Squeak magic

karl karl.ramberg at comhem.se
Thu Jun 7 07:57:57 UTC 2007

subbukk wrote:
> On Tuesday 05 June 2007 11:38 pm, karl wrote:
>> The right BitBlt rules are not implemented in Squeak so problems occur.
>> Test the attached change set to see if the problem is still there.
> The patch is not visible over white or (r:0.8, g:1.0, b:1.0) (e.g. Ruler) with 
> your change set. However, if I drag the rotated morph over a ScrollingText  
> (r:0.972 g: 972, b: 0.662), it is clearly visible. The attached st file when 
> loaded on 3.9/3.10 +your cs will reveal this problem. Translucency is also 
> lost when looked through a HandMagnifier.
> Since it is so sensitive to colors, would round off errors in color 
> calculations be the root cause?
All the magic happens in the BitBlt plugin. The problem is that the 
rules to preserve translucency in rotation are not implemented so what 
my change set does is cheat by using an other rule, which give the color 


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