1#import bevy_pbr::mesh_view_bindings::{view, globals}
2#import bevy_pbr::mesh_bindings::mesh
3#import bevy_pbr::mesh_functions::{get_world_from_local, get_visibility_range_dither_level}
4#import bevy_pbr::view_transformations::position_world_to_clip
5#import bevy_pbr::forward_io::Vertex
6
7
8#import bevy_feronia::forward_sss_io::VertexOutput
9#import bevy_feronia::wind::Wind
10#import bevy_feronia::types::{SampledNoise, DisplacedVertex, InstanceInfo}
11#import bevy_feronia::displace::{displace_vertex_and_calc_normal}
12#import bevy_feronia::noise::sample_noise
13
14#ifdef BINDLESS
15    #import bevy_feronia::bindings::{wind_indices, wind_material}
16#else
17    #import bevy_feronia::bindings::{wind, noise_texture, noise_texture_sampler}
18#endif
19
20
21@vertex
22fn vertex(vertex: Vertex) -> VertexOutput {
23    var out: VertexOutput;
24
25#ifdef BINDLESS
26    let slot = mesh[vertex.instance_index].material_and_lightmap_bind_group_slot & 0xffffu;
27    let wind =  wind_material[wind_indices[slot].material];
28#endif
29
30    let world_from_local = get_world_from_local(vertex.instance_index);
31
32    // --- INSTANCE ---
33    var instance: InstanceInfo;
34    let camera_world_pos = view.world_position.xyz;
35    instance.world_from_local = world_from_local;
36    instance.instance_position = instance.world_from_local[3];
37    instance.wrapped_time = globals.time;
38    instance.instance_index = vertex.instance_index;
39
40    let noise = sample_noise(instance, vertex.position);
41
42    // --- DISPLACEMENT ---
43    let displaced = displace_vertex_and_calc_normal(
44        wind,
45        noise,
46        vertex.position,
47        instance,
48#ifdef VERTEX_NORMALS
49        vertex.normal,
50#endif
51#ifdef VERTEX_TANGENTS
52        vertex.tangent,
53#endif
54#ifdef VERTEX_UVS_A
55        vertex.uv
56#endif
57    );
58
59#ifdef VERTEX_POSITIONS
60    out.position = position_world_to_clip(displaced.world_position.xyz);
61    out.world_position = displaced.world_position;
62#endif
63
64#ifdef VERTEX_NORMALS
65    out.world_normal = displaced.world_normal;
66#endif
67
68#ifdef VERTEX_UVS_A
69    out.uv = vertex.uv;
70#endif
71#ifdef VERTEX_UVS_B
72    out.uv_b = vertex.uv_b;
73#endif
74
75#ifdef VERTEX_TANGENTS
76    out.world_tangent = displaced.world_tangent;
77#endif
78
79#ifdef VERTEX_OUTPUT_INSTANCE_INDEX
80    out.instance_index = vertex.instance_index;
81#endif
82
83#ifdef VISIBILITY_RANGE_DITHER
84    out.visibility_range_dither = get_visibility_range_dither_level(
85        vertex.instance_index, world_from_local[3]);
86#endif
87
88#ifdef SUBSURFACE_SCATTERING
89    let local_pos = vertex.position;
90
91    let height = wind.aabb_max.y - wind.aabb_min.y;
92
93    let inverse_height = 1.0 / max(height, 0.00001);
94
95    // TODO support thickness texture instead of `thinness_factor`
96    out.thinness_factor = saturate((local_pos.y - wind.aabb_min.y) * inverse_height);
97 #endif
98
99    return out;
100}
101