compositing PNGs with alpha

[Paddy Smith]

Hi,

I have code like

       NSImage *imgTest1=[[NSImage alloc] initWithContentsOfFile:
@"test1.png"];
       NSImage *imgTest2=[[NSImage alloc] initWithContentsOfFile:
@"test2.png"];
       NSRect myRect = NSMakeRect(0,0,100,100);
       [imgTest1 drawInRect: myRect
                   fromRect: myRect
                  operation: NSCompositeCopy
                   fraction: 1.0];
       [imgTest2 drawInRect: myRect
                   fromRect: myRect
                  operation: NSCompositeSourceOver
                   fraction: 1.0];

but the semi-transparent pixels in imgTest2 do not render as I would
hope (they are multi-coloured!), although the rest (fully opaque
and fully transparent pixels) render as I would expect.

I saw bug #15903, but it really isn't obvious whether this is the same issue.

I tried digging around for GraphicsCompositing and setting it in
my defaults, but I don't really get what's going on there, and I
understood it was the default?

same old question really: am I missing something or doing it wrong ?

It's a very minor cosmetic issue for me, but it would be nice to get it working.

Regards,
Paddy