glyphon/src/shader.wgsl

130 lines
3.5 KiB
WebGPU Shading Language

struct VertexInput {
@builtin(vertex_index) vertex_idx: u32,
@location(0) pos: vec2<i32>,
@location(1) dim: u32,
@location(2) uv: u32,
@location(3) color: u32,
@location(4) content_type_with_srgb: u32,
@location(5) depth: f32,
}
struct VertexOutput {
@invariant @builtin(position) position: vec4<f32>,
@location(0) color: vec4<f32>,
@location(1) uv: vec2<f32>,
@location(2) @interpolate(flat) content_type: u32,
};
struct Params {
screen_resolution: vec2<u32>,
_pad: vec2<u32>,
};
@group(0) @binding(0)
var color_atlas_texture: texture_2d<f32>;
@group(0) @binding(1)
var mask_atlas_texture: texture_2d<f32>;
@group(0) @binding(2)
var atlas_sampler: sampler;
@group(1) @binding(0)
var<uniform> params: Params;
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;
let width = in_vert.dim & 0xffffu;
let height = (in_vert.dim & 0xffff0000u) >> 16u;
let color = in_vert.color;
var uv = vec2<u32>(in_vert.uv & 0xffffu, (in_vert.uv & 0xffff0000u) >> 16u);
let v = in_vert.vertex_idx;
let corner_position = vec2<u32>(
in_vert.vertex_idx & 1u,
(in_vert.vertex_idx >> 1u) & 1u,
);
let corner_offset = vec2<u32>(width, height) * corner_position;
uv = uv + corner_offset;
pos = pos + vec2<i32>(corner_offset);
var vert_output: VertexOutput;
vert_output.position = vec4<f32>(
2.0 * vec2<f32>(pos) / vec2<f32>(params.screen_resolution) - 1.0,
in_vert.depth,
1.0,
);
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) / 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 content_type {
case 0u: {
dim = textureDimensions(color_atlas_texture);
break;
}
case 1u: {
dim = textureDimensions(mask_atlas_texture);
break;
}
default: {}
}
vert_output.content_type = content_type;
vert_output.uv = vec2<f32>(uv) / vec2<f32>(dim);
return vert_output;
}
@fragment
fn fs_main(in_frag: VertexOutput) -> @location(0) vec4<f32> {
switch in_frag.content_type {
case 0u: {
var sample = textureSampleLevel(color_atlas_texture, atlas_sampler, in_frag.uv, 0.0);
sample[3] = sample[3] * in_frag.color.a;
return sample;
}
case 1u: {
return vec4<f32>(in_frag.color.rgb, in_frag.color.a * textureSampleLevel(mask_atlas_texture, atlas_sampler, in_frag.uv, 0.0).x);
}
default: {
return vec4<f32>(0.0);
}
}
}