Bert Freudenberg wrote:
On 28.03.2009, at 13:31, Juan Vuletich wrote:
Damien Cassou wrote:
On Fri, Mar 27, 2009 at 9:16 PM, Juan Vuletich juan@jvuletich.org wrote:
I'm pleased to announce that Cuis is available. Cuis is a Squeak distribution with emphasis on simplicity. You can download it from http://www.jvuletich.org/Cuis/Cuis1.0-0158.zip . The web is not done yet.
The content looks very ugly when using a composite window manager (I'm on Ubuntu with Compiz). When switching off compiz, things looks ok.
If I remeber correctly, these kind of problems also happened with other Squeak distributions and was due to a kind of bug in BitBlt, right?
Not a BitBlt bug, but how BitBlt is used. If all drawing operations would set the Display's alpha component to 1 then it would be fully opaque.
It is a BitBlt bug. Evaluate and print this:
f1 _ Form extent: 8@8 depth: 32. f1 fillColor: (Color r: 1.0 g: 1.0 b: 0.7 alpha: 0.6). f2 _ Form extent: 8@8 depth: 32. f2 fillColor: (Color r: 0.5 g: 1.0 b: 0.7 alpha: 0.7). bb _(BitBlt toForm: f1) sourceForm: f2; combinationRule: 28; copyBits. f1 display. (f1 colorAt: 2@2) alpha
Rule 28 is rgbMin. The resulting color should be (Color r: 0.5 g: 1.0 b: 0.7 alpha: 0.6). But alpha is set to zero. This is a bug, and it is what causes wrong alpha values in Display in Cuis.
Is it this problem http://bugs.squeak.org/view.php?id=7068 ?
It sounds like that's the one. Old Unix VMs do not ignore the alpha channel of Display.
- Bert -
I believe the best would be to honor the alpha channel, and be able to set it correctly.
Cheers, Juan Vuletich