Hi Folks,

Andreas Raab wrote:
> Juan Vuletich wrote:
>> The fix is in the trunk. There are several issues here.
>> 1) StringMorphs can not be cached by the hand anymore. This has no 
>> relation with the problem you fond, but I found it while testing. So 
>> I added StringMorph >> hasTranslucentColor
>
> Makes sense. With anti-aliased fonts the caching logic is way to 
> simplistic.
>
>> 2) ProjectViewMorph used #stencil:at:color: to draw the project name. 
>> Changed it to #drawImage:at:
>
> Good choice for the moment. It beats an all-black rectangle ;-)
>
>> 3) We have a bug in BitBlt. When using #rgbAdd, alpha values are not 
>> actually added. What happens is more like (alpha1+alpha2)>0 ifTrue: [ 
>> 1.0] ifFalse: [0.0]. The strange thing is that the code seems to be 
>> right, and it works ok in the simulator. Just sent an email to VM-Dev 
>> asking for help on this. As a workaround, I defined 
>> StringMorph>>imageForm:forRectangle: to use a white background 
>> instead of a transparent one.
>
> How strange. I saw your post but didn't realize it was related to this 
> issue.
>
> In any case thanks for the quick help!
>
> Cheers,
>   - Andreas

Still playing with these issues, I realized that the second BitBlt pass 
(rgbAdd) for black text is always needed if the destination might have 
transparent pixels. It is true that we have nothing to add to r, g and 
b, but we need to add to alpha in the pixels used by the text. Otherwise 
they'll remain transparent. I just updated the trunk with this. I also 
removed the #properAlphaForBlackText preference.

Finally, I added the correct alpha values to the colormaps used for 32bpp.

However these fixes will not have any effect until the issue with BitBlt 
rgbAdd I found yesterday is solved. Only then rendering AA StrikeFonts 
over transparent destinations will work ok, and the workaround I did 
yesterday by adding #imageForm:forRectangle: to StringMorph (in 
Morphoic-jmv.170) will be good to remove.

Cheers,
Juan Vuletich