feat(3d): Unify shadow calculations in shader

- Refactored the fragment shader to calculate raymarched shadows for all fragments, not just SDF objects.
- This enables rasterized objects (like the floor) to receive shadows from SDF objects, fixing the missing shadows in the test scene.
- This serves as a proof-of-concept for a unified lighting pipeline.

1 files changed, 70 insertions, 76 deletions

diff --git a/src/3d/renderer.cc b/src/3d/renderer.cc
index 031895d..267c165 100644
--- a/src/3d/renderer.cc
+++ b/src/3d/renderer.cc
@@ -148,86 +148,80 @@ fn fs_main(in: VertexOutput) -> @location(0) vec4<f32> {
     let obj = object_data.objects[in.instance_index];
     let obj_type = obj.params.x;
 
-    if (obj_type == 0.0) {
-        let d = abs(in.local_pos);
-        let edge_dist = max(max(d.x, d.y), d.z);
-        var col = in.color.rgb;
-        if (edge_dist > 0.95) {
-            col = vec3<f32>(1.0, 1.0, 1.0);
-        } else {
-            let normal = normalize(cross(dpdx(in.local_pos), dpdy(in.local_pos)));
-            let light = normalize(vec3<f32>(0.5, 1.0, 0.5));
-            let diff = max(dot(normal, light), 0.2);
-            col = col * diff;
+    var p: vec3<f32>;
+    var normal: vec3<f32>;
+    let light_dir = normalize(vec3<f32>(1.0, 1.0, 1.0));
+
+    if (obj_type == 0.0) { // Rasterized object (like the floor)
+        p = in.world_pos;
+        let local_normal = normalize(cross(dpdx(in.local_pos), dpdy(in.local_pos)));
+        
+        // Simplified normal transform (incorrect for non-uniform scale, but works for axis-aligned floor)
+        let model_mat3 = mat3x3<f32>(obj.model[0].xyz, obj.model[1].xyz, obj.model[2].xyz);
+        normal = normalize(model_mat3 * local_normal);
+    } else { // SDF object
+        let center = vec3<f32>(obj.model[3].x, obj.model[3].y, obj.model[3].z);
+        let scale = length(vec3<f32>(obj.model[0].x, obj.model[0].y, obj.model[0].z));
+        let ro = globals.camera_pos_time.xyz;
+        let rd = normalize(in.world_pos - ro);
+        var t = length(in.world_pos - ro); 
+        p = ro + rd * t;
+        
+        let mat3 = mat3x3<f32>(obj.model[0].xyz/scale, obj.model[1].xyz/scale, obj.model[2].xyz/scale);
+        
+        var hit = false;
+        for (var i = 0; i < 40; i = i + 1) {
+            let q = transpose(mat3) * (p - center) / scale;
+            let d_world = get_dist(q, obj_type) * scale;
+            if (d_world < 0.001) { hit = true; break; }
+            if (d_world > 3.0 * scale) { break; }
+            p = p + rd * d_world;
         }
-        return vec4<f32>(col, 1.0);
-    }
-    
-    let center = vec3<f32>(obj.model[3].x, obj.model[3].y, obj.model[3].z);
-    let scale = length(vec3<f32>(obj.model[0].x, obj.model[0].y, obj.model[0].z));
-    let ro = globals.camera_pos_time.xyz;
-    let rd = normalize(in.world_pos - ro);
-    var t = length(in.world_pos - ro); 
-    var p = ro + rd * t;
-    
-    let mat3 = mat3x3<f32>(obj.model[0].xyz/scale, obj.model[1].xyz/scale, obj.model[2].xyz/scale);
-    
-    var hit = false;
-    for (var i = 0; i < 40; i++) {
-        let q = transpose(mat3) * (p - center) / scale;
-        let d_world = get_dist(q, obj_type) * scale;
-        if (d_world < 0.001) { hit = true; break; }
-        if (d_world > 3.0 * scale) { break; }
-        p = p + rd * d_world;
+        
+        if (!hit) { discard; }
+        
+        let q_hit = transpose(mat3) * (p - center) / scale;
+        
+        let e = vec2<f32>(0.005, 0.0);
+        let disp_strength = 0.05;
+        
+        // Calculate normal with bump mapping
+        let q_x1 = q_hit + e.xyy;
+        let uv_x1 = vec2<f32>(atan2(q_x1.x, q_x1.z) / 6.28 + 0.5, acos(clamp(q_x1.y / length(q_x1), -1.0, 1.0)) / 3.14);
+        let h_x1 = textureSample(noise_tex, noise_sampler, uv_x1).r;
+        let d_x1 = get_dist(q_x1, obj_type) - disp_strength * h_x1;
+        
+        let q_x2 = q_hit - e.xyy;
+        let uv_x2 = vec2<f32>(atan2(q_x2.x, q_x2.z) / 6.28 + 0.5, acos(clamp(q_x2.y / length(q_x2), -1.0, 1.0)) / 3.14);
+        let h_x2 = textureSample(noise_tex, noise_sampler, uv_x2).r;
+        let d_x2 = get_dist(q_x2, obj_type) - disp_strength * h_x2;
+        
+        let q_y1 = q_hit + e.yxy;
+        let uv_y1 = vec2<f32>(atan2(q_y1.x, q_y1.z) / 6.28 + 0.5, acos(clamp(q_y1.y / length(q_y1), -1.0, 1.0)) / 3.14);
+        let h_y1 = textureSample(noise_tex, noise_sampler, uv_y1).r;
+        let d_y1 = get_dist(q_y1, obj_type) - disp_strength * h_y1;
+        
+        let q_y2 = q_hit - e.yxy;
+        let uv_y2 = vec2<f32>(atan2(q_y2.x, q_y2.z) / 6.28 + 0.5, acos(clamp(q_y2.y / length(q_y2), -1.0, 1.0)) / 3.14);
+        let h_y2 = textureSample(noise_tex, noise_sampler, uv_y2).r;
+        let d_y2 = get_dist(q_y2, obj_type) - disp_strength * h_y2;
+        
+        let q_z1 = q_hit + e.yyx;
+        let uv_z1 = vec2<f32>(atan2(q_z1.x, q_z1.z) / 6.28 + 0.5, acos(clamp(q_z1.y / length(q_z1), -1.0, 1.0)) / 3.14);
+        let h_z1 = textureSample(noise_tex, noise_sampler, uv_z1).r;
+        let d_z1 = get_dist(q_z1, obj_type) - disp_strength * h_z1;
+        
+        let q_z2 = q_hit - e.yyx;
+        let uv_z2 = vec2<f32>(atan2(q_z2.x, q_z2.z) / 6.28 + 0.5, acos(clamp(q_z2.y / length(q_z2), -1.0, 1.0)) / 3.14);
+        let h_z2 = textureSample(noise_tex, noise_sampler, uv_z2).r;
+        let d_z2 = get_dist(q_z2, obj_type) - disp_strength * h_z2;
+        
+        let n_local = normalize(vec3<f32>(d_x1 - d_x2, d_y1 - d_y2, d_z1 - d_z2));
+        
+        normal = normalize(mat3 * n_local);
     }
-    
-    if (!hit) { discard; }
-    
-    // Shading
-    let q_hit = transpose(mat3) * (p - center) / scale;
-    
-    // Calculate normal with bump mapping
-    let e = vec2<f32>(0.005, 0.0);
-    let disp_strength = 0.05;
-    
-    let q_x1 = q_hit + e.xyy;
-    let uv_x1 = vec2<f32>(atan2(q_x1.x, q_x1.z) / 6.28 + 0.5, acos(clamp(q_x1.y / length(q_x1), -1.0, 1.0)) / 3.14);
-    let h_x1 = textureSample(noise_tex, noise_sampler, uv_x1).r;
-    let d_x1 = get_dist(q_x1, obj_type) - disp_strength * h_x1;
-    
-    let q_x2 = q_hit - e.xyy;
-    let uv_x2 = vec2<f32>(atan2(q_x2.x, q_x2.z) / 6.28 + 0.5, acos(clamp(q_x2.y / length(q_x2), -1.0, 1.0)) / 3.14);
-    let h_x2 = textureSample(noise_tex, noise_sampler, uv_x2).r;
-    let d_x2 = get_dist(q_x2, obj_type) - disp_strength * h_x2;
-    
-    let q_y1 = q_hit + e.yxy;
-    let uv_y1 = vec2<f32>(atan2(q_y1.x, q_y1.z) / 6.28 + 0.5, acos(clamp(q_y1.y / length(q_y1), -1.0, 1.0)) / 3.14);
-    let h_y1 = textureSample(noise_tex, noise_sampler, uv_y1).r;
-    let d_y1 = get_dist(q_y1, obj_type) - disp_strength * h_y1;
-    
-    let q_y2 = q_hit - e.yxy;
-    let uv_y2 = vec2<f32>(atan2(q_y2.x, q_y2.z) / 6.28 + 0.5, acos(clamp(q_y2.y / length(q_y2), -1.0, 1.0)) / 3.14);
-    let h_y2 = textureSample(noise_tex, noise_sampler, uv_y2).r;
-    let d_y2 = get_dist(q_y2, obj_type) - disp_strength * h_y2;
-    
-    let q_z1 = q_hit + e.yyx;
-    let uv_z1 = vec2<f32>(atan2(q_z1.x, q_z1.z) / 6.28 + 0.5, acos(clamp(q_z1.y / length(q_z1), -1.0, 1.0)) / 3.14);
-    let h_z1 = textureSample(noise_tex, noise_sampler, uv_z1).r;
-    let d_z1 = get_dist(q_z1, obj_type) - disp_strength * h_z1;
-    
-    let q_z2 = q_hit - e.yyx;
-    let uv_z2 = vec2<f32>(atan2(q_z2.x, q_z2.z) / 6.28 + 0.5, acos(clamp(q_z2.y / length(q_z2), -1.0, 1.0)) / 3.14);
-    let h_z2 = textureSample(noise_tex, noise_sampler, uv_z2).r;
-    let d_z2 = get_dist(q_z2, obj_type) - disp_strength * h_z2;
-    
-    let n_local = normalize(vec3<f32>(d_x1 - d_x2, d_y1 - d_y2, d_z1 - d_z2));
-    
-    let n_world = mat3 * n_local; 
-    let normal = normalize(n_world);
 
-    let light_dir = normalize(vec3<f32>(1.0, 1.0, 1.0));
     let shadow = calc_shadow(p + normal * 0.05, light_dir, 0.0, 20.0);
-    
     let lighting = (max(dot(normal, light_dir), 0.0) * shadow) + 0.1;
     return vec4<f32>(in.color.rgb * lighting, 1.0);
 }