1#import bevy_pbr::{
2    pbr_types,
3    pbr_functions::alpha_discard,
4    pbr_fragment::pbr_input_from_standard_material,
5}
6
7#ifdef PREPASS_PIPELINE
8#import bevy_pbr::{
9    prepass_io::{VertexOutput, FragmentOutput},
10    pbr_deferred_functions::deferred_output,
11}
12#else
13#import bevy_pbr::{
14    forward_io::{VertexOutput, FragmentOutput},
15    pbr_functions,
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 MESHLET_MESH_MATERIAL_PASS
22#import bevy_pbr::meshlet_visibility_buffer_resolve::resolve_vertex_output
23#endif
24
25#ifdef OIT_ENABLED
26#import bevy_core_pipeline::oit::oit_draw
27#endif // OIT_ENABLED
28
29@fragment
30fn fragment(
31#ifdef MESHLET_MESH_MATERIAL_PASS
32    @builtin(position) frag_coord: vec4<f32>,
33#else
34    in: VertexOutput,
35    @builtin(front_facing) is_front: bool,
36#endif
37) -> FragmentOutput {
38#ifdef MESHLET_MESH_MATERIAL_PASS
39    let in = resolve_vertex_output(frag_coord);
40    let is_front = true;
41#endif
42
43    // If we're in the crossfade section of a visibility range, conditionally
44    // discard the fragment according to the visibility pattern.
45#ifdef VISIBILITY_RANGE_DITHER
46    pbr_functions::visibility_range_dither(in.position, in.visibility_range_dither);
47#endif
48
49    // generate a PbrInput struct from the StandardMaterial bindings
50    var pbr_input = pbr_input_from_standard_material(in, is_front);
51
52    // alpha discard
53    pbr_input.material.base_color = alpha_discard(pbr_input.material, pbr_input.material.base_color);
54
55#ifdef PREPASS_PIPELINE
56    // write the gbuffer, lighting pass id, and optionally normal and motion_vector textures
57    let out = deferred_output(in, pbr_input);
58#else
59    // in forward mode, we calculate the lit color immediately, and then apply some post-lighting effects here.
60    // in deferred mode the lit color and these effects will be calculated in the deferred lighting shader
61    var out: FragmentOutput;
62    if (pbr_input.material.flags & STANDARD_MATERIAL_FLAGS_UNLIT_BIT) == 0u {
63        out.color = apply_pbr_lighting(pbr_input);
64    } else {
65        out.color = pbr_input.material.base_color;
66    }
67
68    // apply in-shader post processing (fog, alpha-premultiply, and also tonemapping, debanding if the camera is non-hdr)
69    // note this does not include fullscreen postprocessing effects like bloom.
70    out.color = main_pass_post_lighting_processing(pbr_input, out.color);
71#endif
72
73#ifdef OIT_ENABLED
74    let alpha_mode = pbr_input.material.flags & pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_RESERVED_BITS;
75    if alpha_mode != pbr_types::STANDARD_MATERIAL_FLAGS_ALPHA_MODE_OPAQUE {
76        // The fragments will only be drawn during the oit resolve pass.
77        oit_draw(in.position, out.color);
78        discard;
79    }
80#endif // OIT_ENABLED
81
82    return out;
83}