REDESIGN: Move GenTexture*() functions to PBR example #721

Removed functions from rlgl module.

3 files changed, 423 insertions, 426 deletions

diff --git a/examples/models/models_material_pbr.c b/examples/models/models_material_pbr.c
index 36f03636..ed82d397 100644
--- a/examples/models/models_material_pbr.c
+++ b/examples/models/models_material_pbr.c
@@ -28,6 +28,12 @@
 #define LIGHT_DISTANCE 1000.0f
 #define LIGHT_HEIGHT 1.0f
 
+// PBR texture maps generation
+static TextureCubemap GenTextureCubemap(Shader shader, Texture2D panorama, int size, int format); // Generate cubemap (6 faces) from equirectangular (panorama) texture
+static TextureCubemap GenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size);      // Generate irradiance cubemap using cubemap texture
+static TextureCubemap GenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size);       // Generate prefilter cubemap using cubemap texture
+static Texture2D GenTextureBRDF(Shader shader, int size);              // Generate a generic BRDF texture
+
 // PBR material loading
 static Material LoadMaterialPBR(Color albedo, float metalness, float roughness);
 
@@ -188,7 +194,7 @@ static Material LoadMaterialPBR(Color albedo, float metalness, float roughness)
     Shader shdrCubemap = LoadShader("resources/shaders/glsl100/cubemap.vs", "resources/shaders/glsl100/cubemap.fs");
 #endif
     SetShaderValue(shdrCubemap, GetShaderLocation(shdrCubemap, "equirectangularMap"), (int[1]){ 0 }, SHADER_UNIFORM_INT);
-    TextureCubemap cubemap = rlGenTextureCubemap(shdrCubemap, panorama, CUBEMAP_SIZE, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
+    TextureCubemap cubemap = GenTextureCubemap(shdrCubemap, panorama, CUBEMAP_SIZE, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
     UnloadTexture(panorama);
     UnloadShader(shdrCubemap);
     //--------------------------------------------------------------------------------------------------------
@@ -202,7 +208,7 @@ static Material LoadMaterialPBR(Color albedo, float metalness, float roughness)
     Shader shdrIrradiance = LoadShader("resources/shaders/glsl100/skybox.vs", "resources/shaders/glsl100/irradiance.fs");
 #endif
     SetShaderValue(shdrIrradiance, GetShaderLocation(shdrIrradiance, "environmentMap"), (int[1]){ 0 }, SHADER_UNIFORM_INT);
-    mat.maps[MATERIAL_MAP_IRRADIANCE].texture = rlGenTextureIrradiance(shdrIrradiance, cubemap, IRRADIANCE_SIZE);
+    mat.maps[MATERIAL_MAP_IRRADIANCE].texture = GenTextureIrradiance(shdrIrradiance, cubemap, IRRADIANCE_SIZE);
     UnloadShader(shdrIrradiance);
     //--------------------------------------------------------------------------------------------------------
     
@@ -215,7 +221,7 @@ static Material LoadMaterialPBR(Color albedo, float metalness, float roughness)
     Shader shdrPrefilter = LoadShader("resources/shaders/glsl100/skybox.vs", "resources/shaders/glsl100/prefilter.fs");
 #endif
     SetShaderValue(shdrPrefilter, GetShaderLocation(shdrPrefilter, "environmentMap"), (int[1]){ 0 }, SHADER_UNIFORM_INT);
-    mat.maps[MATERIAL_MAP_PREFILTER].texture = rlGenTexturePrefilter(shdrPrefilter, cubemap, PREFILTERED_SIZE);
+    mat.maps[MATERIAL_MAP_PREFILTER].texture = GenTexturePrefilter(shdrPrefilter, cubemap, PREFILTERED_SIZE);
     UnloadTexture(cubemap);
     UnloadShader(shdrPrefilter);
     //--------------------------------------------------------------------------------------------------------
@@ -227,9 +233,315 @@ static Material LoadMaterialPBR(Color albedo, float metalness, float roughness)
 #else
     Shader shdrBRDF = LoadShader("resources/shaders/glsl100/brdf.vs", "resources/shaders/glsl100/brdf.fs");
 #endif
-    mat.maps[MATERIAL_MAP_BRDG].texture = rlGenTextureBRDF(shdrBRDF, BRDF_SIZE);
+    mat.maps[MATERIAL_MAP_BRDG].texture = GenTextureBRDF(shdrBRDF, BRDF_SIZE);
     UnloadShader(shdrBRDF);
     //--------------------------------------------------------------------------------------------------------
 
     return mat;
 }
+
+// Texture maps generation (PBR)
+//-------------------------------------------------------------------------------------------
+// Generate cubemap texture from HDR texture
+TextureCubemap GenTextureCubemap(Shader shader, Texture2D panorama, int size, int format)
+{
+    TextureCubemap cubemap = { 0 };
+#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
+    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
+
+    // STEP 1: Setup framebuffer
+    //------------------------------------------------------------------------------------------
+    unsigned int rbo = rlLoadTextureDepth(size, size, true);
+    cubemap.id = rlLoadTextureCubemap(NULL, size, format);
+
+    unsigned int fbo = rlLoadFramebuffer(size, size);
+    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
+    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X, 0);
+
+    // Check if framebuffer is complete with attachments (valid)
+    if (rlFramebufferComplete(fbo)) TraceLog(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", fbo);
+    //------------------------------------------------------------------------------------------
+
+    // STEP 2: Draw to framebuffer
+    //------------------------------------------------------------------------------------------
+    // NOTE: Shader is used to convert HDR equirectangular environment map to cubemap equivalent (6 faces)
+    rlEnableShader(shader.id);
+
+    // Define projection matrix and send it to shader
+    Matrix matFboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
+    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], matFboProjection);
+
+    // Define view matrix for every side of the cubemap
+    Matrix fboViews[6] = {
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
+    };
+
+#if !defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
+    rlActiveTextureSlot(0);
+    rlEnableTexture(panorama.id);
+#endif
+
+    rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
+
+    for (int i = 0; i < 6; i++)
+    {
+        rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
+        rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i, 0);
+
+        rlEnableFramebuffer(fbo);
+#if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
+        rlSetTexture(panorama.id);   // WARNING: It must be called after enabling current framebuffer if using internal batch system!
+#endif
+        rlClearScreenBuffers();
+        rlLoadDrawCube();
+
+#if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
+        // Using internal batch system instead of raw OpenGL cube creating+drawing
+        // NOTE: DrawCubeV() is actually provided by models.c! -> GenTextureCubemap() should be moved to user code!
+        DrawCubeV(Vector3Zero(), Vector3One(), WHITE);
+        rlDrawRenderBatch(RLGL.currentBatch);
+#endif
+    }
+    //------------------------------------------------------------------------------------------
+
+    // STEP 3: Unload framebuffer and reset state
+    //------------------------------------------------------------------------------------------
+    rlDisableShader();          // Unbind shader
+    rlDisableTexture();         // Unbind texture
+    rlDisableFramebuffer();     // Unbind framebuffer
+    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+
+    // Reset viewport dimensions to default
+    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
+    rlEnableBackfaceCulling();
+    //------------------------------------------------------------------------------------------
+
+    cubemap.width = size;
+    cubemap.height = size;
+    cubemap.mipmaps = 1;
+    cubemap.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
+#endif
+    return cubemap;
+}
+
+// Generate irradiance texture using cubemap data
+TextureCubemap GenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size)
+{
+    TextureCubemap irradiance = { 0 };
+
+#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
+    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
+
+    // STEP 1: Setup framebuffer
+    //------------------------------------------------------------------------------------------
+    unsigned int rbo = rlLoadTextureDepth(size, size, true);
+    irradiance.id = rlLoadTextureCubemap(NULL, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
+
+    unsigned int fbo = rlLoadFramebuffer(size, size);
+    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
+    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X, 0);
+    //------------------------------------------------------------------------------------------
+
+    // STEP 2: Draw to framebuffer
+    //------------------------------------------------------------------------------------------
+    // NOTE: Shader is used to solve diffuse integral by convolution to create an irradiance cubemap
+    rlEnableShader(shader.id);
+
+    // Define projection matrix and send it to shader
+    Matrix matFboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
+    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], matFboProjection);
+
+    // Define view matrix for every side of the cubemap
+    Matrix fboViews[6] = {
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
+    };
+
+    rlActiveTextureSlot(0);
+    rlEnableTextureCubemap(cubemap.id);
+
+    rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
+
+    for (int i = 0; i < 6; i++)
+    {
+        rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
+        rlFramebufferAttach(fbo, irradiance.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i, 0);
+
+        rlEnableFramebuffer(fbo);
+        rlClearScreenBuffers();
+        rlLoadDrawCube();
+    }
+    //------------------------------------------------------------------------------------------
+
+    // STEP 3: Unload framebuffer and reset state
+    //------------------------------------------------------------------------------------------
+    rlDisableShader();          // Unbind shader
+    rlDisableTexture();         // Unbind texture
+    rlDisableFramebuffer();     // Unbind framebuffer
+    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+
+    // Reset viewport dimensions to default
+    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
+    rlEnableBackfaceCulling();
+    //------------------------------------------------------------------------------------------
+
+    irradiance.width = size;
+    irradiance.height = size;
+    irradiance.mipmaps = 1;
+    irradiance.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
+#endif
+    return irradiance;
+}
+
+// Generate prefilter texture using cubemap data
+TextureCubemap GenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size)
+{
+    TextureCubemap prefilter = { 0 };
+
+#if defined(GRAPHICS_API_OPENGL_33) // || defined(GRAPHICS_API_OPENGL_ES2)
+    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
+
+    // STEP 1: Setup framebuffer
+    //------------------------------------------------------------------------------------------
+    unsigned int rbo = rlLoadTextureDepth(size, size, true);
+    prefilter.id = rlLoadTextureCubemap(NULL, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
+    rlTextureParameters(prefilter.id, RL_TEXTURE_MIN_FILTER, RL_TEXTURE_FILTER_MIP_LINEAR);
+
+    unsigned int fbo = rlLoadFramebuffer(size, size);
+    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
+    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X, 0);
+    //------------------------------------------------------------------------------------------
+
+    // Generate mipmaps for the prefiltered HDR texture
+    //glGenerateMipmap(GL_TEXTURE_CUBE_MAP);    // TODO!
+
+    // STEP 2: Draw to framebuffer
+    //------------------------------------------------------------------------------------------
+    // NOTE: Shader is used to prefilter HDR and store data into mipmap levels
+
+    // Define projection matrix and send it to shader
+    Matrix fboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
+    rlEnableShader(shader.id);
+    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], fboProjection);
+
+    // Define view matrix for every side of the cubemap
+    Matrix fboViews[6] = {
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
+        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
+    };
+
+    rlActiveTextureSlot(0);
+    rlEnableTextureCubemap(cubemap.id);
+
+    // TODO: Locations should be taken out of this function... too shader dependant...
+    int roughnessLoc = rlGetLocationUniform(shader.id, "roughness");
+
+    rlEnableFramebuffer(fbo);
+
+    #define MAX_MIPMAP_LEVELS   5   // Max number of prefilter texture mipmaps
+
+    for (int mip = 0; mip < MAX_MIPMAP_LEVELS; mip++)
+    {
+        // Resize framebuffer according to mip-level size.
+        unsigned int mipWidth  = size*(int)powf(0.5f, (float)mip);
+        unsigned int mipHeight = size*(int)powf(0.5f, (float)mip);
+
+        rlViewport(0, 0, mipWidth, mipHeight);
+
+        //glBindRenderbuffer(GL_RENDERBUFFER, rbo);
+        //glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, mipWidth, mipHeight);
+
+        float roughness = (float)mip/(float)(MAX_MIPMAP_LEVELS - 1);
+        rlSetUniform(roughnessLoc, &roughness, SHADER_UNIFORM_FLOAT, 1);
+
+        for (int i = 0; i < 6; i++)
+        {
+            rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
+            rlFramebufferAttach(fbo, prefilter.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i, mip);
+            
+            rlClearScreenBuffers();
+            rlLoadDrawCube();
+        }
+    }
+    //------------------------------------------------------------------------------------------
+
+    // STEP 3: Unload framebuffer and reset state
+    //------------------------------------------------------------------------------------------
+    rlDisableShader();          // Unbind shader
+    rlDisableTexture();         // Unbind texture
+    rlDisableFramebuffer();     // Unbind framebuffer
+    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+
+    // Reset viewport dimensions to default
+    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
+    rlEnableBackfaceCulling();
+    //------------------------------------------------------------------------------------------
+
+    prefilter.width = size;
+    prefilter.height = size;
+    prefilter.mipmaps = MAX_MIPMAP_LEVELS;
+    prefilter.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
+#endif
+    return prefilter;
+}
+
+// Generate BRDF texture using cubemap data
+// TODO: Review implementation: https://github.com/HectorMF/BRDFGenerator
+Texture2D GenTextureBRDF(Shader shader, int size)
+{
+    Texture2D brdf = { 0 };
+#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
+    // STEP 1: Setup framebuffer
+    //------------------------------------------------------------------------------------------
+    unsigned int rbo = rlLoadTextureDepth(size, size, true);
+    brdf.id = rlLoadTexture(NULL, size, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32, 1);
+
+    unsigned int fbo = rlLoadFramebuffer(size, size);
+    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
+    rlFramebufferAttach(fbo, brdf.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D, 0);
+    //------------------------------------------------------------------------------------------
+
+    // STEP 2: Draw to framebuffer
+    //------------------------------------------------------------------------------------------
+    // NOTE: Render BRDF LUT into a quad using FBO
+    rlEnableShader(shader.id);
+
+    rlViewport(0, 0, size, size);
+
+    rlEnableFramebuffer(fbo);
+    rlClearScreenBuffers();
+
+    rlLoadDrawQuad();
+    //------------------------------------------------------------------------------------------
+
+    // STEP 3: Unload framebuffer and reset state
+    //------------------------------------------------------------------------------------------
+    rlDisableShader();          // Unbind shader
+    rlDisableTexture();         // Unbind texture
+    rlDisableFramebuffer();     // Unbind framebuffer
+    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+
+    // Reset viewport dimensions to default
+    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
+    //------------------------------------------------------------------------------------------
+
+    brdf.width = size;
+    brdf.height = size;
+    brdf.mipmaps = 1;
+    brdf.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
+#endif
+    return brdf;
+}
diff --git a/src/rlgl.h b/src/rlgl.h
index f5f41784..f6de9ec2 100644
--- a/src/rlgl.h
+++ b/src/rlgl.h
@@ -624,7 +624,7 @@ RLAPI unsigned char *rlReadScreenPixels(int width, int height);           // Rea
 
 // Framebuffer management (fbo)
 RLAPI unsigned int rlLoadFramebuffer(int width, int height);              // Load an empty framebuffer
-RLAPI void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType);  // Attach texture/renderbuffer to a framebuffer
+RLAPI void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType, int mipLevel);  // Attach texture/renderbuffer to a framebuffer
 RLAPI bool rlFramebufferComplete(unsigned int id);                        // Verify framebuffer is complete
 RLAPI void rlUnloadFramebuffer(unsigned int id);                          // Delete framebuffer from GPU
 
@@ -651,13 +651,9 @@ RLAPI void rlSetMatrixModelview(Matrix view);                             // Set
 RLAPI void rlSetMatrixProjectionStereo(Matrix right, Matrix left);        // Set eyes projection matrices for stereo rendering
 RLAPI void rlSetMatrixViewOffsetStereo(Matrix right, Matrix left);        // Set eyes view offsets matrices for stereo rendering
 
-// Texture maps generation (PBR)
-// TODO: Redesign or remove to avoid requiring external shaders
-RLAPI TextureCubemap rlGenTextureCubemap(Shader shader, Texture2D panorama, int size, int format); // Generate cubemap (6 faces) from equirectangular (panorama) texture
-RLAPI TextureCubemap rlGenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size);      // Generate irradiance cubemap using cubemap texture
-RLAPI TextureCubemap rlGenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size);       // Generate prefilter cubemap using cubemap texture
-RLAPI Texture2D rlGenTextureBRDF(Shader shader, int size);              // Generate a generic BRDF texture
-
+// Quick and dirty cube/quad buffers load->draw->unload
+RLAPI void rlLoadDrawCube(void);     // Load and draw a cube
+RLAPI void rlLoadDrawQuad(void);     // Load and draw a quad
 #if defined(__cplusplus)
 }
 #endif
@@ -912,9 +908,6 @@ static PFNGLVERTEXATTRIBDIVISOREXTPROC glVertexAttribDivisor = NULL;
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
 static Shader rlLoadShaderDefault(void);    // Load default shader (just vertex positioning and texture coloring)
 static void rlUnloadShaderDefault(void);    // Unload default shader
-
-static void rlGenDrawCube(void);            // Generate and draw cube
-static void rlGenDrawQuad(void);            // Generate and draw quad
 #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_ES2
 #if defined(GRAPHICS_API_OPENGL_11)
 static int rlGenerateMipmapsData(unsigned char *data, int baseWidth, int baseHeight);   // Generate mipmaps data on CPU side
@@ -2966,7 +2959,7 @@ unsigned int rlLoadFramebuffer(int width, int height)
 
 // Attach color buffer texture to an fbo (unloads previous attachment)
 // NOTE: Attach type: 0-Color, 1-Depth renderbuffer, 2-Depth texture
-void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType)
+void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType, int texType, int mipLevel)
 {
 #if (defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)) && defined(SUPPORT_RENDER_TEXTURES_HINT)
     glBindFramebuffer(GL_FRAMEBUFFER, fboId);
@@ -2982,20 +2975,20 @@ void rlFramebufferAttach(unsigned int fboId, unsigned int texId, int attachType,
         case RL_ATTACHMENT_COLOR_CHANNEL6:
         case RL_ATTACHMENT_COLOR_CHANNEL7:
         {
-            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_2D, texId, 0);
+            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_2D, texId, mipLevel);
             else if (texType == RL_ATTACHMENT_RENDERBUFFER) glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_RENDERBUFFER, texId);
-            else if (texType >= RL_ATTACHMENT_CUBEMAP_POSITIVE_X) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_CUBE_MAP_POSITIVE_X + texType, texId, 0);
+            else if (texType >= RL_ATTACHMENT_CUBEMAP_POSITIVE_X) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0 + attachType, GL_TEXTURE_CUBE_MAP_POSITIVE_X + texType, texId, mipLevel);
 
         } break;
         case RL_ATTACHMENT_DEPTH:
         {
-            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, texId, 0);
+            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, texId, mipLevel);
             else if (texType == RL_ATTACHMENT_RENDERBUFFER)  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, texId);
 
         } break;
         case RL_ATTACHMENT_STENCIL:
         {
-            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, texId, 0);
+            if (texType == RL_ATTACHMENT_TEXTURE2D) glFramebufferTexture2D(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_TEXTURE_2D, texId, mipLevel);
             else if (texType == RL_ATTACHMENT_RENDERBUFFER)  glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_STENCIL_ATTACHMENT, GL_RENDERBUFFER, texId);
 
         } break;
@@ -3623,312 +3616,119 @@ void rlSetMatrixViewOffsetStereo(Matrix right, Matrix left)
 #endif
 }
 
-// Texture maps generation (PBR)
-//-------------------------------------------------------------------------------------------
-// Generate cubemap texture from HDR texture
-TextureCubemap rlGenTextureCubemap(Shader shader, Texture2D panorama, int size, int format)
+// Load and draw a 1x1 XY quad in NDC
+void rlLoadDrawQuad(void)
 {
-    TextureCubemap cubemap = { 0 };
-#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
-    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
-
-    // STEP 1: Setup framebuffer
-    //------------------------------------------------------------------------------------------
-    unsigned int rbo = rlLoadTextureDepth(size, size, true);
-    cubemap.id = rlLoadTextureCubemap(NULL, size, format);
-
-    unsigned int fbo = rlLoadFramebuffer(size, size);
-    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
-    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
-
-    // Check if framebuffer is complete with attachments (valid)
-    if (rlFramebufferComplete(fbo)) TRACELOG(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", fbo);
-    //------------------------------------------------------------------------------------------
-
-    // STEP 2: Draw to framebuffer
-    //------------------------------------------------------------------------------------------
-    // NOTE: Shader is used to convert HDR equirectangular environment map to cubemap equivalent (6 faces)
-    rlEnableShader(shader.id);
-
-    // Define projection matrix and send it to shader
-    Matrix matFboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
-    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], matFboProjection);
-
-    // Define view matrix for every side of the cubemap
-    Matrix fboViews[6] = {
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
-    };
-
-#if !defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
-    rlActiveTextureSlot(0);
-    rlEnableTexture(panorama.id);
-#endif
-
-    rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
-
-    for (int i = 0; i < 6; i++)
-    {
-        rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
-        rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);
-
-        rlEnableFramebuffer(fbo);
-#if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
-        rlSetTexture(panorama.id);   // WARNING: It must be called after enabling current framebuffer if using internal batch system!
-#endif
-        rlClearScreenBuffers();
-        rlGenDrawCube();
-
-#if defined(GENTEXTURECUBEMAP_USE_BATCH_SYSTEM)
-        // Using internal batch system instead of raw OpenGL cube creating+drawing
-        // NOTE: DrawCubeV() is actually provided by models.c! -> rlGenTextureCubemap() should be moved to user code!
-        DrawCubeV(Vector3Zero(), Vector3One(), WHITE);
-        rlDrawRenderBatch(RLGL.currentBatch);
-#endif
-    }
-    //------------------------------------------------------------------------------------------
-
-    // STEP 3: Unload framebuffer and reset state
-    //------------------------------------------------------------------------------------------
-    rlDisableShader();          // Unbind shader
-    rlDisableTexture();         // Unbind texture
-    rlDisableFramebuffer();     // Unbind framebuffer
-    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
-
-    // Reset viewport dimensions to default
-    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
-    rlEnableBackfaceCulling();
-    //------------------------------------------------------------------------------------------
-
-    cubemap.width = size;
-    cubemap.height = size;
-    cubemap.mipmaps = 1;
-    cubemap.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
-#endif
-    return cubemap;
-}
-
-// Generate irradiance texture using cubemap data
-TextureCubemap rlGenTextureIrradiance(Shader shader, TextureCubemap cubemap, int size)
-{
-    TextureCubemap irradiance = { 0 };
-
-#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
-    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
-
-    // STEP 1: Setup framebuffer
-    //------------------------------------------------------------------------------------------
-    unsigned int rbo = rlLoadTextureDepth(size, size, true);
-    irradiance.id = rlLoadTextureCubemap(NULL, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
-
-    unsigned int fbo = rlLoadFramebuffer(size, size);
-    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
-    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
-    //------------------------------------------------------------------------------------------
-
-    // STEP 2: Draw to framebuffer
-    //------------------------------------------------------------------------------------------
-    // NOTE: Shader is used to solve diffuse integral by convolution to create an irradiance cubemap
-    rlEnableShader(shader.id);
-
-    // Define projection matrix and send it to shader
-    Matrix matFboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
-    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], matFboProjection);
-
-    // Define view matrix for every side of the cubemap
-    Matrix fboViews[6] = {
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
-    };
-
-    rlActiveTextureSlot(0);
-    rlEnableTextureCubemap(cubemap.id);
-
-    rlViewport(0, 0, size, size);   // Set viewport to current fbo dimensions
-
-    for (int i = 0; i < 6; i++)
-    {
-        rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
-        rlFramebufferAttach(fbo, irradiance.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);
+    unsigned int quadVAO = 0;
+    unsigned int quadVBO = 0;
 
-        rlEnableFramebuffer(fbo);
-        rlClearScreenBuffers();
-        rlGenDrawCube();
-    }
-    //------------------------------------------------------------------------------------------
-
-    // STEP 3: Unload framebuffer and reset state
-    //------------------------------------------------------------------------------------------
-    rlDisableShader();          // Unbind shader
-    rlDisableTexture();         // Unbind texture
-    rlDisableFramebuffer();     // Unbind framebuffer
-    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
-
-    // Reset viewport dimensions to default
-    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
-    rlEnableBackfaceCulling();
-    //------------------------------------------------------------------------------------------
-
-    irradiance.width = size;
-    irradiance.height = size;
-    irradiance.mipmaps = 1;
-    irradiance.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
-#endif
-    return irradiance;
-}
-
-// Generate prefilter texture using cubemap data
-TextureCubemap rlGenTexturePrefilter(Shader shader, TextureCubemap cubemap, int size)
-{
-    TextureCubemap prefilter = { 0 };
-
-#if defined(GRAPHICS_API_OPENGL_33) // || defined(GRAPHICS_API_OPENGL_ES2)
-    rlDisableBackfaceCulling();     // Disable backface culling to render inside the cube
-
-    // STEP 1: Setup framebuffer
-    //------------------------------------------------------------------------------------------
-    unsigned int rbo = rlLoadTextureDepth(size, size, true);
-    prefilter.id = rlLoadTextureCubemap(NULL, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32);
-    rlTextureParameters(prefilter.id, RL_TEXTURE_MIN_FILTER, RL_TEXTURE_FILTER_MIP_LINEAR);
-
-    unsigned int fbo = rlLoadFramebuffer(size, size);
-    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
-    rlFramebufferAttach(fbo, cubemap.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X);
-    //------------------------------------------------------------------------------------------
-
-    // Generate mipmaps for the prefiltered HDR texture
-    glGenerateMipmap(GL_TEXTURE_CUBE_MAP);
-
-    // STEP 2: Draw to framebuffer
-    //------------------------------------------------------------------------------------------
-    // NOTE: Shader is used to prefilter HDR and store data into mipmap levels
-
-    // Define projection matrix and send it to shader
-    Matrix fboProjection = MatrixPerspective(90.0*DEG2RAD, 1.0, RL_CULL_DISTANCE_NEAR, RL_CULL_DISTANCE_FAR);
-    rlEnableShader(shader.id);
-    rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_PROJECTION], fboProjection);
-
-    // Define view matrix for every side of the cubemap
-    Matrix fboViews[6] = {
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){ -1.0f,  0.0f,  0.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f,  1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f, -1.0f,  0.0f }, (Vector3){ 0.0f,  0.0f, -1.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f,  1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f }),
-        MatrixLookAt((Vector3){ 0.0f, 0.0f, 0.0f }, (Vector3){  0.0f,  0.0f, -1.0f }, (Vector3){ 0.0f, -1.0f,  0.0f })
+    float vertices[] = {
+         // Positions         Texcoords
+        -1.0f,  1.0f, 0.0f,   0.0f, 1.0f,
+        -1.0f, -1.0f, 0.0f,   0.0f, 0.0f,
+         1.0f,  1.0f, 0.0f,   1.0f, 1.0f,
+         1.0f, -1.0f, 0.0f,   1.0f, 0.0f,
     };
 
-    rlActiveTextureSlot(0);
-    rlEnableTextureCubemap(cubemap.id);
-
-    // TODO: Locations should be taken out of this function... too shader dependant...
-    int roughnessLoc = rlGetLocationUniform(shader.id, "roughness");
-
-    rlEnableFramebuffer(fbo);
-
-    #define MAX_MIPMAP_LEVELS   5   // Max number of prefilter texture mipmaps
-
-    for (int mip = 0; mip < MAX_MIPMAP_LEVELS; mip++)
-    {
-        // Resize framebuffer according to mip-level size.
-        unsigned int mipWidth  = size*(int)powf(0.5f, (float)mip);
-        unsigned int mipHeight = size*(int)powf(0.5f, (float)mip);
-
-        rlViewport(0, 0, mipWidth, mipHeight);
-
-        glBindRenderbuffer(GL_RENDERBUFFER, rbo);
-        glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, mipWidth, mipHeight);
-
-        float roughness = (float)mip/(float)(MAX_MIPMAP_LEVELS - 1);
-        rlSetUniform(roughnessLoc, &roughness, SHADER_UNIFORM_FLOAT);
+    // Gen VAO to contain VBO
+    glGenVertexArrays(1, &quadVAO);
+    glBindVertexArray(quadVAO);
 
-        for (int i = 0; i < 6; i++)
-        {
-            //rlEnableShader(shader.id);
-            rlSetUniformMatrix(shader.locs[SHADER_LOC_MATRIX_VIEW], fboViews[i]);
-            glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, prefilter.id, mip);
-            //rlFramebufferAttach(fbo, irradiance.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_CUBEMAP_POSITIVE_X + i);  // TODO: Support mip levels?
-
-            rlEnableFramebuffer(fbo);
-            rlClearScreenBuffers();
-            rlGenDrawCube();
-        }
-    }
-    //------------------------------------------------------------------------------------------
+    // Gen and fill vertex buffer (VBO)
+    glGenBuffers(1, &quadVBO);
+    glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), &vertices, GL_STATIC_DRAW);
 
-    // STEP 3: Unload framebuffer and reset state
-    //------------------------------------------------------------------------------------------
-    rlDisableShader();          // Unbind shader
-    rlDisableTexture();         // Unbind texture
-    rlDisableFramebuffer();     // Unbind framebuffer
-    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+    // Bind vertex attributes (position, texcoords)
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)0); // Positions
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)(3*sizeof(float))); // Texcoords
 
-    // Reset viewport dimensions to default
-    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
-    rlEnableBackfaceCulling();
-    //------------------------------------------------------------------------------------------
+    // Draw quad
+    glBindVertexArray(quadVAO);
+    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
+    glBindVertexArray(0);
 
-    prefilter.width = size;
-    prefilter.height = size;
-    //prefilter.mipmaps = 1 + (int)floor(log(size)/log(2)); // MAX_MIPMAP_LEVELS
-    //prefilter.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
-#endif
-    return prefilter;
+    // Delete buffers (VBO and VAO)
+    glDeleteBuffers(1, &quadVBO);
+    glDeleteVertexArrays(1, &quadVAO);
 }
 
-// Generate BRDF texture using cubemap data
-// TODO: Review implementation: https://github.com/HectorMF/BRDFGenerator
-Texture2D rlGenTextureBRDF(Shader shader, int size)
+// Load and draw a 1x1 3D cube in NDC
+void rlLoadDrawCube(void)
 {
-    Texture2D brdf = { 0 };
-#if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
-    // STEP 1: Setup framebuffer
-    //------------------------------------------------------------------------------------------
-    unsigned int rbo = rlLoadTextureDepth(size, size, true);
-    brdf.id = rlLoadTexture(NULL, size, size, PIXELFORMAT_UNCOMPRESSED_R32G32B32, 1);
-
-    unsigned int fbo = rlLoadFramebuffer(size, size);
-    rlFramebufferAttach(fbo, rbo, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
-    rlFramebufferAttach(fbo, brdf.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D);
-    //------------------------------------------------------------------------------------------
+    unsigned int cubeVAO = 0;
+    unsigned int cubeVBO = 0;
 
-    // STEP 2: Draw to framebuffer
-    //------------------------------------------------------------------------------------------
-    // NOTE: Render BRDF LUT into a quad using FBO
-    rlEnableShader(shader.id);
+    float vertices[] = {
+         // Positions          Normals               Texcoords
+        -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
+         1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
+         1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 0.0f,
+         1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
+        -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
+        -1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 1.0f,
+        -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
+         1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 0.0f,
+         1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
+         1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
+        -1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 1.0f,
+        -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
+        -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
+        -1.0f,  1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
+        -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
+        -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
+        -1.0f, -1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
+        -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
+         1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
+         1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
+         1.0f,  1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
+         1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
+         1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
+         1.0f, -1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
+        -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
+         1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 1.0f,
+         1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
+         1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
+        -1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 0.0f,
+        -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
+        -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
+         1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
+         1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 1.0f,
+         1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
+        -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
+        -1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 0.0f
+    };
 
-    rlViewport(0, 0, size, size);
+    // Gen VAO to contain VBO
+    glGenVertexArrays(1, &cubeVAO);
+    glBindVertexArray(cubeVAO);
 
-    rlEnableFramebuffer(fbo);
-    rlClearScreenBuffers();
-    rlGenDrawQuad();
-    //------------------------------------------------------------------------------------------
+    // Gen and fill vertex buffer (VBO)
+    glGenBuffers(1, &cubeVBO);
+    glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
 
-    // STEP 3: Unload framebuffer and reset state
-    //------------------------------------------------------------------------------------------
-    rlDisableShader();          // Unbind shader
-    rlDisableTexture();         // Unbind texture
-    rlDisableFramebuffer();     // Unbind framebuffer
-    rlUnloadFramebuffer(fbo);   // Unload framebuffer (and automatically attached depth texture/renderbuffer)
+    // Bind vertex attributes (position, normals, texcoords)
+    glBindVertexArray(cubeVAO);
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)0); // Positions
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(3*sizeof(float))); // Normals
+    glEnableVertexAttribArray(2);
+    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(6*sizeof(float))); // Texcoords
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindVertexArray(0);
 
-    // Reset viewport dimensions to default
-    rlViewport(0, 0, rlGetFramebufferWidth(), rlGetFramebufferHeight());
-    //------------------------------------------------------------------------------------------
+    // Draw cube
+    glBindVertexArray(cubeVAO);
+    glDrawArrays(GL_TRIANGLES, 0, 36);
+    glBindVertexArray(0);
 
-    brdf.width = size;
-    brdf.height = size;
-    brdf.mipmaps = 1;
-    brdf.format = PIXELFORMAT_UNCOMPRESSED_R32G32B32;
-#endif
-    return brdf;
+    // Delete VBO and VAO
+    glDeleteBuffers(1, &cubeVBO);
+    glDeleteVertexArrays(1, &cubeVAO);
 }
 
 //----------------------------------------------------------------------------------
@@ -4048,121 +3848,6 @@ static void rlUnloadShaderDefault(void)
 
     RL_FREE(RLGL.State.defaultShader.locs);
 }
-
-// Renders a 1x1 XY quad in NDC
-static void rlGenDrawQuad(void)
-{
-    unsigned int quadVAO = 0;
-    unsigned int quadVBO = 0;
-
-    float vertices[] = {
-         // Positions         Texcoords
-        -1.0f,  1.0f, 0.0f,   0.0f, 1.0f,
-        -1.0f, -1.0f, 0.0f,   0.0f, 0.0f,
-         1.0f,  1.0f, 0.0f,   1.0f, 1.0f,
-         1.0f, -1.0f, 0.0f,   1.0f, 0.0f,
-    };
-
-    // Gen VAO to contain VBO
-    glGenVertexArrays(1, &quadVAO);
-    glBindVertexArray(quadVAO);
-
-    // Gen and fill vertex buffer (VBO)
-    glGenBuffers(1, &quadVBO);
-    glBindBuffer(GL_ARRAY_BUFFER, quadVBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), &vertices, GL_STATIC_DRAW);
-
-    // Bind vertex attributes (position, texcoords)
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)0); // Positions
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 2, GL_FLOAT, GL_FALSE, 5*sizeof(float), (void *)(3*sizeof(float))); // Texcoords
-
-    // Draw quad
-    glBindVertexArray(quadVAO);
-    glDrawArrays(GL_TRIANGLE_STRIP, 0, 4);
-    glBindVertexArray(0);
-
-    // Delete buffers (VBO and VAO)
-    glDeleteBuffers(1, &quadVBO);
-    glDeleteVertexArrays(1, &quadVAO);
-}
-
-// Renders a 1x1 3D cube in NDC
-static void rlGenDrawCube(void)
-{
-    unsigned int cubeVAO = 0;
-    unsigned int cubeVBO = 0;
-
-    float vertices[] = {
-         // Positions          Normals               Texcoords
-        -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
-         1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
-         1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 0.0f,
-         1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   1.0f, 1.0f,
-        -1.0f, -1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 0.0f,
-        -1.0f,  1.0f, -1.0f,   0.0f,  0.0f, -1.0f,   0.0f, 1.0f,
-        -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
-         1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 0.0f,
-         1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
-         1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   1.0f, 1.0f,
-        -1.0f,  1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 1.0f,
-        -1.0f, -1.0f,  1.0f,   0.0f,  0.0f,  1.0f,   0.0f, 0.0f,
-        -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
-        -1.0f,  1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
-        -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
-        -1.0f, -1.0f, -1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
-        -1.0f, -1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
-        -1.0f,  1.0f,  1.0f,  -1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
-         1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
-         1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
-         1.0f,  1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 1.0f,
-         1.0f, -1.0f, -1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 1.0f,
-         1.0f,  1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   1.0f, 0.0f,
-         1.0f, -1.0f,  1.0f,   1.0f,  0.0f,  0.0f,   0.0f, 0.0f,
-        -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
-         1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 1.0f,
-         1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
-         1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   1.0f, 0.0f,
-        -1.0f, -1.0f,  1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 0.0f,
-        -1.0f, -1.0f, -1.0f,   0.0f, -1.0f,  0.0f,   0.0f, 1.0f,
-        -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
-         1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
-         1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 1.0f,
-         1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   1.0f, 0.0f,
-        -1.0f,  1.0f, -1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 1.0f,
-        -1.0f,  1.0f,  1.0f,   0.0f,  1.0f,  0.0f,   0.0f, 0.0f
-    };
-
-    // Gen VAO to contain VBO
-    glGenVertexArrays(1, &cubeVAO);
-    glBindVertexArray(cubeVAO);
-
-    // Gen and fill vertex buffer (VBO)
-    glGenBuffers(1, &cubeVBO);
-    glBindBuffer(GL_ARRAY_BUFFER, cubeVBO);
-    glBufferData(GL_ARRAY_BUFFER, sizeof(vertices), vertices, GL_STATIC_DRAW);
-
-    // Bind vertex attributes (position, normals, texcoords)
-    glBindVertexArray(cubeVAO);
-    glEnableVertexAttribArray(0);
-    glVertexAttribPointer(0, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)0); // Positions
-    glEnableVertexAttribArray(1);
-    glVertexAttribPointer(1, 3, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(3*sizeof(float))); // Normals
-    glEnableVertexAttribArray(2);
-    glVertexAttribPointer(2, 2, GL_FLOAT, GL_FALSE, 8*sizeof(float), (void *)(6*sizeof(float))); // Texcoords
-    glBindBuffer(GL_ARRAY_BUFFER, 0);
-    glBindVertexArray(0);
-
-    // Draw cube
-    glBindVertexArray(cubeVAO);
-    glDrawArrays(GL_TRIANGLES, 0, 36);
-    glBindVertexArray(0);
-
-    // Delete VBO and VAO
-    glDeleteBuffers(1, &cubeVBO);
-    glDeleteVertexArrays(1, &cubeVAO);
-}
 #endif  // GRAPHICS_API_OPENGL_33 || GRAPHICS_API_OPENGL_ES2
 
 #if defined(GRAPHICS_API_OPENGL_11)
diff --git a/src/textures.c b/src/textures.c
index 9e7d1fb7..bb4a8ed2 100644
--- a/src/textures.c
+++ b/src/textures.c
@@ -2852,8 +2852,8 @@ RenderTexture2D LoadRenderTexture(int width, int height)
         target.depth.mipmaps = 1;
 
         // Attach color texture and depth renderbuffer/texture to FBO
-        rlFramebufferAttach(target.id, target.texture.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D);
-        rlFramebufferAttach(target.id, target.depth.id, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER);
+        rlFramebufferAttach(target.id, target.texture.id, RL_ATTACHMENT_COLOR_CHANNEL0, RL_ATTACHMENT_TEXTURE2D, 0);
+        rlFramebufferAttach(target.id, target.depth.id, RL_ATTACHMENT_DEPTH, RL_ATTACHMENT_RENDERBUFFER, 0);
 
         // Check if fbo is complete with attachments (valid)
         if (rlFramebufferComplete(target.id)) TRACELOG(LOG_INFO, "FBO: [ID %i] Framebuffer object created successfully", target.id);