Change for Windows only: Make demos and examples build again.
Move the inclusion of windows.h from glext.h to gl.h. There are a few
good reasons for this:
- Including it in gl.h is more strightforward and makes it easier to
troubleshoot include file problems. It was sometimes hard to find it
in glext.h.
- Needed to define APIENTRY correctly. APIENTRY is used in gl.h.
- glut.h needs windows.h but does not include it, expecting the app to
include it. Including it in gl.h if not already included by the app
makes glut.h happy. This allows one to write a gl/glut app without
explictly including windows.h, which may only be really important for
toy apps like our samples and demos. But a "real" app can still
include windows.h if it wants.
- add two new Pixel Format Descriptors that do not have alpha bits to
mirror the two that do.
- add logic to wglChoosePixelFormat to match PFD's with respect to alpha.
- Create/clear software alpha buffer as required.
Now a wgl or GLUT program can control the creation of a software alpha
buffer via the PFD or GLUT parms, respectively.
Add GLAPIENTRY to typedef for callback functions (used by tessellator).
This is important now that we're using __stdcall instead of the (default)
__cdecl on WIN32. This gets apps using the tessellator working again
on Windows.