1import package::{
2    prepass::{
3        bindings as prepass_bindings,
4        io::{Vertex, UncompressedVertex, VertexOutput, FragmentOutput, decompress_vertex},
5    },
6    render::{
7        mesh_bindings::mesh,
8        mesh_functions,
9        skinning,
10        morph,
11        morph::{morph_position, morph_normal, morph_tangent},
12        mesh_view_bindings::view,
13        view_transformations::position_world_to_clip,
14    },
15};
16
17@if(DEFERRED_PREPASS)
18import package::render::rgb9e5;
19
20@if(MORPH_TARGETS)
21// The instance_index parameter must match vertex_in.instance_index. This is a work around for a wgpu dx12 bug.
22// See https://github.com/gfx-rs/naga/issues/2416
23fn morph_vertex(vertex_in: UncompressedVertex, instance_index: u32) -> UncompressedVertex  {
24    var vertex = vertex_in;
25    let first_vertex = mesh[instance_index].first_vertex_index;
26    let vertex_index = vertex.index - first_vertex;
27    let morph_descriptor_index  = mesh[instance_index].morph_descriptor_index;
28
29    let weight_count = morph::layer_count(morph_descriptor_index);
30    for (var i: u32 = 0u; i < weight_count; i ++) {
31        let weight = morph::weight_at(i, morph_descriptor_index);
32        if weight == 0.0 {
33            continue;
34        }
35        vertex.position += weight * morph_position(vertex_index, i, morph_descriptor_index);
36@if(VERTEX_NORMALS)
37        vertex.normal += weight * morph_normal(vertex_index, i, morph_descriptor_index);
38@if(VERTEX_TANGENTS)
39        vertex.tangent += vec4(weight * morph_tangent(vertex_index, i, morph_descriptor_index), 0.0);
40    }
41    return vertex;
42}
43
44@if(MORPH_TARGETS)
45/// Returns the morphed position of the given vertex from the previous frame.
46///
47/// This function is used for motion vector calculation, and, as such, it doesn't
48/// bother morphing the normals and tangents.
49///
50/// The instance_index parameter must match vertex_in.instance_index. This is a work around for a wgpu dx12 bug.
51/// See https://github.com/gfx-rs/naga/issues/2416
52fn morph_prev_vertex(vertex_in: UncompressedVertex, instance_index: u32) -> UncompressedVertex {
53    var vertex = vertex_in;
54    let first_vertex = mesh[instance_index].first_vertex_index;
55    let vertex_index = vertex.index - first_vertex;
56    let morph_descriptor_index  = mesh[instance_index].morph_descriptor_index;
57    let weight_count = morph::layer_count(morph_descriptor_index);
58    for (var i: u32 = 0u; i < weight_count; i ++) {
59        let weight = morph::prev_weight_at(i, morph_descriptor_index);
60        if weight == 0.0 {
61            continue;
62        }
63        vertex.position += weight * morph_position(vertex_index, i, morph_descriptor_index);
64        // Don't bother morphing normals and tangents; we don't need them for
65        // motion vector calculation.
66    }
67    return vertex;
68}
69
70@vertex
71fn vertex(vertex_no_morph: Vertex) -> VertexOutput {
72    var out: VertexOutput;
73    let uncompressed_vertex_no_morph = decompress_vertex(vertex_no_morph, vertex_no_morph.instance_index);
74@if(MORPH_TARGETS)
75    var vertex = morph_vertex(uncompressed_vertex_no_morph, vertex_no_morph.instance_index);
76@else
77    var vertex = uncompressed_vertex_no_morph;
78
79    let mesh_world_from_local = mesh_functions::get_world_from_local(vertex_no_morph.instance_index);
80
81@if(SKINNED)
82    // Use vertex_no_morph.instance_index instead of vertex.instance_index to work around a wgpu dx12 bug.
83    // See https://github.com/gfx-rs/naga/issues/2416
84    var world_from_local = skinning::skin_model(
85        vertex.joint_indices,
86        vertex.joint_weights,
87        vertex_no_morph.instance_index
88    );
89@else // SKINNED
90    var world_from_local = mesh_world_from_local;
91
92    out.world_position = mesh_functions::mesh_position_local_to_world(world_from_local, vec4<f32>(vertex.position, 1.0));
93    out.position = position_world_to_clip(out.world_position.xyz);
94@if(UNCLIPPED_DEPTH_ORTHO_EMULATION) {
95    out.unclipped_depth = out.position.z;
96    out.position.z = min(out.position.z, 1.0); // Clamp depth to avoid clipping
97}
98
99@if(VERTEX_UVS_A)
100    out.uv = vertex.uv;
101
102@if(VERTEX_UVS_B)
103    out.uv_b = vertex.uv_b;
104
105@if(NORMAL_PREPASS_OR_DEFERRED_PREPASS) {
106@if(VERTEX_NORMALS && SKINNED)
107    out.world_normal = skinning::skin_normals(world_from_local, vertex.normal);
108@elif(VERTEX_NORMALS)
109    out.world_normal = mesh_functions::mesh_normal_local_to_world(
110        vertex.normal,
111        // Use vertex_no_morph.instance_index instead of vertex.instance_index to work around a wgpu dx12 bug.
112        // See https://github.com/gfx-rs/naga/issues/2416
113        vertex_no_morph.instance_index
114    );
115
116@if(VERTEX_TANGENTS)
117    out.world_tangent = mesh_functions::mesh_tangent_local_to_world(
118        world_from_local,
119        vertex.tangent,
120        // Use vertex_no_morph.instance_index instead of vertex.instance_index to work around a wgpu dx12 bug.
121        // See https://github.com/gfx-rs/naga/issues/2416
122        vertex_no_morph.instance_index
123    );
124}
125
126@if(VERTEX_COLORS)
127    out.color = vertex.color;
128
129    // Compute the motion vector for TAA among other purposes. For this we need
130    // to know where the vertex was last frame.
131@if(MOTION_VECTOR_PREPASS) {
132
133    // Take morph targets into account.
134@if(MORPH_TARGETS && HAS_PREVIOUS_MORPH)
135    let prev_vertex = morph_prev_vertex(uncompressed_vertex_no_morph, vertex_no_morph.instance_index);
136@elif(MORPH_TARGETS)
137    let prev_vertex = uncompressed_vertex_no_morph;
138@else   // MORPH_TARGETS
139    let prev_vertex = uncompressed_vertex_no_morph;
140
141    // Take skinning into account.
142@if(SKINNED && HAS_PREVIOUS_SKIN)
143    let prev_model = skinning::skin_prev_model(
144        prev_vertex.joint_indices,
145        prev_vertex.joint_weights,
146        vertex_no_morph.instance_index
147    );
148@elif(SKINNED)
149    // Use vertex_no_morph.instance_index instead of prev_vertex.instance_index to work around a wgpu dx12 bug.
150    // See https://github.com/gfx-rs/naga/issues/2416
151    let prev_model = mesh_functions::get_previous_world_from_local(vertex_no_morph.instance_index);
152@else   // SKINNED
153    // Use vertex_no_morph.instance_index instead of prev_vertex.instance_index to work around a wgpu dx12 bug.
154    // See https://github.com/gfx-rs/naga/issues/2416
155    let prev_model = mesh_functions::get_previous_world_from_local(vertex_no_morph.instance_index);
156
157    out.previous_world_position = mesh_functions::mesh_position_local_to_world(
158        prev_model,
159        vec4<f32>(prev_vertex.position, 1.0)
160    );
161}
162
163@if(VERTEX_OUTPUT_INSTANCE_INDEX)
164    // Use vertex_no_morph.instance_index instead of vertex.instance_index to work around a wgpu dx12 bug.
165    // See https://github.com/gfx-rs/naga/issues/2416
166    out.instance_index = vertex_no_morph.instance_index;
167
168@if(VISIBILITY_RANGE_DITHER)
169    out.visibility_range_dither = mesh_functions::get_visibility_range_dither_level(
170        vertex_no_morph.instance_index, mesh_world_from_local[3]);
171
172    return out;
173}
174
175@if(PREPASS_FRAGMENT)
176@fragment
177fn fragment(in: VertexOutput) -> FragmentOutput {
178    var out: FragmentOutput;
179
180@if(NORMAL_PREPASS)
181    out.normal = vec4(in.world_normal * 0.5 + vec3(0.5), 1.0);
182
183@if(UNCLIPPED_DEPTH_ORTHO_EMULATION)
184    out.frag_depth = in.unclipped_depth;
185
186@if(MOTION_VECTOR_PREPASS) {
187    let clip_position_t = view.unjittered_clip_from_world * in.world_position;
188    let clip_position = clip_position_t.xy / clip_position_t.w;
189    let previous_clip_position_t = prepass_bindings::previous_view_uniforms.unjittered_clip_from_world * in.previous_world_position;
190    let previous_clip_position = previous_clip_position_t.xy / previous_clip_position_t.w;
191    // These motion vectors are used as offsets to UV positions and are stored
192    // in the range -1,1 to allow offsetting from the one corner to the
193    // diagonally-opposite corner in UV coordinates, in either direction.
194    // A difference between diagonally-opposite corners of clip space is in the
195    // range -2,2, so this needs to be scaled by 0.5. And the V direction goes
196    // down where clip space y goes up, so y needs to be flipped.
197    out.motion_vector = (clip_position - previous_clip_position) * vec2(0.5, -0.5);
198}
199
200@if(DEFERRED_PREPASS) {
201    // There isn't any material info available for this default prepass shader so we are just writing 
202    // emissive magenta out to the deferred gbuffer to be rendered by the first deferred lighting pass layer.
203    // This is here so if the default prepass fragment is used for deferred magenta will be rendered, and also
204    // as an example to show that a user could write to the deferred gbuffer if they were to start from this shader.
205    out.deferred = vec4(0u, package::render::rgb9e5::vec3_to_rgb9e5_(vec3(1.0, 0.0, 1.0)), 0u, 0u);
206    out.deferred_lighting_pass_id = 1u;
207}
208
209    return out;
210}