@group(0) @binding(0) var tex: texture_2d<f32>;

struct VertexOutput {
    @builtin(position) clip_position: vec4<f32>,
    @location(0) uv: vec2<f32>,
};

@vertex
fn vs_main(
    @builtin(vertex_index) i: u32,
) -> VertexOutput {
    var out: VertexOutput;
    let uv = vec2f(f32((i << 1u) & 2u), f32(i & 2u));
    out.clip_position = vec4f(uv.x * 2.0 - 1.0, 1.0 - uv.y * 2.0, 0.0, 1.0);
    out.uv = uv;

    return out;
}

@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    let dims = vec2f(textureDimensions(tex));
    return textureLoad(tex, vec2i(in.uv * dims), 0);
    // return vec4f(0.0, 1.0, 0.0, 1.0);
}