On Fri, 23 May 2025 20:59:41 GMT, Phil Race <p...@openjdk.org> wrote:
>> Graphics copyArea overflow check bails out of copying pixels if there is
>> overflow.
>> The spec says ""If a portion of the source rectangle lies outside the bounds
>> of the component, or is obscured by another window or component, {@code
>> copyArea} *will be unable to copy* the associated pixels"
>>
>> which suggests that we should always copy the parts inside the bounds and
>> never the parts outside the bounds
>> but it seems currently, in the case of overflow it no longer copies any
>> pixels, including the parts that are inside.
>> So, the fix clips the copyarea region to clip bounds so it will only affect
>> pixels within the valid bounds, and any pixels outside will be ignored.
>
> src/java.desktop/share/native/libawt/java2d/loops/Blit.c line 85:
>
>> 83: dstInfo.bounds.x2 = UNSAFE_TO_ADD(dstx, width)
>> 84: ? clipInfo.bounds.x2 : (dstx + width);
>> 85: dstInfo.bounds.y2 = UNSAFE_TO_ADD(dsty, height)
>
> why wouldn't you always want to limit it to the clip ?
> I mean shouldn't it be like this ?
> dstInfo.bounds.x2 = UNSAFE_TO_ADD(dstx, width) ? clipInfo.bounds.x2 :
> (((dstx + width) > clipInfo.bounds.x2) ? clipInfo.bounds.x2 : (dstx + width));
> or maybe a bit more readable as
> dstInfo.bounds.x2 = ((UNSAFE_TO_ADD(dstx, width) || ((dstx + width) >
> clipInfo.bounds.x2)) ? clipInfo.bounds.x2 : (dstx + width);
That is because down below it anyway calls
`SurfaceData_IntersectBounds(&dstInfo.bounds, &clipInfo.bounds); `
so it should clip to clipInfo.bounds there I presume..
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PR Review Comment: https://git.openjdk.org/jdk/pull/25340#discussion_r2106426836
