Thread: Cho Ren Sha 68K
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Old 23 September 2016, 11:45   #33
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Location: Willich/Germany
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Originally Posted by kovacm View Post
I refer not to disk/RAM size of sprites but on bandthwidth needed to copy sprites every frame to framebuffer! How much bandwidth you manage to save using precompiled sprites vs raw sprites.
And is it possible to use precompiled sprites on Amiga with bitplane modes?
Sorry, I missed the point.

The traditional approach for drawing sprites would be simply copying the data. However, due to the fact that the sprite pixel colours refer to a palette dynamically, the drawing is done by using simple "move d0,(a0)+" instructions instead. For small sprites the whole code fits into the instruction cache and so that's quite fast but for the overall performance I cannot give you exact numbers. Probably I'll do some profiling to see what time is spend on that part.

Edit: I am not sure if precompiling sprites on the Amiga would be helpful at all. The plane based graphics does not allow using a dynamic palette for the sprites so I guess you have to stick with the standard "cookie cut" method. I am not sure either if it's faster to do this in the fast RAM and copy the result to the chip RAM because I know that the Amiga 1200 Blitter is not as fast as it could have been.

Last edited by AnimaInCorpore; 23 September 2016 at 11:51. Reason: Answer extended
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