Merge branch 'shadow-atlas-churn'

Author: DoubleStyx

crates/renderide/shaders/passes/backend/world_mesh_radial_shadow_caster.wgsl

@@ -3,17 +3,21 @@
 //! The raster projection selects the shadow volume and atlas UVs. Fragment depth stores normalized
 //! radial distance so point and spot shadows compare consistently across their projected views.
 
-struct ShadowCasterUniforms {
-    view_proj_left: mat4x4<f32>,
-    view_proj_right: mat4x4<f32>,
+struct ShadowCasterDraw {
     model: mat4x4<f32>,
     normal_matrix: mat3x3<f32>,
+    _pad: array<vec4<f32>, 25>,
+}
+
+struct ShadowLayerUniforms {
+    view_proj: mat4x4<f32>,
     light_position_range: vec4<f32>,
     shadow_params: vec4<f32>,
-    _pad: array<vec4<f32>, 15>,
+    _pad: array<vec4<f32>, 26>,
 }
 
-@group(0) @binding(0) var<storage, read> instances: array<ShadowCasterUniforms>;
+@group(0) @binding(0) var<storage, read> instances: array<ShadowCasterDraw>;
+@group(1) @binding(0) var<uniform> shadow_layer: ShadowLayerUniforms;
 
 struct VertexOutput {
     @builtin(position) clip_pos: vec4<f32>,
@@ -30,17 +34,16 @@ fn vs_main(
     let world_p = draw.model * vec4<f32>(pos.xyz, 1.0);
 
     var out: VertexOutput;
-    out.clip_pos = draw.view_proj_left * world_p;
+    out.clip_pos = shadow_layer.view_proj * world_p;
     out.world_pos = world_p.xyz;
     out.instance_index = instance_index;
     return out;
 }
 
 @fragment
 fn fs_main(in: VertexOutput) -> @builtin(frag_depth) f32 {
-    let draw = instances[in.instance_index];
-    let range = max(draw.light_position_range.w, 0.001);
-    let bias = max(draw.shadow_params.x, 0.0);
-    let radial_depth = (length(in.world_pos - draw.light_position_range.xyz) + bias) / range;
+    let range = max(shadow_layer.light_position_range.w, 0.001);
+    let bias = max(shadow_layer.shadow_params.x, 0.0);
+    let radial_depth = (length(in.world_pos - shadow_layer.light_position_range.xyz) + bias) / range;
     return clamp(radial_depth, 0.0, 1.0);
 }

crates/renderide/shaders/passes/backend/world_mesh_shadow_caster.wgsl

@@ -0,0 +1,41 @@
+//! Projected shadow caster for world meshes.
+//!
+//! Per-draw rows carry only model data. The active shadow-view projection is bound once per atlas
+//! layer so cascades and cubemap faces can reuse the same caster slab.
+
+struct ShadowCasterDraw {
+    model: mat4x4<f32>,
+    normal_matrix: mat3x3<f32>,
+    _pad: array<vec4<f32>, 25>,
+}
+
+struct ShadowLayerUniforms {
+    view_proj: mat4x4<f32>,
+    light_position_range: vec4<f32>,
+    shadow_params: vec4<f32>,
+    _pad: array<vec4<f32>, 26>,
+}
+
+@group(0) @binding(0) var<storage, read> instances: array<ShadowCasterDraw>;
+@group(1) @binding(0) var<uniform> shadow_layer: ShadowLayerUniforms;
+
+struct VertexOutput {
+    @builtin(position) clip_pos: vec4<f32>,
+}
+
+@vertex
+fn vs_main(
+    @builtin(instance_index) instance_index: u32,
+    @location(0) pos: vec4<f32>,
+) -> VertexOutput {
+    let draw = instances[instance_index];
+    let world_p = draw.model * vec4<f32>(pos.xyz, 1.0);
+
+    var out: VertexOutput;
+    out.clip_pos = shadow_layer.view_proj * world_p;
+    return out;
+}
+
+@fragment
+fn fs_main() {
+}