Before rendering to a window, one must configure the window according to the rendering requirements. For example, setting

• The number of colour buffers (single or double?) and their format
• If a depth buffer is required and its format
• If a stencil buffer is required
• Version of OpenGL

Once these parameters are set, they cannot be changed.  Reconfiguring will require destroying the window and creating a new window with the desired format. WGL uses pixel formats to encapsulate all of this information.

Specifying the pixel format is done with the function:

wglChoosePixelFormatARB(HDC hdc, const int *piAttribIList, const float    *pfAttribFList, UINT nMaxFomats, const int *piFormats, UINT *nNumFormats);

piAttribIList is a null-terminated array of integer attribute pairs
OpenGL will return a pixel format that is the best match in iPixelFormat

The example below finds a pixel format for a double-buffered, hardware accelerated window with 32 bits colour per pixel, a 24 bit depth buffer, and an 8 bit stencil buffer.

High