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ogle
05-27-2003, 05:33 PM
Hello,
I'm interested to understand OpenGL APIs interfacing the IHV supplied display commands., for a Windows operating system. IHVs like S3, nVIDIA develop their graphic controller specific functions and interface with OpenGL.
Where can I gather the 'driver-OpenGL' interface related information? I'm not asking OpenGL-Windows application interface here.
To ask the above question differently:
What do the OpenGL API glBegin(GL_POLYGON) correspond to for a nVIDIA GeForce3 graphics processing unit, when called?

Is there any specifications/standards that the IHVs adhere to while implementing OpenGL functions for their graphic chips?

Regards,
Al

dorbie
05-29-2003, 09:45 AM
Each platform has a standard interface, but is varies on different platforms. By this I mean the X windows interface, Windows (win32) interface, and Apple Mac OS interfaces are all different. There are libraries that have been ported to each to make code portable this is the role something like GLUT fills. GLUT also provides portable simple i/o (keyboard and joystick), which OpenGL knows nothing about really.

Now each of these platform specific interfaces has something in common, you create a native window, then use some platform specific call to give you an OpenGL context with desired properties for that window. Beyond this they are all quite different.

There is talk of getting a standard 'glue' at least for OpenGL ES, but it isn't decided. You may find that you end up with something Symbian specific for OpenGL ES for example but on another platform you'll have a different windowing interface.

Right now I expect that the libraries like the one Ti announced will be rendering to memory and you just use a standard symbian blit. They'll probably have written something simple to let you create the memory buffer and context. Although they may have something more generic where glSwapbuffers does the blit and it knows abit about windowing and tying a context to the screen.