[comp.sys.amiga] More idiosyncracies

rokicki@rocky.STANFORD.EDU (Tomas Rokicki) (12/03/87)

One more for you hackers out there.  If an OFF_SPRITE is executed after a
sprite data DMA fetch is made (as will happen with the following calls:

	WaitTOF() ;
	OFF_SPRITE ;

when you have the pointer at the bottom of the screen) then the machine
will continue to display that horizontal line of the sprite.  (I'm sure
you've seen this in various display programs.)  A simple way to fix this
is to clear out all of the registers

	custom.spr[0].ctl = 0 ;
        custom.spr[1].ctl = 0 ;
        custom.spr[2].ctl = 0 ;
        custom.spr[3].ctl = 0 ;
        custom.spr[4].ctl = 0 ;
        custom.spr[5].ctl = 0 ;
        custom.spr[6].ctl = 0 ;
        custom.spr[7].ctl = 0 ;

Is there a better way?  (I don't have a window open, and even if I did, I
wouldn't want to Activate() it, so don't tell me to use SetPointer().)

-tom