分别演示透视投影和正射投影的投影方式下平行于xy平面的平面，和平行于xz平面贴图（bmp格式）。-Presentation, respectively, perspective projection and overhead projector are under the projection plane parallel to the xy plane, and parallel to the xz plane mapping (bmp format).

点的生成，通过坐标添加点的算法，矩形算法。改变窗口-Point of generation, the algorithm by adding points coordinates, rectangular algorithm. Change the window