Drawing to a Memory Bitmap for Faster Performance |
Q130805
The information in this article applies to:
- Microsoft Windows Software Development Kit (SDK) 3.1
- Microsoft Win32 Application Programming Interface (API), used with:
- Microsoft Windows 95
- Microsoft Windows NT Server version 3.5
- Microsoft Windows NT Workstation version 3.5
- Microsoft Win32s version 1.25
- Microsoft Windows 2000 Advanced Server
- Microsoft Windows 2000 Server
- Microsoft Windows 2000 Professional
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 Software Library. 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.
MORE INFORMATION
The following files are available for download from the Microsoft Download Center:
For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base:
Q119591 How to Obtain Microsoft Support Files from Online Services
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Additional query words: device context memory DC speed fast buffer kbfile kbgraphic
Keywords : kbfile kbgraphic kbOSWinNT350 kbOSWin2000 kbSDKWin32 kbOSWin95
Issue type : kbinfo
Technology : kbAudDeveloper kbSDKSearch kbWin32sSearch kbWin32API kbWinSDKSearch
Last Reviewed: December 16, 2000 |
