Refactor accelerated baker code to map more closely with the original baker

jme3-core/src/main/resources/Common/IBL/IBLKernels.frag

@@ -4,9 +4,9 @@
 *               https://learnopengl.com/PBR/IBL/Specular-IBL
 *   - Riccardo Balbo
 */
-#import "Common/IBL/Math.glsllib"
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+#import "Common/IBL/Math.glsl"
 
-out vec4 outFragColor;
 in vec2 TexCoords;
 in vec3 LocalPos;
 
@@ -17,6 +17,7 @@ uniform int m_FaceId;
 void brdfKernel(){
     float NdotV=TexCoords.x;
     float m_Roughness=TexCoords.y;
+
     vec3 V;
     V.x = sqrt(1.0 - NdotV*NdotV);
     V.y = 0.0;
@@ -26,8 +27,8 @@ void brdfKernel(){
     vec3 N = vec3(0.0, 0.0, 1.0);
     const uint SAMPLE_COUNT = 1024u;
     for(uint i = 0u; i < SAMPLE_COUNT; i++){
-        vec2 Xi = Hammersley(i, SAMPLE_COUNT);
-        vec3 H  = ImportanceSampleGGX(Xi, N, m_Roughness);
+        vec4 Xi = Hammersley(i, SAMPLE_COUNT);
+        vec3 H  = ImportanceSampleGGX(Xi, m_Roughness, N);
         vec3 L  = normalize(2.0 * dot(V, H) * H - V);
         float NdotL = max(L.z, 0.0);
         float NdotH = max(H.z, 0.0);
@@ -73,13 +74,19 @@ void prefilteredEnvKernel(){
     vec3 N = normalize(LocalPos);    
     vec3 R = N;
     vec3 V = R;
+
+    // float a2 = m_Roughness;
+    float a2 = m_Roughness * m_Roughness; // jme impl, why?
+    a2 *= a2;
+
     const uint SAMPLE_COUNT = 1024u;
     float totalWeight = 0.0;   
     vec3 prefilteredColor = vec3(0.0);     
     for(uint i = 0u; i < SAMPLE_COUNT; ++i) {
-        vec2 Xi = Hammersley(i, SAMPLE_COUNT);
-        vec3 H  = ImportanceSampleGGX(Xi, N, m_Roughness);
-        vec3 L  = normalize(2.0 * dot(V, H) * H - V);
+        vec4 Xi = Hammersley(i, SAMPLE_COUNT);
+        vec3 H  = ImportanceSampleGGX(Xi, a2, N);
+        float VoH = dot(V,H);
+        vec3 L  = normalize(2.0 * VoH * H - V);
         float NdotL = max(dot(N, L), 0.0);
         if(NdotL > 0.0) {
             // TODO: use mipmap

jme3-core/src/main/resources/Common/IBL/IBLKernels.j3md

@@ -1,6 +1,7 @@
 MaterialDef IBLKernels {
     
     MaterialParameters {
+        Int BoundDrawBuffer
         TextureCubeMap EnvMap -LINEAR
         Float Roughness
         Int FaceId : 0
@@ -11,8 +12,8 @@ MaterialDef IBLKernels {
 
     Technique {
     
-        VertexShader GLSL150:  Common/IBL/IBLKernels.vert
-        FragmentShader GLSL150:  Common/IBL/IBLKernels.frag
+        VertexShader   GLSL300 GLSL150 :  Common/IBL/IBLKernels.vert
+        FragmentShader GLSL300 GLSL150 :  Common/IBL/IBLKernels.frag
 
         WorldParameters {
             WorldMatrix
@@ -28,6 +29,7 @@ MaterialDef IBLKernels {
         }
 
         Defines {
+            BOUND_DRAW_BUFFER: BoundDrawBuffer
             BRDF:UseBRDF
             IRRADIANCE: UseIrradiance
             SIBL: UseSpecularIBL

jme3-core/src/main/resources/Common/IBL/IBLKernels.vert

@@ -1,3 +1,5 @@
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+
 /**
 *   This code is based on the following articles:
 *               https://learnopengl.com/PBR/IBL/Diffuse-irradiance

jme3-core/src/main/resources/Common/IBL/Math.glsllib → jme3-core/src/main/resources/Common/IBL/Math.glsl

@@ -15,48 +15,51 @@ float RadicalInverse_VdC(uint bits) {
     return float(bits) * 2.3283064365386963e-10; // / 0x100000000
 }
 
-vec2 Hammersley(uint i, uint N){
-    return vec2(float(i)/float(N), RadicalInverse_VdC(i));
+vec4 Hammersley(uint i, uint N){
+    vec4 store=vec4(0);
+    store.x = float(i) / float(N);
+    store.y = RadicalInverse_VdC(i);
+    
+    float phi = 2.0 * PI *store.x;
+    store.z = cos(phi);
+    store.w = sin(phi);
+
+    return store;
 } 
  
-/*
-Compatible with GL ES 2
-float VanDerCorput(uint n, uint base){
-    float invBase = 1.0 / float(base);
-    float denom   = 1.0;
-    float result  = 0.0;
+// float VanDerCorput(uint n, uint base){
+//     float invBase = 1.0 / float(base);
+//     float denom   = 1.0;
+//     float result  = 0.0;
 
-    for(uint i = 0u; i < 32u; ++i)
-    {
-        if(n > 0u)
-        {
-            denom   = mod(float(n), 2.0);
-            result += denom * invBase;
-            invBase = invBase / 2.0;
-            n       = uint(float(n) / 2.0);
-        }
-    }
+//     for(uint i = 0u; i < 32u; ++i)
+//     {
+//         if(n > 0u)
+//         {
+//             denom   = mod(float(n), 2.0);
+//             result += denom * invBase;
+//             invBase = invBase / 2.0;
+//             n       = uint(float(n) / 2.0);
+//         }
+//     }
 
-    return result;
-}
+//     return result;
+// }
 
-vec2 Hammersley(uint i, uint N){
-    return vec2(float(i)/float(N), VanDerCorput(i, 2u));
-}
-*/
+// vec2 Hammersley(uint i, uint N){
+//     return vec2(float(i)/float(N), VanDerCorput(i, 2u));
+// }
 
 
-vec3 ImportanceSampleGGX(vec2 Xi, vec3 N, float roughness){
-    float a = roughness*roughness;
+vec3 ImportanceSampleGGX(vec4 Xi, float a2, vec3 N){
 	
-    float phi = 2.0 * PI * Xi.x;
-    float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a*a - 1.0) * Xi.y));
+    float cosTheta = sqrt((1.0 - Xi.y) / (1.0 + (a2 - 1.0) * Xi.y));
     float sinTheta = sqrt(1.0 - cosTheta*cosTheta);
 	
     // from spherical coordinates to cartesian coordinates
     vec3 H;
-    H.x = cos(phi) * sinTheta;
-    H.y = sin(phi) * sinTheta;
+    H.x = Xi.z * sinTheta;
+    H.y = Xi.w * sinTheta;
     H.z = cosTheta;
 	
     // from tangent-space vector to world-space sample vector

jme3-core/src/main/resources/Common/IBLSphH/IBLSphH.frag

@@ -2,14 +2,14 @@
 
 *   - Riccardo Balbo
 */
-#import "Common/IBL/Math.glsllib"
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+#import "Common/IBL/Math.glsl"
 
 // #define NUM_SH_COEFFICIENT 9
 #ifndef PI
     #define PI 3.1415926535897932384626433832795
 #endif
 
-out vec4 outFragColor;
 in vec2 TexCoords;
 in vec3 LocalPos;
 
@@ -22,9 +22,9 @@ uniform vec2 m_Resolution;
 uniform int m_FaceId;
 
 const float sqrtPi = sqrt(PI);
-const float sqrt3Pi = sqrt(3 / PI);
-const float sqrt5Pi = sqrt(5 / PI);
-const float sqrt15Pi = sqrt(15 / PI);
+const float sqrt3Pi = sqrt(3. / PI);
+const float sqrt5Pi = sqrt(5. / PI);
+const float sqrt15Pi = sqrt(15. / PI);
 
 #ifdef REMAP_MAX_VALUE
     uniform float m_RemapMaxValue;
@@ -42,31 +42,31 @@ vec3 getVectorFromCubemapFaceTexCoord(float x, float y, float mapSize, int face)
     
 
     // Warp texel centers in the proximity of the edges.
-    float a = pow(mapSize, 2.0) / pow(mapSize - 1, 3.0);
+    float a = pow(mapSize, 2.0) / pow(mapSize - 1., 3.0);
 
-    u = a * pow(u, 3) + u;
-    v = a * pow(v, 3) + v;
+    u = a * pow(u, 3.) + u;
+    v = a * pow(v, 3.) + v;
     //compute vector depending on the face
     // Code from Nvtt : https://github.com/castano/nvidia-texture-tools/blob/master/src/nvtt/CubeSurface.cpp#L101
     vec3 o =vec3(0);
     switch(face) {
         case 0:
-            o= normalize(vec3(1, -v, -u));
+            o= normalize(vec3(1., -v, -u));
             break;
         case 1:
-            o= normalize(vec3(-1, -v, u));
+            o= normalize(vec3(-1., -v, u));
             break;
         case 2:
-            o= normalize(vec3(u, 1, v));
+            o= normalize(vec3(u, 1., v));
             break;
         case 3:
-            o= normalize(vec3(u, -1, -v));
+            o= normalize(vec3(u, -1., -v));
             break;
         case 4:
-            o= normalize(vec3(u, -v, 1));
+            o= normalize(vec3(u, -v, 1.));
             break;
         case 5:
-            o= normalize(vec3(-u, -v, -1.0));
+            o= normalize(vec3(-u, -v, -1.));
             break;
     }
 
@@ -148,8 +148,8 @@ void sphKernel() {
     int width = int(m_Resolution.x);
     int height = int(m_Resolution.y);
     vec3 texelVect=vec3(0);    
-    float shDir=0;
-    float weight=0;
+    float shDir=0.;
+    float weight=0.;
     vec4 color=vec4(0);
 
     int i=int(gl_FragCoord.x);

jme3-core/src/main/resources/Common/IBLSphH/IBLSphH.j3md

@@ -1,6 +1,7 @@
 MaterialDef IBLSphH {
     
     MaterialParameters {
+        Int BoundDrawBuffer
         TextureCubeMap Texture -LINEAR
         Int FaceId : 0
         Texture2D ShCoef -LINEAR
@@ -10,8 +11,8 @@ MaterialDef IBLSphH {
 
     Technique {
     
-        VertexShader GLSL150:  Common/IBLSphH/IBLSphH.vert
-        FragmentShader GLSL150:  Common/IBLSphH/IBLSphH.frag
+        VertexShader   GLSL300 GLSL150 :  Common/IBLSphH/IBLSphH.vert
+        FragmentShader GLSL300 GLSL150 :  Common/IBLSphH/IBLSphH.frag
 
         WorldParameters {
         }
@@ -24,6 +25,7 @@ MaterialDef IBLSphH {
         }
 
         Defines {
+            BOUND_DRAW_BUFFER: BoundDrawBuffer
             REMAP_MAX_VALUE: RemapMaxValue
             SH_COEF: ShCoef
         }

jme3-core/src/main/resources/Common/IBLSphH/IBLSphH.vert

@@ -1,3 +1,5 @@
+#import "Common/ShaderLib/GLSLCompat.glsllib"
+
 /**
 *- Riccardo Balbo
 */