From: Richard A. Smith (rsmith@bitworks.com)
Date: Wed 08 Nov 2000 - 00:31:31 IST
On Tue, 7 Nov 2000 19:29:28 +0200 (IST), Matan Ziv-Av wrote:
Ok.. I didn't figure it out but I did find a way around my problem..
>> Yeah but you can still see it draw... I need to totally draw in video memory and then
flip
>> to that section.
>
>Can you show the code you use? I don't see any way for a loop of
>drawscansegments from system memory to video memory being noticeably
>slow on any pentium class machine. Can you run bankspeed, at 1024x768
>with 16 bits (export SVGALIB_DEFAULT_MODE=G1024x768x64Kand tell me the
>results?
The code I was using was a hacked version of 'seejpeg' I merly hacked it so that it looked
for the presence of a file and then based on the file name displayed a .gif. (This was for
a demo)
seejpeg works by getting a pixel and then displaying it. Very slow.. So I hacked it to
decode a line of data into an array and then display that. Faster but still too slow. Next
I tried to decode the whole entire file into an array and copy it to the screen. I tried
various methods but they were either still slow or didn't work.
Last night I was surfing looking for more info and came across the punchbill code. Which is
if functionally exactly what I needed and is about an order of magnitude simpler than
seejpeg.
So I got liblug hacked punchbill and now it works great. Both gl_copybox and gl_copyscreen
are super fast. I can't really tell the difference.
So it seems to be a problem with seejpeg and the way I hacked it.. Funny though I did
exactly the same thing to punchbill as I did to seejpeg wich was set pageflipping
make a virtualcontext... Set that context.. draw the image and then copyscreen to the
physical display. Which it all works but is slow.
I will send you a copy of my hacked seejpeg as a seperate mail..
>For page flipping, draw the second page at lines 480-959 (using
>drawscansegment), and use vga_setdisplaystart(640*480) to display the
>second page.
Thanks.. I may play with that if I get some free time but for now punchbill has me fixed.
Thanks again for your help..
--
Richard A. Smith Bitworks, Inc.
rsmith@bitworks.com 501.846.5777
Sr. Design Engineer http://www.bitworks.com
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