Road to raylib 1.1 - Testing rlgl

1 files changed, 1364 insertions, 0 deletions

diff --git a/src/rlgl.c b/src/rlgl.c
new file mode 100644
index 00000000..63ed9ec4
--- /dev/null
+++ b/src/rlgl.c
@@ -0,0 +1,1364 @@
+/*********************************************************************************************
+* 
+*   rlgl - raylib OpenGL abstraction layer
+*    
+*   raylib now uses OpenGL 1.1 style functions (rlVertex) that are mapped to selected OpenGL version:
+*       OpenGL 1.1  - Direct map rl* -> gl*
+*       OpenGL 3.3+ - Vertex data is stored in VAOs, call rlglDraw() to render
+*       OpenGL ES 2 - Same behaviour as OpenGL 3.3+
+* 
+*   Copyright (c) 2014 Ramon Santamaria (Ray San - raysan@raysanweb.com)
+*    
+*   This software is provided "as-is", without any express or implied warranty. In no event 
+*   will the authors be held liable for any damages arising from the use of this software.
+*
+*   Permission is granted to anyone to use this software for any purpose, including commercial 
+*   applications, and to alter it and redistribute it freely, subject to the following restrictions:
+*
+*     1. The origin of this software must not be misrepresented; you must not claim that you 
+*     wrote the original software. If you use this software in a product, an acknowledgment 
+*     in the product documentation would be appreciated but is not required.
+*
+*     2. Altered source versions must be plainly marked as such, and must not be misrepresented
+*     as being the original software.
+*
+*     3. This notice may not be removed or altered from any source distribution.
+*
+**********************************************************************************************/
+
+#include "rlgl.h"
+
+#include <stdio.h>          // Standard input / output lib
+#include <stdlib.h>         // Declares malloc() and free() for memory management, rand()
+
+#include "raymath.h"        // Required for data type Matrix and Matrix functions
+
+#ifdef USE_OPENGL_11
+    #include <GL/gl.h>      // Extensions loading lib
+#endif
+
+#ifdef USE_OPENGL_33
+    #define GLEW_STATIC         
+    #include <GL/glew.h>    // Extensions loading lib
+#endif
+
+//#include "glad.h"         // Extensions loading lib? --> REVIEW
+
+#define USE_VBO_DOUBLE_BUFFERS    // Enable VBO double buffers usage --> REVIEW!
+
+//----------------------------------------------------------------------------------
+// Defines and Macros
+//----------------------------------------------------------------------------------
+#define MATRIX_STACK_SIZE          16   // TODO: REVIEW: Matrix stack required?
+#define MAX_DRAWS_BY_TEXTURE      256   // Draws are organized by texture changes
+#define TEMP_VERTEX_BUFFER_SIZE  1024   // Temporal Vertex Buffer (required for post-transformations)
+
+//----------------------------------------------------------------------------------
+// Types and Structures Definition
+//----------------------------------------------------------------------------------
+typedef struct {
+    int numQuads;
+    int texId;
+} QuadsByTexture;
+
+typedef struct {
+    int vCounter;
+    int cCounter;
+    float *vertices;            // 3 components per vertex
+    float *colors;              // 4 components per vertex
+} VertexPositionColorBuffer;
+
+typedef struct {
+    int vCounter;
+    int tcCounter;
+    int cCounter;
+    float *vertices;            // 3 components per vertex
+    float *texcoords;           // 2 components per vertex
+    float *colors;              // 4 components per vertex
+} VertexPositionColorTextureBuffer;
+
+typedef struct {
+    int vCounter;
+    int tcCounter;
+    int cCounter;
+    float *vertices;            // 3 components per vertex
+    float *texcoords;           // 2 components per vertex
+    float *colors;              // 4 components per vertex
+    unsigned int *indices;      // 6 indices per quad
+} VertexPositionColorTextureIndexBuffer;
+
+typedef struct {
+    GLuint texId;
+    int firstVertex;    // Actually, when using glDrawElements, this parameter is useless..
+    int vCount;
+} DrawCall;
+
+//----------------------------------------------------------------------------------
+// Global Variables Definition
+//----------------------------------------------------------------------------------
+#if defined(USE_OPENGL_33) || defined(USE_OPENGL_ES2)
+static Matrix stack[MATRIX_STACK_SIZE];
+static int stackCounter = 0;
+
+static Matrix modelview;
+static Matrix projection;
+static Matrix *currentMatrix;
+static int currentMatrixMode;
+
+static DrawMode currentDrawMode;
+
+// Vertex arrays for lines, triangles and quads
+static VertexPositionColorBuffer lines;
+static VertexPositionColorTextureBuffer triangles;
+static VertexPositionColorTextureIndexBuffer quads;
+
+// Vetex-Fragment Shader Program ID
+static GLuint shaderProgram;       
+
+// Shader program attibutes binding locations
+static GLuint vertexLoc, texcoordLoc, colorLoc;
+static GLuint projectionMatrixLoc, modelviewMatrixLoc;
+static GLuint textureLoc;
+
+// Vertex Array Objects (VAO)
+static GLuint vaoLines, vaoTriangles, vaoQuads;
+
+// Vertex Buffer Objects (VBO)
+static GLuint linesBuffer[2];
+static GLuint trianglesBuffer[2];
+static GLuint quadsBuffer[4];
+
+#ifdef USE_VBO_DOUBLE_BUFFERS
+// Double buffering
+// TODO: REVIEW -> Not getting any performance improvement... why?
+static GLuint vaoQuadsB;
+static GLuint quadsBufferB[4];
+static bool useBufferB = false;
+#endif
+
+static DrawCall *draws;
+static int drawsCounter;
+
+// Temp vertex buffer to be used with rlTranslate, rlRotate, rlScale
+static Vector3 *tempBuffer;
+static int tempBufferCount = 0;
+static bool useTempBuffer = false;
+
+// White texture useful for plain color polys (required by shader)
+static GLuint whiteTexture;
+#endif
+
+//----------------------------------------------------------------------------------
+// Module specific Functions Declaration
+//----------------------------------------------------------------------------------
+#if defined(USE_OPENGL_33) || defined(USE_OPENGL_ES2)
+static GLuint LoadDefaultShaders();
+static void InitializeBuffers();
+static void InitializeVAOs();
+static void UpdateBuffers();
+
+// Shader files loading (external) - Not used but useful...
+static GLuint LoadShaders(char *vertexFileName, char *fragmentFileName);
+static char *TextFileRead(char *fn);
+#endif
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - Matrix operations
+//----------------------------------------------------------------------------------
+
+#ifdef USE_OPENGL_11
+
+// Fallback to OpenGL 1.1 function calls
+//---------------------------------------
+void rlMatrixMode(int mode) 
+{ 
+    switch (mode) 
+    {
+        case RL_PROJECTION: glMatrixMode(GL_PROJECTION); break;
+        case RL_MODELVIEW: glMatrixMode(GL_MODELVIEW); break; 
+        case RL_TEXTURE: glMatrixMode(GL_TEXTURE); break;
+        default: break;
+    }
+}
+
+void rlFrustum(double left, double right, double bottom, double top, double near, double far) 
+{ 
+    glFrustum(left, right, bottom, top, near, far); 
+}
+
+void rlOrtho(double left, double right, double bottom, double top, double near, double far) 
+{ 
+    glOrtho(left, right, bottom, top, near, far); 
+}
+
+void rlPushMatrix() { glPushMatrix(); }
+void rlPopMatrix() { glPopMatrix(); }
+void rlLoadIdentity() { glLoadIdentity(); }
+void rlTranslatef(float x, float y, float z) { glTranslatef(x, y, z); }
+void rlRotatef(float angleDeg, float x, float y, float z) { glRotatef(angleDeg, x, y, z); }
+void rlScalef(float x, float y, float z) { glScalef(x, y, z); }
+void rlMultMatrixf(float *mat) { glMultMatrixf(mat); }
+
+#else
+
+// Choose the current matrix to be transformed
+void rlMatrixMode(int mode)
+{
+    if (mode == RL_PROJECTION) currentMatrix = &projection;
+    else if (mode == RL_MODELVIEW) currentMatrix = &modelview;
+    //else if (mode == GL_TEXTURE) TODO: NEVER USED!
+    
+    currentMatrixMode = mode;
+}
+
+// Push the current matrix to stack
+void rlPushMatrix()
+{
+    if (stackCounter == MATRIX_STACK_SIZE - 1)
+    {
+        printf("ERROR: Stack Buffer Overflow! (MAX 16 MATRIX)");
+        
+        exit(1);
+    }
+
+    stack[stackCounter] = *currentMatrix;
+    rlLoadIdentity();
+    stackCounter++;
+    
+    if (currentMatrixMode == RL_MODELVIEW) useTempBuffer = true;
+}
+
+// Pop lattest inserted matrix from stack
+void rlPopMatrix()
+{
+    if (stackCounter > 0)
+    {   
+        Matrix mat = stack[stackCounter - 1];       
+        *currentMatrix = mat;
+        stackCounter--;
+    }
+}
+
+// Reset current matrix to identity matrix
+void rlLoadIdentity()
+{
+    *currentMatrix = MatrixIdentity();
+}
+
+// Multiply the current matrix by a translation matrix
+void rlTranslatef(float x, float y, float z)
+{
+    Matrix mat = MatrixTranslate(x, y, z);
+    
+    *currentMatrix = MatrixMultiply(*currentMatrix, mat);
+}
+
+// Multiply the current matrix by a rotation matrix
+void rlRotatef(float angleDeg, float x, float y, float z)
+{
+    // TODO: Rotation matrix --> REVIEW!
+    Matrix rot = MatrixIdentity();
+    
+    if (x == 1) rot = MatrixRotateX(angleDeg*DEG2RAD);
+    else if (y == 1) rot = MatrixRotateY(angleDeg*DEG2RAD);
+    else if (z == 1) rot = MatrixRotateZ(angleDeg*DEG2RAD);
+    
+    *currentMatrix = MatrixMultiply(*currentMatrix, rot);
+}
+
+// Multiply the current matrix by a scaling matrix
+void rlScalef(float x, float y, float z)
+{
+    Matrix mat = MatrixScale(x, y, z);
+    
+    *currentMatrix = MatrixMultiply(*currentMatrix, mat);
+}
+
+// Multiply the current matrix by another matrix
+void rlMultMatrixf(float *m)
+{
+    // TODO: review Matrix creation from array
+    Matrix mat = { m[0], m[1], m[2], m[3],
+                   m[4], m[5], m[6], m[7],
+                   m[8], m[9], m[10], m[11],
+                   m[12], m[13], m[14], m[15] };
+
+    *currentMatrix = MatrixMultiply(*currentMatrix, mat);
+}
+
+// Multiply the current matrix by a perspective matrix generated by parameters
+void rlFrustum(double left, double right, double bottom, double top, double near, double far)
+{
+    Matrix matPerps = MatrixFrustum(left, right, bottom, top, near, far);
+    MatrixTranspose(&matPerps);
+
+    *currentMatrix = MatrixMultiply(*currentMatrix, matPerps);
+}
+
+// Multiply the current matrix by an orthographic matrix generated by parameters
+void rlOrtho(double left, double right, double bottom, double top, double near, double far) 
+{
+    Matrix matOrtho = MatrixOrtho(left, right, bottom, top, near, far);
+    MatrixTranspose(&matOrtho);
+    
+    *currentMatrix = MatrixMultiply(*currentMatrix, matOrtho);
+}
+
+#endif
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - Vertex level operations
+//----------------------------------------------------------------------------------
+#ifdef USE_OPENGL_11
+
+// Fallback to OpenGL 1.1 function calls
+//---------------------------------------
+void rlBegin(int mode) 
+{
+    switch (mode)
+    {
+        case RL_LINES: glBegin(GL_LINES); break;
+        case RL_TRIANGLES: glBegin(GL_TRIANGLES); break;
+        case RL_QUADS: glBegin(GL_QUADS); break;
+        default: break;
+    }
+}
+
+void rlEnd() { glEnd(); }
+void rlVertex2i(int x, int y) { glVertex2i(x, y); }
+void rlVertex2f(float x, float y) { glVertex2f(x, y); }
+void rlVertex3f(float x, float y, float z) { glVertex3f(x, y, z); }
+void rlTexCoord2f(float x, float y) { glTexCoord2f(x, y); }
+void rlNormal3f(float x, float y, float z) { glNormal3f(x, y, z); }
+void rlColor4ub(byte r, byte g, byte b, byte a) { glColor4ub(r, g, b, a); }
+void rlColor3f(float x, float y, float z) { glColor3f(x, y, z); }
+void rlColor4f(float x, float y, float z, float w) { glColor4f(x, y, z, w); }
+
+#else
+
+// Initialize drawing mode (how to organize vertex)
+void rlBegin(int mode)
+{
+    // Draw mode can only be RL_LINES, RL_TRIANGLES and RL_QUADS
+    currentDrawMode = mode;
+}
+
+// Finish vertex providing
+void rlEnd()
+{
+    if (useTempBuffer)
+    {
+        // IT WORKS!!! --> Refactor...
+        Matrix mat = *currentMatrix;
+        MatrixTranspose(&mat);
+
+        // Apply transformation matrix to all temp vertices
+        for (int i = 0; i < tempBufferCount; i++) VectorTransform(&tempBuffer[i], mat);
+        
+        // Deactivate tempBuffer usage to allow rlVertex3f do its job
+        useTempBuffer = false;
+        
+        // Copy all transformed vertices to right VAO
+        for (int i = 0; i < tempBufferCount; i++) rlVertex3f(tempBuffer[i].x, tempBuffer[i].y, tempBuffer[i].z);
+        
+        // Reset temp buffer
+        tempBufferCount = 0;
+    }
+
+    // Make sure vertexCounter is the same for vertices-texcoords-normals-colors
+    // NOTE: In OpenGL 1.1, one glColor call can be made for all the subsequent glVertex calls.
+    switch (currentDrawMode)
+    {
+        case RL_LINES:
+        {
+            if (lines.vCounter != lines.cCounter)
+            {
+                int addColors = lines.vCounter - lines.cCounter;
+                
+                for (int i = 0; i < addColors; i++)
+                {
+                    lines.colors[4*lines.cCounter] = lines.colors[4*lines.cCounter - 4];
+                    lines.colors[4*lines.cCounter + 1] = lines.colors[4*lines.cCounter - 3];
+                    lines.colors[4*lines.cCounter + 2] = lines.colors[4*lines.cCounter - 2];
+                    lines.colors[4*lines.cCounter + 3] = lines.colors[4*lines.cCounter - 1];
+                    
+                    lines.cCounter++;
+                }
+            }
+        } break;
+        case RL_TRIANGLES:
+        {
+            if (triangles.vCounter != triangles.cCounter)
+            {
+                int addColors = triangles.vCounter - triangles.cCounter;
+                
+                for (int i = 0; i < addColors; i++)
+                {
+                    triangles.colors[4*triangles.cCounter] = triangles.colors[4*triangles.cCounter - 4];
+                    triangles.colors[4*triangles.cCounter + 1] = triangles.colors[4*triangles.cCounter - 3];
+                    triangles.colors[4*triangles.cCounter + 2] = triangles.colors[4*triangles.cCounter - 2];
+                    triangles.colors[4*triangles.cCounter + 3] = triangles.colors[4*triangles.cCounter - 1];
+                    
+                    triangles.cCounter++;
+                }
+            }    
+        } break;
+        case RL_QUADS:
+        {
+            // Make sure colors count match vertex count
+            if (quads.vCounter != quads.cCounter)
+            {
+                int addColors = quads.vCounter - quads.cCounter;
+                
+                for (int i = 0; i < addColors; i++)
+                {
+                    quads.colors[4*quads.cCounter] = quads.colors[4*quads.cCounter - 4];
+                    quads.colors[4*quads.cCounter + 1] = quads.colors[4*quads.cCounter - 3];
+                    quads.colors[4*quads.cCounter + 2] = quads.colors[4*quads.cCounter - 2];
+                    quads.colors[4*quads.cCounter + 3] = quads.colors[4*quads.cCounter - 1];
+                    
+                    quads.cCounter++;
+                }
+            }
+
+            // Make sure texcoords count match vertex count
+            if (quads.vCounter != quads.tcCounter)
+            {
+                int addTexCoords = quads.vCounter - quads.tcCounter;
+                
+                for (int i = 0; i < addTexCoords; i++)
+                {
+                    quads.texcoords[2*quads.tcCounter] = 0.0f;
+                    quads.texcoords[2*quads.tcCounter + 1] = 0.0f;
+                    
+                    quads.tcCounter++;
+                }
+            }
+            
+            // TODO: Make sure normals count match vertex count
+            
+        } break;
+        default: break;
+    }
+}
+
+// Define one vertex (position)
+void rlVertex3f(float x, float y, float z)
+{
+    if (useTempBuffer)
+    {
+        tempBuffer[tempBufferCount].x = x;
+        tempBuffer[tempBufferCount].y = y;
+        tempBuffer[tempBufferCount].z = z;
+        tempBufferCount++;
+    }
+    else
+    {
+        switch (currentDrawMode)
+        {
+            case RL_LINES:
+            {
+                lines.vertices[3*lines.vCounter] = x;
+                lines.vertices[3*lines.vCounter + 1] = y;
+                lines.vertices[3*lines.vCounter + 2] = z;
+                
+                lines.vCounter++;
+                
+            } break;
+            case RL_TRIANGLES:
+            {
+                triangles.vertices[3*triangles.vCounter] = x;
+                triangles.vertices[3*triangles.vCounter + 1] = y;
+                triangles.vertices[3*triangles.vCounter + 2] = z;
+                
+                triangles.vCounter++;
+                
+            } break;
+            case RL_QUADS:
+            {
+                quads.vertices[3*quads.vCounter] = x;
+                quads.vertices[3*quads.vCounter + 1] = y;
+                quads.vertices[3*quads.vCounter + 2] = z;
+                
+                quads.vCounter++;
+                
+                draws[drawsCounter - 1].vCount++;
+                
+            } break;
+            default: break;
+        }
+    }
+}
+
+// Define one vertex (position)
+void rlVertex2f(float x, float y)
+{
+    rlVertex3f(x, y, 0.0);
+}
+
+// Define one vertex (position)
+void rlVertex2i(int x, int y)
+{
+    rlVertex3f((float)x, (float)y, 0.0);
+}
+
+// Define one vertex (texture coordinate)
+// NOTE: Texture coordinates are limited to TRIANGLES only
+void rlTexCoord2f(float x, float y)
+{
+    if (currentDrawMode == RL_QUADS)
+    {
+        quads.texcoords[2*quads.tcCounter] = x;
+        quads.texcoords[2*quads.tcCounter + 1] = y;
+
+        quads.tcCounter++;
+    }
+}
+
+// Define one vertex (normal)
+// NOTE: Normals limited to TRIANGLES only ?
+void rlNormal3f(float x, float y, float z)
+{
+    // TODO: Normals usage...
+}
+
+// Define one vertex (color)
+void rlColor4f(float x, float y, float z, float w)
+{
+    switch (currentDrawMode)
+    {
+        case RL_LINES:
+        {
+            lines.colors[4*lines.cCounter] = x;
+            lines.colors[4*lines.cCounter + 1] = y;
+            lines.colors[4*lines.cCounter + 2] = z;
+            lines.colors[4*lines.cCounter + 3] = w;
+            
+            lines.cCounter++;
+            
+        } break;
+        case RL_TRIANGLES:
+        {
+            triangles.colors[4*triangles.cCounter] = x;
+            triangles.colors[4*triangles.cCounter + 1] = y;
+            triangles.colors[4*triangles.cCounter + 2] = z;
+            triangles.colors[4*triangles.cCounter + 3] = w;
+            
+            triangles.cCounter++;
+            
+        } break;
+        case RL_QUADS:
+        {
+            quads.colors[4*quads.cCounter] = x;
+            quads.colors[4*quads.cCounter + 1] = y;
+            quads.colors[4*quads.cCounter + 2] = z;
+            quads.colors[4*quads.cCounter + 3] = w;
+            
+            quads.cCounter++;
+            
+        } break;
+        default: break;
+    }
+}
+
+// Define one vertex (color)
+void rlColor4ub(byte r, byte g, byte b, byte a)
+{
+    rlColor4f((float)r/255, (float)g/255, (float)b/255, (float)a/255); 
+}
+
+// Define one vertex (color)
+void rlColor3f(float x, float y, float z)
+{
+    rlColor4f(x, y, z, 1.0);
+}
+
+#endif
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - OpenGL equivalent functions (common to 1.1, 3.3+, ES2)
+//----------------------------------------------------------------------------------
+
+// Enable texture usage
+void rlEnableTexture(unsigned int id)
+{
+#ifdef USE_OPENGL_11
+    glEnable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, id);
+#endif
+
+#if defined(USE_OPENGL_33) || defined(USE_OPENGL_ES2)
+    if (draws[drawsCounter - 1].texId != id)
+    {
+        if (draws[drawsCounter - 1].vCount > 0) drawsCounter++;
+        
+        draws[drawsCounter - 1].texId = id;
+        draws[drawsCounter - 1].firstVertex = draws[drawsCounter - 2].vCount;
+        draws[drawsCounter - 1].vCount = 0;
+    }
+#endif
+}
+
+// Disable texture usage
+void rlDisableTexture()
+{
+#ifdef USE_OPENGL_11
+    glDisable(GL_TEXTURE_2D);
+    glBindTexture(GL_TEXTURE_2D, 0);
+#endif
+}
+
+// Unload texture from GPU memory
+void rlDeleteTextures(unsigned int id)
+{
+    glDeleteTextures(1, &id);
+}
+
+// Clear color buffer with color
+void rlClearColor(byte r, byte g, byte b, byte a)
+{
+    // Color values clamp to 0.0f(0) and 1.0f(255)
+    float cr = (float)r / 255;
+    float cg = (float)g / 255;
+    float cb = (float)b / 255;
+    float ca = (float)a / 255;
+
+    glClearColor(cr, cg, cb, ca);
+}
+
+// Clear used screen buffers (color and depth)
+void rlClearScreenBuffers()
+{
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     // Clear used buffers: Color and Depth (Depth is used for 3D)
+    //glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);     // Stencil buffer not used...
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - rlgl Functions
+//----------------------------------------------------------------------------------
+
+#if defined(USE_OPENGL_33) || defined(USE_OPENGL_ES2)
+
+// Init OpenGL 3.3+ required data
+void rlglInit()
+{                 
+    // Initialize GLEW
+    glewExperimental = 1;       // Needed for core profile
+
+    GLenum error = glewInit();
+    
+    if (error != GLEW_OK) 
+    {
+        fprintf(stderr, "Failed to initialize GLEW - Error: %s\n", glewGetErrorString(error));
+        exit(1);
+    }
+
+    if (glewIsSupported("GL_VERSION_3_3")) printf("OpenGL 3.3 initialized\n"); 
+/*
+    if (!gladLoadGL()) 
+    {
+        printf("Something went wrong!\n");
+        exit(-1);
+    }
+*/    
+    // Set default draw mode
+    currentDrawMode = RL_TRIANGLES;
+    
+    // Reset projection and modelview matrices
+    projection = MatrixIdentity();
+    modelview = MatrixIdentity();
+    currentMatrix = &modelview;
+    
+    // Initialize matrix stack
+    for (int i = 0; i < MATRIX_STACK_SIZE; i++) stack[i] = MatrixIdentity();
+
+    // Init default Shader (GLSL 110) -> Common for GL 3.3+ and ES2
+    shaderProgram = LoadDefaultShaders();
+    //shaderProgram = LoadShaders("simple150.vert", "simple150.frag");
+    
+    // Get handles to GLSL input vars locations
+    vertexLoc = glGetAttribLocation(shaderProgram, "vertexPosition");
+    texcoordLoc = glGetAttribLocation(shaderProgram, "vertexTexCoord");
+    colorLoc = glGetAttribLocation(shaderProgram, "vertexColor");
+    
+    // Get handles to GLSL uniform vars locations (vertex-shader)
+    modelviewMatrixLoc = glGetUniformLocation(shaderProgram, "modelviewMatrix");
+    projectionMatrixLoc = glGetUniformLocation(shaderProgram, "projectionMatrix");
+    
+    // Get handles to GLSL uniform vars locations (fragment-shader)
+    textureLoc  = glGetUniformLocation(shaderProgram, "texture0");
+    
+    printf("Default shaders loaded\n\n");
+    
+    // Print OpenGL and GLSL version
+    printf("Vendor:   %s\n", glGetString(GL_VENDOR));
+    printf("Renderer: %s\n", glGetString(GL_RENDERER));
+    printf("Version:  %s\n", glGetString(GL_VERSION));
+    printf("GLSL:     %s\n\n", glGetString(0x8B8C));  // GL_SHADING_LANGUAGE_VERSION
+    
+    InitializeBuffers();    // Init vertex arrays
+    InitializeVAOs();       // Init VBO and VAO
+    
+    // Init temp vertex buffer, used when transformation required (translate, rotate, scale)
+    tempBuffer = (Vector3 *)malloc(sizeof(Vector3)*TEMP_VERTEX_BUFFER_SIZE);
+    
+    for (int i = 0; i < TEMP_VERTEX_BUFFER_SIZE; i++) tempBuffer[i] = VectorZero();
+    
+    // Create default white texture for plain colors (required by shader)
+    unsigned char pixels[4] = { 255, 255, 255, 255 };   // 1 pixel RGBA (4 bytes)
+    
+    whiteTexture = rlglTexture(1, 1, pixels);     
+    
+    // Init draw calls tracking system
+    draws = (DrawCall *)malloc(sizeof(DrawCall)*MAX_DRAWS_BY_TEXTURE);
+    
+    for (int i = 0; i < MAX_DRAWS_BY_TEXTURE; i++)
+    {
+        draws[i].texId = 0;
+        draws[i].firstVertex = 0;
+        draws[i].vCount = 0;
+    }
+    
+    drawsCounter = 1;
+    draws[drawsCounter - 1].texId = whiteTexture;
+}
+
+// Vertex Buffer Object deinitialization (memory free)
+void rlglClose()
+{
+    // Unbind everything
+    glBindVertexArray(0);
+    glDisableVertexAttribArray(0);
+    glDisableVertexAttribArray(1);
+    glDisableVertexAttribArray(2);
+    glDisableVertexAttribArray(3);
+    glBindBuffer(GL_ARRAY_BUFFER, 0);
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
+
+    glUseProgram(0);
+
+    // Delete VAOs and VBOs
+    glDeleteBuffers(1, &linesBuffer[0]);
+    glDeleteBuffers(1, &linesBuffer[1]);
+    glDeleteBuffers(1, &trianglesBuffer[0]);
+    glDeleteBuffers(1, &trianglesBuffer[1]);
+    glDeleteBuffers(1, &quadsBuffer[0]);
+    glDeleteBuffers(1, &quadsBuffer[1]);
+    glDeleteBuffers(1, &quadsBuffer[2]);
+    glDeleteBuffers(1, &quadsBuffer[3]);
+
+    glDeleteVertexArrays(1, &vaoLines);
+    glDeleteVertexArrays(1, &vaoTriangles);
+    glDeleteVertexArrays(1, &vaoQuads);
+
+    //glDetachShader(shaderProgram, v);
+    //glDetachShader(shaderProgram, f);
+    //glDeleteShader(v);
+    //glDeleteShader(f);
+    glDeleteProgram(shaderProgram);
+
+    // Free vertex arrays memory
+    free(lines.vertices);
+    free(lines.colors);
+
+    free(triangles.vertices);
+    free(triangles.colors);
+    
+    free(quads.vertices);
+    free(quads.texcoords);
+    free(quads.colors);
+    
+    // Free GPU texture
+    glDeleteTextures(1, &whiteTexture);
+}
+
+void rlglDraw()
+{
+    glUseProgram(shaderProgram);        // Use our shader
+    
+    glUniformMatrix4fv(projectionMatrixLoc, 1, false, GetMatrixVector(projection));
+    glUniformMatrix4fv(modelviewMatrixLoc, 1, false, GetMatrixVector(modelview));
+    glUniform1i(textureLoc, 0);
+
+    UpdateBuffers();
+
+    if (lines.vCounter > 0)
+    {
+        glBindTexture(GL_TEXTURE_2D, whiteTexture);
+    
+        glBindVertexArray(vaoLines);
+        glDrawArrays(GL_LINES, 0, lines.vCounter);
+        
+        glBindTexture(GL_TEXTURE_2D, 0);
+    }
+    
+    if (triangles.vCounter > 0)
+    {
+        glBindVertexArray(vaoTriangles);
+        glDrawArrays(GL_TRIANGLES, 0, triangles.vCounter);
+    }
+    
+    if (quads.vCounter > 0)
+    {
+        int numQuads = 0;
+        int numIndicesToProcess = 0;
+        int indicesOffset = 0;
+
+#ifdef USE_VBO_DOUBLE_BUFFERS
+        // Depending on useBufferB, use Buffer A or Buffer B
+        if (useBufferB) glBindVertexArray(vaoQuadsB);
+        else
+#endif
+        { 
+            glBindVertexArray(vaoQuads);
+        }
+        
+        //printf("\nRequired Draws: %i\n", drawsCounter);
+     
+        for (int i = 0; i < drawsCounter; i++)
+        {
+            numQuads = draws[i].vCount/4;
+            numIndicesToProcess = numQuads*6;  // Get number of Quads * 6 index by Quad
+            
+            //printf("Quads to render: %i - ", numQuads);
+            //printf("Vertex Count: %i - ", draws[i].vCount);
+            //printf("Binding texture: %i\n", draws[i].texId);
+
+            glBindTexture(GL_TEXTURE_2D, draws[i].texId);
+            
+            // NOTE: The final parameter tells the GPU the offset in bytes from the start of the index buffer to the location of the first index to process
+            glDrawElements(GL_TRIANGLES, numIndicesToProcess, GL_UNSIGNED_INT, (GLvoid*) (sizeof(GLuint) * indicesOffset));
+
+            indicesOffset += draws[i].vCount/4*6;
+            
+            //printf("-------Next vertex offset: %i\n", indicesOffset/6*4);
+        }
+    }
+    
+    glBindTexture(GL_TEXTURE_2D, 0);  // Unbind textures
+    glBindVertexArray(0);   // Unbind VAO
+    
+    // Reset draws counter
+    drawsCounter = 1;
+    draws[0].texId = whiteTexture;
+    draws[0].firstVertex = 0;
+    draws[0].vCount = 0;
+    
+    // Reset vertex counters for next frame
+    lines.vCounter = 0;
+    lines.cCounter = 0;
+    
+    triangles.vCounter = 0;
+    triangles.vCounter = 0;
+    
+    quads.vCounter = 0;
+    quads.tcCounter = 0;
+    quads.cCounter = 0;
+ 
+    // TODO: Review double buffer performance -> no improvement! (?)
+#ifdef USE_VBO_DOUBLE_BUFFERS
+    useBufferB = !useBufferB;   // Change buffers usage!
+#endif
+}
+
+#endif
+
+// Initialize Graphics Device (OpenGL stuff)
+void rlglInitGraphicsDevice(int fbWidth, int fbHeight)
+{
+    //glViewport(0, 0, fbWidth, fbHeight);  // Set viewport width and height
+                                            // NOTE: Not required, viewport will be full window space
+
+    // NOTE: Don't confuse glViewport with the transformation matrix
+    // NOTE: glViewport just defines the area of the context that you will actually draw to.
+    
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);     // Clear used buffers, depth buffer is used for 3D
+    glClearColor(0.0f, 0.0f, 0.0f, 1.0f);                   // Set background color (black)
+    //glClearDepth(1.0f);                                   // Clear depth buffer (default)
+    
+    glEnable(GL_DEPTH_TEST);                                // Enables depth testing (required for 3D)
+    glDepthFunc(GL_LEQUAL);                                 // Type of depth testing to apply
+    
+    glEnable(GL_BLEND);                                     // Enable color blending (required to work with transparencies)
+    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);      // Color blending function (how colors are mixed)
+
+#ifdef USE_OPENGL_11    
+    glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST);      // Improve quality of color and texture coordinate interpolation (Deprecated in OGL 3.0)
+                                                            // Other options: GL_FASTEST, GL_DONT_CARE (default)
+#endif
+    
+    rlMatrixMode(RL_PROJECTION);                // Switch to PROJECTION matrix
+    rlLoadIdentity();                           // Reset current matrix (PROJECTION)
+    
+    rlOrtho(0, fbWidth, fbHeight, 0, 0, 1);     // Config orthographic mode: top-left corner --> (0,0)
+    
+    rlMatrixMode(RL_MODELVIEW);                 // Switch back to MODELVIEW matrix
+    rlLoadIdentity();                           // Reset current matrix (MODELVIEW)
+    
+    // TODO: Review all shapes/models are drawn CCW and enable backface culling
+
+    glEnable(GL_CULL_FACE);       // Enable backface culling (Disabled by default)
+    //glCullFace(GL_BACK);        // Cull the Back face (default)
+    //glFrontFace(GL_CCW);        // Front face are defined counter clockwise (default)
+
+#ifdef USE_OPENGL_11    
+    glShadeModel(GL_SMOOTH);      // Smooth shading between vertex (vertex colors interpolation) (Deprecated on OpenGL 3.3+)
+                                  // Possible options: GL_SMOOTH (Color interpolation) or GL_FLAT (no interpolation)
+#endif
+}
+
+// Convert image data to OpenGL texture (returns OpenGL valid Id)
+// NOTE: Image is not unloaded, it should be done manually...
+unsigned int rlglTexture(int width, int height, unsigned char *pixels)
+{
+    glBindTexture(GL_TEXTURE_2D,0); // Free any old binding
+
+    GLuint id;
+    glGenTextures(1, &id);         // Generate Pointer to the texture
+    
+    //glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, id);
+    
+    // NOTE: glTexParameteri does NOT affect texture uploading, just the way it's used!
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);       // Set texture to repead on x-axis
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);       // Set texture to repead on y-axis
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);  // Filter for pixel-perfect drawing, alternative: GL_LINEAR 
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);  // Filter for pixel-perfect drawing, alternative: GL_LINEAR
+ 
+#ifdef USE_OPENGL_33 
+    // Trilinear filtering!
+    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    //glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_LINEAR);   // Activate use of mipmaps (must be available)
+    //glGenerateMipmap(GL_TEXTURE_2D);    // OpenGL 3.3!
+#endif  
+
+    // NOTE: Not using mipmappings (texture for 2D drawing)
+    // At this point we have the image converted to texture and uploaded to GPU
+    
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels);
+    
+    // At this point we have the image converted to texture and uploaded to GPU
+    
+    // Unbind current texture
+    glBindTexture(GL_TEXTURE_2D, 0);
+    
+    printf("New texture created, id: %i (%i x %i)\n", id, width, height);
+    
+    return id;
+}
+
+// Read screen pixel data (color buffer)
+unsigned char *rlglReadScreenPixels(int width, int height)
+{
+    unsigned char *screenData = (unsigned char *)malloc(width * height * sizeof(unsigned char) * 4);
+
+    // NOTE: glReadPixels returns image flipped vertically -> (0,0) is the bottom left corner of the framebuffer
+    glReadPixels(0, 0, width, height, GL_RGBA, GL_UNSIGNED_BYTE, screenData);
+    
+    // Flip image vertically!
+    unsigned char *imgData = (unsigned char *)malloc(width * height * sizeof(unsigned char) * 4);
+    
+    for (int y = height-1; y >= 0; y--)
+    {
+        for (int x = 0; x < (width*4); x++)
+        {
+            imgData[x + (height - y - 1)*width*4] = screenData[x + (y*width*4)];
+        }
+    }
+    
+    free(screenData);
+    
+    return imgData;     // NOTE: image data should be freed
+}
+
+#ifdef USE_OPENGL_33
+
+void PrintProjectionMatrix()
+{
+    PrintMatrix(projection);
+}
+
+void PrintModelviewMatrix()
+{
+    PrintMatrix(modelview);
+}
+
+#endif
+
+//----------------------------------------------------------------------------------
+// Module specific Functions Definition
+//----------------------------------------------------------------------------------
+
+#if defined(USE_OPENGL_33) || defined(USE_OPENGL_ES2)
+
+// Load Shaders (Vertex and Fragment)
+static GLuint LoadDefaultShaders()
+{
+    // NOTE: Shaders are written using GLSL 110 (desktop), that is equivalent to GLSL 100 on ES2 
+
+    // Vertex shader directly defined, no external file required
+    char vShaderStr[] = " #version 110      \n"     // Equivalent to version 100 on ES2
+        "uniform mat4 projectionMatrix;     \n"
+        "uniform mat4 modelviewMatrix;      \n"
+        "attribute vec3 vertexPosition;     \n"
+        "attribute vec2 vertexTexCoord;     \n"
+        "attribute vec4 vertexColor;        \n"
+        "varying vec2 fragTexCoord;         \n"
+        "varying vec4 fragColor;            \n"
+        "void main()                        \n"
+        "{                                  \n"
+        "    fragTexCoord = vertexTexCoord; \n"
+        "    fragColor = vertexColor;       \n"
+        "    gl_Position = projectionMatrix * modelviewMatrix * vec4(vertexPosition, 1.0); \n"
+        "}                                  \n";
+    
+    // Fragment shader directly defined, no external file required
+    char fShaderStr[] = " #version 110      \n"     // Equivalent to version 100 on ES2
+        "uniform sampler2D texture0;        \n"
+        "varying vec2 fragTexCoord;         \n"
+        "varying vec4 fragColor;            \n"
+        "void main()                        \n"
+        "{                                  \n"
+        "    gl_FragColor = texture2D(texture0, fragTexCoord) * fragColor; \n"
+        "}                                  \n";
+
+    GLuint program;
+    GLuint vertexShader;
+    GLuint fragmentShader;
+ 
+    vertexShader = glCreateShader(GL_VERTEX_SHADER);
+    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+ 
+    const char *pvs = vShaderStr;
+    const char *pfs = fShaderStr;
+ 
+    glShaderSource(vertexShader, 1, &pvs, NULL);
+    glShaderSource(fragmentShader, 1, &pfs, NULL);
+
+    glCompileShader(vertexShader);
+    glCompileShader(fragmentShader);
+ 
+    program = glCreateProgram();
+    
+    glAttachShader(program, vertexShader);
+    glAttachShader(program, fragmentShader);
+ 
+    glLinkProgram(program);
+ 
+    glDeleteShader(vertexShader);
+    glDeleteShader(fragmentShader);
+ 
+    return(program);
+}
+
+
+// Load Shaders
+static GLuint LoadShaders(char *vertexFileName, char *fragmentFileName)
+{
+    // Shaders loading from external text file
+    char *vShaderStr = TextFileRead(vertexFileName);
+    char *fShaderStr = TextFileRead(fragmentFileName);
+
+    GLuint program;
+    GLuint vertexShader;
+    GLuint fragmentShader;
+ 
+    vertexShader = glCreateShader(GL_VERTEX_SHADER);
+    fragmentShader = glCreateShader(GL_FRAGMENT_SHADER);
+ 
+    const char *pvs = vShaderStr;
+    const char *pfs = fShaderStr;
+ 
+    glShaderSource(vertexShader, 1, &pvs, NULL);
+    glShaderSource(fragmentShader, 1, &pfs, NULL);
+
+    glCompileShader(vertexShader);
+    glCompileShader(fragmentShader);
+ 
+    program = glCreateProgram();
+    
+    glAttachShader(program, vertexShader);
+    glAttachShader(program, fragmentShader);
+ 
+    glLinkProgram(program);
+ 
+    glDeleteShader(vertexShader);
+    glDeleteShader(fragmentShader);
+ 
+    return(program);
+}
+
+// Read shader text file
+static char *TextFileRead(char *fn) 
+{
+    FILE *fp;
+    char *content = NULL;
+
+    int count=0;
+
+    if (fn != NULL) 
+    {
+        fp = fopen(fn,"rt");
+
+        if (fp != NULL) 
+        {
+            fseek(fp, 0, SEEK_END);
+            count = ftell(fp);
+            rewind(fp);
+
+            if (count > 0) 
+            {
+                content = (char *)malloc(sizeof(char) * (count+1));
+                count = fread(content, sizeof(char), count, fp);
+                content[count] = '\0';
+            }
+            
+            fclose(fp);
+        }
+    }
+    return content;
+}
+
+// Allocate and initialize float array buffers to store vertex data (lines, triangles, quads)
+static void InitializeBuffers()
+{
+    // Initialize lines arrays (vertex position and color data)
+    lines.vertices = (float *)malloc(sizeof(float)*3*2*MAX_LINES_BATCH);    // 3 float by vertex, 2 vertex by line
+    lines.colors = (float *)malloc(sizeof(float)*4*2*MAX_LINES_BATCH);      // 4 float by color, 2 colors by line
+
+    for (int i = 0; i < (3*2*MAX_LINES_BATCH); i++) lines.vertices[i] = 0.0;
+    for (int i = 0; i < (4*2*MAX_LINES_BATCH); i++) lines.colors[i] = 0.0;
+    
+    lines.vCounter = 0;
+    lines.cCounter = 0;
+    
+    // Initialize triangles arrays (vertex position and color data)
+    triangles.vertices = (float *)malloc(sizeof(float)*3*3*MAX_TRIANGLES_BATCH);    // 3 float by vertex, 3 vertex by triangle
+    triangles.colors = (float *)malloc(sizeof(float)*4*3*MAX_TRIANGLES_BATCH);      // 4 float by color, 3 colors by triangle
+
+    for (int i = 0; i < (3*3*MAX_TRIANGLES_BATCH); i++) triangles.vertices[i] = 0.0;
+    for (int i = 0; i < (4*3*MAX_TRIANGLES_BATCH); i++) triangles.colors[i] = 0.0;
+    
+    triangles.vCounter = 0;
+    triangles.cCounter = 0;
+    
+    // Initialize quads arrays (vertex position, texcoord and color data... and indexes)
+    quads.vertices = (float *)malloc(sizeof(float)*3*4*MAX_QUADS_BATCH);    // 3 float by vertex, 4 vertex by quad
+    quads.texcoords = (float *)malloc(sizeof(float)*2*4*MAX_QUADS_BATCH);   // 2 float by texcoord, 4 texcoord by quad
+    quads.colors = (float *)malloc(sizeof(float)*4*4*MAX_QUADS_BATCH);      // 4 float by color, 4 colors by quad
+    quads.indices = (unsigned int *)malloc(sizeof(int)*6*MAX_QUADS_BATCH);  // 6 int by quad (indices)
+    
+    for (int i = 0; i < (3*4*MAX_QUADS_BATCH); i++) quads.vertices[i] = 0.0;
+    for (int i = 0; i < (2*4*MAX_QUADS_BATCH); i++) quads.texcoords[i] = 0.0;
+    for (int i = 0; i < (4*4*MAX_QUADS_BATCH); i++) quads.colors[i] = 0.0;
+    
+    int k = 0;
+    
+    // Indices can be initialized right now
+    for (int i = 0; i < (6*MAX_QUADS_BATCH); i+=6)
+    {
+        quads.indices[i] = 4*k;
+        quads.indices[i+1] = 4*k+1;
+        quads.indices[i+2] = 4*k+2;
+        quads.indices[i+3] = 4*k;
+        quads.indices[i+4] = 4*k+2;
+        quads.indices[i+5] = 4*k+3;
+        
+        k++;
+    }
+    
+    quads.vCounter = 0;
+    quads.tcCounter = 0;
+    quads.cCounter = 0;
+}
+
+// Initialize Vertex Array Objects (Contain VBO)
+static void InitializeVAOs()
+{
+    // Initialize Lines VAO
+    glGenVertexArrays(1, &vaoLines);
+    glBindVertexArray(vaoLines);
+ 
+    // Create buffers for our vertex data
+    glGenBuffers(2, linesBuffer);
+ 
+    // Lines - Vertex positions buffer binding and attributes enable
+    glBindBuffer(GL_ARRAY_BUFFER, linesBuffer[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*2*MAX_LINES_BATCH, lines.vertices, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(vertexLoc);
+    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, 0, 0, 0);
+    
+    // Lines - colors buffer
+    glBindBuffer(GL_ARRAY_BUFFER, linesBuffer[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*2*MAX_LINES_BATCH, lines.colors, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(colorLoc);
+    glVertexAttribPointer(colorLoc, 4, GL_FLOAT, 0, 0, 0);
+
+    //-------------------------------------------------------------- 
+    
+    // Initialize Triangles VAO
+    glGenVertexArrays(1, &vaoTriangles);
+    glBindVertexArray(vaoTriangles);
+ 
+    // Create buffers for our vertex data
+    glGenBuffers(2, trianglesBuffer);
+ 
+    // Enable vertex attributes
+    glBindBuffer(GL_ARRAY_BUFFER, trianglesBuffer[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*3*MAX_TRIANGLES_BATCH, triangles.vertices, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(vertexLoc);
+    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, 0, 0, 0);
+    
+    glBindBuffer(GL_ARRAY_BUFFER, trianglesBuffer[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*3*MAX_TRIANGLES_BATCH, triangles.colors, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(colorLoc);
+    glVertexAttribPointer(colorLoc, 4, GL_FLOAT, 0, 0, 0);
+
+    //-------------------------------------------------------------- 
+    
+    // Initialize Quads VAO (Buffer A)
+    glGenVertexArrays(1, &vaoQuads);
+    glBindVertexArray(vaoQuads);
+ 
+    // Create buffers for our vertex data
+    glGenBuffers(4, quadsBuffer);
+ 
+    // Enable vertex attributes
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*4*MAX_QUADS_BATCH, quads.vertices, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(vertexLoc);
+    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, 0, 0, 0);
+    
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*2*4*MAX_QUADS_BATCH, quads.texcoords, GL_DYNAMIC_DRAW);      
+    glEnableVertexAttribArray(texcoordLoc);
+    glVertexAttribPointer(texcoordLoc, 2, GL_FLOAT, 0, 0, 0);
+    
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[2]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*4*MAX_QUADS_BATCH, quads.colors, GL_DYNAMIC_DRAW);   
+    glEnableVertexAttribArray(colorLoc);
+    glVertexAttribPointer(colorLoc, 4, GL_FLOAT, 0, 0, 0);
+    
+    // Fill index buffer
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, quadsBuffer[3]);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int)*6*MAX_QUADS_BATCH, quads.indices, GL_STATIC_DRAW);
+    
+#ifdef USE_VBO_DOUBLE_BUFFERS
+    // Initialize Quads VAO (Buffer B)
+    glGenVertexArrays(1, &vaoQuadsB);
+    glBindVertexArray(vaoQuadsB);
+ 
+    // Create buffers for our vertex data
+    glGenBuffers(4, quadsBufferB);
+ 
+    // Enable vertex attributes
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*4*MAX_QUADS_BATCH, quads.vertices, GL_DYNAMIC_DRAW);
+    glEnableVertexAttribArray(vertexLoc);
+    glVertexAttribPointer(vertexLoc, 3, GL_FLOAT, 0, 0, 0);
+    
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*2*4*MAX_QUADS_BATCH, quads.texcoords, GL_DYNAMIC_DRAW);      
+    glEnableVertexAttribArray(texcoordLoc);
+    glVertexAttribPointer(texcoordLoc, 2, GL_FLOAT, 0, 0, 0);
+    
+    glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[2]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*4*MAX_QUADS_BATCH, quads.colors, GL_DYNAMIC_DRAW);   
+    glEnableVertexAttribArray(colorLoc);
+    glVertexAttribPointer(colorLoc, 4, GL_FLOAT, 0, 0, 0);
+    
+    // Fill index buffer
+    glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, quadsBufferB[3]);
+    glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(int)*6*MAX_QUADS_BATCH, quads.indices, GL_STATIC_DRAW);
+    
+    printf("Using VBO double buffering\n");
+#endif
+ 
+    printf("Vertex buffers initialized (lines, triangles, quads)\n\n");
+ 
+    // Unbind the current VAO
+    glBindVertexArray(0);
+}
+
+// Update VBOs with vertex array data
+static void UpdateBuffers()
+{
+    // Activate Lines VAO
+    glBindVertexArray(vaoLines);
+ 
+    // Lines - vertex positions buffer
+    glBindBuffer(GL_ARRAY_BUFFER, linesBuffer[0]);
+    //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*2*MAX_LINES_BATCH, lines.vertices, GL_DYNAMIC_DRAW);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*3*lines.vCounter, lines.vertices);    // target - offset (in bytes) - size (in bytes) - data pointer
+    
+    // Lines - colors buffer
+    glBindBuffer(GL_ARRAY_BUFFER, linesBuffer[1]);
+    //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*2*MAX_LINES_BATCH, lines.colors, GL_DYNAMIC_DRAW);
+    glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*4*lines.vCounter, lines.colors);
+    
+    //--------------------------------------------------------------    
+    
+    // Activate Triangles VAO
+    glBindVertexArray(vaoTriangles);
+ 
+    // Triangles - vertex positions buffer
+    glBindBuffer(GL_ARRAY_BUFFER, trianglesBuffer[0]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*3*MAX_TRIANGLES_BATCH, triangles.vertices, GL_DYNAMIC_DRAW);
+
+    // Triangles - colors buffer
+    glBindBuffer(GL_ARRAY_BUFFER, trianglesBuffer[1]);
+    glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*3*MAX_TRIANGLES_BATCH, triangles.colors, GL_DYNAMIC_DRAW);
+    
+    //--------------------------------------------------------------
+
+    // Depending on useBufferB, update Buffer A or Buffer B
+#ifdef USE_VBO_DOUBLE_BUFFERS
+    if (useBufferB)
+    {
+        // Activate Quads VAO (Buffer B)
+        glBindVertexArray(vaoQuadsB);
+     
+        // Quads - vertex positions buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[0]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*4*MAX_QUADS_BATCH, quads.vertices, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*3*quads.vCounter, quads.vertices);
+
+        // Quads - texture coordinates buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[1]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*2*4*MAX_QUADS_BATCH, quads.texcoords, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*2*quads.vCounter, quads.texcoords);
+        
+        // Quads - colors buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBufferB[2]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*4*MAX_QUADS_BATCH, quads.colors, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*4*quads.vCounter, quads.colors);
+    }
+    else
+#endif
+    {
+        // Activate Quads VAO (Buffer A)
+        glBindVertexArray(vaoQuads);
+     
+        // Quads - vertex positions buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[0]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*3*4*MAX_QUADS_BATCH, quads.vertices, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*3*quads.vCounter, quads.vertices);
+
+        // Quads - texture coordinates buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[1]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*2*4*MAX_QUADS_BATCH, quads.texcoords, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*2*quads.vCounter, quads.texcoords);
+        
+        // Quads - colors buffer
+        glBindBuffer(GL_ARRAY_BUFFER, quadsBuffer[2]);
+        //glBufferData(GL_ARRAY_BUFFER, sizeof(float)*4*4*MAX_QUADS_BATCH, quads.colors, GL_DYNAMIC_DRAW);
+        glBufferSubData(GL_ARRAY_BUFFER, 0, sizeof(float)*4*quads.vCounter, quads.colors);
+    }
+    
+    //--------------------------------------------------------------
+    
+    // Unbind the current VAO
+    glBindVertexArray(0);
+}
+
+#endif
\ No newline at end of file