forestiles/assets/render/pbr_prepass.wgsl
2025-07-20 12:00:43 +02:00

152 lines
4.6 KiB
WebGPU Shading Language

#import bevy_pbr::{
pbr_prepass_functions,
pbr_bindings,
pbr_bindings::material,
pbr_types,
pbr_functions,
pbr_functions::SampleBias,
prepass_io,
mesh_bindings::mesh,
mesh_view_bindings::view,
}
#import bevy_render::bindless::{bindless_samplers_filtering, bindless_textures_2d}
#ifdef MESHLET_MESH_MATERIAL_PASS
#import bevy_pbr::meshlet_visibility_buffer_resolve::resolve_vertex_output
#endif
#ifdef BINDLESS
#import bevy_pbr::pbr_bindings::material_indices
#endif // BINDLESS
#ifdef PREPASS_FRAGMENT
@fragment
fn fragment(
#ifdef MESHLET_MESH_MATERIAL_PASS
@builtin(position) frag_coord: vec4<f32>,
#else
in: prepass_io::VertexOutput,
@builtin(front_facing) is_front: bool,
#endif
) -> prepass_io::FragmentOutput {
#ifdef MESHLET_MESH_MATERIAL_PASS
let in = resolve_vertex_output(frag_coord);
let is_front = true;
#else // MESHLET_MESH_MATERIAL_PASS
#ifdef BINDLESS
let slot = mesh[in.instance_index].material_and_lightmap_bind_group_slot & 0xffffu;
let flags = pbr_bindings::material_array[material_indices[slot].material].flags;
let uv_transform = pbr_bindings::material_array[material_indices[slot].material].uv_transform;
#else // BINDLESS
let flags = pbr_bindings::material.flags;
let uv_transform = pbr_bindings::material.uv_transform;
#endif // BINDLESS
// If we're in the crossfade section of a visibility range, conditionally
// discard the fragment according to the visibility pattern.
#ifdef VISIBILITY_RANGE_DITHER
pbr_functions::visibility_range_dither(in.position, in.visibility_range_dither);
#endif // VISIBILITY_RANGE_DITHER
pbr_prepass_functions::prepass_alpha_discard(in);
#endif // MESHLET_MESH_MATERIAL_PASS
var out: prepass_io::FragmentOutput;
#ifdef UNCLIPPED_DEPTH_ORTHO_EMULATION
out.frag_depth = in.unclipped_depth;
#endif // UNCLIPPED_DEPTH_ORTHO_EMULATION
#ifdef NORMAL_PREPASS
// NOTE: Unlit bit not set means == 0 is true, so the true case is if lit
if (flags & pbr_types::STANDARD_MATERIAL_FLAGS_UNLIT_BIT) == 0u {
let double_sided = (flags & pbr_types::STANDARD_MATERIAL_FLAGS_DOUBLE_SIDED_BIT) != 0u;
let world_normal = pbr_functions::prepare_world_normal(
in.world_normal,
double_sided,
is_front,
);
var normal = world_normal;
#ifdef VERTEX_UVS
#ifdef VERTEX_TANGENTS
#ifdef STANDARD_MATERIAL_NORMAL_MAP
// TODO: Transforming UVs mean we need to apply derivative chain rule for meshlet mesh material pass
#ifdef STANDARD_MATERIAL_NORMAL_MAP_UV_B
let uv = (uv_transform * vec3(in.uv_b, 1.0)).xy;
#else
let uv = (uv_transform * vec3(in.uv, 1.0)).xy;
#endif
// Fill in the sample bias so we can sample from textures.
var bias: SampleBias;
#ifdef MESHLET_MESH_MATERIAL_PASS
bias.ddx_uv = in.ddx_uv;
bias.ddy_uv = in.ddy_uv;
#else // MESHLET_MESH_MATERIAL_PASS
bias.mip_bias = view.mip_bias;
#endif // MESHLET_MESH_MATERIAL_PASS
let Nt =
#ifdef MESHLET_MESH_MATERIAL_PASS
textureSampleGrad(
#else // MESHLET_MESH_MATERIAL_PASS
textureSampleBias(
#endif // MESHLET_MESH_MATERIAL_PASS
#ifdef BINDLESS
bindless_textures_2d[material_indices[slot].normal_map_texture],
bindless_samplers_filtering[material_indices[slot].normal_map_sampler],
#else // BINDLESS
pbr_bindings::normal_map_texture,
pbr_bindings::normal_map_sampler,
#endif // BINDLESS
uv,
#ifdef MESHLET_MESH_MATERIAL_PASS
bias.ddx_uv,
bias.ddy_uv,
#else // MESHLET_MESH_MATERIAL_PASS
bias.mip_bias,
#endif // MESHLET_MESH_MATERIAL_PASS
).rgb;
let TBN = pbr_functions::calculate_tbn_mikktspace(normal, in.world_tangent);
normal = pbr_functions::apply_normal_mapping(
flags,
TBN,
double_sided,
is_front,
Nt,
);
#endif // STANDARD_MATERIAL_NORMAL_MAP
#endif // VERTEX_TANGENTS
#endif // VERTEX_UVS
out.normal = vec4(normal * 0.5 + vec3(0.5), 1.0);
} else {
out.normal = vec4(in.world_normal * 0.5 + vec3(0.5), 1.0);
}
#endif // NORMAL_PREPASS
#ifdef MOTION_VECTOR_PREPASS
#ifdef MESHLET_MESH_MATERIAL_PASS
out.motion_vector = in.motion_vector;
#else
out.motion_vector = pbr_prepass_functions::calculate_motion_vector(in.world_position, in.previous_world_position);
#endif
#endif
return out;
}
#else
@fragment
fn fragment(in: prepass_io::VertexOutput) {
pbr_prepass_functions::prepass_alpha_discard(in);
}
#endif // PREPASS_FRAGMENT