[OpenJDK 2D-Dev] RFR: [9] JDK-8040689 Fonts antialiasing artifacts appear when using translucent composited images

[Jim Graham]

Hi Prasanta,

I want Phil to evaluate this as well since we are now using a different 
and potentially slower or less capable pipeline in what may be a common 
case.

Have you measured the performance difference before and after this change?

With respect to the code, please maintain the "{" on the next line style 
(when coming after a conditional that had a line continuation) that is 
used throughout this code.

Also pare down the test case to not require a GUI and to not create a 
Frame and not require a call to invokeAndWait().  None of that is 
necessary...

			...jim

On 9/18/15 3:27 AM, prasanta sadhukhan wrote:
> Hi All,
>
> Please review a fix for a problem where Antialiased font drawn on a
> translucent bufferedimage creates artifacts.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8040689
> webrev: http://cr.openjdk.java.net/~psadhukhan/8040689/webrev.00/
>
> Antialiased font rendering was done via software loops whose blending
> maths do not handle AA glyphs on translucent destinations correctly.
> Since modifying the loop will have impact on other things and since it
> seems intention was to handle AA font on opaque destination from the comment
> on AATextRenderer.java
> //**//
> // * A delegate pipe of SG2D for drawing anti-aliased text with//
> // * a solid source colour to an opaque destination.//
> // *///
> //public class AATextRenderer extends GlyphListLoopPipe
>
> /I have modified//the code to use other text pipeline like XRender in
> linux or D3D in windows to handle AA font for translucent destinations.
>
> Regards
> Prasanta