1import package::mesh2d::{
2    functions as mesh_functions,
3    view_bindings::view,
4    vertex_output::VertexOutput,
5};
6
7@group(constants::MATERIAL_BIND_GROUP) @binding(0) var tileset: texture_2d_array<f32>;
8@group(constants::MATERIAL_BIND_GROUP) @binding(1) var tileset_sampler: sampler;
9@group(constants::MATERIAL_BIND_GROUP) @binding(2) var tile_data: texture_2d<u32>;
10
11struct TileData {
12    tileset_index: u32,
13    color: vec4<f32>,
14    visible: bool,
15    mirror_h: bool,
16    mirror_v: bool,
17    mirror_d: bool,
18}
19
20fn get_tile_data(coord: vec2<u32>) -> TileData {
21    let data = textureLoad(tile_data, coord, 0);
22
23    let tileset_index = data.r;
24
25    let color_r = f32(data.g & 0xFFu) / 255.0;
26    let color_g = f32((data.g >> 8u) & 0xFFu) / 255.0;
27    let color_b = f32(data.b & 0xFFu) / 255.0;
28    let color_a = f32((data.b >> 8u) & 0xFFu) / 255.0;
29
30    let color = vec4<f32>(color_r, color_g, color_b, color_a);
31
32    let mirror_h = (data.a & 0x8u) != 0u;
33    let mirror_v = (data.a & 0x4u) != 0u;
34    let mirror_d = (data.a & 0x2u) != 0u;
35    let visible = (data.a & 0x1u) != 0u;
36
37    return TileData(tileset_index, color, visible, mirror_h, mirror_v, mirror_d);
38}
39
40@fragment
41fn fragment(in: VertexOutput) -> @location(0) vec4<f32> {
42    let chunk_size = textureDimensions(tile_data, 0);
43    let tile_uv = in.uv * vec2<f32>(chunk_size);
44    var tile_coord = clamp(vec2<u32>(floor(tile_uv)), vec2<u32>(0), chunk_size - 1);
45    var local_uv = tile_uv - vec2<f32>(tile_coord);
46
47    tile_coord.y = chunk_size.y - 1 - tile_coord.y;
48
49    let tile = get_tile_data(tile_coord);
50
51    if (tile.tileset_index == 0xffffu || !tile.visible) {
52        discard;
53    }
54
55    if (tile.mirror_h) {
56        local_uv.x = 1 - local_uv.x;
57    }
58
59    if (tile.mirror_v) {
60        local_uv.y = 1 - local_uv.y;
61    }
62
63    if (tile.mirror_d) {
64        local_uv = local_uv.yx;
65    }
66
67    let tex_color = textureSample(tileset, tileset_sampler, local_uv, tile.tileset_index);
68    let final_color = tex_color * tile.color;
69
70    if (final_color.a < 0.001) {
71        discard;
72    }
73
74    return final_color;
75}