I was not able to get sample 2-18 from OpenGL Programming Guide 7th edition to work. I tried it with two different graphics cards, with ATI Radeon HD3850 and HD4870x2. HD3850 was running with drivers 9.7 and HD4870x2 with 9.8.
I believe that I’m doing something wrong in main().
// vao.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <GL/glew.h>
#include <GL/freeglut.h>
#include <math.h>
#define M_PI 3.141592653589793238462643
#define BUFFER_OFFSET(offset) ((GLvoid*)(NULL + offset))
#define NumberOf(array_) (sizeof(array_)/sizeof(array_[0]))
typedef struct {
GLfloat x, y, z;
} vec3;
typedef struct {
vec3 xlate;
GLfloat angle;
vec3 axis;
} XForm;
enum { Cube, Cone, NumVAOs };
GLuint VAO[NumVAOs];
GLenum PrimType[NumVAOs];
GLsizei NumElements[NumVAOs];
XForm Xform[NumVAOs] = {
{ { -2.0, 0.0, 0.0 } , 0.0, { 0.0, 1.0, 0.0 } },
{ { 0.0, 0.0, 2.0 } , 0.0, { 1.0, 0.0, 0.0 } }
};
GLfloat Angle = 0.0;
void
init()
{
enum { Vertices, Colors, Elements, NumVBOs };
GLuint buffers[NumVBOs];
glGenVertexArrays(NumVAOs, VAO);
{
GLfloat cubeVerts[][3] = {
{ -1.0, -1.0, -1.0 },
{ -1.0, -1.0, 1.0 },
{ -1.0, 1.0, -1.0 },
{ -1.0, 1.0, 1.0 },
{ 1.0, -1.0, -1.0 },
{ 1.0, -1.0, 1.0 },
{ 1.0, 1.0, -1.0 },
{ 1.0, 1.0, 1.0 },
};
GLfloat cubeColors[][3] = {
{ 0.0, 0.0, 0.0 },
{ 0.0, 0.0, 1.0 },
{ 0.0, 1.0, 0.0 },
{ 0.0, 1.0, 1.0 },
{ 1.0, 0.0, 0.0 },
{ 1.0, 0.0, 1.0 },
{ 1.0, 1.0, 0.0 },
{ 1.0, 1.0, 1.0 },
};
GLubyte cubeIndices[] = {
0, 1, 3, 2,
4, 6, 7, 5,
2, 3, 7, 6,
0, 4, 5, 1,
0, 2, 6, 4,
1, 5, 7, 3
};
glBindVertexArray(VAO[Cube]);
glGenBuffers(NumVBOs, buffers);
glBindBuffer(GL_ARRAY_BUFFER, buffers[Vertices]);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeVerts),
cubeVerts, GL_STATIC_DRAW);
glVertexPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glEnableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, buffers[Colors]);
glBufferData(GL_ARRAY_BUFFER, sizeof(cubeColors),
cubeColors, GL_STATIC_DRAW);
glColorPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
buffers[Elements]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
sizeof(cubeIndices), cubeIndices, GL_STATIC_DRAW);
PrimType[Cube] = GL_QUADS;
NumElements[Cube] = NumberOf(cubeIndices);
}
{
int i, idx;
float dTheta;
#define NumConePoints 36
/* We add one more vertex for the cone's apex */
GLfloat coneVerts[NumConePoints+1][3] = {
{0.0, 0.0, 1.0}
};
GLfloat coneColors[NumConePoints+1][3] = {
{1.0, 1.0, 1.0}
};
GLubyte coneIndices[NumConePoints+1];
dTheta = 2*M_PI / (NumConePoints - 1);
idx = 1;
for (i = 0; i < NumConePoints; ++i, ++idx) {
float theta = i*dTheta;
coneVerts[idx][0] = cos(theta);
coneVerts[idx][1] = sin(theta);
coneVerts[idx][2] = 0.0;
coneColors[idx][0] = cos(theta);
coneColors[idx][1] = sin(theta);
coneColors[idx][2] = 0.0;
coneIndices[idx] = idx;
}
glBindVertexArray(VAO[Cone]);
glGenBuffers(NumVBOs, buffers);
glBindBuffer(GL_ARRAY_BUFFER, buffers[Vertices]);
glBufferData(GL_ARRAY_BUFFER, sizeof(coneVerts),
coneVerts, GL_STATIC_DRAW);
glVertexPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glEnableClientState(GL_VERTEX_ARRAY);
glBindBuffer(GL_ARRAY_BUFFER, buffers[Colors]);
glBufferData(GL_ARRAY_BUFFER, sizeof(coneColors),
coneColors, GL_STATIC_DRAW);
glColorPointer(3, GL_FLOAT, 0, BUFFER_OFFSET(0));
glEnableClientState(GL_COLOR_ARRAY);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER,
buffers[Elements]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER,
sizeof(coneIndices), coneIndices, GL_STATIC_DRAW);
PrimType[Cone] = GL_TRIANGLE_FAN;
NumElements[Cone] = NumberOf(coneIndices);
}
glEnable(GL_DEPTH_TEST);
}
void
display()
{
int i;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glPushMatrix();
glRotatef(Angle, 0.0, 1.0, 0.0);
for (i = 0; i < NumVAOs; ++i) {
glPushMatrix();
glTranslatef(Xform[i].xlate.x, Xform[i].xlate.y,
Xform[i].xlate.z);
glRotatef(Xform[i].angle, Xform[i].axis.x,
Xform[i].axis.y, Xform[i].axis.z);
glBindVertexArray(VAO[i]);
glDrawElements(PrimType[i], NumElements[i],
GL_UNSIGNED_BYTE, BUFFER_OFFSET(0));
glPopMatrix();
}
glPopMatrix();
glutSwapBuffers();
}
int _tmain(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
glutInitWindowSize(400, 400);
glutInitWindowPosition(100, 100);
glutCreateWindow("vao");
if (glewInit() != GLEW_OK)
{
printf("GLEW initialization failed...
");
return 1;
}
init();
glutDisplayFunc(display);
glutMainLoop();
return 0;
}