144103e"
+checksum = "cbc538057e648b67f72a982e708d485b2efa771e1ac05fec311f9f63e5800db4"
 dependencies = [
 "unicode-ident",
 ]
@@ -3018,9 +3052,9 @@ dependencies = [

 [[package]]
 name = "web-sys"
-version = "0.3.105"
+version = "0.3.83"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9fbddc4a036f00ec4f18c83445bd3115cb306a91da554919a099d9222fe4a7f8"
+checksum = "9b32828d774c412041098d182a8b38b16ea816958e07cf40eec2bc080ae137ac"
 dependencies = [
 "js-sys",
 "wasm-bindgen",
@@ -3044,9 +3078,9 @@ checksum = "a28ac98ddc8b9274cb41bb4d9d4d5c425b6020c50c46f25559911905610b4a88"

 [[package]]
 name = "wgpu"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "527ccdf43dd5b2e8676eed9984ce00e2bbb0a1b85b70c1969dcb6cd2eb55ab9e"
+checksum = "f9cb534d5ffd109c7d1135f34cdae29e60eab94855a625dcfe1705f8bc7ad79f"
 dependencies = [
 "arrayvec",
 "bitflags 2.10.0",
@@ -3054,7 +3088,7 @@ dependencies = [
 "cfg-if",
 "cfg_aliases",
 "document-features",
- "hashbrown 0.17.1",
+ "hashbrown 0.16.1",
 "js-sys",
 "log",
 "naga",
@@ -3074,9 +3108,9 @@ dependencies = [

 [[package]]
 name = "wgpu-core"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "14c018fce9b6270aa203c2fdd56f3cce996713534bd757e4ea58c8560b121f14"
+checksum = "8bb4c8b5db5f00e56f1f08869d870a0dff7c8bc7ebc01091fec140b0cf0211a9"
 dependencies = [
 "arrayvec",
 "bit-set",
@@ -3085,11 +3119,10 @@ dependencies = [
 "bytemuck",
 "cfg_aliases",
 "document-features",
- "hashbrown 0.17.1",
+ "hashbrown 0.16.1",
 "indexmap",
 "log",
 "naga",
- "naga-types",
 "once_cell",
 "parking_lot",
 "portable-atomic",
@@ -3102,70 +3135,66 @@ 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 = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "061f3d319a40d39d00b1ecc2c33b89fe21d4e6fe01859df3500a3a8ecccd6b68"
+checksum = "87b7b696b918f337c486bf93142454080a32a37832ba8a31e4f48221890047da"
 dependencies = [
 "wgpu-hal",
 ]

 [[package]]
 name = "wgpu-core-deps-emscripten"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d98b86cf4abf524a902dd35f18ca6a3f08fc2ae9847c8f10b48e30491b1f0b86"
+checksum = "34b251c331f84feac147de3c4aa3aa45112622a95dd7ee1b74384fa0458dbd79"
 dependencies = [
 "wgpu-hal",
 ]

 [[package]]
 name = "wgpu-core-deps-windows-linux-android"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7586165fd5f6d881cb9ce4bb71f40d6caab2c0f1837e3fc1d9788a197fb6004f"
+checksum = "68ca976e72b2c9964eb243e281f6ce7f14a514e409920920dcda12ae40febaae"
 dependencies = [
 "wgpu-hal",
 ]

 [[package]]
 name = "wgpu-hal"
-version = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6b7fb58561a792bc237628ba0792e332de418fefe145f13b5ed8201e6d52f58"
+checksum = "293080d77fdd14d6b08a67c5487dfddbf874534bb7921526db56a7b75d7e3bef"
 dependencies = [
 "android_system_properties",
 "arrayvec",
 "ash",
 "bit-set",
 "bitflags 2.10.0",
- "block2 0.6.2",
+ "block",
 "bytemuck",
 "cfg-if",
 "cfg_aliases",
+ "core-graphics-types 0.2.0",
 "glow",
 "glutin_wgl_sys",
 "gpu-allocator",
- "hashbrown 0.17.1",
+ "gpu-descriptor",
+ "hashbrown 0.16.1",
 "js-sys",
 "khronos-egl",
 "libc",
 "libloading",
 "log",
+ "metal",
 "naga",
- "naga-types",
 "ndk-sys",
- "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",
+ "objc",
 "once_cell",
 "ordered-float",
 "parking_lot",
@@ -3174,44 +3203,26 @@ 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 = "30.0.1"
+version = "28.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "99dad6f1fbdbbdb4c278a6508b059d44688f5cebddf78d005a46a31340269286"
+checksum = "e18308757e594ed2cd27dddbb16a139c42a683819d32a2e0b1b0167552f5840c"
 dependencies = [
 "bitflags 2.10.0",
 "bytemuck",
 "js-sys",
 "log",
- "naga-types",
- "raw-window-handle",
- "static_assertions",
 "web-sys",
 ]

@@ -3575,12 +3586,12 @@ dependencies = [
 "android-activity",
 "atomic-waker",
 "bitflags 2.10.0",
- "block2 0.5.1",
+ "block2",
 "bytemuck",
 "calloop",
 "cfg_aliases",
 "concurrent-queue",
- "core-foundation",
+ "core-foundation 0.9.4",
 "core-graphics",
 "cursor-icon",
 "dpi",
@@ -3847,6 +3858,12 @@ 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"
@@ -3862,11 +3879,20 @@ 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",
+ "zune-core 0.5.0",
 ]
@@ -29,9 +29,9 @@ edition = "2024"
 [workspace.dependencies]
 pollster = "0.4.0"
 winit = "0.30.12"
-wgpu = "30.0.1"
+wgpu = "28.0.0"
 bytemuck = "1.23.1"
-image = "0.25.10"
+image = "0.25.6"
 parley = "0.11.1"
 swash = "0.2.10"
 fxhash = "0.2.1"
@@ -1,7 +1,8 @@
 use std::ops::{Index, IndexMut};

 use crate::{
-    render::{LayerDraws, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
+    UiRegion, WidgetId,
+    render::{MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst, Primitives},
    util::to_mut,
 };

@@ -39,7 +40,7 @@ struct Child {
    tail: usize,
 }

-pub type DrawLayers = Layers<LayerDraws>;
+pub type PrimitiveLayers = Layers<Primitives>;

 impl<T: Default> Layers<T> {
    pub fn new() -> Layers<T> {
@@ -119,7 +120,7 @@ impl<T: Default> Layers<T> {
    }
 }

-impl DrawLayers {
+impl PrimitiveLayers {
    pub fn write<P: Primitive>(
        &mut self,
        layer: LayerId,
@@ -131,6 +132,17 @@ impl DrawLayers {
    pub fn free(&mut self, h: &PrimitiveHandle) -> MaskIdx {
        self[h.layer].free(h)
    }
+
+    pub fn write_image(
+        &mut self,
+        layer: LayerId,
+        id: WidgetId,
+        texture_idx: u32,
+        region: UiRegion,
+        mask_idx: MaskIdx,
+    ) -> PrimitiveHandle {
+        self[layer].write_image(layer, id, texture_idx, region, mask_idx)
+    }
 }

 impl<T: Default> Default for Layers<T> {
@@ -1,5 +1,6 @@
 use crate::{
-    Align, GlyphAtlas, GlyphEntry, GlyphKey, PlacedGlyph, RegionAlign, UiColor, util::Vec2,
+    Align, GlyphAtlas, GlyphEntry, GlyphKey, PlacedGlyph, RegionAlign, Textures, UiColor,
+    util::Vec2,
 };
 use parley::{
    Alignment, AlignmentOptions, FontContext, FontFamily, FontFamilyName, GenericFamily, Layout,
@@ -158,7 +159,7 @@ impl TextBuffer {
 }

 impl TextData {
-    pub fn place(&mut self, buffer: &TextBuffer) -> Vec<PlacedGlyph> {
+    pub fn place(&mut self, buffer: &TextBuffer, textures: &mut Textures) -> Vec<PlacedGlyph> {
        let mut placed = Vec::new();
        for line in buffer.layout.lines() {
            for item in line.items() {
@@ -184,14 +185,17 @@ impl TextData {
                        subpixel,
                        coords: coords_hash,
                    };
-                    let Some(entry) = self.glyph_entry(GlyphRaster {
-                        key,
-                        font: font_ref,
-                        font_size,
-                        coords,
-                        subpixel,
-                        glyph_id: glyph.id,
-                    }) else {
+                    let Some(entry) = self.glyph_entry(
+                        GlyphRaster {
+                            key,
+                            font: font_ref,
+                            font_size,
+                            coords,
+                            subpixel,
+                            glyph_id: glyph.id,
+                        },
+                        textures,
+                    ) else {
                        continue;
                    };
                    placed.push(PlacedGlyph {
@@ -207,7 +211,11 @@ impl TextData {
        placed
    }

-    fn glyph_entry(&mut self, glyph: GlyphRaster<'_>) -> Option<GlyphEntry> {
+    fn glyph_entry(
+        &mut self,
+        glyph: GlyphRaster<'_>,
+        textures: &mut Textures,
+    ) -> Option<GlyphEntry> {
        if let Some(entry) = self.atlas.get(&glyph.key) {
            return entry;
        }
@@ -229,7 +237,7 @@ impl TextData {
        .render(&mut scaler, glyph.glyph_id as u16);

        if let Some(image) = image {
-            self.atlas.insert(glyph.key, &image)
+            self.atlas.insert(glyph.key, &image, textures)
        } else {
            self.atlas.insert_empty(glyph.key);
            None
@@ -270,9 +278,10 @@ impl TextData {
        buffer: &mut TextBuffer,
        attrs: &TextAttrs,
        width: Option<f32>,
+        textures: &mut Textures,
    ) -> RenderedText {
        buffer.shape(self, attrs, width);
-        let glyphs = self.place(buffer);
+        let glyphs = self.place(buffer, textures);
        RenderedText {
            glyphs,
            size: buffer.size(),
@@ -5,12 +5,28 @@ use std::{
    sync::mpsc::{Receiver, Sender, channel},
 };

+/// Which of the two things a texture slot holds. The two are drawn very
+/// differently: a page is a layer of one shared array texture and never gets
+/// its own bind group; a standalone image is the opposite, one texture and
+/// one bind group, never a layer.
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum TextureKind {
+    Image,
+    /// The array-texture layer this page was assigned. Chosen synchronously
+    /// by `Textures::add_page` rather than by the renderer, because glyph
+    /// insertion needs it in the same call, before any GPU sync happens.
+    Page {
+        layer: u32,
+    },
+}
+
 #[derive(Debug, Clone)]
 pub struct TextureHandle {
    slot: u32,
+    kind: TextureKind,
    size: Vec2,
    counter: RefCounter,
-    send: Sender<u32>,
+    send: Sender<(TextureKind, u32)>,
 }

 /// a texture manager for a ui
@@ -18,19 +34,24 @@ pub struct TextureHandle {
 pub struct Textures {
    free: Vec<u32>,
    images: Vec<Option<DynamicImage>>,
+    /// Next layer to hand out to an atlas page. Pages are never freed (no
+    /// atlas eviction), so this only grows and `free` never holds one.
+    next_page_layer: u32,
    updates: Vec<Update>,
-    send: Sender<u32>,
-    recv: Receiver<u32>,
+    send: Sender<(TextureKind, u32)>,
+    recv: Receiver<(TextureKind, u32)>,
 }

 pub enum TextureUpdate<'a> {
-    Push(&'a DynamicImage),
-    Set(u32, &'a DynamicImage),
+    Push(TextureKind, &'a DynamicImage),
+    Set(TextureKind, u32, &'a DynamicImage),
+    /// Overwrite a rectangle of an existing texture, rather than replacing it.
+    /// The glyph atlas grows a glyph at a time, and re-uploading a whole atlas
+    /// per glyph is megabytes of copy for a few hundred bytes of change.
+    /// Only ever issued against a page -- a standalone image is never patched.
    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,
+    PushFree(TextureKind),
    SetFree,
 }

@@ -43,8 +64,8 @@ pub struct PatchRect {
 }

 enum Update {
-    Push(u32),
-    Set(u32),
+    Push(TextureKind, u32),
+    Set(TextureKind, u32),
    Patch(u32, PatchRect),
    Free(u32),
 }
@@ -55,31 +76,54 @@ impl Textures {
        Self {
            free: Vec::new(),
            images: Vec::new(),
+            next_page_layer: 0,
            updates: Vec::new(),
            send,
            recv,
        }
    }
+
    pub fn add(&mut self, image: impl Into<DynamicImage>) -> TextureHandle {
        let image = image.into();
        let size = image.dimensions().into();
+        let kind = TextureKind::Image;
+        let slot = self.push(kind, image);
        TextureHandle {
-            slot: self.push(image),
+            slot,
+            kind,
            size,
            counter: RefCounter::new(),
            send: self.send.clone(),
        }
    }

-    fn push(&mut self, image: DynamicImage) -> u32 {
+    /// Adds a page of the shared glyph atlas array. Only `atlas.rs` should
+    /// call this -- everything else wants `add`.
+    pub fn add_page(&mut self, image: impl Into<DynamicImage>) -> TextureHandle {
+        let image = image.into();
+        let size = image.dimensions().into();
+        let layer = self.next_page_layer;
+        self.next_page_layer += 1;
+        let kind = TextureKind::Page { layer };
+        let slot = self.push(kind, image);
+        TextureHandle {
+            slot,
+            kind,
+            size,
+            counter: RefCounter::new(),
+            send: self.send.clone(),
+        }
+    }
+
+    fn push(&mut self, kind: TextureKind, image: DynamicImage) -> u32 {
        if let Some(i) = self.free.pop() {
            self.images[i as usize] = Some(image);
-            self.updates.push(Update::Set(i));
+            self.updates.push(Update::Set(kind, i));
            i
        } else {
            let i = self.images.len() as u32;
            self.images.push(Some(image));
-            self.updates.push(Update::Push(i));
+            self.updates.push(Update::Push(kind, i));
            i
        }
    }
@@ -95,29 +139,30 @@ impl Textures {
        self.updates.push(Update::Patch(handle.slot, 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) {
-        for idx in self.recv.try_iter() {
+        for (kind, idx) in self.recv.try_iter() {
            self.images[idx as usize] = None;
            self.updates.push(Update::Free(idx));
-            self.free.push(idx);
+            // A page's slot is never reclaimed: `GlyphAtlas` never drops the
+            // handles it holds, and there is no eviction path for a hole in
+            // the middle of the array's layers. So `free` holds ordinary
+            // image slots only, and a page's layer would need a free list of
+            // its own were that to change.
+            if kind == TextureKind::Image {
+                self.free.push(idx);
+            }
        }
    }

    pub fn updates(&mut self) -> impl Iterator<Item = TextureUpdate<'_>> {
        self.updates.drain(..).map(|u| match u {
-            Update::Push(i) => self.images[i as usize]
+            Update::Push(kind, i) => self.images[i as usize]
                .as_ref()
-                .map(TextureUpdate::Push)
-                .unwrap_or(TextureUpdate::PushFree),
-            Update::Set(i) => self.images[i as usize]
+                .map(|img| TextureUpdate::Push(kind, img))
+                .unwrap_or(TextureUpdate::PushFree(kind)),
+            Update::Set(kind, i) => self.images[i as usize]
                .as_ref()
-                .map(|img| TextureUpdate::Set(i, img))
+                .map(|img| TextureUpdate::Set(kind, i, img))
                .unwrap_or(TextureUpdate::SetFree),
            Update::Patch(i, rect) => self.images[i as usize]
                .as_ref()
@@ -129,19 +174,36 @@ impl Textures {
 }

 impl TextureHandle {
-    /// Index into `Textures`, and into the renderer's parallel slots.
-    pub fn slot(&self) -> u32 {
-        self.slot
-    }
    pub fn size(&self) -> Vec2 {
        self.size
    }
+
+    /// The bind-group index this handle draws with. Only valid for a
+    /// standalone image; an atlas page has no bind group of its own -- it
+    /// samples the shared array via `layer()` instead. Getting this wrong is
+    /// a caller bug (the wrong kind of handle reached the wrong draw path),
+    /// not a recoverable condition, so it panics rather than drawing garbage.
+    pub fn image_index(&self) -> u32 {
+        match self.kind {
+            TextureKind::Image => self.slot,
+            TextureKind::Page { .. } => panic!("image_index() called on an atlas page handle"),
+        }
+    }
+
+    /// The layer this page occupies in the shared atlas array texture.
+    /// Only valid for a page handle; see `image_index`'s note.
+    pub fn layer(&self) -> u32 {
+        match self.kind {
+            TextureKind::Page { layer } => layer,
+            TextureKind::Image => panic!("layer() called on a standalone image handle"),
+        }
+    }
 }

 impl Drop for TextureHandle {
    fn drop(&mut self) {
        if self.counter.drop() {
-            let _ = self.send.send(self.slot);
+            let _ = self.send.send((self.kind, self.slot));
        }
    }
 }
@@ -1,11 +1,15 @@
 use crate::{
-    PatchRect,
+    PatchRect, TextureHandle, Textures,
    util::{HashMap, Vec2},
 };
 use image::RgbaImage;
 use swash::scale::image::{Content, Image};

-/// Side of one page, and so of every layer of `render::page`'s array texture.
+/// Side of one atlas page, in pixels. 1024 is 4 MB at RGBA8 -- enough for a
+/// few thousand glyphs at UI sizes, and small enough that a page nobody fills
+/// is not a big waste. Also the fixed width/height of every layer of the
+/// shared array texture in `render::texture` -- `pub(crate)` so that module
+/// can size it without a second constant to keep in sync.
 pub(crate) const PAGE: u32 = 1024;

 /// Transparent margin kept around every glyph, so that sampling one cannot
@@ -36,7 +40,7 @@ pub struct GlyphEntry {
    pub width: u32,
    pub height: u32,
    pub is_colored: bool,
-    /// Which atlas array layer this glyph is on.
+    /// The atlas array layer this glyph's page occupies.
    pub layer: u32,
 }

@@ -49,26 +53,18 @@ impl GlyphEntry {
 }

 struct Page {
-    image: RgbaImage,
+    handle: TextureHandle,
    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 {
@@ -76,7 +72,12 @@ impl GlyphAtlas {
        self.entries.get(key).copied()
    }

-    pub fn insert(&mut self, key: GlyphKey, image: &Image) -> Option<GlyphEntry> {
+    pub fn insert(
+        &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 {
@@ -98,11 +99,23 @@ impl GlyphAtlas {
            return None;
        }

-        let upload = self.allocate(w, h);
-        let PatchRect { x, y, .. } = upload.rect;
-        write_glyph(&mut self.pages[upload.layer as usize].image, image, x, y);
-        self.uploads.push(upload);
+        let (page_idx, x, y) = self.allocate(w, h, textures);
+        let page = &self.pages[page_idx];

+        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),
@@ -112,60 +125,38 @@ impl GlyphAtlas {
            width: w,
            height: h,
            is_colored: matches!(image.content, Content::Color),
-            layer: upload.layer,
+            layer: page.handle.layer(),
        };
        self.entries.insert(key, Some(entry));
        Some(entry)
    }

-    /// 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,
-        };
+    fn allocate(&mut self, w: u32, h: u32, textures: &mut Textures) -> (usize, u32, u32) {
        if let Some((i, (x, y))) = self
            .pages
            .iter_mut()
            .enumerate()
            .find_map(|(i, page)| page.allocate(w, h).map(|position| (i, position)))
        {
-            return PageUpload {
-                layer: i as u32,
-                rect: rect(x, y),
-            };
+            return (i, x, y);
        }

+        let handle = textures.add_page(RgbaImage::new(PAGE, PAGE));
        self.pages.push(Page {
-            image: RgbaImage::new(PAGE, PAGE),
+            handle,
            x: PAD + w + PAD,
            y: PAD,
            shelf_height: h + 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))
+        (self.pages.len() - 1, PAD, PAD)
    }

    pub fn insert_empty(&mut self, key: GlyphKey) {
        self.entries.insert(key, None);
    }

-    pub fn page_count(&self) -> u32 {
-        self.pages.len() as u32
+    pub fn page_count(&self) -> usize {
+        self.pages.len()
    }

    pub fn glyph_count(&self) -> usize {
@@ -12,16 +12,20 @@ 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; 5] = vertex_attr_array![
+    const ATTRIBS: [VertexAttribute; 7] = vertex_attr_array![
        0 => Float32x2,
        1 => Float32x2,
        2 => Float32x2,
        3 => Float32x2,
        4 => Uint32,
+        5 => Uint32,
+        6 => Uint32,
    ];

    pub fn desc() -> VertexBufferLayout<'static> {
@@ -1,6 +1,6 @@
 use crate::{
    UiData, UiRenderState,
-    render::{data::PrimitiveInstance, util::ArrBuf},
+    render::{data::PrimitiveInstance, texture::GpuTextures, util::ArrBuf},
    util::{HashMap, Vec2},
 };
 use data::WindowUniform;
@@ -11,7 +11,6 @@ use wgpu::{

 mod atlas;
 mod data;
-mod page;
 mod primitive;
 mod texture;
 mod util;
@@ -20,62 +19,64 @@ pub use atlas::*;
 pub use data::{Mask, MaskIdx};
 pub use primitive::*;

-const PRELUDE: &str = include_str!("./shader/prelude.wgsl");
+const SHAPE_SHADER: &str = include_str!("./shader.wgsl");

 pub struct UiRenderNode {
-    shared_layout: BindGroupLayout,
-    shared_group: BindGroup,
-    format: TextureFormat,
+    uniform_group: BindGroup,
+    primitive_layout: BindGroupLayout,
+    rsc_layout: BindGroupLayout,
+    rsc_group: BindGroup,

-    /// One per registered primitive, in id order.
-    primitives: Vec<PrimitivePipeline>,
+    pipeline: RenderPipeline,

    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>,
-    data: ArrBuf<u8>,
-    group: Option<BindGroup>,
-    /// What the primitive asked to keep per instance, if anything.
-    bindings: Vec<u32>,
+    primitives: PrimitiveBuffers,
+    primitive_group: BindGroup,
+    /// A standalone image's instances, kept apart from `instance` because
+    /// each one draws with its own bind group -- see `UiRenderNode::draw`.
+    image_instance: ArrBuf<PrimitiveInstance>,
+    /// The texture slot each entry of `image_instance` draws with, in the
+    /// same order, refreshed alongside it. Not stored in the vertex buffer
+    /// itself because it names a bind group, not shader data.
+    image_tex_indices: Vec<u32>,
 }

 impl UiRenderNode {
    pub fn draw<'a>(&'a self, pass: &mut RenderPass<'a>) {
-        pass.set_bind_group(0, &self.shared_group, &[]);
+        pass.set_pipeline(&self.pipeline);
+        pass.set_bind_group(0, &self.uniform_group, &[]);
        for i in &self.active {
            let layer = &self.layers[i];
-            for (id, list) in layer.primitives.iter().enumerate() {
-                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,
-                    },
-                );
+            if layer.instance.len() == 0 && layer.image_instance.len() == 0 {
+                continue;
+            }
+            pass.set_bind_group(1, &layer.primitive_group, &[]);
+            if layer.instance.len() > 0 {
+                pass.set_bind_group(2, &self.rsc_group, &[]);
+                pass.set_vertex_buffer(0, layer.instance.buffer.slice(..));
+                pass.draw(0..4, 0..layer.instance.len() as u32);
+            }
+            // Images draw after this layer's rects and glyphs, one draw call
+            // each with its own bind group. That draws every image "on top"
+            // within the layer, which loses nothing that currently exists:
+            // `Primitives::apply_free` frees with `swap_remove`, so a layer's
+            // draw order was already undefined before images had their own
+            // list -- nothing before this relied on interleaving a rect
+            // between two images at a particular position.
+            if layer.image_instance.len() > 0 {
+                pass.set_vertex_buffer(0, layer.image_instance.buffer.slice(..));
+                for (k, &tex_idx) in layer.image_tex_indices.iter().enumerate() {
+                    pass.set_bind_group(2, self.textures.image_bind_group(tex_idx), &[]);
+                    pass.draw(0..4, k as u32..k as u32 + 1);
+                }
            }
        }
    }
@@ -87,57 +88,83 @@ 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, draws) in ui_render.layers.iter_mut() {
+        for (i, primitives) in ui_render.layers.iter_mut() {
            self.active.push(i);
-            for change in draws.apply_free() {
+            for change in primitives.apply_free() {
                if let Some(inst) = ui_render.active.get_mut(&change.id) {
                    for h in &mut inst.primitives {
-                        if h.layer == i && h.kind == change.kind && h.inst_idx == change.old {
+                        // `is_image` disambiguates: `instances` and `images`
+                        // are separate lists with independent indices, so
+                        // without it a rect's renumbering could be applied to
+                        // an image handle that happened to share the same
+                        // (layer, inst_idx).
+                        if h.layer == i
+                            && h.inst_idx == change.old
+                            && (h.binding == IMAGE_BINDING) == change.is_image
+                        {
                            h.inst_idx = change.new;
                            break;
                        }
                    }
                }
            }
-            let rlayer = self.layers.entry(i).or_insert_with(RenderLayer::new);
-            if draws.updated {
-                let lists = draws.primitives();
-                // The zip would otherwise skip a list with no pipeline.
-                assert!(lists.len() <= self.primitives.len());
-                rlayer.primitives.resize_with(lists.len(), || None);
-                for ((buffers, list), primitive) in rlayer
-                    .primitives
-                    .iter_mut()
-                    .zip(lists)
-                    .zip(&self.primitives)
-                {
-                    let Some(list) = list else {
-                        continue;
-                    };
-                    buffers
-                        .get_or_insert_with(|| ListBuffers::new(device))
-                        .update(device, queue, primitive, list);
+            let rlayer = self.layers.entry(i).or_insert_with(|| {
+                let primitives = PrimitiveBuffers::new(device);
+                let primitive_group =
+                    Self::primitive_group(device, &self.primitive_layout, primitives.buffers());
+                RenderLayer {
+                    instance: ArrBuf::new(
+                        device,
+                        BufferUsages::VERTEX | BufferUsages::COPY_DST,
+                        "instance",
+                    ),
+                    primitives,
+                    primitive_group,
+                    image_instance: ArrBuf::new(
+                        device,
+                        BufferUsages::VERTEX | BufferUsages::COPY_DST,
+                        "image instance",
+                    ),
+                    image_tex_indices: Vec::new(),
                }
-                draws.updated = false;
-            }
-        }
-        for primitive in &mut self.primitives {
-            primitive.render.update(ui);
-        }
-        if ui.masks.changed {
-            ui.masks.changed = false;
-            if self.masks.update(device, queue, &ui.masks[..]) {
-                self.shared_group = Self::shared_group(
+            });
+            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.shared_layout,
-                    &self.window_buffer,
-                    &self.masks,
+                    &self.primitive_layout,
+                    rlayer.primitives.buffers(),
                );
+                rlayer
+                    .image_instance
+                    .update(device, queue, primitives.image_instances());
+                rlayer.image_tex_indices = primitives
+                    .image_instances()
+                    .iter()
+                    .map(|inst| inst.idx)
+                    .collect();
+                primitives.updated = false;
            }
        }
+        let masks_resized = if ui.masks.changed {
+            ui.masks.changed = false;
+            self.masks.update(device, queue, &ui.masks[..])
+        } else {
+            false
+        };
+        let rebuild_main = self.textures.update(
+            &mut ui.textures,
+            &self.rsc_layout,
+            &self.masks,
+            masks_resized,
+        );
+        if rebuild_main {
+            self.rsc_group = Self::rsc_group(device, &self.rsc_layout, &self.textures, &self.masks);
+        }
    }

    pub fn resize(&mut self, size: impl Into<Vec2>, queue: &Queue) {
@@ -149,7 +176,12 @@ impl UiRenderNode {
        queue.write_buffer(&self.window_buffer, 0, bytemuck::cast_slice(slice));
    }

-    pub fn new(device: &Device, config: &SurfaceConfiguration) -> Self {
+    pub fn new(device: &Device, queue: &Queue, config: &SurfaceConfiguration) -> 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,
@@ -160,73 +192,65 @@ impl UiRenderNode {
            usage: BufferUsages::UNIFORM | BufferUsages::COPY_DST,
        });

-        let shared_layout = Self::shared_layout(device);
+        let uniform_layout = device.create_bind_group_layout(&BindGroupLayoutDescriptor {
+            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: &PrimitiveBuffers::BINDINGS.map(|binding| BindGroupLayoutEntry {
+                binding,
+                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);

-        Self {
-            shared_layout,
-            shared_group,
-            format: config.format,
-            primitives: Vec::new(),
-            window_buffer,
-            layers: HashMap::default(),
-            active: Vec::new(),
-            masks,
-        }
-    }
+        let rsc_layout = Self::rsc_layout(device);
+        let rsc_group = Self::rsc_group(device, &rsc_layout, &tex_manager, &masks);

-    /// Compiles a pipeline for every primitive registered since the last call.
-    /// Sources only ever arrive at the end, so an id keeps its pipeline.
-    fn build_pipelines(&mut self, device: &Device, queue: &Queue, registry: &PrimitiveRegistry) {
-        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_layout = device.create_pipeline_layout(&PipelineLayoutDescriptor {
+            label: Some("UI Shape Pipeline Layout"),
+            bind_group_layouts: &[&uniform_layout, &primitive_layout, &rsc_layout],
+            immediate_size: 0,
        });
-        device.create_render_pipeline(&RenderPipelineDescriptor {
-            label: Some(label),
-            layout: Some(layout),
+        let pipeline = device.create_render_pipeline(&RenderPipelineDescriptor {
+            label: Some("UI Shape Pipeline"),
+            layout: Some(&pipeline_layout),
            vertex: VertexState {
-                module: &module,
+                module: &shader,
                entry_point: Some("vs_main"),
-                buffers: &[Some(PrimitiveInstance::desc())],
+                buffers: &[PrimitiveInstance::desc()],
                compilation_options: Default::default(),
            },
            fragment: Some(FragmentState {
-                module: &module,
+                module: &shader,
                entry_point: Some("fs_main"),
                targets: &[Some(ColorTargetState {
-                    format,
+                    format: config.format,
                    blend: Some(BlendState::ALPHA_BLENDING),
                    write_mask: ColorWrites::ALL,
                })],
@@ -249,42 +273,107 @@ 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"),
        })
    }

-    /// What every draw in the ui is given: the window and the masks.
-    fn shared_layout(device: &Device) -> BindGroupLayout {
+    fn primitive_group(
+        device: &Device,
+        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"),
+        })
+    }
+
+    /// Group 2: the shared atlas array, one standalone-image slot (a null
+    /// view for the main draw, a real one for each image's own bind group --
+    /// see `GpuTextures`), one sampler and the masks buffer. No `count` on
+    /// any entry: this needs nothing beyond plain Vulkan 1.0 / GLES
+    /// sampling, unlike the `binding_array` layout it replaced.
+    fn rsc_layout(device: &Device) -> BindGroupLayout {
        device.create_bind_group_layout(&BindGroupLayoutDescriptor {
            entries: &[
                BindGroupLayoutEntry {
                    binding: 0,
-                    visibility: ShaderStages::VERTEX | ShaderStages::FRAGMENT,
-                    ty: BindingType::Buffer {
-                        ty: BufferBindingType::Uniform,
-                        has_dynamic_offset: false,
-                        min_binding_size: BufferSize::new(size_of::<WindowUniform>() as u64),
+                    visibility: ShaderStages::FRAGMENT,
+                    ty: BindingType::Texture {
+                        sample_type: TextureSampleType::Float { filterable: false },
+                        view_dimension: TextureViewDimension::D2Array,
+                        multisampled: false,
                    },
                    count: None,
                },
                BindGroupLayoutEntry {
                    binding: 1,
                    visibility: ShaderStages::FRAGMENT,
+                    ty: BindingType::Texture {
+                        sample_type: TextureSampleType::Float { filterable: false },
+                        view_dimension: TextureViewDimension::D2,
+                        multisampled: false,
+                    },
+                    count: None,
+                },
+                BindGroupLayoutEntry {
+                    binding: 2,
+                    visibility: ShaderStages::FRAGMENT,
+                    ty: BindingType::Sampler(SamplerBindingType::NonFiltering),
+                    count: None,
+                },
+                BindGroupLayoutEntry {
+                    binding: 3,
+                    visibility: ShaderStages::FRAGMENT,
                    ty: BindingType::Buffer {
                        ty: BufferBindingType::Storage { read_only: true },
                        has_dynamic_offset: false,
-                        min_binding_size: BufferSize::new(size_of::<Mask>() as u64),
+                        min_binding_size: None,
                    },
                    count: None,
                },
            ],
-            label: Some("ui shared"),
+            label: Some("ui rsc"),
        })
    }

-    fn shared_group(
+    /// The main group: rects and glyphs never sample the image slot, so it
+    /// gets a 1x1 null view rather than any live standalone image's.
+    fn rsc_group(
        device: &Device,
        layout: &BindGroupLayout,
-        window: &Buffer,
+        tex_manager: &GpuTextures,
        masks: &ArrBuf<Mask>,
    ) -> BindGroup {
        device.create_bind_group(&BindGroupDescriptor {
@@ -292,85 +381,26 @@ impl UiRenderNode {
            entries: &[
                BindGroupEntry {
                    binding: 0,
-                    resource: window.as_entire_binding(),
+                    resource: BindingResource::TextureView(tex_manager.array_view()),
                },
                BindGroupEntry {
                    binding: 1,
+                    resource: BindingResource::TextureView(tex_manager.null_view()),
+                },
+                BindGroupEntry {
+                    binding: 2,
+                    resource: BindingResource::Sampler(tex_manager.sampler()),
+                },
+                BindGroupEntry {
+                    binding: 3,
                    resource: masks.buffer.as_entire_binding(),
                },
            ],
-            label: Some("ui shared"),
+            label: Some("ui rsc"),
        })
    }

-    /// Layout for a list of one primitive's data. Every size in the ui is
-    /// 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"),
-        })
-    }
-}
-
-impl RenderLayer {
-    fn new() -> Self {
-        Self {
-            primitives: Vec::new(),
-        }
-    }
-}
-
-impl ListBuffers {
-    fn new(device: &Device) -> Self {
-        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(),
-        }
-    }
-
-    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"),
-            }));
-        }
+    pub fn view_count(&self) -> usize {
+        self.textures.view_count()
    }
 }
@@ -1,156 +0,0 @@
-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: &[],
-    })
-}
@@ -1,247 +1,144 @@
-use std::{any::TypeId, marker::PhantomData};
+use std::ops::{Deref, DerefMut};

 use crate::{
-    Color, TextureHandle, UiData, UiRegion, WidgetId,
+    Color, UiRegion, WidgetId,
    render::{
+        ArrBuf,
        data::{MaskIdx, PrimitiveInstance},
-        page::GlyphRender,
-        texture::ImageRender,
    },
-    util::{HashMap, Vec2},
+    util::Vec2,
 };
 use bytemuck::Pod;
-use wgpu::{BindGroupLayout, Device, Queue, RenderPass};
+use wgpu::*;

-/// 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 {
+pub struct Primitives {
    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>(),
-        }
-    }
+    /// Standalone images, kept apart from `instances` because each one draws
+    /// with its own bind group rather than sharing the layer's one instanced
+    /// draw. `idx` on each `PrimitiveInstance` here is the texture's slot in
+    /// `Textures`/`GpuTextures`, not an index into `data`: a bind group has
+    /// already picked the texture, so there is nothing left to look up
+    /// per-instance and no per-image entry in `data` at all.
+    images: Vec<PrimitiveInstance>,
+    image_assoc: Vec<WidgetId>,
+    image_free: Vec<usize>,

-    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 LayerDraws {
+impl Default for Primitives {
    fn default() -> Self {
        Self {
-            primitives: Vec::new(),
+            instances: Default::default(),
+            assoc: Default::default(),
+            data: Default::default(),
+            free: Vec::new(),
+            images: Default::default(),
+            image_assoc: Default::default(),
+            image_free: Vec::new(),
            updated: true,
        }
    }
 }

-impl LayerDraws {
+/// The `binding` tag `Painter` writes on an image instance. Distinct from any
+/// `Primitive::BINDING` because images have no `PrimitiveData` entry to key
+/// one from -- a bind group already selects the texture -- so this only ever
+/// has to match the shader's `TEXTURE` constant and flag "this instance lives
+/// in `Primitives::images`, not `Primitives::instances`" to the code below.
+pub const IMAGE_BINDING: u32 = 1;
+
+pub trait Primitive: Pod {
+    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)*);
+            /// The group-1 binding number each primitive's storage buffer
+            /// sits at, in declaration order. Not `0..LEN`: a primitive's
+            /// `BINDING` also tags its instances for the shader's dispatch
+            /// switch, and a removed primitive (as `TEXTURE` was, once
+            /// images stopped needing a per-instance storage entry) can
+            /// leave a gap, so the pipeline layout has to ask for these
+            /// exact numbers rather than assuming they are contiguous.
+            pub const BINDINGS: [u32; Self::LEN] = [$(<$ty>::BINDING,)*];
+            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,
@@ -249,67 +146,151 @@ impl LayerDraws {
        }: PrimitiveInst<P>,
    ) -> PrimitiveHandle {
        self.updated = true;
-        // Grown on first use rather than sized from the registry, which a
-        // layer cannot see.
-        if self.primitives.len() <= kind.id as usize {
-            self.primitives.resize_with(kind.id as usize + 1, || None);
-        }
-        let inst_idx = self.primitives[kind.id as usize]
-            .get_or_insert_with(InstanceList::new::<P>)
-            .push(
-                id,
-                PrimitiveInstance { region, mask_idx },
-                bytemuck::bytes_of(&primitive),
-            );
+        let vec = P::vec(&mut self.data);
+        let i = vec.add(primitive);
+        let inst = PrimitiveInstance {
+            region,
+            idx: i as u32,
+            mask_idx,
+            binding: P::BINDING,
+        };
+        let inst_i = if let Some(i) = self.free.pop() {
+            self.instances[i] = inst;
+            self.assoc[i] = id;
+            i
+        } else {
+            let i = self.instances.len();
+            self.instances.push(inst);
+            self.assoc.push(id);
+            i
+        };
+        PrimitiveHandle::new::<P>(layer, inst_i, i)
+    }
+
+    /// Writes an image instance directly -- there is no `Primitive` impl for
+    /// it to go through `write`, since it has nowhere in `PrimitiveData` to
+    /// put a per-instance entry. `texture_idx` is the slot the bind group at
+    /// draw time is chosen from, carried in the otherwise-unused `idx` field.
+    pub fn write_image(
+        &mut self,
+        layer: usize,
+        id: WidgetId,
+        texture_idx: u32,
+        region: UiRegion,
+        mask_idx: MaskIdx,
+    ) -> PrimitiveHandle {
+        self.updated = true;
+        let inst = PrimitiveInstance {
+            region,
+            idx: texture_idx,
+            mask_idx,
+            binding: IMAGE_BINDING,
+        };
+        let inst_i = if let Some(i) = self.image_free.pop() {
+            self.images[i] = inst;
+            self.image_assoc[i] = id;
+            i
+        } else {
+            let i = self.images.len();
+            self.images.push(inst);
+            self.image_assoc.push(id);
+            i
+        };
        PrimitiveHandle {
            layer,
-            kind: kind.id,
-            inst_idx,
+            inst_idx: inst_i,
+            data_idx: 0,
+            binding: IMAGE_BINDING,
        }
    }

-    pub fn primitives(&self) -> &[Option<InstanceList>] {
-        &self.primitives
+    pub fn image_instances(&self) -> &Vec<PrimitiveInstance> {
+        &self.images
    }

-    pub fn apply_free(&mut self) -> impl Iterator<Item = PrimitiveChange> {
-        self.primitives
-            .iter_mut()
-            .enumerate()
-            .filter_map(|(kind, list)| Some((kind as u32, list.as_mut()?)))
-            .flat_map(|(kind, list)| list.apply_free(kind))
+    /// returns (old index, new index) for both lists this layer keeps --
+    /// `PrimitiveChange::is_image` says which, since the two have separate
+    /// index spaces and `old`/`new` alone would collide between them.
+    ///
+    /// Both lists free with `swap_remove`, so a layer's draw order was
+    /// already undefined before images existed: nothing here may assume one
+    /// primitive stays adjacent to another once anything in the layer has
+    /// been freed.
+    pub fn apply_free(&mut self) -> Vec<PrimitiveChange> {
+        let mut changes =
+            Self::apply_free_list(&mut self.free, &mut self.instances, &mut self.assoc, false);
+        changes.extend(Self::apply_free_list(
+            &mut self.image_free,
+            &mut self.images,
+            &mut self.image_assoc,
+            true,
+        ));
+        changes
+    }
+
+    fn apply_free_list(
+        free: &mut Vec<usize>,
+        instances: &mut Vec<PrimitiveInstance>,
+        assoc: &mut Vec<WidgetId>,
+        is_image: bool,
+    ) -> Vec<PrimitiveChange> {
+        free.sort_by(|a, b| b.cmp(a));
+        free.drain(..)
+            .filter_map(|i| {
+                instances.swap_remove(i);
+                assoc.swap_remove(i);
+                if i == instances.len() {
+                    return None;
+                }
+                let id = assoc[i];
+                let old = instances.len();
+                Some(PrimitiveChange {
+                    id,
+                    is_image,
+                    old,
+                    new: i,
+                })
+            })
+            .collect()
    }

    pub fn free(&mut self, h: &PrimitiveHandle) -> MaskIdx {
        self.updated = true;
-        self.list(h).free(h.inst_idx)
+        if h.binding == IMAGE_BINDING {
+            self.image_free.push(h.inst_idx);
+            self.images[h.inst_idx].mask_idx
+        } else {
+            self.data.free(h.binding, h.data_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.list(h).instances[h.inst_idx].region
+        if h.binding == IMAGE_BINDING {
+            &mut self.images[h.inst_idx].region
+        } else {
+            &mut self.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,
+    /// Which of `Primitives::instances`/`Primitives::images` this change
+    /// belongs to -- their `old`/`new` indices are independent, so a
+    /// consumer matching only on `(layer, inst_idx)` could apply an image's
+    /// renumbering to a rect's handle that happens to share the same index.
+    pub is_image: bool,
    pub old: usize,
    pub new: usize,
 }
@@ -317,12 +298,29 @@ 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,
+    glyphs: GlyphPrimitive => 2,
+);
+
 #[repr(C)]
-#[derive(Copy, Clone, bytemuck::Pod, bytemuck::Zeroable)]
+#[derive(Copy, Clone)]
 pub struct RectPrimitive {
    pub color: Color<u8>,
    pub radius: f32,
@@ -330,10 +328,6 @@ 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 {
@@ -345,51 +339,91 @@ impl RectPrimitive {
    }
 }

-/// `color` is multiplied by the atlas alpha for a mask glyph; a colour glyph
-/// takes the texel unchanged, which `GlyphEntry::IS_COLORED` selects.
-#[repr(C, align(8))]
+/// One glyph, drawn as a sub-rectangle of the glyph atlas array.
+///
+/// `color` is the text colour and is multiplied by the atlas's alpha for an
+/// ordinary mask glyph; a colour glyph (emoji) carries its own colour and
+/// takes the atlas texel unchanged, which is what `GlyphEntry::IS_COLORED`
+/// selects.
+#[repr(C)]
 #[derive(Debug, Copy, Clone)]
 pub struct GlyphPrimitive {
    pub uv_min: Vec2,
    pub uv_max: Vec2,
-    /// Which atlas array layer this glyph is on.
+    /// Layer of the shared atlas array texture this glyph's page occupies --
+    /// not a bind-group or view index, since a page never gets one of its own.
    pub layer: u32,
    pub color: Color<u8>,
    pub flags: u32,
+    /// Pads this struct's Rust size to match WGSL's storage-buffer layout for
+    /// `GlyphInfo`: two `vec2<f32>` members give the struct an 8-byte
+    /// alignment, which rounds the WGSL size up to 32 bytes even though the
+    /// fields above only total 28. `bytemuck` does not check this for us.
+    _pad: u32,
 }

-// Manual rather than derived: the align(8) leaves four bytes of padding, which
-// is how WGSL lays the struct out.
-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))
-    }
-}
-
-/// One drawn image. Its shader reads nothing per instance; the slot names the
-/// 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 {
+impl GlyphPrimitive {
+    /// The only constructor, since `_pad` is private: callers outside this
+    /// module cannot write the struct literal.
+    pub fn new(uv_min: Vec2, uv_max: Vec2, layer: u32, color: Color<u8>, flags: u32) -> Self {
        Self {
-            slot: handle.slot(),
+            uv_min,
+            uv_max,
+            layer,
+            color,
+            flags,
+            _pad: 0,
        }
    }
 }
+
+pub struct PrimitiveVec<T> {
+    vec: Vec<T>,
+    free: Vec<usize>,
+}
+
+impl<T> PrimitiveVec<T> {
+    pub fn new() -> Self {
+        Self {
+            vec: Vec::new(),
+            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
+    }
+}
@@ -0,0 +1,210 @@
+const RECT: u32 = 0u;
+// TEXTURE has no entry in group 1: a standalone image draws with its own
+// bind group (see UiRenderNode::draw), so there is nothing per-instance left
+// to look up here -- the bind group already picked the texture.
+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(GLYPH)
+var<storage> glyphs: array<GlyphInfo>;
+
+struct Rect {
+    color: u32,
+    radius: f32,
+    thickness: f32,
+    inner_radius: f32,
+}
+
+struct GlyphInfo {
+    uv_min: vec2<f32>,
+    uv_max: vec2<f32>,
+    // Layer of the shared atlas array texture, not a view or bind-group
+    // index -- a page never gets its own bind group.
+    layer: 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>,
+}
+
+// The shared glyph atlas: every page is one layer. Growing it recreates this
+// texture with headroom and copies the old layers across -- see
+// GpuTextures::grow_array -- rather than the binding_array<texture_2d<f32>>
+// this replaced, which needed VK_EXT_descriptor_indexing and does not survive
+// a real share of Android GPUs.
+@group(2) @binding(0)
+var atlas: texture_2d_array<f32>;
+// One standalone image's texture. The main draw (rects and glyphs) binds a
+// 1x1 null texture here, since neither samples it; each image draw call
+// binds its own -- see UiRenderNode::draw.
+@group(2) @binding(1)
+var image_texture: texture_2d<f32>;
+@group(2) @binding(2)
+var samp: sampler;
+@group(2) @binding(3)
+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);
+        }
+        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;
+}
+
+fn draw_texture(region: Region) -> vec4<f32> {
+    return textureSample(image_texture, samp, 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(atlas, samp, uv, i32(g.layer));
+    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;
+}
+
@@ -1,33 +0,0 @@
-// 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);
-}
@@ -1,96 +0,0 @@
-// 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;
-}
@@ -1,39 +0,0 @@
-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;
-}
@@ -1,10 +0,0 @@
-// 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));
-}
@@ -1,112 +1,289 @@
-use image::{DynamicImage, EncodableLayout, GenericImageView, RgbaImage};
+use image::{DynamicImage, EncodableLayout, GenericImageView};
 use wgpu::{util::DeviceExt, *};

-use crate::{
-    PatchRect, TextureUpdate, Textures, UiData,
-    render::{
-        TexturePrimitive,
-        primitive::{ListDraw, PrimitiveRender},
-    },
-};
+use crate::{Mask, PatchRect, TextureKind, TextureUpdate, Textures, render::util::ArrBuf};

-/// 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,
-}
+use super::atlas::PAGE;

-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,
-    slots: Vec<Option<ImageGpu>>,
+/// What one texture slot is, GPU-side. Parallel to `Textures`' own slot
+/// numbering (`TextureKind`'s `Image`/`Page`), so a slot's index means the
+/// same thing on both sides without a second map to keep in sync.
+enum Slot {
+    /// A slot that was freed, or pushed and freed within the same batch
+    /// before ever reaching here.
+    Empty,
+    Image(ImageGpu),
+    /// The array layer a page occupies. Pages are never freed (see
+    /// `Textures::free`), so this is the only variant that outlives a `Free`.
+    Page(u32),
 }

 struct ImageGpu {
-    /// Kept for `patch`, which needs the texture rather than the view.
-    texture: Texture,
-    group: BindGroup,
+    /// Kept because a masks or atlas-array rebuild has to build a new bind
+    /// group from it. The `Texture` it came from is not kept: a `TextureView`
+    /// holds its own reference to that, so the image survives without one.
+    view: TextureView,
+    bind_group: BindGroup,
+}
+
+/// Owns the two kinds of texture iris draws:
+///
+/// - **The glyph atlas**, one `texture_2d_array` whose layers are pages
+///   (`Slot::Page`), grown by recreating the array with headroom and
+///   `copy_texture_to_texture`-ing the old layers across. No feature beyond
+///   Vulkan 1.0/GLES sampling is needed for this -- a layer index is an
+///   ordinary sampling operand.
+/// - **Standalone images** (`Slot::Image`), each its own `Texture` and
+///   `BindGroup`, drawn one `draw()` call at a time with that bind group
+///   bound -- see `UiRenderNode::draw`.
+///
+/// This replaced one giant `binding_array<texture_2d<f32>>`, which needed
+/// `VK_EXT_descriptor_indexing` -- an extension a real share of Android GPUs
+/// lack, so the old shape did not run there at all.
+pub struct GpuTextures {
+    device: Device,
+    queue: Queue,
+
+    slots: Vec<Slot>,
+
+    array_texture: Texture,
+    array_view: TextureView,
+    array_capacity: u32,
+    /// Layers actually written. Only grows -- see `Slot::Page`.
+    page_count: u32,
+
+    sampler: Sampler,
+    /// Bound in the image slot of the main draw's bind group, which has
+    /// nothing of its own to put there: rects and glyphs never sample it,
+    /// but the layout requires something bound regardless.
+    null_view: TextureView,
 }

 impl GpuTextures {
-    pub fn new(device: &Device, queue: &Queue) -> Self {
-        Self {
-            device: device.clone(),
-            queue: queue.clone(),
-            slots: Vec::new(),
+    /// Applies queued `Textures` updates, then reports whether the *main*
+    /// bind group (the one rects and glyphs draw with) needs rebuilding --
+    /// true when the atlas array was recreated (its view identity changed)
+    /// or the masks buffer was, since both are bound there. Pushing or
+    /// freeing a standalone image never touches that group: it built or drops
+    /// its own.
+    pub fn update(
+        &mut self,
+        textures: &mut Textures,
+        rsc_layout: &BindGroupLayout,
+        masks: &ArrBuf<Mask>,
+        masks_resized: bool,
+    ) -> bool {
+        let mut rebuild_main = masks_resized;
+        if masks_resized {
+            // The masks buffer just moved, so every bind group holding a
+            // reference to it -- one per live standalone image -- is stale.
+            self.rebuild_image_bind_groups(rsc_layout, masks);
        }
-    }
-
-    pub fn update(&mut self, textures: &mut Textures, layout: &BindGroupLayout, sampler: &Sampler) {
        for update in textures.updates() {
            match update {
-                TextureUpdate::Push(image) => {
-                    let image = self.create(image, layout, sampler);
-                    self.slots.push(Some(image));
+                TextureUpdate::Push(kind, image) => {
+                    rebuild_main |= self.push(kind, image, rsc_layout, masks);
                }
-                TextureUpdate::Set(i, image) => {
-                    let image = self.create(image, layout, sampler);
-                    self.slots[i as usize] = Some(image);
+                TextureUpdate::Set(kind, i, image) => {
+                    rebuild_main |= self.set(kind, i, image, rsc_layout, masks);
                }
+                // A patch changes texture contents, not which layer or bind
+                // group exists, so it never asks for a rebuild -- rebuilding
+                // per glyph is exactly the cost this exists to avoid.
                TextureUpdate::Patch(i, rect, image) => self.patch(i, rect, image),
-                TextureUpdate::PushFree => self.slots.push(None),
                TextureUpdate::SetFree => {}
-                TextureUpdate::Free(i) => self.slots[i as usize] = None,
+                TextureUpdate::Free(i) => self.free(i),
+                TextureUpdate::PushFree(_kind) => self.slots.push(Slot::Empty),
+            }
+        }
+        rebuild_main
+    }
+
+    fn push(
+        &mut self,
+        kind: TextureKind,
+        image: &DynamicImage,
+        rsc_layout: &BindGroupLayout,
+        masks: &ArrBuf<Mask>,
+    ) -> bool {
+        let (slot, rebuilt) = self.make_slot(kind, image, rsc_layout, masks);
+        self.slots.push(slot);
+        rebuilt
+    }
+
+    fn set(
+        &mut self,
+        kind: TextureKind,
+        i: u32,
+        image: &DynamicImage,
+        rsc_layout: &BindGroupLayout,
+        masks: &ArrBuf<Mask>,
+    ) -> bool {
+        let (slot, rebuilt) = self.make_slot(kind, image, rsc_layout, masks);
+        self.slots[i as usize] = slot;
+        rebuilt
+    }
+
+    fn make_slot(
+        &mut self,
+        kind: TextureKind,
+        image: &DynamicImage,
+        rsc_layout: &BindGroupLayout,
+        masks: &ArrBuf<Mask>,
+    ) -> (Slot, bool) {
+        match kind {
+            TextureKind::Image => {
+                let gpu = self.create_image(image, rsc_layout, masks);
+                (Slot::Image(gpu), false)
+            }
+            TextureKind::Page { layer } => {
+                let mut rebuilt = false;
+                if layer >= self.array_capacity {
+                    self.grow_array(rsc_layout, masks);
+                    rebuilt = true;
+                }
+                self.write_full_layer(layer, image);
+                self.page_count = self.page_count.max(layer + 1);
+                (Slot::Page(layer), rebuilt)
            }
        }
    }

-    pub fn group(&self, slot: u32) -> Option<&BindGroup> {
-        self.slots.get(slot as usize)?.as_ref().map(|i| &i.group)
+    fn free(&mut self, i: u32) {
+        if let Some(slot) = self.slots.get_mut(i as usize) {
+            *slot = Slot::Empty;
+        }
+        // A page's layer is not reclaimed here either -- see `Slot::Page`.
    }

-    fn create(
+    fn patch(&mut self, i: u32, rect: PatchRect, image: &DynamicImage) {
+        let Some(&Slot::Page(layer)) = self.slots.get(i as usize) else {
+            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: &self.array_texture,
+                mip_level: 0,
+                origin: Origin3d {
+                    x: rect.x,
+                    y: rect.y,
+                    z: layer,
+                },
+                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 write_full_layer(&self, layer: u32, image: &DynamicImage) {
+        // Every page is created as exactly PAGE x PAGE (`GlyphAtlas::allocate`),
+        // so this is always a whole-layer write, never a crop.
+        let rgba = image.to_rgba8();
+        self.queue.write_texture(
+            TexelCopyTextureInfo {
+                texture: &self.array_texture,
+                mip_level: 0,
+                origin: Origin3d {
+                    x: 0,
+                    y: 0,
+                    z: layer,
+                },
+                aspect: TextureAspect::All,
+            },
+            rgba.as_bytes(),
+            TexelCopyBufferLayout {
+                offset: 0,
+                bytes_per_row: Some(PAGE * 4),
+                rows_per_image: Some(PAGE),
+            },
+            Extent3d {
+                width: PAGE,
+                height: PAGE,
+                depth_or_array_layers: 1,
+            },
+        );
+    }
+
+    /// Doubles the array's layer capacity (headroom, so this is rare) and
+    /// copies the old layers across GPU-side -- no readback. Recreates the
+    /// array's view, which invalidates every bind group that referenced it,
+    /// so this also rebuilds all of them before returning.
+    fn grow_array(&mut self, rsc_layout: &BindGroupLayout, masks: &ArrBuf<Mask>) {
+        let new_capacity = self.array_capacity * 2;
+        let new_texture = Self::create_array_texture(&self.device, new_capacity);
+        if self.page_count > 0 {
+            let mut encoder = self
+                .device
+                .create_command_encoder(&CommandEncoderDescriptor {
+                    label: Some("atlas array grow"),
+                });
+            encoder.copy_texture_to_texture(
+                TexelCopyTextureInfo {
+                    texture: &self.array_texture,
+                    mip_level: 0,
+                    origin: Origin3d::ZERO,
+                    aspect: TextureAspect::All,
+                },
+                TexelCopyTextureInfo {
+                    texture: &new_texture,
+                    mip_level: 0,
+                    origin: Origin3d::ZERO,
+                    aspect: TextureAspect::All,
+                },
+                Extent3d {
+                    width: PAGE,
+                    height: PAGE,
+                    depth_or_array_layers: self.page_count,
+                },
+            );
+            self.queue.submit(std::iter::once(encoder.finish()));
+        }
+        self.array_texture = new_texture;
+        self.array_view = self.array_texture.create_view(&TextureViewDescriptor {
+            dimension: Some(TextureViewDimension::D2Array),
+            ..Default::default()
+        });
+        self.array_capacity = new_capacity;
+        self.rebuild_image_bind_groups(rsc_layout, masks);
+    }
+
+    fn rebuild_image_bind_groups(&mut self, rsc_layout: &BindGroupLayout, masks: &ArrBuf<Mask>) {
+        for slot in &mut self.slots {
+            if let Slot::Image(gpu) = slot {
+                gpu.bind_group = Self::make_image_bind_group(
+                    &self.device,
+                    rsc_layout,
+                    &self.array_view,
+                    &gpu.view,
+                    &self.sampler,
+                    masks,
+                );
+            }
+        }
+    }
+
+    fn create_image(
        &self,
        image: &DynamicImage,
-        layout: &BindGroupLayout,
-        sampler: &Sampler,
+        rsc_layout: &BindGroupLayout,
+        masks: &ArrBuf<Mask>,
    ) -> ImageGpu {
        let rgba = image.to_rgba8();
        let (width, height) = rgba.dimensions();
@@ -130,112 +307,151 @@ impl GpuTextures {
            rgba.as_bytes(),
        );
        let view = texture.create_view(&TextureViewDescriptor::default());
-        let group = sampled_group(&self.device, layout, &view, sampler, "ui image");
-        ImageGpu { texture, group }
+        let bind_group = Self::make_image_bind_group(
+            &self.device,
+            rsc_layout,
+            &self.array_view,
+            &view,
+            &self.sampler,
+            masks,
+        );
+        ImageGpu { view, bind_group }
    }

-    fn patch(&mut self, i: u32, rect: PatchRect, image: &DynamicImage) {
-        let Some(Some(slot)) = self.slots.get(i as usize) else {
-            return;
-        };
-        let dst = TexelCopyTextureInfo {
-            texture: &slot.texture,
-            mip_level: 0,
-            origin: Origin3d {
-                x: rect.x,
-                y: rect.y,
-                z: 0,
+    /// Builds group 2 for one standalone image: the shared atlas array, this
+    /// image's own view, the shared sampler, and the shared masks buffer --
+    /// the same layout the main draw uses with a null view in the image slot.
+    fn make_image_bind_group(
+        device: &Device,
+        rsc_layout: &BindGroupLayout,
+        array_view: &TextureView,
+        image_view: &TextureView,
+        sampler: &Sampler,
+        masks: &ArrBuf<Mask>,
+    ) -> BindGroup {
+        device.create_bind_group(&BindGroupDescriptor {
+            layout: rsc_layout,
+            entries: &[
+                BindGroupEntry {
+                    binding: 0,
+                    resource: BindingResource::TextureView(array_view),
+                },
+                BindGroupEntry {
+                    binding: 1,
+                    resource: BindingResource::TextureView(image_view),
+                },
+                BindGroupEntry {
+                    binding: 2,
+                    resource: BindingResource::Sampler(sampler),
+                },
+                BindGroupEntry {
+                    binding: 3,
+                    resource: masks.buffer.as_entire_binding(),
+                },
+            ],
+            label: Some("ui rsc image"),
+        })
+    }
+
+    fn create_array_texture(device: &Device, capacity: u32) -> Texture {
+        device.create_texture(&TextureDescriptor {
+            label: Some("glyph atlas array"),
+            size: Extent3d {
+                width: PAGE,
+                height: PAGE,
+                depth_or_array_layers: capacity,
            },
-            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 });
-            }
+            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: &[],
+        })
+    }
+
+    pub fn new(device: &Device, queue: &Queue) -> Self {
+        let sampler = default_sampler(device);
+        let null_view = null_texture_view(device);
+        let array_capacity = 1;
+        let array_texture = Self::create_array_texture(device, array_capacity);
+        let array_view = array_texture.create_view(&TextureViewDescriptor {
+            dimension: Some(TextureViewDimension::D2Array),
+            ..Default::default()
+        });
+        Self {
+            device: device.clone(),
+            queue: queue.clone(),
+            slots: Vec::new(),
+            array_texture,
+            array_view,
+            array_capacity,
+            page_count: 0,
+            sampler,
+            null_view,
+        }
+    }
+
+    pub fn array_view(&self) -> &TextureView {
+        &self.array_view
+    }
+
+    pub fn null_view(&self) -> &TextureView {
+        &self.null_view
+    }
+
+    pub fn sampler(&self) -> &Sampler {
+        &self.sampler
+    }
+
+    /// The bind group a standalone image draws with. Panics if `idx` names an
+    /// atlas page or a freed slot instead -- either is a caller bug (the
+    /// wrong kind of instance reached this draw path), not a condition to
+    /// recover from.
+    pub fn image_bind_group(&self, idx: u32) -> &BindGroup {
+        match self.slots.get(idx as usize) {
+            Some(Slot::Image(gpu)) => &gpu.bind_group,
+            other => panic!("texture slot {idx} is not a live standalone image: {other:?}"),
+        }
+    }
+
+    pub fn view_count(&self) -> usize {
+        self.slots
+            .iter()
+            .filter(|s| !matches!(s, Slot::Empty))
+            .count()
+    }
+}
+
+impl std::fmt::Debug for Slot {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Slot::Empty => write!(f, "Empty"),
+            Slot::Image(_) => write!(f, "Image"),
+            Slot::Page(layer) => write!(f, "Page(layer={layer})"),
        }
    }
 }

-pub fn write_region(queue: &Queue, dst: TexelCopyTextureInfo, src: &RgbaImage, rect: PatchRect) {
-    if rect.width == 0 || rect.height == 0 {
-        return;
-    }
-    let stride = src.width() * 4;
-    queue.write_texture(
-        dst,
-        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),
+pub fn null_texture_view(device: &Device) -> TextureView {
+    device
+        .create_texture(&TextureDescriptor {
+            label: Some("null"),
+            size: Extent3d {
+                width: 1,
+                height: 1,
+                depth_or_array_layers: 1,
            },
-            BindGroupEntry {
-                binding: 1,
-                resource: BindingResource::Sampler(sampler),
-            },
-        ],
-        label: Some(label),
-    })
-}
-
-/// 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),
-    })
+            mip_level_count: 1,
+            sample_count: 1,
+            dimension: TextureDimension::D2,
+            format: TextureFormat::Rgba8Unorm,
+            usage: TextureUsages::TEXTURE_BINDING,
+            view_formats: &[],
+        })
+        .create_view(&TextureViewDescriptor::default())
 }

 pub fn default_sampler(device: &Device) -> Sampler {
@@ -21,8 +21,9 @@ impl<T: Pod> ArrBuf<T> {
            _pd: PhantomData,
        }
    }
-    /// Returns whether the `Buffer` was recreated, which stales any cached
-    /// `BindGroup` holding it.
+    /// Returns whether the underlying `Buffer` was recreated -- a caller that
+    /// cached a `BindGroup` referencing it (as `GpuTextures` does for the
+    /// masks buffer) needs to know to rebuild that too.
    pub fn update(&mut self, device: &Device, queue: &Queue, data: &[T]) -> bool {
        let resized = self.len != data.len();
        if resized {
@@ -33,13 +34,9 @@ impl<T: Pod> ArrBuf<T> {
        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 {
@@ -49,4 +46,8 @@ impl<T: Pod> ArrBuf<T> {
            usage,
        })
    }
+    #[allow(clippy::len_without_is_empty)]
+    pub fn len(&self) -> usize {
+        self.len
+    }
 }
@@ -1,6 +1,4 @@
-use crate::{
-    Mask, PrimitiveRegistry, TextData, Textures, WeakWidget, WidgetId, Widgets, util::TrackedArena,
-};
+use crate::{Mask, TextData, Textures, WeakWidget, WidgetId, Widgets, util::TrackedArena};

 mod active;
 mod cache;
@@ -9,15 +7,13 @@ mod render_state;
 mod size;

 pub use active::*;
-pub use painter::{Painter, PrimitiveLike};
+pub use painter::Painter;
 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>,
@@ -1,10 +1,7 @@
 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, PrimitiveKind,
-        TexturePrimitive,
-    },
+    render::{GlyphPrimitive, Mask, MaskIdx, Primitive, PrimitiveHandle, PrimitiveInst},
    util::Vec2,
 };

@@ -24,26 +21,15 @@ 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);
@@ -52,13 +38,11 @@ impl<'a> Painter<'a> {
    }

    /// Writes a primitive to be rendered
-    pub fn primitive(&mut self, primitive: impl PrimitiveLike) {
-        let primitive = primitive.into_primitive(self);
+    pub fn primitive<P: Primitive>(&mut self, primitive: P) {
        self.primitive_at(primitive, self.region)
    }

-    pub fn primitive_within(&mut self, primitive: impl PrimitiveLike, region: UiRegion) {
-        let primitive = primitive.into_primitive(self);
+    pub fn primitive_within<P: Primitive>(&mut self, primitive: P, region: UiRegion) {
        self.primitive_at(primitive, region.within(&self.region));
    }

@@ -91,6 +75,35 @@ impl<'a> Painter<'a> {
        );
    }

+    pub fn texture_within(&mut self, handle: &TextureHandle, region: UiRegion) {
+        self.textures.push(handle.clone());
+        self.write_image(handle.image_index(), region.within(&self.region));
+    }
+
+    pub fn texture(&mut self, handle: &TextureHandle) {
+        self.textures.push(handle.clone());
+        self.write_image(handle.image_index(), self.region);
+    }
+
+    pub fn texture_at(&mut self, handle: &TextureHandle, region: UiRegion) {
+        self.textures.push(handle.clone());
+        self.write_image(handle.image_index(), region);
+    }
+
+    /// A standalone image draws with its own bind group rather than sharing
+    /// the layer's one instanced draw, so it goes through
+    /// `Primitives::write_image` instead of `primitive_at`/`Primitive::vec`.
+    fn write_image(&mut self, texture_idx: u32, region: UiRegion) {
+        let h = self
+            .state
+            .layers
+            .write_image(self.layer, self.id, texture_idx, region, self.mask);
+        if self.mask != MaskIdx::NONE {
+            self.rsc.ui_mut().masks.push_ref(self.mask);
+        }
+        self.primitives.push(h);
+    }
+
    pub fn render_text(
        &mut self,
        buffer: &mut TextBuffer,
@@ -98,12 +111,10 @@ impl<'a> Painter<'a> {
        width: Option<f32>,
    ) -> RenderedText {
        let ui = self.rsc.ui_mut();
-        ui.text.render(buffer, attrs, width)
+        ui.text.render(buffer, attrs, width, &mut ui.textures)
    }

-    // 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;
@@ -111,15 +122,14 @@ 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.write(
-                kind,
-                GlyphPrimitive {
-                    uv_min: glyph.entry.uv_min,
-                    uv_max: glyph.entry.uv_max,
-                    layer: glyph.entry.layer,
-                    color: text.color,
-                    flags: glyph.entry.flags(),
-                },
+            self.primitive_at(
+                GlyphPrimitive::new(
+                    glyph.entry.uv_min,
+                    glyph.entry.uv_max,
+                    glyph.entry.layer,
+                    text.color,
+                    glyph.entry.flags(),
+                ),
                region,
            );
        }
@@ -172,28 +182,3 @@ 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, DrawLayers, IdLike, MaskIdx, Painter, PixelRegion, SizeCtx, StrongWidget,
-    UiRegion, UiRsc, UiVec2, WidgetId, Widgets,
+    ActiveData, Axis, IdLike, MaskIdx, Painter, PixelRegion, PrimitiveLayers, SizeCtx,
+    StrongWidget, UiRegion, UiRsc, UiVec2, WidgetId, Widgets,
    ui::cache::Cache,
    util::{HashMap, HashSet, Vec2, forget_ref},
 };

 pub struct UiRenderState {
    pub active: HashMap<WidgetId, ActiveData>,
-    pub layers: DrawLayers,
+    pub layers: PrimitiveLayers,
    pub(super) output_size: Vec2,
    pub cache: Cache,

@@ -243,14 +243,14 @@ impl UiRenderState {
    }

    pub fn debug_layers(&self) {
-        for ((idx, depth), draws) in self.layers.iter_depth() {
+        for ((idx, depth), primitives) in self.layers.iter_depth() {
            let indent = " ".repeat(depth * 2);
-            let counts: Vec<String> = draws
-                .primitives()
-                .iter()
-                .map(|l| l.as_ref().map_or(0, |l| l.instances().len()).to_string())
-                .collect();
-            println!("{indent}{idx}: [{}]", counts.join(", "));
+            let len = primitives.instances().len();
+            print!("{indent}{idx}: {len} primitives");
+            if len >= 1 {
+                print!(" ({})", primitives.instances()[0].binding);
+            }
+            println!();
        }
    }

@@ -308,6 +308,7 @@ impl UiRenderState {
            source,
            cache: &mut self.cache,
            text: &mut ui.text,
+            textures: &mut ui.textures,
            widgets: &ui.widgets,
            outer,
            output_size: self.output_size,
@@ -1,10 +1,11 @@
 use crate::{
-    Axis, AxisT, IdLike, Len, RenderedText, Size, TextAttrs, TextBuffer, TextData, UiVec2,
-    WidgetAxisFns, WidgetId, Widgets, XAxis, YAxis, ui::cache::Cache, util::Vec2,
+    Axis, AxisT, IdLike, Len, RenderedText, Size, TextAttrs, TextBuffer, TextData, Textures,
+    UiVec2, 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,
@@ -32,6 +33,7 @@ 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,
@@ -80,7 +82,7 @@ impl SizeCtx<'_> {
        attrs: &TextAttrs,
        width: Option<f32>,
    ) -> RenderedText {
-        self.text.render(buffer, attrs, width)
+        self.text.render(buffer, attrs, width, self.textures)
    }

    pub fn label(&self, id: WidgetId) -> &String {
@@ -212,10 +212,10 @@ impl DefaultAppState for Client {
        render: &mut UiRenderState,
    ) {
        let new = format!(
-            "widgets: {}\nactive: {}\ntextures: {}",
+            "widgets: {}\nactive: {}\nviews: {}",
            rsc.widgets().len(),
            render.active_widgets(),
-            rsc.ui().textures.count(),
+            self.ui_state.renderer.ui.view_count(),
        );
        if new != *rsc.widgets()[self.info].content {
            *rsc.widgets_mut()[self.info].content = new;
@@ -22,20 +22,7 @@ impl UiRenderer {
    }

    pub fn draw(&mut self) {
-        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 output = self.surface.get_current_texture().unwrap();
        let view = output
            .texture
            .create_view(&TextureViewDescriptor::default());
@@ -59,7 +46,7 @@ impl UiRenderer {

        self.queue.submit(std::iter::once(encoder.finish()));
        self.window.pre_present_notify();
-        self.queue.present(output);
+        output.present();
    }

    pub fn resize(&mut self, size: &PhysicalSize<u32>) {
@@ -78,10 +65,9 @@ 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,
-            display: Some(Box::new(window.clone())),
-            ..InstanceDescriptor::new_without_display_handle()
+            ..Default::default()
        });

        let surface = instance
@@ -93,11 +79,16 @@ 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!");

+        // No features beyond what wgpu asks for by default, and no
+        // binding-array limits: the atlas is one texture_2d_array and a
+        // standalone image is its own ordinary bind group, neither of which
+        // needs descriptor indexing. The binding array this replaced asked
+        // for VK_EXT_descriptor_indexing unconditionally and so did not run
+        // on a real share of Android GPUs.
        let (device, queue) = adapter
            .request_device(&DeviceDescriptor {
                required_limits: Limits {
@@ -120,7 +111,6 @@ 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,
@@ -133,7 +123,7 @@ impl UiRenderer {

        let encoder = Self::create_encoder(&device);

-        let ui = UiRenderNode::new(&device, &config);
+        let ui = UiRenderNode::new(&device, &queue, &config);

        Self {
            surface,
@@ -7,7 +7,7 @@ pub struct Image {

 impl Widget for Image {
    fn draw(&mut self, painter: &mut Painter) {
-        painter.primitive(&self.handle);
+        painter.texture(&self.handle);
    }

    fn desired_width(&mut self, _: &mut SizeCtx) -> Len {
@@ -1,205 +0,0 @@
-//! 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
-        );
-    }
-}