[OpenJDK 2D-Dev] RFR: 8252070 Some platform-specific BLIT optimizations are not effective

[Philip Race]

I note that you change the signature of blitSurfaceData to private.
I think this is fine. Since it is only used in this class I imagine 
whatever reason
it was supposed it might need to be over-ridden has never arisen ..

But I still had to first go check that it isn't actually used elsewhere !

I'm not sure I get the comment about the intersection operation causing 
performance problems.
Are you referring to the cost of that intersection operation itself, or 
some downstream consequence ?

-phil

On 8/28/20, 6:26 PM, Sergey Bylokhov wrote:
> Hello.
> Please review the fix for jdk/client.
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8252070
> Fix: http://cr.openjdk.java.net/~serb/8252070/webrev.01
>
> Some of our code assumes that the native system(XRender, D3D, OGL) 
> makes some
> effective optimizations, but in some cases, we can do better.
>
> One of the areas for improvements is direct blitting. If the source is 
> much
> bigger than the destination we should not try to copy the non-existent 
> area
> and could cut coordinates accordingly.
>
> The actual change is:
>  951         Rectangle dst =
>  952                 new Rectangle(dx, dy, w, 
> h).intersection(dstData.getBounds());
>  953         if (dst.isEmpty()) {
>  972                 // return
>  975         }
>  979         sx += dst.x - dx;
>  980         sy += dst.y - dy;
>
>
> See performance data and some additional comments:
> https://bugs.openjdk.java.net/browse/JDK-8252070?focusedCommentId=14365864&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-14365864 
>
>