Flickering sine scroller

pmc · 23 June 2009, 13:24

Watcha boys.

Sorry to be asking for help *again* but...

I've been playing around with updating my sine scroll source into more of a proper sine scroll intro - source code (non dbl buf version) attached.

Problem is that the actual sine scroll flickers big style.

My first thought was double buffering was needed. However, I tried adding double buffering and it made no difference so I took it out again.

Now, I know that my sine scroll routine when it was running on its own worked OK without double buffering, certainly while it was a four pixel sinus copy anyway but this one won't.

There's a couple of other things going on in this intro (scrolling logo, some copper colour poking and music playing) but I don't think it's those things causing the problem cos if I turn them off the sine scroll still flixx0rs all to shit.

Anyone got any ideas what stoopid thing I'm doing wrong this time?

EDIT: bugged code attachment removed.

StingRay · 23 June 2009, 14:25

Check if you fetch the right values from the sintable, looks like your sintab ptr gets trashed somewhere to me. Don't have time to check the code atm though.

pmc · 23 June 2009, 14:39

Cheers Stingray - I'll check.

pmc · 24 June 2009, 08:08

Quote:

Originally Posted by StingRay

Check if you fetch the right values from the sintable, looks like your sintab ptr gets trashed somewhere to me.

Had some time this morning so I changed the routine for reading in the sin values and... no more flickering sine scroll text.

StingRay, I'm starting to think you're a Jedi.

You've reached a higher plane where you 'feel' the errors in code!

StingRay · 24 June 2009, 09:19

Wasn't that hard to guess actually, characters seemed to appear at random y-positions and since the position is read from the sintable that was my first guess. =)

23 June 2009, 13:24	#1
pmc gone Join Date: Apr 2007 Location: completely gone Posts: 1,596	Flickering sine scroller Watcha boys. Sorry to be asking for help again but... I've been playing around with updating my sine scroll source into more of a proper sine scroll intro - source code (non dbl buf version) attached. Problem is that the actual sine scroll flickers big style. My first thought was double buffering was needed. However, I tried adding double buffering and it made no difference so I took it out again. Now, I know that my sine scroll routine when it was running on its own worked OK without double buffering, certainly while it was a four pixel sinus copy anyway but this one won't. There's a couple of other things going on in this intro (scrolling logo, some copper colour poking and music playing) but I don't think it's those things causing the problem cos if I turn them off the sine scroll still flixx0rs all to shit. Anyone got any ideas what stoopid thing I'm doing wrong this time? EDIT: bugged code attachment removed. Last edited by pmc; 24 June 2009 at 08:09.

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23 June 2009, 14:25	#2
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,848	Check if you fetch the right values from the sintable, looks like your sintab ptr gets trashed somewhere to me. Don't have time to check the code atm though.

23 June 2009, 14:39	#3
pmc gone Join Date: Apr 2007 Location: completely gone Posts: 1,596	Cheers Stingray - I'll check.

24 June 2009, 09:19	#5
StingRay move.l #$c0ff33,throat Join Date: Dec 2005 Location: Berlin/Joymoney Posts: 6,848	Wasn't that hard to guess actually, characters seemed to appear at random y-positions and since the position is read from the sintable that was my first guess. =)

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