I'm always interested in old graphics drivers, that's because they apparently lived in "two worlds" -- the world of "framebuffer is on the GPU and the GPU can perform the required graphics function being requested by the driver" and the second world of "framebuffer is of necessity in main RAM, the GPU doesn't support the required graphics function being requested(!) -- so let's use the CPU and the CPU's RAM and software on the PC side of the equation (as opposed to hardware on the GPU) to emulate in software the required hardware graphics function being requested (in your driver's case, this would be using the Windows DIBENG / Windows code -- for that functionality).
That dichotomy, from an OS/graphics driver/engineering standpoint -- is fascinating...
These days of course, we have shared (CPU/GPU) memory and GPU's where all graphics drawing operations are implemented on the GPU side -- so there's little need to set up an additional unshared frame buffer in PC memory, draw on it with software ran by the CPU, then copy it to the graphics card to update the old graphic's card's then unshared frame buffer -- as was apparently necessary in very old PC's with very old graphics cards...
But from an (old) OS/graphics driver/engineering standpoint -- it's fascinating!
I'm always interested in old graphics drivers, that's because they apparently lived in "two worlds" -- the world of "framebuffer is on the GPU and the GPU can perform the required graphics function being requested by the driver" and the second world of "framebuffer is of necessity in main RAM, the GPU doesn't support the required graphics function being requested(!) -- so let's use the CPU and the CPU's RAM and software on the PC side of the equation (as opposed to hardware on the GPU) to emulate in software the required hardware graphics function being requested (in your driver's case, this would be using the Windows DIBENG / Windows code -- for that functionality).
That dichotomy, from an OS/graphics driver/engineering standpoint -- is fascinating...
These days of course, we have shared (CPU/GPU) memory and GPU's where all graphics drawing operations are implemented on the GPU side -- so there's little need to set up an additional unshared frame buffer in PC memory, draw on it with software ran by the CPU, then copy it to the graphics card to update the old graphic's card's then unshared frame buffer -- as was apparently necessary in very old PC's with very old graphics cards...
But from an (old) OS/graphics driver/engineering standpoint -- it's fascinating!
Ya gotta love the old stuff! :-)