Some minor tweaks analyzing code

Specific textures generation code is quite redundant and not flexible for the user, I'm trying to figure out some easy way to allow raylib users to do the same without needing those functions (very specific and shader dependant). RenderTexture loading and Cubemap textures support must be improved.

src/rlgl.h

@@ -3004,6 +3004,7 @@ Texture2D GenTextureCubemap(Shader shader, Texture2D skyHDR, int size)
         if (texFloatSupported) glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB, size, size, 0, GL_RGB, GL_FLOAT, NULL);
 #endif
     }
+    
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 #if defined(GRAPHICS_API_OPENGL_33)
@@ -3033,7 +3034,7 @@ Texture2D GenTextureCubemap(Shader shader, Texture2D skyHDR, int size)
     glViewport(0, 0, size, size);
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 
-    for (unsigned int i = 0; i < 6; i++)
+    for (int i = 0; i < 6; i++)
     {
         SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, cubemap.id, 0);
@@ -3048,12 +3049,11 @@ Texture2D GenTextureCubemap(Shader shader, Texture2D skyHDR, int size)
     glViewport(0, 0, screenWidth, screenHeight);
     //glEnable(GL_CULL_FACE);
 
+    // NOTE: Texture2D is a GL_TEXTURE_CUBE_MAP, not a GL_TEXTURE_2D!
     cubemap.width = size;
     cubemap.height = size;
     cubemap.mipmaps = 1;
     cubemap.format = UNCOMPRESSED_R32G32B32;
-    
-    // TODO: Texture2D is a GL_TEXTURE_CUBE_MAP, not a GL_TEXTURE_2D! Only cubemap.id makes some sense...
 #endif
     return cubemap;
 }
@@ -3081,7 +3081,10 @@ Texture2D GenTextureIrradiance(Shader shader, Texture2D cubemap, int size)
     glGenTextures(1, &irradiance.id);
     glBindTexture(GL_TEXTURE_CUBE_MAP, irradiance.id);
     for (unsigned int i = 0; i < 6; i++)
+    {
         glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, size, size, 0, GL_RGB, GL_FLOAT, NULL);
+    }
+    
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
@@ -3109,7 +3112,7 @@ Texture2D GenTextureIrradiance(Shader shader, Texture2D cubemap, int size)
     glViewport(0, 0, size, size);
     glBindFramebuffer(GL_FRAMEBUFFER, fbo);
 
-    for (unsigned int i = 0; i < 6; i++)
+    for (int i = 0; i < 6; i++)
     {
         SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
         glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, irradiance.id, 0);
@@ -3125,6 +3128,8 @@ Texture2D GenTextureIrradiance(Shader shader, Texture2D cubemap, int size)
 
     irradiance.width = size;
     irradiance.height = size;
+    irradiance.mipmaps = 1;
+    //irradiance.format = UNCOMPRESSED_R16G16B16;
 #endif
     return irradiance;
 }
@@ -3154,7 +3159,10 @@ Texture2D GenTexturePrefilter(Shader shader, Texture2D cubemap, int size)
     glGenTextures(1, &prefilter.id);
     glBindTexture(GL_TEXTURE_CUBE_MAP, prefilter.id);
     for (unsigned int i = 0; i < 6; i++)
+    {
         glTexImage2D(GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, 0, GL_RGB16F, size, size, 0, GL_RGB, GL_FLOAT, NULL);
+    }
+    
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
     glTexParameteri(GL_TEXTURE_CUBE_MAP, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
@@ -3185,11 +3193,11 @@ Texture2D GenTexturePrefilter(Shader shader, Texture2D cubemap, int size)
 
     #define MAX_MIPMAP_LEVELS   5   // Max number of prefilter texture mipmaps
 
-    for (unsigned int mip = 0; mip < MAX_MIPMAP_LEVELS; mip++)
+    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);
+        unsigned int mipWidth  = size*(int)powf(0.5f, (float)mip);
+        unsigned int mipHeight = size*(int)powf(0.5f, (float)mip);
 
         glBindRenderbuffer(GL_RENDERBUFFER, rbo);
         glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT24, mipWidth, mipHeight);
@@ -3198,7 +3206,7 @@ Texture2D GenTexturePrefilter(Shader shader, Texture2D cubemap, int size)
         float roughness = (float)mip/(float)(MAX_MIPMAP_LEVELS - 1);
         glUniform1f(roughnessLoc, roughness);
 
-        for (unsigned int i = 0; i < 6; o">++i)
+        for (int i = 0; i < 6; n">i++)
         {
             SetShaderValueMatrix(shader, shader.locs[LOC_MATRIX_VIEW], fboViews[i]);
             glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_CUBE_MAP_POSITIVE_X + i, prefilter.id, mip);
@@ -3215,6 +3223,8 @@ Texture2D GenTexturePrefilter(Shader shader, Texture2D cubemap, int size)
 
     prefilter.width = size;
     prefilter.height = size;
+    //prefilter.mipmaps = 1 + (int)floor(log(size)/log(2));
+    //prefilter.format = UNCOMPRESSED_R16G16B16;
 #endif
     return prefilter;
 }