Re: A85: Got it to work, but I still have questions...
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Re: A85: Got it to work, but I still have questions...
At 02:16 1998-05-15 GMT, you wrote:
>
>If you did this, you would need to keep two area's of memory with the
>current graphics though, wouldn't you (like how gray scale has to
>write to 2 memory buffers)? i guess you could change the sprite
>routine to draw to one video memory during an even iteration through
>your game's drawing loop, then draw to the other video memory on an
>odd time through the loop. Ben Sferrazza suggested to me what i think
>is a more practical purpose, to be able to write text to your buffer
>(which would be VIDEO_MEM for the output functions), and use GRAPH_MEM
>as the video memory. that would make a *great* function for a shell -
>to switch between GRAPH_MEM and VIDEO_MEM for where the video memory
>is. i don't know how many people would use it though.
You still can't use the GRAPH_MEM as the real video memory. If you
don't want to use the $FC00->, you have to find 1024 bytes (aligned)
between variable data and the VAT table.
All precompiled ("fake" functions) sprite routines in Usgard uses
a special word, DEST_ADDR, which is the address to the memory to
put the sprite.
Switching between two video memories is a piece of cake though
(just OUT a value to a port, don't remember which), and I don't
believe it's a necessary function in a shell.
--
Real name: Jimmy Mårdell "can't go mucking with a 'void *'"
IRC......: Yarin // Apple's MPW C compiler
Email....: mailto:yarin@acc.umu.se
Homepage.: http://www.algonet.se/~mja/
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