| From: | Rick Jones |
| Date: | 12 Aug 2000 at 08:30:49 |
| Subject: | Re: AMIOPEN: pixmap stride |
----- Original Message ----- From: Patrick Roberts
> Can anyone tell me what application having a pixmap stride (as in the
> ave/avo/##bit/open) different than Xdimention*sizeof(pixel) has?
Sometimes this is used to "align" each horizontal row of pixels to some
natural memory alignment so as to simplify certain raster operations.
If you don't do the alignment some "words", "cache lines" or whatever
contain data for pixels at the end of one line plus data for the start of
the next line and software must handle this essentially one pixel at a
time whereas an algorithim exists (and wide enough registers) to do
multiple pixels in parallel.
Rick Jones
Subscribe/Unsubscribe: open-request@amiga.com
Amiga FAQ: http://www.amiga.com/faq.html