[Coco] Help with speeding up sprite rendering

Walter Zambotti zambotti at iinet.net.au
Fri Mar 17 03:16:15 EDT 2017


Yes. Because of value the pul loads into the cc register the irq could be re-enabled. The byte could potential be anything afterall.

Just guessing!

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---- Glen Hewlett wrote ----

>Hi All,
>
>I’m working on some routines to draw sprites on the screen faster and I have a lot of it working fine.
>If I use PULS and PSHU commands I can really improve the speed of my sprite rendering.
>
>For example instead of using a bunch of
>LDD		,X++
>STD		,U++
>...
>I’m using
>PULS	A,B,X,Y,DP
>PSHU	A,B,X,Y,DP
>>
>That’s all great for sprites that are 7 bytes wide, but I also need to move sprites that are 8 bytes wide.  I’ve read on the net about using the condition code (CC) in the same way I described above but it breaks my program.  I couldn’t find some example code, just some talk about doing it.
>
>I’ve tried:
>ANDCC	#$00
>PULS	A,B,X,Y,DP,CC
>PSHU	A,B,X,Y,DP,CC
>>ANDCC	#$EF	- re-enable the IRQ
>
>I’m not sure what this is doing, as the computer is still running and the IRQ is triggering but it’s not generating the sprites when I do this.  In fact the computer seems to be stuck in the IRQ loop.
>
>Normally my program is moving the sprites around while in the IRQ routine, is this the part of the problem when using the CC register?  Or am I just handling the CC register improperly?
>
>If anyone has some sample code or can offer some advice I sure would appreciate it.
>
>Cheers,
>Glen.
>
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