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  • Drawing using Dynamic Array and Buffer Object

    - by user1905910
    I have a problem when creating the vertex array and the indices array. I don't know what really is the problem with the code, but I guess is something with the type of the arrays, can someone please give me a light on this? #define GL_GLEXT_PROTOTYPES #include<GL/glut.h> #include<iostream> using namespace std; #define BUFFER_OFFSET(offset) ((GLfloat*) NULL + offset) const GLuint numDiv = 2; const GLuint numVerts = 9; GLuint VAO; void display(void) { enum vertex {VERTICES, INDICES, NUM_BUFFERS}; GLuint * buffers = new GLuint[NUM_BUFFERS]; GLfloat (*squareVerts)[2] = new GLfloat[numVerts][2]; GLubyte * indices = new GLubyte[numDiv*numDiv*4]; GLuint delta = 80/numDiv; for(GLuint i = 0; i < numVerts; i++) { squareVerts[i][1] = (i/(numDiv+1))*delta; squareVerts[i][0] = (i%(numDiv+1))*delta; } for(GLuint i=0; i < numDiv; i++){ for(GLuint j=0; j < numDiv; j++){ //cada iteracao gera 4 pontos #define NUM_VERT(ii,jj) ((ii)*(numDiv+1)+(jj)) #define INDICE(ii,jj) (4*((ii)*numDiv+(jj))) indices[INDICE(i,j)] = NUM_VERT(i,j); indices[INDICE(i,j)+1] = NUM_VERT(i,j+1); indices[INDICE(i,j)+2] = NUM_VERT(i+1,j+1); indices[INDICE(i,j)+3] = NUM_VERT(i+1,j); } } glGenVertexArrays(1, &VAO); glBindVertexArray(VAO); glGenBuffers(NUM_BUFFERS, buffers); glBindBuffer(GL_ARRAY_BUFFER, buffers[VERTICES]); glBufferData(GL_ARRAY_BUFFER, sizeof(squareVerts), squareVerts, GL_STATIC_DRAW); glVertexPointer(2, GL_FLOAT, 0, BUFFER_OFFSET(0)); glEnableClientState(GL_VERTEX_ARRAY); glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, buffers[INDICES]); glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indices), indices, GL_STATIC_DRAW); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0,1.0,1.0); glDrawElements(GL_POINTS, 16, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0)); glutSwapBuffers(); } void init() { glClearColor(0.0, 0.0, 0.0, 0.0); gluOrtho2D((GLdouble) -1.0, (GLdouble) 90.0, (GLdouble) -1.0, (GLdouble) 90.0); } int main(int argv, char** argc) { glutInit(&argv, argc); glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE); glutInitWindowSize(500,500); glutInitWindowPosition(100,100); glutCreateWindow("myCode.cpp"); init(); glutDisplayFunc(display); glutMainLoop(); return 0; } Edit: The problem here is that drawing don't work at all. But I don't get any error, this just don't display what I want to display. Even if I put the code that make the vertices and put them in the buffers in a diferent function, this don't work. I just tried to do this: void display(void) { glBindVertexArray(VAO); glClear(GL_COLOR_BUFFER_BIT); glColor3f(1.0,1.0,1.0); glDrawElements(GL_POINTS, 16, GL_UNSIGNED_BYTE, BUFFER_OFFSET(0)); glutSwapBuffers(); } and I placed the rest of the code in display in another function that is called on the start of the program. But the problem still

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