说明：  通过等值线的绘制与填充过程分离的编程思想,先用OpenGL硬件加速的光栅化技术实现区域快速填充,然后利用MFC下的GD I绘图功能在相同的区域上绘制等值线。该方法不涉及到复杂的算法,用很简单的代码就能实现与商业软件视觉效果相媲美的等值线填充效果,且适用于离散区域为任意形状的多边形网格系统。
(Through the contour of the drawing and filling process of the separation of programming ideas, use OpenGL hardware-accelerated rasterization technology to achieve regional rapid filling, then the use of MFC under the GD I drawing function in the same region on the map contour lines. This method does not involve complex algorithms, using very simple code could be achieved with the commercial software visual effects comparable to the effect of contour filling, and applied to discrete regions of arbitrarily shaped polygon grid.)