// Full-screen quad vertex shader.
struct VertexOutput {
@builtin(position) position: vec4<f32>,
@location(0) uv: vec2<f32>,
}
@vertex
fn vs_main(@builtin(vertex_index) vertex_idx: u32) -> VertexOutput {
var positions = array<vec2<f32>, 6>(
vec2<f32>(-1.0, 1.0), vec2<f32>( 1.0, 1.0), vec2<f32>(-1.0, -1.0),
vec2<f32>(-1.0, -1.0), vec2<f32>( 1.0, 1.0), vec2<f32>( 1.0, -1.0),
);
var uvs = array<vec2<f32>, 6>(
vec2<f32>(0.0, 0.0), vec2<f32>(1.0, 0.0), vec2<f32>(0.0, 1.0),
vec2<f32>(0.0, 1.0), vec2<f32>(1.0, 0.0), vec2<f32>(1.0, 1.0),
);
var out: VertexOutput;
out.position = vec4<f32>(positions[vertex_idx], 0.0, 1.0);
out.uv = uvs[vertex_idx];
return out;
}
// ── Fragment ──────────────────────────────────────────────────────────────────
@group(0) @binding(0) var tex_from: texture_2d<f32>;
@group(0) @binding(1) var tex_to: texture_2d<f32>;
@group(0) @binding(2) var tex_sampler: sampler;
@group(0) @binding(3) var<uniform> u: CrossfadeUniforms;
struct CrossfadeUniforms {
factor: f32,
_pad0: f32,
_pad1: f32,
_pad2: f32,
}
@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
let from_color = textureSample(tex_from, tex_sampler, in.uv);
let to_color = textureSample(tex_to, tex_sampler, in.uv);
return mix(from_color, to_color, u.factor);
}