1#define_import_path bevy_pbr::morph
2
3#ifdef MORPH_TARGETS
4
5#import bevy_pbr::mesh_types::{MorphAttributes, MorphDescriptor, MorphWeights}
6#import bevy_pbr::mesh_bindings::mesh
7
8#ifdef SKINS_USE_UNIFORM_BUFFERS
9
10@group(2) @binding(2) var<uniform> morph_weights: MorphWeights;
11@group(2) @binding(3) var morph_targets: texture_3d<f32>;
12@group(2) @binding(7) var<uniform> prev_morph_weights: MorphWeights;
13
14#else   // SKINS_USE_UNIFORM_BUFFERS
15
16@group(2) @binding(2) var<storage> morph_weights: array<f32>;
17@group(2) @binding(3) var<storage> morph_targets: array<MorphAttributes>;
18@group(2) @binding(7) var<storage> prev_morph_weights: array<f32>;
19@group(2) @binding(8) var<storage> morph_descriptors: array<MorphDescriptor>;
20
21#endif  // SKINS_USE_UNIFORM_BUFFERS
22
23// NOTE: Those are the "hardcoded" values found in `MorphAttributes` struct
24// in crates/bevy_render/src/mesh/morph/visitors.rs
25// In an ideal world, the offsets are established dynamically and passed as #defines
26// to the shader, but it's out of scope for the initial implementation of morph targets.
27const position_offset: u32 = 0u;
28const normal_offset: u32 = 3u;
29const tangent_offset: u32 = 6u;
30const total_component_count: u32 = 9u;
31
32fn layer_count(instance_index: u32) -> u32 {
33#ifdef SKINS_USE_UNIFORM_BUFFERS
34    let dimensions = textureDimensions(morph_targets);
35    return u32(dimensions.z);
36#else   // SKINS_USE_UNIFORM_BUFFERS
37    let morph_descriptor_index = mesh[instance_index].morph_descriptor_index;
38    return morph_descriptors[morph_descriptor_index].weight_count;
39#endif  // SKINS_USE_UNIFORM_BUFFERS
40}
41
42#ifdef SKINS_USE_UNIFORM_BUFFERS
43fn component_texture_coord(vertex_index: u32, component_offset: u32) -> vec2<u32> {
44    let width = u32(textureDimensions(morph_targets).x);
45    let component_index = total_component_count * vertex_index + component_offset;
46    return vec2<u32>(component_index % width, component_index / width);
47}
48#endif  // SKINS_USE_UNIFORM_BUFFERS
49
50fn weight_at(weight_index: u32, instance_index: u32) -> f32 {
51#ifdef SKINS_USE_UNIFORM_BUFFERS
52    let i = weight_index;
53    return morph_weights.weights[i / 4u][i % 4u];
54#else   // SKINS_USE_UNIFORM_BUFFERS
55    let morph_descriptor_index = mesh[instance_index].morph_descriptor_index;
56    let weights_offset = morph_descriptors[morph_descriptor_index].current_weights_offset;
57    return morph_weights[weights_offset + weight_index];
58#endif  // SKINS_USE_UNIFORM_BUFFERS
59}
60
61fn prev_weight_at(weight_index: u32, instance_index: u32) -> f32 {
62#ifdef SKINS_USE_UNIFORM_BUFFERS
63    let i = weight_index;
64    return prev_morph_weights.weights[i / 4u][i % 4u];
65#else   // SKINS_USE_UNIFORM_BUFFERS
66    let morph_descriptor_index = mesh[instance_index].morph_descriptor_index;
67    let weights_offset = morph_descriptors[morph_descriptor_index].prev_weights_offset;
68    return prev_morph_weights[weights_offset + weight_index];
69#endif  // SKINS_USE_UNIFORM_BUFFERS
70}
71
72#ifdef SKINS_USE_UNIFORM_BUFFERS
73
74fn morph_pixel(vertex: u32, component: u32, weight: u32) -> f32 {
75    let coord = component_texture_coord(vertex, component);
76    // Due to https://gpuweb.github.io/gpuweb/wgsl/#texel-formats
77    // While the texture stores a f32, the textureLoad returns a vec4<>, where
78    // only the first component is set.
79    return textureLoad(morph_targets, vec3(coord, weight), 0).r;
80}
81
82fn morph(vertex_index: u32, component_offset: u32, weight_index: u32) -> vec3<f32> {
83    return vec3<f32>(
84        morph_pixel(vertex_index, component_offset, weight_index),
85        morph_pixel(vertex_index, component_offset + 1u, weight_index),
86        morph_pixel(vertex_index, component_offset + 2u, weight_index),
87    );
88}
89
90fn morph_position(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
91    return morph(vertex_index, position_offset, weight_index);
92}
93
94fn morph_normal(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
95    return morph(vertex_index, normal_offset, weight_index);
96}
97
98fn morph_tangent(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
99    return morph(vertex_index, tangent_offset, weight_index);
100}
101
102#else   // SKINS_USE_UNIFORM_BUFFERS
103
104fn get_morph_target(vertex_index: u32, weight_index: u32, instance_index: u32) -> MorphAttributes {
105    let morph_descriptor_index = mesh[instance_index].morph_descriptor_index;
106    let targets_offset = morph_descriptors[morph_descriptor_index].targets_offset;
107    let vertex_count = morph_descriptors[morph_descriptor_index].vertex_count;
108    return morph_targets[targets_offset + weight_index * vertex_count + vertex_index];
109}
110
111fn morph_position(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
112    return get_morph_target(vertex_index, weight_index, instance_index).position;
113}
114
115fn morph_normal(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
116    return get_morph_target(vertex_index, weight_index, instance_index).normal;
117}
118
119fn morph_tangent(vertex_index: u32, weight_index: u32, instance_index: u32) -> vec3<f32> {
120    return get_morph_target(vertex_index, weight_index, instance_index).tangent;
121}
122
123#endif  // SKINS_USE_UNIFORM_BUFFERS
124
125#endif // MORPH_TARGETS