Size and power ratio of backpattern images

Wilhelm Sanke sanke at
Tue Oct 10 06:29:52 EDT 2006

On Mon Oct 9, J. Landman Gay jacque at wrote:

> Wilhelm Sanke wrote:
> > I experience no limitations so far on MacOS and on Windows concerning
> > the size of the images or constraints of divisibility. Backpattern
> > images can be of a size of 500X300 pixels - or *any* other size - on
> > MacOS and Windows and can have indivisible ratios for example of 151 
> X 259!
> >
> > So I am wondering to what Kevin is referring?
> The size limit on patterned images was lifted in 2.7.x (I forget exactly
> which version.) So Kevin was stating older restrictions. They still
> apply on Mac OS though; only Mac OS X (and other platforms) can work
> with any size image as a backpattern.
> -- 
> Jacqueline Landman Gay

I did not mean to distinguish between Mac OS and Mac OS X, I am using 
Mac OS rarely now, mostly for playing chess.

I see that the new docs of  2.7.4 state:

>  ... in Revolution version 2.7, this restriction was partially lifted 
> and the engine will tile rectangular regions correctly with 
> arbitrarily sized background patterns.To be used on Windows and Unix 
> systems, height and width must be divisible by 8. To be used as a 
> fully cross-platform pattern, both an image's dimensions should be one 
> of 8, 16, 32, 64, or 128.

But the restrictions mentioned in the second sentence above about 
divisibility by 8 and the dimensions do not apply here for my Windows 
and Mac OS X computers. I just transferred a stack in both directions 
with an backpattern image of 351X251, i.e.

1. I produced the tile in question with my "Seamless Tiles Generator" on 
both platforms.
2. Put the 351X251 tile into a new stack on each platform and set the 
backpattern of the card to it
3. Exchanged the stacks from Win to Mac and from Mac to Win

The result is identical, the backpatterns are displayed as expected 
although they do not conform to the above stated restrictions.

The Mac-to-Windows stack produced with 2.7.4 can also be used in pre-2.7 
versions (tested within the Metacard IDE 2.6.5) after the 
stackfileversion is set to 2.4, meaning that the new - still 
undocumented - format of backpatterns is also backwards compatible.

-- Wilhelm Sanke


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