Add opacity

This reduces the amount of growing necessary for large glyphs

Cargo.toml

@@ -1,18 +1,18 @@
 [package]
 name = "glyphon"
 description = "Fast, simple 2D text rendering for wgpu"
-version = "0.3.0"
+version = "0.5.0"
 edition = "2021"
 homepage = "https://github.com/grovesNL/glyphon.git"
 repository = "https://github.com/grovesNL/glyphon"
 license = "MIT OR Apache-2.0 OR Zlib"
 
 [dependencies]
-wgpu = "0.18"
+wgpu = "0.19"
 etagere = "0.2.10"
-cosmic-text = "0.10"
-lru = "0.11"
+lru = "0.12.1"
+cosmic-text = "0.11.2"
 
 [dev-dependencies]
-winit = "0.28.7"
+winit = { version = "0.29.10", features = ["rwh_05"] }
 pollster = "0.3.0"

examples/hello-world.rs

@@ -11,10 +11,12 @@ use wgpu::{
 use winit::{
     dpi::LogicalSize,
     event::{Event, WindowEvent},
-    event_loop::{ControlFlow, EventLoop},
+    event_loop::EventLoop,
     window::WindowBuilder,
 };
 
+use std::sync::Arc;
+
 fn main() {
     pollster::block_on(run());
 }
@@ -22,12 +24,12 @@ fn main() {
 async fn run() {
     // Set up window
     let (width, height) = (800, 600);
-    let event_loop = EventLoop::new();
-    let window = WindowBuilder::new()
+    let event_loop = EventLoop::new().unwrap();
+    let window = Arc::new(WindowBuilder::new()
         .with_inner_size(LogicalSize::new(width as f64, height as f64))
         .with_title("glyphon hello world")
         .build(&event_loop)
-        .unwrap();
+        .unwrap());
     let size = window.inner_size();
     let scale_factor = window.scale_factor();
 
@@ -41,14 +43,15 @@ async fn run() {
         .request_device(
             &DeviceDescriptor {
                 label: None,
-                features: Features::empty(),
-                limits: Limits::downlevel_defaults(),
+                required_features: Features::empty(),
+                required_limits: Limits::downlevel_defaults(),
             },
             None,
         )
         .await
         .unwrap();
-    let surface = unsafe { instance.create_surface(&window) }.expect("Create surface");
+
+    let surface = instance.create_surface(window.clone()).expect("Create surface");
     let swapchain_format = TextureFormat::Bgra8UnormSrgb;
     let mut config = SurfaceConfiguration {
         usage: TextureUsages::RENDER_ATTACHMENT,
@@ -58,6 +61,7 @@ async fn run() {
         present_mode: PresentMode::Fifo,
         alpha_mode: CompositeAlphaMode::Opaque,
         view_formats: vec![],
+        desired_maximum_frame_latency: 2,
     };
     surface.configure(&device, &config);
 
@@ -76,21 +80,21 @@ async fn run() {
     buffer.set_text(&mut font_system, "Hello world! 👋\nThis is rendered with 🦅 glyphon 🦁\nThe text below should be partially clipped.\na b c d e f g h i j k l m n o p q r s t u v w x y z", Attrs::new().family(Family::SansSerif), Shaping::Advanced);
     buffer.shape_until_scroll(&mut font_system);
 
-    event_loop.run(move |event, _, control_flow| {
-        let _ = (&instance, &adapter);
-
-        *control_flow = ControlFlow::Poll;
+    event_loop
+        .run(move |event, target| {
+            if let Event::WindowEvent {
+                window_id: _,
+                event,
+            } = event
+            {
                 match event {
-            Event::WindowEvent {
-                event: WindowEvent::Resized(size),
-                ..
-            } => {
+                    WindowEvent::Resized(size) => {
                         config.width = size.width;
                         config.height = size.height;
                         surface.configure(&device, &config);
                         window.request_redraw();
                     }
-            Event::RedrawRequested(_) => {
+                    WindowEvent::RedrawRequested => {
                         text_renderer
                             .prepare(
                                 &device,
@@ -120,8 +124,8 @@ async fn run() {
 
                         let frame = surface.get_current_texture().unwrap();
                         let view = frame.texture.create_view(&TextureViewDescriptor::default());
-                let mut encoder =
-                    device.create_command_encoder(&CommandEncoderDescriptor { label: None });
+                        let mut encoder = device
+                            .create_command_encoder(&CommandEncoderDescriptor { label: None });
                         {
                             let mut pass = encoder.begin_render_pass(&RenderPassDescriptor {
                                 label: None,
@@ -146,14 +150,10 @@ async fn run() {
 
                         atlas.trim();
                     }
-            Event::WindowEvent {
-                event: WindowEvent::CloseRequested,
-                ..
-            } => *control_flow = ControlFlow::Exit,
-            Event::MainEventsCleared => {
-                window.request_redraw();
-            }
+                    WindowEvent::CloseRequested => target.exit(),
                     _ => {}
                 }
-    });
+            }
+        })
+        .unwrap();
 }

src/lib.rs

@@ -51,7 +51,7 @@ pub(crate) struct GlyphToRender {
     dim: [u16; 2],
     uv: [u16; 2],
     color: u32,
-    content_type: u32,
+    content_type_with_srgb: [u16; 2],
     depth: f32,
 }
 
@@ -111,6 +111,8 @@ pub struct TextArea<'a> {
     /// The visible bounds of the text area. This is used to clip the text and doesn't have to
     /// match the `left` and `top` values.
     pub bounds: TextBounds,
-    // The default color of the text area.
+    /// The default color of the text area.
     pub default_color: Color,
+    /// The opacity to set the text area to (in gamma space)
+    pub opacity: f32,
 }

src/shader.wgsl

@@ -4,7 +4,7 @@ struct VertexInput {
     @location(1) dim: u32,
     @location(2) uv: u32,
     @location(3) color: u32,
-    @location(4) content_type: u32,
+    @location(4) content_type_with_srgb: u32,
     @location(5) depth: f32,
 }
 
@@ -32,6 +32,14 @@ var mask_atlas_texture: texture_2d<f32>;
 @group(0) @binding(3)
 var atlas_sampler: sampler;
 
+fn srgb_to_linear(c: f32) -> f32 {
+    if c <= 0.04045 {
+        return c / 12.92;
+    } else {
+        return pow((c + 0.055) / 1.055, 2.4);
+    }
+}
+
 @vertex
 fn vs_main(in_vert: VertexInput) -> VertexOutput {
     var pos = in_vert.pos;
@@ -69,15 +77,31 @@ fn vs_main(in_vert: VertexInput) -> VertexOutput {
 
     vert_output.position.y *= -1.0;
 
+    let content_type = in_vert.content_type_with_srgb & 0xffffu;
+    let srgb = (in_vert.content_type_with_srgb & 0xffff0000u) >> 16u;
+
+    switch srgb {
+        case 0u: {
             vert_output.color = vec4<f32>(
-        f32((color & 0x00ff0000u) >> 16u),
-        f32((color & 0x0000ff00u) >> 8u),
-        f32(color & 0x000000ffu),
-        f32((color & 0xff000000u) >> 24u),
-    ) / 255.0;
+                f32((color & 0x00ff0000u) >> 16u) / 255.0,
+                f32((color & 0x0000ff00u) >> 8u) / 255.0,
+                f32(color & 0x000000ffu) / 255.0,
+                f32((color & 0xff000000u) >> 24u) / 255.0,
+            );
+        }
+        case 1u: {
+            vert_output.color = vec4<f32>(
+                srgb_to_linear(f32((color & 0x00ff0000u) >> 16u) / 255.0),
+                srgb_to_linear(f32((color & 0x0000ff00u) >> 8u) / 255.0),
+                srgb_to_linear(f32(color & 0x000000ffu) / 255.0),
+                f32((color & 0xff000000u) >> 24u) / 255.0,
+            );
+        }
+        default: {}
+    }
 
     var dim: vec2<u32> = vec2(0u);
-    switch in_vert.content_type {
+    switch content_type {
         case 0u: {
             dim = textureDimensions(color_atlas_texture);
             break;
@@ -89,7 +113,7 @@ fn vs_main(in_vert: VertexInput) -> VertexOutput {
         default: {}
     }
 
-    vert_output.content_type = in_vert.content_type;
+    vert_output.content_type = content_type;
 
     vert_output.uv = vec2<f32>(uv) / vec2<f32>(dim);
 

src/text_atlas.rs

@@ -131,8 +131,10 @@ impl InnerAtlas {
             return false;
         }
 
-        // TODO: Better resizing logic (?)
-        let new_size = (self.size + Self::INITIAL_SIZE).min(self.max_texture_dimension_2d);
+        // Grow each dimension by a factor of 2. The growth factor was chosen to match the growth
+        // factor of `Vec`.`
+        const GROWTH_FACTOR: u32 = 2;
+        let new_size = (self.size * GROWTH_FACTOR).min(self.max_texture_dimension_2d);
 
         self.packer.grow(size2(new_size as i32, new_size as i32));
 
@@ -269,6 +271,7 @@ pub struct TextAtlas {
     pub(crate) shader: ShaderModule,
     pub(crate) vertex_buffers: [wgpu::VertexBufferLayout<'static>; 1],
     pub(crate) format: TextureFormat,
+    pub(crate) color_mode: ColorMode,
 }
 
 impl TextAtlas {
@@ -448,6 +451,7 @@ impl TextAtlas {
             shader,
             vertex_buffers,
             format,
+            color_mode,
         }
     }
 

src/text_render.rs

@@ -1,6 +1,6 @@
 use crate::{
-    FontSystem, GlyphDetails, GlyphToRender, GpuCacheStatus, Params, PrepareError, RenderError,
-    Resolution, SwashCache, SwashContent, TextArea, TextAtlas,
+    ColorMode, FontSystem, GlyphDetails, GlyphToRender, GpuCacheStatus, Params, PrepareError,
+    RenderError, Resolution, SwashCache, SwashContent, TextArea, TextAtlas,
 };
 use std::{iter, mem::size_of, slice, sync::Arc};
 use wgpu::{
@@ -268,6 +268,13 @@ impl TextRenderer {
                         None => text_area.default_color,
                     };
 
+                    let color = cosmic_text::Color::rgba(
+                        (color.r() as f32 * text_area.opacity + 0.5) as u8,
+                        (color.g() as f32 * text_area.opacity + 0.5) as u8,
+                        (color.b() as f32 * text_area.opacity + 0.5) as u8,
+                        (color.a() as f32 * text_area.opacity + 0.5) as u8,
+                    );
+
                     let depth = metadata_to_depth(glyph.metadata);
 
                     glyph_vertices.extend(
@@ -276,7 +283,13 @@ impl TextRenderer {
                             dim: [width as u16, height as u16],
                             uv: [atlas_x, atlas_y],
                             color: color.0,
-                            content_type: content_type as u32,
+                            content_type_with_srgb: [
+                                content_type as u16,
+                                match atlas.color_mode {
+                                    ColorMode::Accurate => TextColorConversion::ConvertToLinear,
+                                    ColorMode::Web => TextColorConversion::None,
+                                } as u16,
+                            ],
                             depth,
                         })
                         .take(4),
@@ -405,13 +418,20 @@ impl TextRenderer {
     }
 }
 
-#[repr(u32)]
+#[repr(u16)]
 #[derive(Debug, Clone, Copy, Eq, PartialEq)]
 pub enum ContentType {
     Color = 0,
     Mask = 1,
 }
 
+#[repr(u16)]
+#[derive(Debug, Clone, Copy, Eq, PartialEq)]
+enum TextColorConversion {
+    None = 0,
+    ConvertToLinear = 1,
+}
+
 fn next_copy_buffer_size(size: u64) -> u64 {
     let align_mask = COPY_BUFFER_ALIGNMENT - 1;
     ((size.next_power_of_two() + align_mask) & !align_mask).max(COPY_BUFFER_ALIGNMENT)