1import package::{
2    render::{
3        pbr_types,
4        pbr_functions::alpha_discard,
5        pbr_fragment::pbr_input_from_standard_material,
6    },
7    decal::clustered::apply_decals,
8};
9
10@if(PREPASS_PIPELINE)
11import package::{
12    prepass::io::{VertexOutput, FragmentOutput},
13    deferred::functions::deferred_output,
14};
15@else
16import package::render::{
17    forward_io::{VertexOutput, FragmentOutput},
18    pbr_functions::{apply_pbr_lighting, main_pass_post_lighting_processing},
19    pbr_types::STANDARD_MATERIAL_FLAGS_UNLIT_BIT,
20};
21
22@if(VISIBILITY_RANGE_DITHER)
23import package::render::pbr_functions::visibility_range_dither;
24
25@if(MESHLET_MESH_MATERIAL_PASS)
26import package::meshlet::visibility_buffer_resolve::resolve_vertex_output;
27
28@if(MATERIAL_OIT_ENABLED)
29import bevy_core_pipeline::oit::draw::oit_draw;
30
31@if(FORWARD_DECAL)
32import package::decal::forward::get_forward_decal_info;
33
34@fragment
35fn fragment(
36@if(MESHLET_MESH_MATERIAL_PASS)
37    @builtin(position) frag_coord: vec4<f32>,
38@if(!MESHLET_MESH_MATERIAL_PASS)
39    vertex_output: VertexOutput,
40@if(!MESHLET_MESH_MATERIAL_PASS)
41    @builtin(front_facing) is_front: bool,
42) -> FragmentOutput {
43@if(MESHLET_MESH_MATERIAL_PASS)
44    let vertex_output = resolve_vertex_output(frag_coord);
45@if(MESHLET_MESH_MATERIAL_PASS)
46    let is_front = true;
47
48    var in = vertex_output;
49
50    // If we're in the crossfade section of a visibility range, conditionally
51    // discard the fragment according to the visibility pattern.
52@if(VISIBILITY_RANGE_DITHER)
53    visibility_range_dither(in.position, in.visibility_range_dither);
54
55@if(FORWARD_DECAL)
56    let forward_decal_info = get_forward_decal_info(in);
57@if(FORWARD_DECAL)
58    in.world_position = forward_decal_info.world_position;
59@if(FORWARD_DECAL)
60    in.uv = forward_decal_info.uv;
61
62    // generate a PbrInput struct from the StandardMaterial bindings
63    var pbr_input = pbr_input_from_standard_material(in, is_front);
64
65    // alpha discard
66    pbr_input.material.base_color = alpha_discard(
67        pbr_input.material.flags,
68        pbr_input.material.alpha_cutoff,
69        pbr_input.material.base_color
70    );
71
72    // clustered decals
73    apply_decals(&pbr_input);
74
75    // write the gbuffer, lighting pass id, and optionally normal and motion_vector textures
76@if(PREPASS_PIPELINE)
77    let out = deferred_output(in, pbr_input);
78    // in forward mode, we calculate the lit color immediately, and then apply some post-lighting effects here.
79    // in deferred mode the lit color and these effects will be calculated in the deferred lighting shader
80@if(!PREPASS_PIPELINE)
81    var out: FragmentOutput;
82@if(!PREPASS_PIPELINE)
83    if (pbr_input.material.flags & STANDARD_MATERIAL_FLAGS_UNLIT_BIT) == 0u {
84        out.color = apply_pbr_lighting(pbr_input);
85    } else {
86        out.color = pbr_input.material.base_color;
87    }
88
89    // apply in-shader post processing (fog, alpha-premultiply, and also tonemapping, debanding if the camera is non-hdr)
90    // note this does not include fullscreen postprocessing effects like bloom.
91@if(!PREPASS_PIPELINE)
92    out.color = main_pass_post_lighting_processing(pbr_input, out.color);
93
94@if(MATERIAL_OIT_ENABLED) {
95    let alpha_mode = pbr_input.material.flags & pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_RESERVED_BITS;
96    if alpha_mode == pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_BLEND {
97        // The fragments will only be drawn during the oit resolve pass.
98        oit_draw(in.position, vec4(out.color.rgb * out.color.a, out.color.a));
99        discard;
100    }
101    // Both `Premultiplied` and `Add` colors are premultiplied in `premultiply_alpha()`
102    if alpha_mode == pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_PREMULTIPLIED
103        || alpha_mode == pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_ADD {
104        // The fragments will only be drawn during the oit resolve pass.
105        oit_draw(in.position, out.color);
106        discard;
107    }
108}
109
110@if(FORWARD_DECAL)
111        out.color.a = min(forward_decal_info.alpha, out.color.a);
112
113        return out;
114}