OpenGL step to step(1)

#include <GLUT/GLUT.h>

void init()

{

glClearColor(0.0,0.0,0.0,0.0);

glShadeModel(GL_FLAT);

}

void display()

{

glClear(GL_COLOR_BUFFER_BIT);

glColor3f(1.0,1.0,1.0);

glLoadIdentity();

gluLookAt(0.0,0.0, 5.0, 0.0,0.0,0.0,0.0,1.0,0.0);

glScalef(1.0,2.0,1.0);

glutWireCube(1.0);

glFlush();

}

void reshape(int w,int h)

{

glViewport(0, 0, (GLsizei)w, (GLsizei)h);

glMatrixMode(GL_PROJECTION);

glLoadIdentity();

glFrustum(-1, 1.0, -1, 1.0, 1.5, 20.0);

glMatrixMode(GL_MODELVIEW);

}

int main(int argc, char ** argv)

{

glutInit(&argc, argv);

glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);

glutInitWindowSize(500, 500);

glutInitWindowPosition(100,100);

glutCreateWindow("Xcode Glut Demo");

init();

glutDisplayFunc(display);

glutReshapeFunc(reshape);

glutMainLoop();

return 0;

}