On 13/04/2018 17:46, Dilwyn Jones via Ql-Users wrote:
Could someone please explain the rules to me regarding the padding of
graphics objects for the two main formats: Sprites and Pics/PSA?

I thought Id worked it all out, at least for some modes, but my rule-
book does not appear to be complete, nor provide stable answers in all
cases. Also, there are someĀ  formats Im not able to test.. So now Im
confused and would like to get a "definitive" take on the matter.


As I understand it,
Sprites must always be padded to Longs for all modes QL or GD2.

PIC/PSA must be padded for modes 4 & 8.
The GD2 modes 16 to 33 should/need not be padded and some viewers may have problems if they are.
SQRview will detect excess padding and not show it.

This agrees with my experience of sprites and PIC files from when I was writing Q-Dock. Some unusual things can happen if the sprites aren't long word padded.

I haven't much experience of PSA files, but since they are essentially PIC files with an extra long word in the preamble, I would assume they would handle exactly the same as PIC files after taking the extra long word into account.

Thanks for your replies, most of which agree with my understanding but, unfortunately, not with my recent experience. (Eg see my post on the Forum for one example: http://www.qlforum.co.uk/viewtopic.php?f=3&t=2272&start=40#p22823)

And that is the crux of the matter: Without a definitive description its each to his own interpretation. This is bad for those of us trying to produce fun or useful stuff. And the number of offerings out there that dont really work, or work inconsistently, dont exactly evoke the sense that "The QL" is a serious or relieable machine. It certainly puts me off at times (my own failings in this regard notwithstanding ;)

If those who "wrote the book" on these matters arent able/willing to pipe up, then we'll have to waste some time R-ingTFBs and doing the tests ourselves. I'll be back.

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