2D平面直线扫过的格子情况，精确计算到边缘坐标-2D linear sweep of the lattice plane, the accurate calculation of the coordinates-to-edge

包含多重纹理、纹理映射、坐标转换、反射计算相关技术，都是很实用的内容。-Inclue Multiple Textures/Texture Map /coordinate transformation/StencilMirror,Very practical content