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2-tile vertical scroll

Posted: Sun Aug 17, 2014 12:02 pm
by bioloid
Hello,

I'm trying to use the 2-tile vertical scroll mode, is there a fast way to write those ? I want to set different values per line in the HIntCallback.

Alex

Posted: Sun Aug 17, 2014 12:15 pm
by bioloid
Oh, and my callback is this now :

Code: Select all

    void hblank()
    {
        *pl = addr;
    
        int i = width;
        while(i--) *pw = *scanline++;
    }
Unfortunately it's too slow (works only when width = 2).
(sent Steph a PM as well).

Posted: Sun Aug 17, 2014 7:07 pm
by Stef
As i replied you by email, you definitely can't update the whole VSRAM during hblank, far from it actually ! maybe 5 or 6 entries at max with asm optimized code.

Posted: Sun Aug 17, 2014 7:13 pm
by bioloid
Got it, thanks again!