Tighten glyph atlas updates

core/src/render/atlas.rs

@@ -1,5 +1,5 @@
 use crate::{
-    PatchRect, TextureHandle, Textures,
+    GlyphPrimitive, PatchRect, TextureHandle, Textures,
     util::{HashMap, Vec2},
 };
 use image::RgbaImage;
@@ -27,18 +27,28 @@ pub struct GlyphKey {
 
 #[derive(Clone, Copy)]
 pub struct GlyphEntry {
-    pub uv_min: [f32; 2],
-    pub uv_max: [f32; 2],
+    pub uv_min: Vec2,
+    pub uv_max: Vec2,
     /// Offset from the glyph's pen position to the top-left of its pixels.
     pub left: i32,
     pub top: i32,
     pub width: u32,
     pub height: u32,
-    pub is_color: bool,
+    pub is_colored: bool,
     pub view_idx: u32,
     pub sampler_idx: u32,
 }
 
+impl GlyphEntry {
+    pub(crate) fn flags(&self) -> u32 {
+        if self.is_colored {
+            GlyphPrimitive::IS_COLORED
+        } else {
+            0
+        }
+    }
+}
+
 struct Page {
     handle: TextureHandle,
     x: u32,
@@ -95,13 +105,13 @@ impl GlyphAtlas {
         let page = &self.pages[page_idx];
         let scale = 1.0 / PAGE as f32;
         let entry = GlyphEntry {
-            uv_min: [x as f32 * scale, y as f32 * scale],
-            uv_max: [(x + w) as f32 * scale, (y + h) as f32 * scale],
+            uv_min: Vec2::new(x as f32 * scale, y as f32 * scale),
+            uv_max: Vec2::new((x + w) as f32 * scale, (y + h) as f32 * scale),
             left: image.placement.left,
             top: image.placement.top,
             width: w,
             height: h,
-            is_color: matches!(image.content, Content::Color),
+            is_colored: matches!(image.content, Content::Color),
             view_idx: page.handle.primitive().view_idx,
             sampler_idx: page.handle.primitive().sampler_idx,
         };
@@ -110,18 +120,12 @@ impl GlyphAtlas {
     }
 
     fn allocate(&mut self, w: u32, h: u32, textures: &mut Textures) -> (usize, u32, u32) {
-        let need_w = w + PAD;
-        let need_h = h + PAD;
-        if let Some(i) = self.pages.iter().position(|p| fits(p, need_w, need_h)) {
-            let page = &mut self.pages[i];
-            if page.x + need_w > PAGE {
-                page.y += page.shelf_height;
-                page.x = PAD;
-                page.shelf_height = 0;
-            }
-            let (x, y) = (page.x, page.y);
-            page.x += need_w;
-            page.shelf_height = page.shelf_height.max(need_h);
+        if let Some((i, (x, y))) = self
+            .pages
+            .iter_mut()
+            .enumerate()
+            .find_map(|(i, page)| page.allocate(w, h).map(|position| (i, position)))
+        {
             return (i, x, y);
         }
 
@@ -148,45 +152,65 @@ impl GlyphAtlas {
     }
 }
 
-fn fits(page: &Page, need_w: u32, need_h: u32) -> bool {
-    (page.x + need_w <= PAGE && page.y + need_h <= PAGE)
-        || (need_w + PAD <= PAGE && page.y + page.shelf_height + need_h <= PAGE)
+impl Page {
+    fn allocate(&mut self, w: u32, h: u32) -> Option<(u32, u32)> {
+        let need_w = w + PAD;
+        let need_h = h + PAD;
+        if self.x + need_w > PAGE {
+            if need_w + PAD > PAGE || self.y + self.shelf_height + need_h > PAGE {
+                return None;
+            }
+            self.y += self.shelf_height;
+            self.x = PAD;
+            self.shelf_height = 0;
+        } else if self.y + need_h > PAGE {
+            return None;
+        }
+
+        let position = (self.x, self.y);
+        self.x += need_w;
+        self.shelf_height = self.shelf_height.max(need_h);
+        Some(position)
+    }
 }
 
 /// Mask glyphs keep coverage in alpha so their raster can be tinted at draw time.
 fn write_glyph(page: &mut RgbaImage, image: &Image, x: u32, y: u32) {
-    let w = image.placement.width;
-    let h = image.placement.height;
-    match image.content {
-        Content::Mask => {
-            for row in 0..h {
-                for col in 0..w {
-                    let a = image.data[(row * w + col) as usize];
-                    page.put_pixel(x + col, y + row, image::Rgba([255, 255, 255, a]));
+    let width = image.placement.width as usize;
+    let height = image.placement.height as usize;
+    let page_stride = page.width() as usize * 4;
+    let x = x as usize * 4;
+    let y = y as usize;
+    let page = page.as_mut();
+
+    for row in 0..height {
+        let start = (y + row) * page_stride + x;
+        let target = &mut page[start..start + width * 4];
+        match image.content {
+            Content::Color => {
+                let start = row * width * 4;
+                target.copy_from_slice(&image.data[start..start + width * 4]);
+            }
+            Content::Mask => {
+                let start = row * width;
+                for (target, &alpha) in target
+                    .as_chunks_mut::<4>()
+                    .0
+                    .iter_mut()
+                    .zip(&image.data[start..start + width])
+                {
+                    target.copy_from_slice(&[255, 255, 255, alpha]);
                 }
             }
-        }
-        Content::Color => {
-            for row in 0..h {
-                for col in 0..w {
-                    let i = ((row * w + col) * 4) as usize;
-                    let px = [
-                        image.data[i],
-                        image.data[i + 1],
-                        image.data[i + 2],
-                        image.data[i + 3],
-                    ];
-                    page.put_pixel(x + col, y + row, image::Rgba(px));
-                }
-            }
-        }
-        Content::SubpixelMask => {
-            // Preserve readable output if the rasterizer returns a subpixel mask.
-            for row in 0..h {
-                for col in 0..w {
-                    let i = ((row * w + col) * 4) as usize;
-                    let a = image.data[i + 1];
-                    page.put_pixel(x + col, y + row, image::Rgba([255, 255, 255, a]));
+            Content::SubpixelMask => {
+                let start = row * width * 4;
+                for (target, source) in target
+                    .as_chunks_mut::<4>()
+                    .0
+                    .iter_mut()
+                    .zip(image.data[start..start + width * 4].as_chunks::<4>().0)
+                {
+                    target.copy_from_slice(&[255, 255, 255, source[1]]);
                 }
             }
         }

core/src/render/primitive.rs

@@ -6,6 +6,7 @@ use crate::{
         ArrBuf,
         data::{MaskIdx, PrimitiveInstance},
     },
+    util::Vec2,
 };
 use bytemuck::Pod;
 use wgpu::*;
@@ -234,8 +235,8 @@ pub struct TexturePrimitive {
 #[repr(C)]
 #[derive(Debug, Copy, Clone)]
 pub struct GlyphPrimitive {
-    pub uv_min: [f32; 2],
-    pub uv_max: [f32; 2],
+    pub uv_min: Vec2,
+    pub uv_max: Vec2,
     pub view_idx: u32,
     pub sampler_idx: u32,
     pub color: Color<u8>,
@@ -243,7 +244,7 @@ pub struct GlyphPrimitive {
 }
 
 impl GlyphPrimitive {
-    pub const IS_COLOR: u32 = 1;
+    pub const IS_COLORED: u32 = 1;
 }
 
 pub struct PrimitiveVec<T> {

core/src/render/texture.rs

@@ -17,36 +17,36 @@ pub struct GpuTextures {
 
 impl GpuTextures {
     pub fn update(&mut self, textures: &mut Textures) -> bool {
-        let mut changed = false;
+        let mut bindings_changed = false;
         for update in textures.updates() {
-            match update {
+            bindings_changed |= match update {
                 TextureUpdate::Push(image) => {
                     self.push(image);
-                    changed = true;
+                    true
                 }
                 TextureUpdate::Set(i, image) => {
                     self.set(i, image);
-                    changed = true;
+                    true
                 }
                 TextureUpdate::Patch(i, rect, image) => {
-                    // Patching contents leaves the binding array unchanged.
                     self.patch(i, rect, image);
+                    false
                 }
                 TextureUpdate::SetFree => {
                     self.view_count += 1;
-                    changed = true;
+                    true
                 }
                 TextureUpdate::Free(i) => {
                     self.free(i);
-                    changed = true;
+                    true
                 }
                 TextureUpdate::PushFree => {
                     self.push_free();
-                    changed = true;
+                    true
                 }
-            }
+            };
         }
-        changed
+        bindings_changed
     }
     fn set(&mut self, i: u32, image: &DynamicImage) {
         self.view_count += 1;

core/src/ui/painter.rs

@@ -101,13 +101,6 @@ impl<'a> Painter<'a> {
     }
 
     pub fn glyphs(&mut self, text: &RenderedText, origin: UiRegion) {
-        let flags_for = |is_color| {
-            if is_color {
-                GlyphPrimitive::IS_COLOR
-            } else {
-                0
-            }
-        };
         for glyph in text.glyphs.iter() {
             let mut region = origin;
             region.x.end = region.x.start;
@@ -122,7 +115,7 @@ impl<'a> Painter<'a> {
                     view_idx: glyph.entry.view_idx,
                     sampler_idx: glyph.entry.sampler_idx,
                     color: text.color,
-                    flags: flags_for(glyph.entry.is_color),
+                    flags: glyph.entry.flags(),
                 },
                 region,
             );