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