C / OpenGL (GLUT) Modifier Keys (ALT/CTRL/SHIFT) activation help needed!

Hi everyone (again!),

Does anybody know how to acknowledge the pressing of the modifier keys (ALT,CTRL or SHIFT) in C / OpenGL (GLUT).

The Code below works for the pressing of the ALT key, HOWEVER, the 'r' key must also be pressed as a pre-condition. I just want to be able to press the ALT key (or the CTRL or SHIFT keys). Of course, I've tried simply removing the 'r' conditional statement, but that doesn't work! Any ideas?!

Code:

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void processNormalKeys(unsigned char key, int x, int y) {

        if (key == 27)
                exit(0);
        else if (key=='r') {
                int mod = glutGetModifiers();
                if (mod == GLUT_ACTIVE_ALT)
                        red = 0.0;
                else
                        red = 1.0;
        }
}

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