Drawing to a Memory Bitmap for Faster Performance

SUMMARY

An application whose client area is a complex image can realize a performance benefit from drawing to a memory bitmap. The complex, time consuming drawing code need only be performed once - to initialize the offscreen bitmap. During the handling of the WM_PAINT message, the only work that needs to be done is a simple BitBlt from the memory bitmap to the screen.

Sample code demonstrating this technique is available in the Microsoft Dowload Center. The MemDC sample code draws a complex pattern on its client area. A menu option toggle allows the user to see the speed difference between using and not using the offscreen bitmap.