1import package::{
2    meshlet::visibility_buffer_resolve::resolve_vertex_output,
3    prepass::io as prepass_io,
4    render::{
5        view_transformations::uv_to_ndc,
6        pbr_prepass_functions,
7        utils::rand_f,
8    },
9};
10
11@vertex
12fn vertex(@builtin(vertex_index) vertex_input: u32) -> @builtin(position) vec4<f32> {
13    let vertex_index = vertex_input % 3u;
14    let material_id = vertex_input / 3u;
15    let material_depth = f32(material_id) / 65535.0;
16    let uv = vec2<f32>(vec2(vertex_index >> 1u, vertex_index & 1u)) * 2.0;
17    return vec4(uv_to_ndc(uv), material_depth, 1.0);
18}
19
20@fragment
21fn fragment(@builtin(position) frag_coord: vec4<f32>) -> @location(0) vec4<f32> {
22    let vertex_output = resolve_vertex_output(frag_coord);
23    var rng = vertex_output.cluster_id;
24    let color = vec3(rand_f(&rng), rand_f(&rng), rand_f(&rng));
25    return vec4(color, 1.0);
26}
27
28@if(PREPASS_FRAGMENT)
29@fragment
30fn prepass_fragment(@builtin(position) frag_coord: vec4<f32>) -> prepass_io::FragmentOutput {
31    let vertex_output = resolve_vertex_output(frag_coord);
32
33    var out: prepass_io::FragmentOutput;
34
35    @if(NORMAL_PREPASS)
36    out.normal = vec4(vertex_output.world_normal * 0.5 + vec3(0.5), 1.0);
37
38    @if(MOTION_VECTOR_PREPASS)
39    out.motion_vector = vertex_output.motion_vector;
40
41    @if(DEFERRED_PREPASS)
42    // There isn't any material info available for this default prepass shader so we are just writing 
43    // emissive magenta out to the deferred gbuffer to be rendered by the first deferred lighting pass layer.
44    // This is here so if the default prepass fragment is used for deferred magenta will be rendered, and also
45    // as an example to show that a user could write to the deferred gbuffer if they were to start from this shader.
46    out.deferred = vec4(0u, package::render::rgb9e5::vec3_to_rgb9e5_(vec3(1.0, 0.0, 1.0)), 0u, 0u);
47    @if(DEFERRED_PREPASS)
48    out.deferred_lighting_pass_id = 1u;
49
50    return out;
51}