OpenGL1_Test_Pattern.c

void DrawTestPattern_OpenGL1(float w, float h)
{
    glCullFace(GL_FRONT_AND_BACK);
    glBegin(GL_TRIANGLES);
        glColor3f(1, 0, 0); // top-left
        glVertex2f(-w,  h); // triangle 1
        glVertex2f(-w,  0);
        glVertex2f( 0,  0);
        glVertex2f( 0,  0); // triangle 2
        glVertex2f( 0,  h);
        glVertex2f(-w,  h);

        glColor3f(1, 1, 0); // bottom-left
        glVertex2f(-w,  0); // triangle 1
        glVertex2f(-w, -h);
        glVertex2f( 0, -h);
        glVertex2f( 0, -h); // triangle 2
        glVertex2f( 0,  0);
        glVertex2f(-w,  0);

        glColor3f(1, .5, 0); // bottom-right
        glVertex2f( 0,  0); // triangle 1
        glVertex2f( 0, -h);
        glVertex2f( w, -h);
        glVertex2f( w, -h); // triangle 2
        glVertex2f( w,  0);
        glVertex2f( 0,  0);

        glColor3f(0, 1, 0); // top-left
        glVertex2f( 0,  0); // triangle 1
        glVertex2f( 0,  h);
        glVertex2f( w,  h);
        glVertex2f( w,  h); // triangle 2
        glVertex2f( w,  0);
        glVertex2f( 0,  0);
    glEnd();
}