sample1.cpp

#define GLEW_STATIC

#include<GL/glew.h>
#include<GL/glut.h>
#include <GL/freeglut_ext.h>
#include<iostream>

using namespace std;

void display();
void triangle();
void init();
void keyBoardMonitor(unsigned char key, int x, int y);

GLuint VBOid;
bool initTriangle = true;
float angle = 1.0f;

GLfloat trianglevertices[] = {
	0.0f, .75f, 0.0f,
	-0.75f, 0.0f, 0.0f,
	0.75f, 0.0f, 0.0f
};

int main(int argc, char** argv) {
	glutInit(&argc, argv);
	glutInitWindowSize(600, 600);
	glutCreateWindow("OpenGL Setup Test");
	
	glutKeyboardFunc(keyBoardMonitor);
	glutDisplayFunc(display);
	
	GLenum err = glewInit();
	if (err == GLEW_OK) {
		glutMainLoop();
	} else {
		cout << "Error in initializing GLEW extension library...";
	}
	return 0;
}

void triangle(){
	if (initTriangle) {
		glGenBuffers(1, &VBOid);
		glBindBuffer(GL_ARRAY_BUFFER, VBOid);
		glBufferData(GL_ARRAY_BUFFER, sizeof(GLfloat) * 9, trianglevertices, GL_STATIC_DRAW);
		
		glEnableClientState(GL_VERTEX_ARRAY);
		
		glMatrixMode(GL_MODELVIEW); // triangle itself
		glLoadIdentity();
		
		glTranslatef(0.0f, -0.5f, 0.0f);
		glScalef(.75f, .75f, 0.0f);
		
		initTriangle = false;
	}
	
	glPushMatrix(); // reset on the initial value (in this case, the original rotation)
	glRotatef(angle, 0.0f, 0.0f, 1.0);
	
	glVertexPointer(3, GL_FLOAT, 0, 0);
	glDrawArrays(GL_TRIANGLES,0,6);
	
	glPopMatrix();
}

void animateTriangle(int value){
	angle++;
	glutPostRedisplay();
}

void display() {
	glClear(GL_COLOR_BUFFER_BIT);
	glColor4f(.16f, .72f, .08f, 1.0f);
	triangle();
	glFlush();
	glutTimerFunc(200, animateTriangle, 1);
}

void keyBoardMonitor(unsigned char key, int x, int y){
	if (key == 'x') {
		glDisableClientState(GL_VERTEX_ARRAY);
		glBindBuffer(GL_ARRAY_BUFFER, 0);
		glDeleteBuffers(1, &VBOid);
		exit(0);
	}
}