(resend) programs/winemenubuilder: scale 64x64 classic icons to 48x48 for Icns format

[Francois Gouget]

On Wed, 17 Oct 2012, Aric Stewart wrote:
[...]
> The issue I am working on resolving here is that many older windows 
> programs only provide a 64x64 icon. With the old code, because there 
> is no 64x64 slot in icns files, these applications where loosing there 
> icons.

If the Mac behaves sensibly when there's a a single 128x128 icon, then 
in the case where there's only a 64x64 icon in the source Vincent's 
suggestion of scaling up would seem to be better.

As far as I know, scaling 64x64 -> 48x48 will produce a somewhat 
fuzzy-looking icon, more so than scaling down by a factor of two like 
64x64 -> 32x32. Similarly, scaling up by a factor of two will produce a 
blocky icon (assuming you do it by simply replicating pixels) but 
scaling that back down should produce the same result as starting from 
the original 64x64 icon. Scaling up by any other factor will produce a 
very fuzzy icon.

So we have the following scenarios:

Windows   Icns file      Needed for display  Result
64x64     Fuzzy 48x48    32x32               Fuzzy twice
64x64     Fuzzy 48x48    48x48               Fuzzy
64x64     Fuzzy 48x48    64x64               Fuzzy twice
64x64     Fuzzy 48x48    128x128             Fuzzy+Very fuzzy

64x64     Blocky 128x128 32x32               Fuzzy
64x64     Blocky 128x128 48x48               Fuzzy
64x64     Blocky 128x128 64x64               Perfect
64x64     Blocky 128x128 128x128             Blocky


Even if you actually have other sizes in addition to 64x64 I think the 
upscaling option would actually work pretty well. So it may make sense 
to change the code to scale up to 128x128 unless there's already a 
128x128 icon.

-- 
Francois Gouget <fgouget at codeweavers.com>