[Vm-dev] Re: [squeak-dev] Cuis updated to #0204

Juan Vuletich juan at jvuletich.org
Sat May 23 12:43:37 UTC 2009

Karl Ramberg wrote:
> On 2009-05-23 14:15, Juan Vuletich wrote:
>> ...
>> BTW, at http://www.jvuletich.org/Cuis I uploaded some screen shots of 
>> Cuis with and without subpixel AA and at various Display depth, for 
>> those too lazy to actually download it.
>> Cheers,
>> Juan Vuletich
> Not to be nit picking but being it anyway...
> In the SubPixelAA pictures in the Workspace on top I see white pixels 
> in the f,  t, 1, B and s....
> Karl
> I see some artifacts on the subpixel

You are right! It is in the 32bpp image. Of course you don't see those 
in Squeak, it is a problem of how I saved the PNG file. I fixed it now.

The details... The alpha channel of Display is ignored by VMs. So we 
don't pay much attention to it, but it usually contains "garbage". This 
was noted by people using composing window managers in Linux. You see in 
the png that I evaluated 'Display fixAlpha. PNGReadWriter putForm:...'. 
That fixed the alpha channel for the whole Display. But it seems that 
when evaluating, Squeak redered the selected text again, creating the 
defect you noticed.

Juan Vuletich

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