Re: Turn off Antialiasing for Rendering with Palette

[Alexandre Julliard]

Glenn Wurster  writes:
> Description:
> - When we are working with a palette, we need to disable antialiasing.
>
> Antialiasing results in a lot of extra colour values which are not
> mapped in the palette, causing bad display artifacts.
>
> Changelog:
> - Disable antialiasing when working with the palette

You shouldn't change the global antialias flag, this is ugly and it
will most likely break the font caching. You have to add checks for a
palette directly at the places that handle the anti-aliasing (and your
palette check is wrong too, you shouldn't peek into the internals of
the DC bitmap).

Turn off Antialiasing for Rendering with Palette

[Glenn Wurster]

> You shouldn't change the global antialias flag, this is ugly and it
> will most likely break the font caching. You have to add checks for a
> palette directly at the places that handle the anti-aliasing (and your
> palette check is wrong too, you shouldn't peek into the internals of
> the DC bitmap).

Ok, I've removed the setting of antialias. A revised patch will be
forthcoming when we settle on the use of the DIB (unless you want it
sooner).

I'm not sure we can get around poking in the DIB.  The problem is that
we are working with a bitmap which is at a different colour depth in X
and Windows.  X is operating with a 24(or whatever) bit bitmap, while
the windows equivilent DIB is running at 8 bit.  Lower down, we render
in the full 24 bit happyness, but when it gets converted back to the 8
bit palette for windows, we loose all of the pixels which were
antialiased because they can not be matched against known palette
values.  That's why we need to check the depth of the DIB at this
level as opposed to lower down where we only ever get to see what X
thinks the depth is.

Glenn & Doug.