Ok, I am a little confused on how to use z coordinates. The following code does not display a yellow triangle. When I remove the glOrtho call and change the z coordinates of the vertices back to 0.0 from 2.0 it displays. I would have expected changing all three z coordinates to affect the size of the triangle (similar to a scale). What am I missing here?
Code :
    glClearColor(.0f, .0f, .0f, 1.0f);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glEnable (GL_DEPTH_TEST);
    glColor3f(1.0f, 0.85f, 0.35f);
    glOrtho(-1, 1, -1, 1, 1, 100);
    glBegin(GL_POLYGON);
    {
        glVertex3f(  0.0,  0.6, 2.0);
        glVertex3f( -0.2, -0.3, 2.0);
        glVertex3f(  0.0, -0.3 ,2.0);
    }
    glEnd();