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OpenGL Beginners question: Can't get OpenGL to draw outside coordinates -1 - 1. Why?

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Hey all

I've been studing OpenGL at the uni' and I'm a bit stuck on this topic.
No matter how I define the gluOrtho2D coordinates, or the glViewport, I just can't seem to draw anything outside of coordinates -1.0 - 1.0. Anything I draw outside of these coordinates is just not shown.

Here's a test code I've been trying to play with:

void myMouseFunc(int button, int state, int x, int y) {
if (state == GLUT_DOWN)
exit(0);
}

void myDispFunc() {
glClearColor(1.0f, 1.0f, 0.0f, 0.0);
glClear(GL_COLOR_BUFFER_BIT);

glRectf(0, 0, 1, 1);

glFlush();
}

void testFunc(int* argc, char** argv) {
glutInit(argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE);
glutInitWindowSize(800,600);
glutInitWindowPosition(0,0);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
gluOrtho2D(0, 15, 0, 15);
glViewport(0,0,800,600);
glutCreateWindow("Test window!");
glutMouseFunc(myMouseFunc);
glutDisplayFunc(myDispFunc);

glutMainLoop();
}


Thank you all in advance for trying to help smile.png

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You need to move the OpenGL code to after glutCreateWindow. No window means no rendering context, and no rendering context means no OpenGL.

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