How to overlay a bitmap on an image in OpenGL

Are you using wglCreateLayerContext()?

http://msdn.microsoft.com/en-us/library/ms537553(VS.85).aspx

Also take a look at
http://www.codeproject.com/KB/graphics/bitmapmanip.aspx

Thanks for your reply.

Unfortunately I have not been able to make this work, because  I can not get a pixel format that supports multiple planes. Looks like my display does not have this capability.  

i am not sure i get what you are saying...you can do a setpixelformat() for each of the layers you are using....

I guess I was confused - from reading this post from Microsoft  http://support.microsoft.com/kb/169954
I had the impression that hardware support for layer planes was required.

I haven't been able to find an example of how to set the pixel format for a layer plane other than the main plane, and my own attempts have not worked. If you could post an example of how to do this I  would appreciate it very much.

Thanks very much for the information. However, the documentation for the wglCreateLayerContext states that the layer context cannot be created until after a suitable pixel format has been found and selected, rather than before as you have suggested.

My problem is that I can't find a pixel format that allows multiple layers. When I enumerate all available  pixel formats using wglDescribeLayerPlane, none of them supports multiple layers (i.e. none returns bReserved > 0).  I am wondering if the implementation of OpenGL that I am using does not support  this feature.

Is it necessary to use layer planes in order to overlay a bitmap, such as a font character, on an image? If so, it looks like I am out of luck.

Thanks for your help.





































































































 , or is there something ?  

great job at debugging the issue!