On 2017-05-17 14:28, Reimar Grabowski wrote:
But I don't get why you have to *calculate* *all*.
The CPU (your program) calculates all the 3D vertex points, as objects (made out of vertex points) move through the scene. Lots of triangles really.
The GPU calculates the individual pixel colors based on those vertex points (using shaders and textures). eg: CPU calculates 3 points of a triangle. The GPU calculates all the points between those 3 points, making up the triangle color. The GPU also does clipping calculations based on the viewpoint (camera position) in the 3D scene.
So if you work out how many vertex points there are, compared to everything that the GPU has to do (a LOT more points and calculations), the CPU does relatively little in comparison.
Regards, Graeme -- fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal http://fpgui.sourceforge.net/ My public PGP key: http://tinyurl.com/graeme-pgp _______________________________________________ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
