Path: chuka.playstation.co.uk!tjs
From: tjs@cs.monash.edu.au (Toby Sargeant)
Newsgroups: scee.yaroze.programming.2d_graphics,scea.yaroze.programming.2d_graphics
Subject: Cookie cutter VRAM copies.
Date: 17 May 1999 00:48:43 GMT
Organization: PlayStation Net Yaroze (SCEE)
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Can anyone think of an efficient way to do a cookie cutter type of copy
from a dynamically created image in VRAM?

i.e.:

DST = SRC1&MASK | SRC2&~MASK

I realise that the STP bit can be used to do this, but because SRC1 is
dynamically created, I can't see any way that I can set the STP bits for
the pixels.

I'm going to assume that DMA between VRAM and main mem is much slower than
a similar amount of data transfer internal to VRAM, and also has the
advantage that it won't cause system bus contention.

Toby.