Transformasi Objek Grafika Rotasi 45⁰

#include <GL/glut.h>
#include <windows.h>
GLfloat  xangle=0.0, yangle=0.0;
void init (void) {
glClearColor (1.0, 1.0, 1.0, 0.0);
glLineWidth(1.0);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glOrtho(-6,6,-6,6,-6,6);
}
void display (void) {
glClear (GL_COLOR_BUFFER_BIT);
glPushMatrix();
glColor3f (1.0, 0.0, 0.0);
glBegin (GL_POLYGON);
glVertex2f (-4.0, -5.0);
glVertex2f (-1.0, -5.0);
glVertex2f (-1.0, -1.0);
glVertex2f (-4.0, -1.0);
glEnd ();
glPopMatrix ();
glutSwapBuffers ();
glFlush ();
}
void KeyboardAssign (GLubyte key, GLint x, GLint y) { switch (key) {
case 'g':
glRotatef (-45.0, 2.0, 2.0, 2.0);   
glutPostRedisplay ();
break;
}
}
int main (int argc, char** argv) {
glutInit (&argc, argv);
glutInitDisplayMode (GLUT_DOUBLE | GLUT_RGB); glutInitWindowPosition (0, 0); glutInitWindowSize (1500, 1500); glutCreateWindow ("Transformasi"); init ();
glutDisplayFunc (display);
glutKeyboardFunc (KeyboardAssign);
glutMainLoop ();
}

Tekan "G" maka akan terlihat Skalanya