egui/crates/egui-wgpu/src/egui.wgsl
2022-08-20 10:41:49 +02:00

80 lines
2.2 KiB
WebGPU Shading Language

// Vertex shader bindings
struct VertexOutput {
@location(0) tex_coord: vec2<f32>,
@location(1) color: vec4<f32>,
@builtin(position) position: vec4<f32>,
};
struct Locals {
screen_size: vec2<f32>,
// Uniform buffers need to be at least 16 bytes in WebGL.
// See https://github.com/gfx-rs/wgpu/issues/2072
_padding: vec2<u32>,
};
@group(0) @binding(0) var<uniform> r_locals: Locals;
// 0-1 from 0-255
fn linear_from_srgb(srgb: vec3<f32>) -> vec3<f32> {
let cutoff = srgb < vec3<f32>(10.31475);
let lower = srgb / vec3<f32>(3294.6);
let higher = pow((srgb + vec3<f32>(14.025)) / vec3<f32>(269.025), vec3<f32>(2.4));
return select(higher, lower, cutoff);
}
// [u8; 4] SRGB as u32 -> [r, g, b, a]
fn unpack_color(color: u32) -> vec4<f32> {
return vec4<f32>(
f32(color & 255u),
f32((color >> 8u) & 255u),
f32((color >> 16u) & 255u),
f32((color >> 24u) & 255u),
);
}
fn position_from_screen(screen_pos: vec2<f32>) -> vec4<f32> {
return vec4<f32>(
2.0 * screen_pos.x / r_locals.screen_size.x - 1.0,
1.0 - 2.0 * screen_pos.y / r_locals.screen_size.y,
0.0,
1.0,
);
}
@vertex
fn vs_main(
@location(0) a_pos: vec2<f32>,
@location(1) a_tex_coord: vec2<f32>,
@location(2) a_color: u32,
) -> VertexOutput {
var out: VertexOutput;
out.tex_coord = a_tex_coord;
let color = unpack_color(a_color);
out.color = vec4<f32>(linear_from_srgb(color.rgb), color.a / 255.0);
out.position = position_from_screen(a_pos);
return out;
}
@vertex
fn vs_conv_main(
@location(0) a_pos: vec2<f32>,
@location(1) a_tex_coord: vec2<f32>,
@location(2) a_color: u32,
) -> VertexOutput {
var out: VertexOutput;
out.tex_coord = a_tex_coord;
let color = unpack_color(a_color);
out.color = vec4<f32>(color.rgba / 255.0);
out.position = position_from_screen(a_pos);
return out;
}
// Fragment shader bindings
@group(1) @binding(0) var r_tex_color: texture_2d<f32>;
@group(1) @binding(1) var r_tex_sampler: sampler;
@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
return in.color * textureSample(r_tex_color, r_tex_sampler, in.tex_coord);
}