2025 WebGPU sandbox

Small test of what this API can do. Shaders using WGSL are really powerfull.

@group(0) @binding(0) var<uniform> grid: vec2f;

struct VertexInput {
    @location(0) pos: vec2f,
    @builtin(instance_index) instance: u32,
};

struct VertexOutput {
    @builtin(position) pos: vec4f,
    @location(0) cell: vec2f,
};

@vertex
fn vertexMain(input: VertexInput) -> VertexOutput {
    let i = f32(input.instance);
    let cell = vec2f(i % grid.x, floor(i / grid.x));

    let cellOffset = cell / grid * 2;
    let gridPos = (input.pos + 1) / grid - 1 + cellOffset;

    var output: VertexOutput;
    output.pos = vec4f(gridPos, 0, 1);
    output.cell = cell;
    return output;
}

struct FragInput {
    @location(0) cell: vec2f,
};

@fragment
fn fragmentMain(input: FragInput) -> @location(0) vec4f {
    let c = input.cell / grid;
    return vec4f(c, 1-c.x, 1);
}