Deferred lighting implementation in progress. Now generating view-space normal fragments for the 1st pass G-buffer.

Added transpose() method to KRMat4

--HG--
extra : convert_revision : svn%3A7752d6cf-9f14-4ad2-affc-04f1e67b81a5/trunk%4043

KREngine/KREngine/Classes/KRCamera.cpp

@@ -47,6 +47,7 @@ KRCamera::KRCamera() {
     bEnableSpecular = true;
     bEnableLightMap = true;
     bDebugSuperShiny = false;
+    bEnableDeferredLighting = false;
     
     
     dAmbientR = 0.25f;

KREngine/KREngine/Classes/KRCamera.h

@@ -54,6 +54,7 @@ public:
     bool bEnableAmbient;
     bool bEnableDiffuse;
     bool bEnableSpecular;
+    bool bEnableDeferredLighting;
     double dSunR;
     double dSunG;
     double dSunB;

KREngine/KREngine/Classes/KREngine.h

@@ -65,6 +65,7 @@ typedef enum KREngineParameterType {KRENGINE_PARAMETER_INT, KRENGINE_PARAMETER_F
         KRENGINE_UNIFORM_MATERIAL_DIFFUSE,
         KRENGINE_UNIFORM_MATERIAL_SPECULAR,
         KRENGINE_UNIFORM_MVP,
+        KRENGINE_UNIFORM_M2V,
         KRENGINE_UNIFORM_SHADOWMVP1,
         KRENGINE_UNIFORM_SHADOWMVP2,
         KRENGINE_UNIFORM_SHADOWMVP3,

KREngine/KREngine/Classes/KREngine.mm

@@ -746,12 +746,12 @@ double const PI = 3.141592653589793f;
 
 -(int)getParameterCount
 {
-    return 31;
+    return 32;
 }
 
 -(NSString *)getParameterNameWithIndex: (int)i
 {
-    NSString *parameter_names[31] = {
+    NSString *parameter_names[32] = {
         @"camera_fov",
         @"sun_direction",
         @"sun_attitude",
@@ -782,13 +782,14 @@ double const PI = 3.141592653589793f;
         @"debug_enable_ambient",
         @"debug_enable_diffuse",
         @"debug_enable_specular",
-        @"debug_super_shiny"
+        @"debug_super_shiny",
+        @"enable_deferred_lighting"
     };
     return parameter_names[i];
 }
 -(NSString *)getParameterLabelWithIndex: (int)i
 {
-    NSString *parameter_labels[31] = {
+    NSString *parameter_labels[32] = {
         @"Camera FOV",
         @"Sun Direction",
         @"Sun Attitude",
@@ -819,13 +820,15 @@ double const PI = 3.141592653589793f;
         @"Debug - Enable Ambient",
         @"Debug - Enable Diffuse",
         @"Debug - Enable Specular",
-        @"Debug - Super Shiny"
+        @"Debug - Super Shiny",
+        @"Enable Deferred Lighting"
     };
     return parameter_labels[i];
 }
 -(KREngineParameterType)getParameterTypeWithIndex: (int)i
 {
-    KREngineParameterType types[31] = {
+    KREngineParameterType types[32] = {
+        
         KRENGINE_PARAMETER_FLOAT,
         KRENGINE_PARAMETER_FLOAT,
         KRENGINE_PARAMETER_FLOAT,
@@ -856,13 +859,14 @@ double const PI = 3.141592653589793f;
         KRENGINE_PARAMETER_BOOL,
         KRENGINE_PARAMETER_BOOL,
         KRENGINE_PARAMETER_BOOL,
+        KRENGINE_PARAMETER_BOOL,
         KRENGINE_PARAMETER_BOOL
     };
     return types[i];
 }
 -(double)getParameterValueWithIndex: (int)i
 {
-    double values[31] = {
+    double values[32] = {
         m_camera.perspective_fov,
         sun_yaw,
         sun_pitch,
@@ -893,7 +897,8 @@ double const PI = 3.141592653589793f;
         m_camera.bEnableAmbient ? 1.0f : 0.0f,
         m_camera.bEnableDiffuse ? 1.0f : 0.0f,
         m_camera.bEnableSpecular ? 1.0f : 0.0f,
-        m_camera.bDebugSuperShiny ? 1.0f : 0.0f
+        m_camera.bDebugSuperShiny ? 1.0f : 0.0f,
+        m_camera.bEnableDeferredLighting ? 1.0f : 0.0f
     };
     return values[i];
 }
@@ -1043,18 +1048,22 @@ double const PI = 3.141592653589793f;
                 m_camera.bDebugSuperShiny = bNewBoolVal;
             }
             break;
+        case 31:
+            if(m_camera.bEnableDeferredLighting != bNewBoolVal) {
+                m_camera.bEnableDeferredLighting = bNewBoolVal;
+            }
     }
 }
 
 -(double)getParameterMinWithIndex: (int)i
 {
-    double minValues[31] = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};
+    double minValues[32] = {0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f};
     return minValues[i];
 }
 
 -(double)getParameterMaxWithIndex: (int)i
 {
-    double maxValues[31] = {PI, 2.0f * PI, PI, 3.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 3.0f, 3.0f, 3.0f, 3.0f, 3.0f, 3.0f, 2.0f, 1.0f, 1.0f, 1.0f, 5.0f, 1.0f, 0.5f, 1.0f, 2.0f, 2.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f};
+    double maxValues[32] = {PI, 2.0f * PI, PI, 3.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 3.0f, 3.0f, 3.0f, 3.0f, 3.0f, 3.0f, 2.0f, 1.0f, 1.0f, 1.0f, 5.0f, 1.0f, 0.5f, 1.0f, 2.0f, 2.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f, 1.0f};
     return maxValues[i];
 }
 

KREngine/KREngine/Classes/KRInstance.cpp

@@ -91,6 +91,9 @@ void KRInstance::render(KRCamera *pCamera, KRContext *pContext, KRBoundingVolume
             projectionMatrix = pCamera->getProjectionMatrix();
         }
         KRMat4 mvpmatrix = m_modelMatrix * viewMatrix * projectionMatrix;
+        KRMat4 matModelToView = viewMatrix * m_modelMatrix;
+        matModelToView.transpose();
+        matModelToView.invert();
         
         // Transform location of camera to object space for calculation of specular halfVec
         KRMat4 inverseModelMatrix = m_modelMatrix;
@@ -98,7 +101,7 @@ void KRInstance::render(KRCamera *pCamera, KRContext *pContext, KRBoundingVolume
         KRVector3 cameraPosObject = inverseModelMatrix.dot(cameraPosition);
         KRVector3 lightDirObject = inverseModelMatrix.dot(lightDirection);
         
-        m_pModel->render(pCamera, pContext, bRenderShadowMap, mvpmatrix, cameraPosObject, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers, m_pLightMap);
+        m_pModel->render(pCamera, pContext, bRenderShadowMap, matModelToView, mvpmatrix, cameraPosObject, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers, m_pLightMap);
             
     }
     

KREngine/KREngine/Classes/KRMat4.cpp

@@ -241,6 +241,16 @@ bool KRMat4::invert() {
     return true;
 }
 
+void KRMat4::transpose() {
+    GLfloat trans[16];
+    for(int x=0; x<4; x++) {
+        for(int y=0; y<4; y++) {
+            trans[x + y * 4] = m_mat[y + x * 4];
+        }
+    }
+    memcpy(m_mat, trans, sizeof(GLfloat) * 16);
+}
+
 /* Dot Product */
 KRVector3 KRMat4::dot(const KRVector3 &v) const {
     return KRVector3(

KREngine/KREngine/Classes/KRMat4.h

@@ -95,6 +95,7 @@ public:
     void rotate(GLfloat angle, AXIS axis);
     void bias();
     bool invert();
+    void transpose();
     KRVector3 dot(const KRVector3 &v) const;
 };
 

KREngine/KREngine/Classes/KRMaterial.cpp

@@ -158,7 +158,7 @@ bool KRMaterial::isTransparent() {
     return m_tr != 0.0;
 }
 #if TARGET_OS_IPHONE
-void KRMaterial::bind(KRMaterial **prevBoundMaterial, char *szPrevShaderKey, KRCamera *pCamera, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRContext *pContext, KRTexture *pLightMap) {
+void KRMaterial::bind(KRMaterial **prevBoundMaterial, char *szPrevShaderKey, KRCamera *pCamera, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRContext *pContext, KRTexture *pLightMap) {
     bool bSameMaterial = *prevBoundMaterial == this;
     bool bLightMap = pLightMap && pCamera->bEnableLightMap;
     
@@ -191,7 +191,7 @@ void KRMaterial::bind(KRMaterial **prevBoundMaterial, char *szPrevShaderKey, KRC
 
         bool bSameShader = strcmp(pShader->getKey(), szPrevShaderKey) == 0;
         if(!bSameShader) {
-            pShader->bind(pCamera, mvpMatrix, cameraPosition, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers);
+            pShader->bind(pCamera, matModelToView, mvpMatrix, cameraPosition, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers);
             glUniform1f(pShader->m_uniforms[KRShader::KRENGINE_UNIFORM_MATERIAL_SHININESS], pCamera->bDebugSuperShiny ? 20.0 : m_ns );
             strcpy(szPrevShaderKey, pShader->getKey());
         }

KREngine/KREngine/Classes/KRMaterial.h

@@ -76,7 +76,7 @@ public:
     char *getName();
     
 #if TARGET_OS_IPHONE
-    void bind(KRMaterial **prevBoundMaterial, char *szPrevShaderKey, KRCamera *pCamera, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRContext *pContext, KRTexture *pLightMap);
+    void bind(KRMaterial **prevBoundMaterial, char *szPrevShaderKey, KRCamera *pCamera, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRContext *pContext, KRTexture *pLightMap);
     
 #endif
     

KREngine/KREngine/Classes/KRModel.cpp

@@ -67,7 +67,7 @@ KRModel::~KRModel() {
 }
 #if TARGET_OS_IPHONE
 
-void KRModel::render(KRCamera *pCamera, KRContext *pContext, bool bRenderShadowMap, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRTexture *pLightMap) {
+void KRModel::render(KRCamera *pCamera, KRContext *pContext, bool bRenderShadowMap, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRTexture *pLightMap) {
     
     if(m_materials.size() == 0) {
         vector<KRMesh::Submesh *> submeshes = m_pMesh->getSubmeshes();
@@ -104,7 +104,7 @@ void KRModel::render(KRCamera *pCamera, KRContext *pContext, bool bRenderShadowM
                 KRMaterial *pMaterial = m_materials[iSubmesh];
                 
                 if(pMaterial != NULL && pMaterial == (*mat_itr)) {
-                    pMaterial->bind(&pPrevBoundMaterial, szPrevShaderKey, pCamera, mvpMatrix, cameraPosition, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers, pContext, pLightMap);
+                    pMaterial->bind(&pPrevBoundMaterial, szPrevShaderKey, pCamera, matModelToView, mvpMatrix, cameraPosition, lightDirection, pShadowMatrices, shadowDepthTextures, cShadowBuffers, pContext, pLightMap);
                     m_pMesh->renderSubmesh(iSubmesh, &iPrevBuffer);
                 }
             }

KREngine/KREngine/Classes/KRModel.h

@@ -55,7 +55,7 @@ public:
     
 #if TARGET_OS_IPHONE
     
-    void render(KRCamera *pCamera, KRContext *pContext, bool bRenderShadowMap, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRTexture *pLightMap);
+    void render(KRCamera *pCamera, KRContext *pContext, bool bRenderShadowMap, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers, KRTexture *pLightMap);
     
 #endif
     

KREngine/KREngine/Classes/KRShader.cpp

@@ -79,6 +79,7 @@ KRShader::KRShader(char *szKey, std::string options, const GLchar *szVertShaderS
         m_uniforms[KRENGINE_UNIFORM_MATERIAL_SHININESS] = glGetUniformLocation(m_iProgram, "material_shininess");
         
         m_uniforms[KRENGINE_UNIFORM_MVP] = glGetUniformLocation(m_iProgram, "myMVPMatrix");
+        m_uniforms[KRENGINE_UNIFORM_M2V] = glGetUniformLocation(m_iProgram, "model_to_view");
         m_uniforms[KRENGINE_UNIFORM_SHADOWMVP1] = glGetUniformLocation(m_iProgram, "myShadowMVPMatrix1");
         m_uniforms[KRENGINE_UNIFORM_SHADOWMVP2] = glGetUniformLocation(m_iProgram, "myShadowMVPMatrix2");
         m_uniforms[KRENGINE_UNIFORM_SHADOWMVP3] = glGetUniformLocation(m_iProgram, "myShadowMVPMatrix3");
@@ -133,12 +134,13 @@ KRShader::~KRShader() {
     }
 }
 
-void KRShader::bind(KRCamera *pCamera, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers) {
+void KRShader::bind(KRCamera *pCamera, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers) {
     glUseProgram(m_iProgram);
     
 
     // Bind our modelmatrix variable to be a uniform called mvpmatrix in our shaderprogram
     glUniformMatrix4fv(m_uniforms[KRENGINE_UNIFORM_MVP], 1, GL_FALSE, mvpMatrix.getPointer());
+    glUniformMatrix4fv(m_uniforms[KRENGINE_UNIFORM_M2V], 1, GL_FALSE, matModelToView.getPointer());
 
     KRVector3 nLightDir = lightDirection;
     nLightDir.normalize();

KREngine/KREngine/Classes/KRShader.h

@@ -51,7 +51,7 @@ public:
     GLuint getProgram();
     char *getKey();
     
-    void bind(KRCamera *pCamera, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers);
+    void bind(KRCamera *pCamera, KRMat4 &matModelToView, KRMat4 &mvpMatrix, KRVector3 &cameraPosition, KRVector3 &lightDirection, KRMat4 *pShadowMatrices, GLuint *shadowDepthTextures, int cShadowBuffers);
     
     enum {
         KRENGINE_ATTRIB_VERTEX,
@@ -69,6 +69,7 @@ public:
         KRENGINE_UNIFORM_MATERIAL_ALPHA,
         KRENGINE_UNIFORM_MATERIAL_SHININESS,
         KRENGINE_UNIFORM_MVP,
+        KRENGINE_UNIFORM_M2V,
         KRENGINE_UNIFORM_LIGHTDIRECTION,
         KRENGINE_UNIFORM_CAMERAPOS,
         KRENGINE_UNIFORM_DIFFUSETEXTURE,

KREngine/KREngine/Classes/KRShaderManager.cpp

@@ -50,7 +50,7 @@ KRShaderManager::~KRShaderManager() {
 KRShader *KRShaderManager::getShader(KRCamera *pCamera, bool bDiffuseMap, bool bNormalMap, bool bSpecMap, int iShadowQuality, bool bLightMap, bool bDiffuseMapScale,bool bSpecMapScale, bool bNormalMapScale, bool bDiffuseMapOffset, bool bSpecMapOffset, bool bNormalMapOffset) {
 
     char szKey[128];
-    sprintf(szKey, "%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d", pCamera->bEnablePerPixel, bDiffuseMap, bNormalMap, bSpecMap, pCamera->bDebugPSSM, iShadowQuality, /*pCamera->dAmbientR, pCamera->dAmbientG, pCamera->dAmbientB, pCamera->dSunR, pCamera->dSunG, pCamera->dSunB, */pCamera->bEnableAmbient, pCamera->bEnableDiffuse, pCamera->bEnableSpecular, bLightMap, bDiffuseMapScale, bSpecMapScale, bNormalMapScale, bDiffuseMapOffset, bSpecMapOffset, bNormalMapOffset);
+    sprintf(szKey, "%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d_%d", pCamera->bEnablePerPixel, bDiffuseMap, bNormalMap, bSpecMap, pCamera->bDebugPSSM, iShadowQuality, pCamera->bEnableAmbient, pCamera->bEnableDiffuse, pCamera->bEnableSpecular, bLightMap, bDiffuseMapScale, bSpecMapScale, bNormalMapScale, bDiffuseMapOffset, bSpecMapOffset, bNormalMapOffset);
     
     
     /*

KREngine/KREngine/Shaders/ObjectShader.fsh

@@ -25,6 +25,16 @@
 //  or implied, of Kearwood Gilbert.
 //
 
+#define GBUFFER_PASS 0
+
+#if GBUFFER_PASS == 1
+#if HAS_NORMAL_MAP == 1
+varying highp mat3 tangent_to_view;
+#else
+uniform highp mat4 model_to_view;
+#endif
+#endif
+
 uniform lowp vec3       material_ambient, material_diffuse, material_specular;
 uniform lowp float   material_alpha;
 
@@ -178,36 +188,53 @@ void main()
         specularFactor = 0.0;
     }
 #endif
+
     
-#if ENABLE_AMBIENT
+#if GBUFFER_PASS == 0
-    // -------------------- Add ambient light and alpha component --------------------
+        
-    gl_FragColor = vec4(vec3(diffuseMaterial) * material_ambient, material_alpha);
+    #if ENABLE_AMBIENT
-#else
+        // -------------------- Add ambient light and alpha component --------------------
-    gl_FragColor = vec4(0.0, 0.0, 0.0, material_alpha);
+        gl_FragColor = vec4(vec3(diffuseMaterial) * material_ambient, material_alpha);
-#endif
+    #else
-    
+        gl_FragColor = vec4(0.0, 0.0, 0.0, material_alpha);
-#if ENABLE_DIFFUSE
+    #endif
-    // -------------------- Add diffuse light --------------------
+        
-    gl_FragColor += vec4(vec3(diffuseMaterial) * material_diffuse * lamberFactor, 0.0);
+    #if ENABLE_DIFFUSE
-#endif
+        // -------------------- Add diffuse light --------------------
-    
+        gl_FragColor += vec4(vec3(diffuseMaterial) * material_diffuse * lamberFactor, 0.0);
-#if ENABLE_SPECULAR
+    #endif
-    
+        
-    // -------------------- Add specular light --------------------
+    #if ENABLE_SPECULAR
-#if HAS_SPEC_MAP == 1    
+        
-    gl_FragColor += vec4(material_specular * vec3(texture2D(specularTexture, spec_uv)) * specularFactor, 0.0);
+        // -------------------- Add specular light --------------------
-#else
+    #if HAS_SPEC_MAP == 1    
-    gl_FragColor += vec4(material_specular * specularFactor, 0.0);
+        gl_FragColor += vec4(material_specular * vec3(texture2D(specularTexture, spec_uv)) * specularFactor, 0.0);
-#endif
+    #else
-    
+        gl_FragColor += vec4(material_specular * specularFactor, 0.0);
-#endif
+    #endif
+        
+    #endif
 
 
-    // -------------------- Multiply light map -------------------- 
+        // -------------------- Multiply light map -------------------- 
+        
+    #if HAS_LIGHT_MAP
+        mediump vec3 shadowColor = vec3(texture2D(shadowTexture1, shadowCoord));
+        gl_FragColor = vec4(gl_FragColor.r * shadowColor.r, gl_FragColor.g * shadowColor.g, gl_FragColor.b * shadowColor.b, 1.0);
+    #endif
+#endif
     
-#if HAS_LIGHT_MAP
+#if GBUFFER_PASS == 1
-    mediump vec3 shadowColor = vec3(texture2D(shadowTexture1, shadowCoord));
+    
-    gl_FragColor = vec4(gl_FragColor.r * shadowColor.r, gl_FragColor.g * shadowColor.g, gl_FragColor.b * shadowColor.b, 1.0);
+    //gl_FragColor = vec4((normal + 1.0) / 2.0, 1.0f);
+    
+#if HAS_NORMAL_MAP == 1
+    mediump vec3 view_space_normal = tangent_to_view * normal;
+#else
+    mediump vec3 view_space_normal = vec3(model_to_view * vec4(normal, 1.0));
+#endif
+    gl_FragColor = vec4(view_space_normal * 0.5 + 0.5, 1.0);
+
 #endif
     
 }

KREngine/KREngine/Shaders/ObjectShader.vsh

@@ -29,11 +29,21 @@
 //  or implied, of Kearwood Gilbert.
 //
 
+#define GBUFFER_PASS 0
+
 attribute highp vec3	myVertex, myNormal;
 attribute highp vec3    myTangent;
 attribute mediump vec2	myUV;
 attribute mediump vec2   shadowuv;
 uniform highp mat4      myMVPMatrix, myShadowMVPMatrix1,myShadowMVPMatrix2,myShadowMVPMatrix3; // mvpmatrix is the result of multiplying the model, view, and projection matrices 
+
+#if GBUFFER_PASS == 1 && HAS_NORMAL_MAP == 1
+uniform highp mat4 model_to_view;
+varying highp mat3 tangent_to_view;
+
+#endif
+
+
 // uniform lowp vec3       material_ambient, material_diffuse, material_specular;
 uniform highp vec3      lightDirection; // Must be normalized before entering shader
 uniform highp vec3      cameraPosition;
@@ -187,12 +197,15 @@ void main()
 #endif
     
 
+#if (HAS_NORMAL_MAP == 1 && ENABLE_PER_PIXEL == 1) || GBUFFER_PASS == 1
+    mediump vec3 a_bitangent = cross(myNormal, myTangent);
+#endif
+    
      // ----------- Directional Light (Sun) -----------
-     
 #if HAS_NORMAL_MAP == 1 && ENABLE_PER_PIXEL == 1
     // ----- Calculate per-pixel lighting in tangent space, for normal mapping ------
     mediump vec3 eyeVec = normalize(cameraPosition - myVertex);
-    mediump vec3 a_bitangent = cross(myNormal, myTangent);
+    
     lightVec = normalize(vec3(dot(lightDirection, myTangent), dot(lightDirection, a_bitangent), dot(lightDirection, myNormal)));
     halfVec = normalize(vec3(dot(eyeVec, myTangent), dot(eyeVec, a_bitangent), dot(eyeVec, myNormal)));
     halfVec = normalize(halfVec + lightVec); // Normalizing anyways, no need to divide by 2
@@ -211,4 +224,11 @@ void main()
     specularFactor = max(0.0,pow(dot(halfVec,myNormal), material_shininess));
 #endif
 #endif
+
+    
+#if GBUFFER_PASS == 1 && HAS_NORMAL_MAP == 1
+    tangent_to_view[0] = vec3(model_to_view * vec4(myTangent, 1.0));
+    tangent_to_view[1] = vec3(model_to_view * vec4(a_bitangent, 1.0));
+    tangent_to_view[2] = vec3(model_to_view * vec4(myNormal, 1.0));
+#endif
 }