1struct Transform {
2    scale: vec2<f32>,
3    translation: vec2<f32>,
4}
5
6struct VertexInput {
7    @location(0) position: vec2<f32>,
8    @location(1) uv: vec2<f32>,
9    @location(2) color: vec4<f32>,
10}
11
12struct VertexOutput {
13    @builtin(position) position: vec4<f32>,
14    @location(0) color: vec4<f32>,
15    @location(1) uv: vec2<f32>,
16}
17
18@group(0) @binding(0) var<uniform> transform: Transform;
19@group(1) @binding(0) var image_texture: texture_2d<f32>;
20@group(1) @binding(1) var image_sampler: sampler;
21
22fn linear_from_srgb(srgb: vec3<f32>) -> vec3<f32> {
23    let cutoff = srgb < vec3<f32>(0.04045);
24    let lower = srgb / 12.92;
25    let higher = pow((srgb + 0.055) / 1.055, vec3<f32>(2.4));
26    return select(higher, lower, cutoff);
27}
28
29@vertex
30fn vs_main(in: VertexInput) -> VertexOutput {
31    let position = in.position * transform.scale + transform.translation;
32    let color = vec4<f32>(linear_from_srgb(in.color.rgb), in.color.a);
33    return VertexOutput(vec4<f32>(position, 0.0, 1.0), color, in.uv);
34}
35
36@fragment
37fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
38    let texture_color = textureSample(image_texture, image_sampler, in.uv);
39    // This assumes that texture images are not premultiplied.
40    let color = in.color * vec4<f32>(texture_color.rgb * texture_color.a, texture_color.a);
41
42    return color;
43}