AW: [squeak-dev] The Trunk: Graphics-mt.152.mcz

Juan Vuletich juan at
Tue Nov 16 13:24:52 UTC 2010

Hi Marcel,

I see. Then I suggest putting this change on hold until it is complete 
enough to really fix the issue.

WRT the fix itself, I don't thing that DisplayScanner should set 
combination rules. It should be done in 
#installStrikeFont:foregroundColor:backgroundColor: . If the color has 
translucency, you'll need a specific colormap and combination rules.

Good luck with it!

Juan Vuletich

Marcel Taeumel wrote:
> Hi.
> Obviously, using #rgbMul there was kind of an optimization that should
> render fonts faster.
> Unfortunately nobody seems to use the correct combination rule for font
> rendering in the first place, e.g., in the DisplayScanner. With translucent
> colors you need #blend (or "Form blend").
> I could not find the exactly the point, where the wrong combination rule for
> BitBlt was set, but as my fix does not override it with #rgbMul anymore, a
> next bugfix should spot the right place where the combination rule is
> chosen. It should be in the DisplayScanner. I continue looking for it.
> Bye,
> Marcel Taeumel
> -----Ursprüngliche Nachricht-----
> Von: squeak-dev-bounces at
> [mailto:squeak-dev-bounces at] Im Auftrag von Juan
> Vuletich
> Gesendet: Dienstag, 16. November 2010 13:50
> An: squeak-dev at
> Cc: packages at
> Betreff: Re: [squeak-dev] The Trunk: Graphics-mt.152.mcz
> Hi Folks,
> Can someone comment on this? I tried
> Set desktop color to blue.
> Display getCanvas drawString: 'This is a Test' at: 20 at 20 font: TextStyle 
> defaultFont color: (Color red alpha: 0.05)
> with this code loaded (updated trunk), and I don't think translucent 
> colors are working properly... With the old code, translucency was 
> ignored, but text was rendered properly. With the new code, translucency 
> is also ignored, and the text has an ugly black border...
> What's the rationale behind this change? What situations does it fix? 
> Maybe a code snippet (or better yet a test) that fails with the old code 
> and works ok with this?
> Thanks,
> Juan Vuletich

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