struct ChunkData {
    origin: vec2<i32>,
};

var<immediate> chunk: ChunkData;

struct Camera {
    scale: vec2f,
    centre: vec2f,
};

@group(0) @binding(0) var<uniform> camera: Camera;
@group(1) @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;
    // (0,0),(1,0),(0,1),(1,1)
    let corner = vec2f(f32(i & 1u), f32(i >> 1u));

    // CHUNK_SIZE
    let world = (vec2f(chunk.origin) + corner) * 32.0;
    let ndc = (world - camera.centre) * camera.scale;

    out.clip_position = vec4f(ndc, 0.0, 1.0);
    out.uv = corner;

    return out;
}

@fragment
fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
    // CHUNK_SIZE
    let dims = vec2f(32.0, 32.0);
    return textureLoad(tex, vec2i(in.uv * dims), 0);
    // return vec4f(0.0, 1.0, 0.0, 1.0);
}