Re: [MACTCL] Partial PNG transparency not working in Cocoa Tk

[Kevin W. <kw...@co...>]

On 11/29/13, 3:58 AM, Wojciech Kocjan wrote:
> - happens on OS X 10.9 only - does not happen on 10.8 and below (also,
> transparency works fine on all other systems and all other OS X
> versions, so I suspect this is a change in OS X 10.9 that broke it)
>
> - happens with latest Tcl/Tk from fossil, latest ActiveTcl
>
> - happens with both tkpng and Img
>
> - I can also confirm it only happens with Cocoa, not Carbon
>
> So this is definitely an issue with Tk.

I'm not certain where to start with this. I've seen reports in Apple's 
dev forums about wonky color calibration in Mavericks (sRGB is no longer 
accurately rendered in many contexts, which is causing headaches for 
graphics shops), yet Linus reports that images created with the 
tk::mac::IconBitmap command (which is just a thin wrapper around various 
NSImage methods) work just fine. NSImage is itself an opaque wrapper 
around many, many different things.

If the issues with alpha channel rendering are based in the system 
changes in Mavericks, I am not optimistic about fixing them...it does 
not seem like a good idea to try to special-case image code in the Img, 
TkPNG, and 8.6 core, I would think. (Nor would I even know where to 
start here.)

--Kevin

-- 
Kevin Walzer
Code by Kevin/Mobile Code by Kevin
http://www.codebykevin.com
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