OpenGL GL_点结果与输入不同

我的测试计划:

int w = atoi(argv[1]);
int h = atoi(argv[2]);

glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glOrtho(0, w, h, 0, 1.0, -1.0);
glMatrixMode(GL_MODELVIEW);
glEnable(GL_TEXTURE_2D);
glLoadIdentity();

unsigned int wf,hf;
unsigned char rgb[3];

while(!glfwWindowShouldClose(window)){
    glClear(GL_COLOR_BUFFER_BIT);
    glPointSize(1);
    glBegin(GL_POINTS);
    for(hf=0;hf<h;hf++){
        for(wf=0;wf<w;wf++){
            memset(rgb,0,3);
            rgb[wf%3]=0xff;
            glColor3ub(rgb[0],rgb[1],rgb[2]);
            glVertex2f(wf,hf);
        }
    }
    glEnd();
    glfwSwapBuffers(window);
    glfwPollEvents();
}

结果:

未着色

有色的