Por: And0rXor

Código:
void glCircle3i(GLint x, GLint y, GLint radius) {     float angle; 
    orig_glPushMatrix(); 
    orig_glLoadIdentity(); 
    orig_glDisable(GL_TEXTURE_2D); 
    orig_glColor3f(0.0f, 1.0f, 0.0f); 
    orig_glLineWidth(1.0f); 
    orig_glBegin(GL_LINE_LOOP); 
    for(int i = 0; i < 100; i++) { 
        angle = i*2*M_PI/100; 
        glVertex2f(x + (cos(angle) * radius), y + (sin(angle) * radius)); 
    } 
    glEnd(); 
    orig_glEnable(GL_TEXTURE_2D); 
    orig_glPopMatrix(); 
}