WIP on shaders and textures

Moved functions: LoadShader(), UnloadShader()
Add support for PVR textures compressed/uncompressed
WIP: Detect available extensions for compressed textures

5 files changed, 189 insertions, 14 deletions

diff --git a/src/models.c b/src/models.c
index f4f83fd8..ffb077d4 100644
--- a/src/models.c
+++ b/src/models.c
@@ -1101,12 +1101,33 @@ void UnloadModel(Model model)
     rlDeleteShader(model.shader.id);
 }
 
+// Link a texture to a model
 void SetModelTexture(Model *model, Texture2D texture)
 {
     if (texture.id <= 0) model->texture.id = whiteTexture;  // Default white texture (use mesh color)
     else model->texture = texture;
 }
 
+// Load a custom shader (vertex shader + fragment shader)
+Shader LoadShader(char *vsFileName, char *fsFileName)
+{
+    Shader shader = rlglLoadShader(vsFileName, fsFileName); 
+    
+    return shader;
+}
+
+// Unload a custom shader from memory
+void UnloadShader(Shader shader)
+{
+    rlDeleteShader(shader.id);
+}
+
+// Set shader for a model
+void SetModelShader(Model *model, Shader shader)
+{
+    rlglSetModelShader(model, shader);
+}
+
 // Draw a model (with texture if set)
 void DrawModel(Model model, Vector3 position, float scale, Color tint)
 {
diff --git a/src/raylib.h b/src/raylib.h
index 0e532ebe..603cc47d 100644
--- a/src/raylib.h
+++ b/src/raylib.h
@@ -338,6 +338,8 @@ typedef enum {
     COMPRESSED_ETC1_RGB,            // 4 bpp
     COMPRESSED_ETC2_RGB,            // 4 bpp
     COMPRESSED_ETC2_EAC_RGBA,       // 8 bpp
+    COMPRESSED_PVRT_RGB,            // 4 bpp
+    COMPRESSED_PVRT_RGBA,           // 4 bpp
     /*COMPRESSED_ASTC_RGBA_4x4*/    // 8 bpp
 } TextureFormat;
 
@@ -543,6 +545,7 @@ void DrawBillboard(Camera camera, Texture2D texture, Vector3 center, float size,
 void DrawBillboardRec(Camera camera, Texture2D texture, Rectangle sourceRec, Vector3 center, float size, Color tint); // Draw a billboard texture defined by sourceRec
 
 Shader LoadShader(char *vsFileName, char *fsFileName);                                             // Load a custom shader (vertex shader + fragment shader)
+void UnloadShader(Shader shader);                                                                  // Unload a custom shader from memory
 
 bool CheckCollisionSpheres(Vector3 centerA, float radiusA, Vector3 centerB, float radiusB);
 bool CheckCollisionBoxes(Vector3 minBBox1, Vector3 maxBBox1, Vector3 minBBox2, Vector3 maxBBox2);
diff --git a/src/rlgl.c b/src/rlgl.c
index c4deda8f..cedad6a7 100644
--- a/src/rlgl.c
+++ b/src/rlgl.c
@@ -793,7 +793,7 @@ void rlglInit(void)
         const GLubyte *extensionName = glGetStringi(GL_EXTENSIONS, i);
         if (strcmp(extensionName, (const GLubyte *)"GL_ARB_vertex_array_object") == 0)
         {
-            // The extension is supported by our hardware and driver, try to get related functions popinters
+            // The extension is supported by our hardware and driver, try to get related functions pointers
             glGenVertexArrays = (PFNGLGENVERTEXARRAYSOESPROC)wglGetProcAddress("glGenVertexArrays");
             glBindVertexArray = (PFNGLBINDVERTEXARRAYOESPROC)wglGetProcAddress("glBindVertexArray");
             glDeleteVertexArrays = (PFNGLDELETEVERTEXARRAYSOESPROC)wglGetProcAddress("glDeleteVertexArrays");
@@ -851,14 +851,40 @@ void rlglInit(void)
 
     // Show supported extensions
     // NOTE: We don't need that much data on screen... right now...
-/*
+
 #if defined(GRAPHICS_API_OPENGL_33)
     GLint numExt;
     glGetIntegerv(GL_NUM_EXTENSIONS, &numExt);
 
     for (int i = 0; i < numExt; i++)
     {
-        TraceLog(INFO, "Supported extension: %s", glGetStringi(GL_EXTENSIONS, i));
+        //TraceLog(INFO, "Supported extension: %s", glGetStringi(GL_EXTENSIONS, i));
+        /*
+        if (strcmp(glGetStringi(GL_EXTENSIONS, i),"GL_EXT_texture_compression_s3tc") == 0)
+        {
+            // DDS texture compression support
+            
+            // TODO: Check required tokens
+        }
+        else if (strcmp(glGetStringi(GL_EXTENSIONS, i),"GL_OES_compressed_ETC1_RGB8_texture") == 0)
+        {
+            // ETC1 texture compression support
+        }
+        else if (strcmp(glGetStringi(GL_EXTENSIONS, i),"GL_ARB_ES3_compatibility") == 0)
+        {
+            //OES_compressed_ETC2_RGB8_texture,
+            //OES_compressed_ETC2_RGBA8_texture,
+            // ETC2/EAC texture compression support
+        }
+        else if (strcmp(glGetStringi(GL_EXTENSIONS, i),"GL_IMG_texture_compression_pvrtc") == 0)
+        {
+            // PVR texture compression support
+        }
+        else if (strcmp(glGetStringi(GL_EXTENSIONS, i),"GL_KHR_texture_compression_astc_hdr") == 0)
+        {
+            // ASTC texture compression support
+        }
+        */
     }
 #elif defined(GRAPHICS_API_OPENGL_ES2)
     char *extensions = (char *)glGetString(GL_EXTENSIONS);  // One big string
@@ -866,7 +892,7 @@ void rlglInit(void)
     // NOTE: String could be splitted using strtok() function (string.h)
     TraceLog(INFO, "Supported extension: %s", extensions);
 #endif
-*/
+
 /*
     GLint numComp = 0;
     glGetIntegerv(GL_NUM_COMPRESSED_TEXTURE_FORMATS, &numComp);
@@ -894,7 +920,7 @@ void rlglInit(void)
     // Init default Shader (GLSL 110) -> Common for GL 3.3+ and ES2
     defaultShader = LoadDefaultShader();
     simpleShader = LoadSimpleShader();
-    //customShader = LoadShader("custom.vs", "custom.fs");     // Works ok
+    //customShader = rlglLoadShader("custom.vs", "custom.fs");     // Works ok
 
     InitializeBuffers();        // Init vertex arrays
     InitializeBuffersGPU();     // Init VBO and VAO
@@ -1795,7 +1821,7 @@ Model rlglLoadModel(VertexData mesh)
 
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
 // Load a shader (vertex shader + fragment shader) from text data
-unsigned int rlglLoadShader(char *vShaderStr, char *fShaderStr)
+unsigned int rlglLoadShaderFromText(char *vShaderStr, char *fShaderStr)
 {
     unsigned int program;
     GLuint vertexShader;
@@ -1915,17 +1941,17 @@ unsigned char *rlglReadScreenPixels(int width, int height)
     return imgData;     // NOTE: image data should be freed
 }
 
-// Load a shader (vertex shader + fragment shader) from text data
-Shader LoadShader(char *vsFileName, char *fsFileName)
+// Load a shader (vertex shader + fragment shader) from files
+Shader rlglLoadShader(char *vsFileName, char *fsFileName)
 {
     Shader shader;
-    
+
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
     // Shaders loading from external text file
     char *vShaderStr = TextFileRead(vsFileName);
     char *fShaderStr = TextFileRead(fsFileName);
 
-    shader.id = rlglLoadShader(vShaderStr, fShaderStr);
+    shader.id = rlglLoadShaderFromText(vShaderStr, fShaderStr);
 
     if (shader.id != 0) TraceLog(INFO, "[SHDR ID %i] Custom shader loaded successfully", shader.id);
     else TraceLog(WARNING, "[SHDR ID %i] Custom shader could not be loaded", shader.id);
@@ -1955,7 +1981,7 @@ Shader LoadShader(char *vsFileName, char *fsFileName)
 }
 
 // Link shader to model
-void SetModelShader(Model *model, Shader shader)
+void rlglSetModelShader(Model *model, Shader shader)
 {
 #if defined(GRAPHICS_API_OPENGL_33) || defined(GRAPHICS_API_OPENGL_ES2)
     model->shader = shader;
@@ -2079,7 +2105,7 @@ static Shader LoadDefaultShader(void)
         "    gl_FragColor = texture2D(texture0, fragTexCoord) * fragColor; \n"
         "}                                  \n";
 
-    shader.id = rlglLoadShader(vShaderStr, fShaderStr);
+    shader.id = rlglLoadShaderFromText(vShaderStr, fShaderStr);
 
     if (shader.id != 0) TraceLog(INFO, "[SHDR ID %i] Default shader loaded successfully", shader.id);
     else TraceLog(WARNING, "[SHDR ID %i] Default shader could not be loaded", shader.id);
@@ -2145,7 +2171,7 @@ static Shader LoadSimpleShader(void)
         "    gl_FragColor = texture2D(texture0, fragTexCoord) * tintColor; \n"
         "}                                  \n";
 
-    shader.id = rlglLoadShader(vShaderStr, fShaderStr);
+    shader.id = rlglLoadShaderFromText(vShaderStr, fShaderStr);
 
     if (shader.id != 0) TraceLog(INFO, "[SHDR ID %i] Simple shader loaded successfully", shader.id);
     else TraceLog(WARNING, "[SHDR ID %i] Simple shader could not be loaded", shader.id);
diff --git a/src/rlgl.h b/src/rlgl.h
index c1d71cc9..3335fe16 100644
--- a/src/rlgl.h
+++ b/src/rlgl.h
@@ -104,6 +104,8 @@ typedef enum { OPENGL_11 = 1, OPENGL_33, OPENGL_ES_20 } GlVersion;
         COMPRESSED_ETC1_RGB,            // 4 bpp
         COMPRESSED_ETC2_RGB,            // 4 bpp
         COMPRESSED_ETC2_EAC_RGBA,       // 8 bpp
+        COMPRESSED_PVRT_RGB,            // 4 bpp
+        COMPRESSED_PVRT_RGBA,           // 4 bpp
         /*COMPRESSED_ASTC_RGBA_4x4*/    // 8 bpp
     } TextureFormat;
 
@@ -208,10 +210,12 @@ void rlglDraw(void);                            // Draw VAO/VBO
 void rlglInitGraphics(int offsetX, int offsetY, int width, int height);  // Initialize Graphics (OpenGL stuff)
 
 unsigned int rlglLoadTexture(void *data, int width, int height, int textureFormat, int mipmapCount, bool genMipmaps);       // Load in GPU OpenGL texture
-unsigned int rlglLoadShader(char *vShaderStr, char *fShaderStr);        // Load a shader from text data
+Shader rlglLoadShader(char *vsFileName, char *fsFileName);                  // Load a shader (vertex shader + fragment shader) from files
+unsigned int rlglLoadShaderFromText(char *vShaderStr, char *fShaderStr);    // Load a shader from text data
 void rlglInitPostpro(void);                     // Initialize postprocessing system
 void rlglDrawPostpro(void);                     // Draw with postprocessing shader
 void rlglSetPostproShader(Shader shader);       // Set postprocessing shader
+void rlglSetModelShader(Model *model, Shader shader);   // Set shader for a model
 
 Model rlglLoadModel(VertexData mesh);           // Upload vertex data into GPU and provided VAO/VBO ids
 void rlglDrawModel(Model model, Vector3 position, float rotationAngle, Vector3 rotationAxis, Vector3 scale, Color color, bool wires);
diff --git a/src/textures.c b/src/textures.c
index e45739ac..1d22e509 100644
--- a/src/textures.c
+++ b/src/textures.c
@@ -70,6 +70,7 @@ typedef struct {
 //----------------------------------------------------------------------------------
 static ImageEx LoadDDS(const char *fileName);   // Load DDS file
 static ImageEx LoadPKM(const char *fileName);   // Load PKM file
+static ImageEx LoadPVR(const char *fileName);   // Load PVR file
 
 //----------------------------------------------------------------------------------
 // Module Functions Definition
@@ -326,6 +327,20 @@ Texture2D LoadTexture(const char *fileName)
 
         free(image.data);
     }
+    else if (strcmp(GetExtension(fileName),"pvr") == 0)
+    {
+        ImageEx image = LoadPVR(fileName);
+        
+        texture.id = rlglLoadTexture(image.data, image.width, image.height, image.format, image.mipmaps, false);
+
+        texture.width = image.width;
+        texture.height = image.height;
+
+        if (texture.id == 0) TraceLog(WARNING, "[%s] PVR texture could not be loaded", fileName);
+        else TraceLog(INFO, "[%s] PVR texture loaded successfully", fileName);
+
+        free(image.data);
+    }
     else
     {
         Image image = LoadImage(fileName);
@@ -694,6 +709,7 @@ static ImageEx LoadDDS(const char *fileName)
 // Loading PKM image data (ETC1/ETC2 compression)
 // NOTE: KTX is the standard Khronos Group compression format (ETC1/ETC2, mipmaps)
 // PKM is a much simpler file format used mainly to contain a single ETC1/ETC2 compressed image (no mipmaps)
+// ETC1 compression support requires extension GL_OES_compressed_ETC1_RGB8_texture
 static ImageEx LoadPKM(const char *fileName)
 {
     // If OpenGL ES 2.0. the following format could be supported (ETC1):
@@ -772,4 +788,109 @@ static ImageEx LoadPKM(const char *fileName)
     }
 
     return image;
+}
+
+// Loading PVR image data (uncompressed or PVRT compression)
+// NOTE: PVR compression requires extension GL_IMG_texture_compression_pvrtc (PowerVR GPUs)
+static ImageEx LoadPVR(const char *fileName)
+{
+    // If supported in OpenGL ES 2.0. the following formats could be defined:
+    // GL_COMPRESSED_RGB_PVRTC_4BPPV1_IMG      (RGB)
+    // GL_COMPRESSED_RGBA_PVRTC_4BPPV1_IMG     (RGBA)
+    
+    // PVR file v2 Header (52 bytes)
+    typedef struct {
+        unsigned int headerLength;
+        unsigned int height;
+        unsigned int width;
+        unsigned int numMipmaps;
+        unsigned int flags;
+        unsigned int dataLength;
+        unsigned int bpp;
+        unsigned int bitmaskRed;
+        unsigned int bitmaskGreen;
+        unsigned int bitmaskBlue;
+        unsigned int bitmaskAlpha;
+        unsigned int pvrTag;
+        unsigned int numSurfs;
+    } pvrHeaderV2;
+
+    // PVR file v3 Header (52 bytes)
+    // NOTE: After it could be metadata (15 bytes?)
+    typedef struct {
+        unsigned int version;            
+        unsigned int flags;          
+        unsigned long long pixelFormat;        
+        unsigned int colourSpace;        
+        unsigned int channelType;        
+        unsigned int height;         
+        unsigned int width;          
+        unsigned int depth;          
+        unsigned int numSurfaces;        
+        unsigned int numFaces;       
+        unsigned int numMipmaps;     
+        unsigned int metaDataSize;   
+    } pvrHeaderV3;
+    
+    // Bytes Swap (little-endian <-> big-endian)
+    //unsigned short data;
+    //unsigned short swap = ((data & 0x00FF) << 8) | ((data & 0xFF00) >> 8);
+
+    ImageEx image;
+
+    image.data = NULL;
+    image.width = 0;
+    image.height = 0;
+    image.mipmaps = 0;
+    image.format = 0;
+
+    FILE *pvrFile = fopen(fileName, "rb");
+
+    if (pvrFile == NULL)
+    {
+        TraceLog(WARNING, "[%s] PVR image file could not be opened", fileName);
+    }
+    else
+    {
+        // Check PVR image version
+        unsigned int pvrVersion = 0;
+        fread(&pvrVersion, sizeof(unsigned int), 1, pvrFile);
+        fsetpos(pvrFile, 0);
+        
+        if (pvrVersion == 52)
+        {
+            pvrHeaderV2 header;
+            
+            fread(&header, sizeof(pvrHeaderV2), 1, pvrFile);
+            
+            image.width = header.width;
+            image.height = header.height;
+            image.mipmaps = header.numMipmaps;
+            image.format = COMPRESSED_PVRT_RGB; //COMPRESSED_PVRT_RGBA
+        }
+        else if (pvrVersion == 3)
+        {
+            pvrHeaderV3 header;
+            
+            fread(&header, sizeof(pvrHeaderV3), 1, pvrFile);
+            
+            image.width = header.width;
+            image.height = header.height;
+            image.mipmaps = header.numMipmaps;
+            
+            // TODO: Skip metaDataSize
+            
+            image.format = COMPRESSED_PVRT_RGB; //COMPRESSED_PVRT_RGBA
+        }
+
+        int size = (image.width/4)*(image.height/4)*8;  // Total data size in bytes
+
+        image.data = (unsigned char*)malloc(size * sizeof(unsigned char));
+
+        fread(image.data, 1, size, pvrFile);
+
+        fclose(pvrFile);    // Close file pointer
+    }
+
+    return image;
 }
\ No newline at end of file