ADD: IBL glsl cleaning

shaders/background_env.frag

@@ -1,21 +1,11 @@
 #version 450
 #extension GL_GOOGLE_include_directive : require
 #include "input_structures.glsl"
+#include "ibl_common.glsl"
 
 layout(location=0) in vec2 inUV;
 layout(location=0) out vec4 outColor;
 
-// IBL specular equirect 2D (LOD 0 for background)
-layout(set=3, binding=0) uniform sampler2D iblSpec2D;
-
-vec2 dir_to_equirect(vec3 d)
-{
-    d = normalize(d);
-    float phi = atan(d.z, d.x);
-    float theta = acos(clamp(d.y, -1.0, 1.0));
-    return vec2(phi * (0.15915494309) + 0.5, theta * (0.31830988618));
-}
-
 void main()
 {
     // Reconstruct world-space direction from screen UV

shaders/deferred_lighting.frag

@@ -2,6 +2,7 @@
 #extension GL_GOOGLE_include_directive : require
 #extension GL_EXT_ray_query : require
 #include "input_structures.glsl"
+#include "ibl_common.glsl"
 
 layout(location=0) in vec2 inUV;
 layout(location=0) out vec4 outColor;
@@ -10,33 +11,6 @@ layout(set=1, binding=0) uniform sampler2D posTex;
 layout(set=1, binding=1) uniform sampler2D normalTex;
 layout(set=1, binding=2) uniform sampler2D albedoTex;
 layout(set=2, binding=0) uniform sampler2D shadowTex[4];
-// IBL (set=3): specular prefiltered cube, diffuse irradiance cube, BRDF LUT
-layout(set=3, binding=0) uniform sampler2D iblSpec2D;
-layout(set=3, binding=1) uniform sampler2D iblBRDF;
-layout(std140, set=3, binding=2) uniform IBL_SH { vec4 sh[9]; } iblSH;
-
-vec3 sh_eval_irradiance(vec3 n)
-{
-    float x=n.x, y=n.y, z=n.z;
-    const float c0=0.2820947918;
-    const float c1=0.4886025119;
-    const float c2=1.0925484306;
-    const float c3=0.3153915653;
-    const float c4=0.5462742153;
-    float Y[9];
-    Y[0]=c0; Y[1]=c1*y; Y[2]=c1*z; Y[3]=c1*x; Y[4]=c2*x*y; Y[5]=c2*y*z; Y[6]=c3*(3.0*z*z-1.0); Y[7]=c2*x*z; Y[8]=c4*(x*x-y*y);
-    vec3 r=vec3(0.0);
-    for (int i=0;i<9;++i) r += iblSH.sh[i].rgb * Y[i];
-    return r;
-}
-
-vec2 dir_to_equirect(vec3 d)
-{
-    d = normalize(d);
-    float phi = atan(d.z, d.x);
-    float theta = acos(clamp(d.y, -1.0, 1.0));
-    return vec2(phi * (0.15915494309) + 0.5, theta * (0.31830988618));
-}
 // TLAS for ray query (optional, guarded by sceneData.rtOptions.x)
 #ifdef GL_EXT_ray_query
 layout(set=0, binding=1) uniform accelerationStructureEXT topLevelAS;
@@ -369,7 +343,7 @@ void main(){
     // Image-Based Lighting: split-sum approximation
     vec3 R = reflect(-V, N);
     float levels = float(textureQueryLevels(iblSpec2D));
-    float lod = clamp(roughness * max(levels - 1.0, 0.0), 0.0, max(levels - 1.0, 0.0));
+    float lod = ibl_lod_from_roughness(roughness, levels);
     vec2 uv = dir_to_equirect(R);
     vec3 prefiltered = textureLod(iblSpec2D, uv, lod).rgb;
     vec2 brdf = texture(iblBRDF, vec2(max(dot(N, V), 0.0), roughness)).rg;

shaders/deferred_lighting_nort.frag

@@ -1,6 +1,7 @@
 #version 450
 #extension GL_GOOGLE_include_directive : require
 #include "input_structures.glsl"
+#include "ibl_common.glsl"
 
 layout(location=0) in vec2 inUV;
 layout(location=0) out vec4 outColor;
@@ -10,34 +11,6 @@ layout(set=1, binding=1) uniform sampler2D normalTex;
 layout(set=1, binding=2) uniform sampler2D albedoTex;
 layout(set=2, binding=0) uniform sampler2D shadowTex[4];
 
-// IBL (set=3): specular prefiltered cube, diffuse irradiance cube, BRDF LUT
-layout(set=3, binding=0) uniform sampler2D iblSpec2D; // equirect 2D with prefiltered mips
-layout(set=3, binding=1) uniform sampler2D iblBRDF;   // RG LUT
-layout(std140, set=3, binding=2) uniform IBL_SH { vec4 sh[9]; } iblSH;
-
-vec3 sh_eval_irradiance(vec3 n)
-{
-    float x=n.x, y=n.y, z=n.z;
-    const float c0=0.2820947918;
-    const float c1=0.4886025119;
-    const float c2=1.0925484306;
-    const float c3=0.3153915653;
-    const float c4=0.5462742153;
-    float Y[9];
-    Y[0]=c0; Y[1]=c1*y; Y[2]=c1*z; Y[3]=c1*x; Y[4]=c2*x*y; Y[5]=c2*y*z; Y[6]=c3*(3.0*z*z-1.0); Y[7]=c2*x*z; Y[8]=c4*(x*x-y*y);
-    vec3 r=vec3(0.0);
-    for (int i=0;i<9;++i) r += iblSH.sh[i].rgb * Y[i];
-    return r; // already convolved with Lambert in CPU bake
-}
-
-vec2 dir_to_equirect(vec3 d)
-{
-    d = normalize(d);
-    float phi = atan(d.z, d.x);
-    float theta = acos(clamp(d.y, -1.0, 1.0));
-    return vec2(phi * (0.15915494309) + 0.5, theta * (0.31830988618));
-}
-
 // Tunables for shadow quality and blending
 // Border smoothing width in light-space NDC (0..1). Larger = wider cross-fade.
 const float SHADOW_BORDER_SMOOTH_NDC = 0.08;
@@ -299,7 +272,7 @@ void main(){
     // Image-Based Lighting: split-sum approximation
     vec3 R = reflect(-V, N);
     float levels = float(textureQueryLevels(iblSpec2D));
-    float lod = clamp(roughness * max(levels - 1.0, 0.0), 0.0, max(levels - 1.0, 0.0));
+    float lod = ibl_lod_from_roughness(roughness, levels);
     vec2 uv = dir_to_equirect(R);
     vec3 prefiltered = textureLod(iblSpec2D, uv, lod).rgb;
     vec2 brdf = texture(iblBRDF, vec2(max(dot(N, V), 0.0), roughness)).rg;

shaders/ibl_common.glsl

@@ -0,0 +1,57 @@
+#ifndef IBL_COMMON_GLSL
+#define IBL_COMMON_GLSL
+
+// IBL bindings (set=3): specular equirect 2D, BRDF LUT, SH UBO.
+layout(set=3, binding=0) uniform sampler2D iblSpec2D;
+layout(set=3, binding=1) uniform sampler2D iblBRDF;
+layout(std140, set=3, binding=2) uniform IBL_SH { vec4 sh[9]; } iblSH;
+
+// Evaluate diffuse irradiance from 2nd-order SH coefficients (9 coeffs).
+// Coefficients are pre-convolved with the Lambert kernel on the CPU.
+vec3 sh_eval_irradiance(vec3 n)
+{
+    float x = n.x, y = n.y, z = n.z;
+    const float c0 = 0.2820947918;
+    const float c1 = 0.4886025119;
+    const float c2 = 1.0925484306;
+    const float c3 = 0.3153915653;
+    const float c4 = 0.5462742153;
+    float Y[9];
+    Y[0] = c0;
+    Y[1] = c1 * y;
+    Y[2] = c1 * z;
+    Y[3] = c1 * x;
+    Y[4] = c2 * x * y;
+    Y[5] = c2 * y * z;
+    Y[6] = c3 * (3.0 * z * z - 1.0);
+    Y[7] = c2 * x * z;
+    Y[8] = c4 * (x * x - y * y);
+    vec3 r = vec3(0.0);
+    for (int i = 0; i < 9; ++i)
+    {
+        r += iblSH.sh[i].rgb * Y[i];
+    }
+    return r;
+}
+
+// Map direction to equirectangular UV (same convention across shaders).
+vec2 dir_to_equirect(vec3 d)
+{
+    d = normalize(d);
+    float phi = atan(d.z, d.x);
+    float theta = acos(clamp(d.y, -1.0, 1.0));
+    // 1/(2*pi) = 0.15915494309, 1/pi = 0.31830988618
+    return vec2(phi * 0.15915494309 + 0.5, theta * 0.31830988618);
+}
+
+// Helper for selecting mip LOD from roughness and available levels.
+// Uses roughness^2 to bias towards blurrier reflections at mid roughness.
+float ibl_lod_from_roughness(float roughness, float levels)
+{
+    float maxLevel = max(levels - 1.0, 0.0);
+    float r = clamp(roughness, 0.0, 1.0);
+    return r * r * maxLevel;
+}
+
+#endif // IBL_COMMON_GLSL
+

shaders/mesh.frag

@@ -2,6 +2,7 @@
 
 #extension GL_GOOGLE_include_directive : require
 #include "input_structures.glsl"
+#include "ibl_common.glsl"
 
 layout (location = 0) in vec3 inNormal;
 layout (location = 1) in vec3 inColor;
@@ -13,28 +14,6 @@ layout (location = 0) out vec4 outFragColor;
 
 const float PI = 3.14159265359;
 
-// IBL bindings (set=3): specular equirect 2D + BRDF LUT + SH UBO
-layout(set=3, binding=0) uniform sampler2D iblSpec2D;
-layout(set=3, binding=1) uniform sampler2D iblBRDF;
-layout(std140, set=3, binding=2) uniform IBL_SH { vec4 sh[9]; } iblSH;
-
-vec3 sh_eval_irradiance(vec3 n)
-{
-    float x=n.x, y=n.y, z=n.z;
-    const float c0=0.2820947918; const float c1=0.4886025119; const float c2=1.0925484306; const float c3=0.3153915653; const float c4=0.5462742153;
-    float Y[9];
-    Y[0]=c0; Y[1]=c1*y; Y[2]=c1*z; Y[3]=c1*x; Y[4]=c2*x*y; Y[5]=c2*y*z; Y[6]=c3*(3.0*z*z-1.0); Y[7]=c2*x*z; Y[8]=c4*(x*x-y*y);
-    vec3 r=vec3(0.0); for (int i=0;i<9;++i) r += iblSH.sh[i].rgb * Y[i]; return r;
-}
-
-vec2 dir_to_equirect(vec3 d)
-{
-    d = normalize(d);
-    float phi = atan(d.z, d.x);
-    float theta = acos(clamp(d.y, -1.0, 1.0));
-    return vec2(phi * (0.15915494309) + 0.5, theta * (0.31830988618));
-}
-
 vec3 fresnelSchlick(float cosTheta, vec3 F0)
 {
     return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
@@ -118,7 +97,7 @@ void main()
     // IBL: specular from equirect 2D mips; diffuse from SH
     vec3 R = reflect(-V, N);
     float levels = float(textureQueryLevels(iblSpec2D));
-    float lod = clamp(roughness * max(levels - 1.0, 0.0), 0.0, max(levels - 1.0, 0.0));
+    float lod = ibl_lod_from_roughness(roughness, levels);
     vec2 uv = dir_to_equirect(R);
     vec3 prefiltered = textureLod(iblSpec2D, uv, lod).rgb;
     vec2 brdf = texture(iblBRDF, vec2(max(dot(N, V), 0.0), roughness)).rg;