The future of raylib!

Mapping of OpenGL 1.1 immediate mode functions to OpenGL 3.2+ (and
OpenGL ES 2.0) programmable pipeline

src/rllegacy.c

@@ -0,0 +1,1015 @@
+/*********************************************************************************************
+* 
+*   rllegacy - raylib OpenGL 1.1 functions replacement
+*    
+*   OpenGL 1.1 functions mapping to OpenGL 3.2+ (and OpenGL ES 2.0)
+* 
+*   Copyright (c) 2014 Ramon Santamaria (Ray San - [email protected])
+*    
+*   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 "rllegacy.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
+
+#define GLEW_STATIC         
+#include <GL/glew.h>        // Extensions loading lib
+
+//----------------------------------------------------------------------------------
+// Defines and Macros
+//----------------------------------------------------------------------------------
+#define MATRIX_STACK_SIZE         16   
+#define MAX_DRAWS_BY_TEXTURE     256    // Draws are organized by texture changes
+
+//----------------------------------------------------------------------------------
+// Types and Structures Definition
+//----------------------------------------------------------------------------------
+typedef enum { LINES, TRIANGLES, QUADS } DrawMode;
+
+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
+//----------------------------------------------------------------------------------
+static Matrix stack[MATRIX_STACK_SIZE];
+static int stackCounter = 0;
+
+static Matrix modelview;
+static Matrix projection;
+static Matrix *currentMatrix;
+
+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];
+
+// TODO: Review -> Do not get any performance improvement... why?
+static GLuint vaoQuadsB;
+static GLuint quadsBufferB[4];
+static int useBufferB = 0;
+    
+static DrawCall *draws;
+static int drawsCounter;
+
+// White texture useful for plain color polys (required by shader)
+static GLuint whiteTexture;
+
+//----------------------------------------------------------------------------------
+// Module specific Functions Declaration
+//----------------------------------------------------------------------------------
+static GLuint LoadShaders(char *vertexFileName, char *fragmentFileName);
+static char *TextFileRead(char *fn);
+static void CreateDefaultTexture();
+static void InitializeBuffers();
+static void InitializeVAOs();
+static void UpdateBuffers();
+static void rlDrawRangeElements(GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, void *indices);
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - Matrix operations
+//----------------------------------------------------------------------------------
+
+// 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!
+}
+
+// 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++;
+}
+
+// Pop lattest inserted matrix from stack
+void rlPopMatrix()
+{
+    if (stackCounter > 0)
+    {
+        Matrix mat = stack[stackCounter - 1];
+
+        stackCounter--;
+        
+        *currentMatrix = mat;
+    }
+}
+
+// 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 mat = MatrixFrustum(left, right, bottom, top, near, far);
+
+    *currentMatrix = MatrixMultiply(*currentMatrix, mat);
+}
+
+// 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);
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - Vertex level operations
+//----------------------------------------------------------------------------------
+
+// Initialize drawing mode (how to organize vertex)
+void rlBegin(int mode)
+{
+    // TODO: Code shouldn't include other modes than RL_POINTS, RL_LINES and RL_TRIANGLES
+    switch (mode)
+    {
+        case RL_POINTS: currentDrawMode = LINES; break;
+        case RL_LINES: currentDrawMode = LINES; break;
+        case RL_LINE_LOOP: currentDrawMode = LINES; break;
+        case RL_TRIANGLE_FAN: currentDrawMode = TRIANGLES; break;
+        case RL_QUADS: currentDrawMode = QUADS; break;
+        case RL_QUAD_STRIP: currentDrawMode = QUADS; break;
+        default: break;
+    }
+    
+    int id;
+    glGetIntegerv(GL_TEXTURE_BINDING_2D, &id);
+    
+    if (id == 0)
+    {    
+        glBindTexture(GL_TEXTURE_2D, whiteTexture);
+        id = 1;
+    }
+    
+    if (draws[drawsCounter - 1].texId != id)
+    {   
+        drawsCounter++;
+    
+        draws[drawsCounter - 1].texId = id;
+        draws[drawsCounter - 1].firstVertex = draws[drawsCounter - 2].vCount;
+        draws[drawsCounter - 1].vCount = 0;
+    }
+}
+
+// Finish vertex providing
+void rlEnd()
+{
+    // 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 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 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 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)
+{
+    switch (currentDrawMode)
+    {
+        case 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 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 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 == QUADS)
+    {
+        quads.texcoords[2*quads.tcCounter] = x;
+        quads.texcoords[2*quads.tcCounter + 1] = y;
+
+        quads.tcCounter++;
+    }
+}
+
+// Define one vertex (normal)
+// NOTE: Normals are 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 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 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 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);
+}
+
+//----------------------------------------------------------------------------------
+// Module Functions Definition - RlLegacy Init-Close
+//----------------------------------------------------------------------------------
+
+// Init OpenGL 3.3+ required data
+void InitRlLegacy()
+{                           
+    // 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("Ready for OpenGL 3.3\n"); 
+
+    // Set default draw mode
+    currentDrawMode = 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 150)
+    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("Shaders loaded!\n");
+    
+    InitializeBuffers();    // Init vertex arrays
+    InitializeVAOs();       // Init VBO and VAO
+    
+    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;
+    
+    // Default white texture for plain colors (required by shader)   
+    CreateDefaultTexture();
+    
+    draws[drawsCounter - 1].texId = whiteTexture;
+}
+
+// Vertex Buffer Object deinitialization (memory free)
+void CloseRlLegacy()
+{
+    // 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 DrawRlLegacy()
+{
+    glUseProgram(shaderProgram);        // Use our shader
+
+    glBindTexture(GL_TEXTURE_2D, whiteTexture);
+    
+    glUniformMatrix4fv(projectionMatrixLoc, 1, false, GetMatrixVector(projection));
+    glUniformMatrix4fv(modelviewMatrixLoc, 1, false, GetMatrixVector(modelview));
+    glUniform1i(textureLoc, 0);
+
+    UpdateBuffers();
+
+    if (lines.vCounter > 0)
+    {
+        glBindVertexArray(vaoLines);
+        glDrawArrays(GL_LINES, 0, lines.vCounter);
+    }
+    
+    if (triangles.vCounter > 0)
+    {
+        glBindVertexArray(vaoTriangles);
+        glDrawArrays(GL_TRIANGLES, 0, triangles.vCounter);
+    }
+    
+    if (quads.vCounter > 0)
+    {
+        int numQuads = 0;
+ 
+        // Depending on useBufferB, use Buffer A or Buffer B
+        if (useBufferB) glBindVertexArray(vaoQuadsB);
+        else glBindVertexArray(vaoQuads);
+        
+        for (int i = 0; i < drawsCounter; i++)
+        {
+            numQuads += draws[i].vCount/4;
+
+            glBindTexture(GL_TEXTURE_2D, draws[i].texId);
+            rlDrawRangeElements(GL_TRIANGLES, draws[i].firstVertex, draws[i].firstVertex + draws[i].vCount - 1, 6*numQuads, GL_UNSIGNED_INT, 0);
+        }
+    }
+  
+    glBindTexture(GL_TEXTURE_2D, whiteTexture);
+
+    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!
+    //useBufferB = !useBufferB;   // Change buffers usage!
+}
+
+//----------------------------------------------------------------------------------
+// Module specific Functions Definition
+//----------------------------------------------------------------------------------
+
+// Load shader (GLSL 150)
+static GLuint LoadShaders(char *vertexFileName, char *fragmentFileName)
+{
+    char *vs = NULL;
+    char *fs = NULL;
+ 
+    GLuint p,v,f;
+ 
+    v = glCreateShader(GL_VERTEX_SHADER);
+    f = glCreateShader(GL_FRAGMENT_SHADER);
+ 
+    vs = TextFileRead(vertexFileName);
+    fs = TextFileRead(fragmentFileName);
+ 
+    const char *vv = vs;
+    const char *ff = fs;
+ 
+    glShaderSource(v, 1, &vv, NULL);
+    glShaderSource(f, 1, &ff, NULL);
+ 
+    free(vs);
+    free(fs);
+ 
+    glCompileShader(v);
+    glCompileShader(f);
+ 
+    p = glCreateProgram();
+    
+    glAttachShader(p,v);
+    glAttachShader(p,f);
+ 
+    glLinkProgram(p);
+ 
+    glDeleteShader(v);
+	glDeleteShader(f);
+ 
+    return(p);
+}
+
+// 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;
+    
+    printf("All buffers initialized - lines, triangles, quads(indexed).\n");
+}
+
+// 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);
+    
+
+    // 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);
+ 
+    // 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
+    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
+    {
+        // 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);
+}
+
+// Create default white texture to be used on plain colors (required by default shader)
+static void CreateDefaultTexture()
+{       
+    unsigned char *imgData = (unsigned char *)malloc(4);   // 1 pixel RGBA (4 bytes)
+    
+    for (int i = 0; i < 4; i++) imgData[i] = 255;        // Initialize array
+
+    // Convert data to OpenGL texture
+    //--------------------------------
+    GLuint id;
+    glGenTextures(1, &id);                    // Generate pointer to the texture
+    
+    glActiveTexture(GL_TEXTURE0);
+    glBindTexture(GL_TEXTURE_2D, id);
+    
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);            // Set texture to clamp on x-axis
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);            // Set texture to clamp on y-axis
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);      // Filter for pixel-perfect drawing, alternative: GL_LINEAR 
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);      // Filter for pixel-perfect drawing, alternative: GL_LINEAR 
+    
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 1, 1, 0, GL_RGBA, GL_UNSIGNED_BYTE, imgData);
+    
+    // At this point we have the image converted to texture and uploaded to GPU
+    
+    free(imgData);                    // Now we can free loaded data from RAM memory
+    
+    whiteTexture = id;
+    
+    // Unbind current texture
+    glBindTexture(GL_TEXTURE_2D, 0);
+}
+
+// Replacement for glDrawRangeElements (OpenGL 3.3+)
+// NOTE: glDrawRangeElement is not supported by OpenGL ES 2.0 so, we use glDrawElements instead
+static void rlDrawRangeElements(GLenum mode, GLuint start, GLuint end, GLsizei count, GLenum type, void *indices)
+{
+    glDrawElements(mode, count, type, indices);
+}

src/rllegacy.h

@@ -0,0 +1,87 @@
+/*********************************************************************************************
+* 
+*   rllegacy - raylib OpenGL 1.1 functions replacement
+*    
+*   OpenGL 1.1 functions mapping to OpenGL 3.2+ (and OpenGL ES 2.0)
+* 
+*   Copyright (c) 2014 Ramon Santamaria (Ray San - [email protected])
+*    
+*   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.
+*
+**********************************************************************************************/
+
+#ifndef RLLEGACY_H
+#define RLLEGACY_H
+
+//----------------------------------------------------------------------------------
+// Defines and Macros
+//----------------------------------------------------------------------------------
+#define MAX_LINES_BATCH         1024
+#define MAX_TRIANGLES_BATCH     2048
+#define MAX_QUADS_BATCH         2048
+
+//----------------------------------------------------------------------------------
+// Types and Structures Definition
+//----------------------------------------------------------------------------------
+typedef unsigned char byte;
+
+typedef enum { RL_PROJECTION, RL_MODELVIEW, RL_TEXTURE } MatrixMode;
+
+typedef enum { RL_POINTS, RL_LINES, RL_LINE_STRIP, RL_LINE_LOOP, RL_TRIANGLES, 
+               RL_TRIANGLE_STRIP, RL_TRIANGLE_FAN, RL_QUADS, RL_QUAD_STRIP, RL_POLYGON } PrimitiveType;
+
+
+#ifdef __cplusplus
+extern "C" {            // Prevents name mangling of functions
+#endif
+
+//------------------------------------------------------------------------------------
+// Functions Declaration - Matrix operations
+//------------------------------------------------------------------------------------
+void rlMatrixMode(int mode);                    // Choose the current matrix to be transformed
+void rlPushMatrix();                            // Push the current matrix to stack
+void rlPopMatrix();                             // Pop lattest inserted matrix from stack
+void rlLoadIdentity();                          // Reset current matrix to identity matrix
+void rlTranslatef(float x, float y, float z);   // Multiply the current matrix by a translation matrix
+void rlRotatef(float angleDeg, float x, float y, float z);  // Multiply the current matrix by a rotation matrix
+void rlScalef(float x, float y, float z);       // Multiply the current matrix by a scaling matrix
+void rlMultMatrixf(float *mat);                 // Multiply the current matrix by another matrix
+void rlFrustum(double left, double right, double bottom, double top, double near, double far);
+void rlOrtho(double left, double right, double bottom, double top, double near, double far);
+
+//------------------------------------------------------------------------------------
+// Functions Declaration - Vertex level operations
+//------------------------------------------------------------------------------------
+void rlBegin(int mode);                         // Initialize drawing mode (how to organize vertex)
+void rlEnd();                                   // Finish vertex providing
+void rlVertex3f(float x, float y, float z);     // Define one vertex (position) - 3 float
+void rlVertex2f(float x, float y);              // Define one vertex (position) - 2 float
+void rlVertex2i(int x, int y);                  // Define one vertex (position) - 2 int
+void rlTexCoord2f(float x, float y);            // Define one vertex (texture coordinate) - 2 float
+void rlNormal3f(float x, float y, float z);     // Define one vertex (normal) - 3 float
+void rlColor4ub(byte r, byte g, byte b, byte a);    // Define one vertex (color) - 4 byte
+void rlColor3f(float x, float y, float z);          // Define one vertex (color) - 3 float
+void rlColor4f(float x, float y, float z, float w); // Define one vertex (color) - 4 float
+
+void InitRlLegacy();
+void CloseRlLegacy();
+void DrawRlLegacy();
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif // RLLEGACY_H

src/simple150.frag

@@ -0,0 +1,15 @@
+#version 150
+
+uniform sampler2D texture0;
+
+in vec2 fragTexCoord;
+in vec4 fragColor;
+
+out vec4 pixelColor;
+
+void main()
+{
+    // Output pixel color
+    pixelColor = texture(texture0, fragTexCoord) * fragColor;
+    //pixelColor = fragColor;
+}

src/simple150.vert

@@ -0,0 +1,21 @@
+#version 150
+
+uniform mat4 projectionMatrix;
+uniform mat4 modelviewMatrix;
+
+in vec3 vertexPosition;
+in vec2 vertexTexCoord;
+in vec4 vertexColor;
+
+out vec2 fragTexCoord;
+out vec4 fragColor;
+
+void main()
+{
+    // Pass some variables to the fragment shader
+    fragTexCoord = vertexTexCoord;
+    fragColor = vertexColor;
+    
+    // Apply all matrix transformations to vertex
+    gl_Position = projectionMatrix * modelviewMatrix * vec4(vertexPosition, 1.0);
+}