Image filters in Skia currently clip the size of the the offscreen
bitmap used for filtering to the device clip bounds. This means that
any pixel-moving filter (e.g., blur) has edge artifacts at the clip
boundaries. This is problematic for tiling, where a single SkPicture
is played back with a clip set to the tile boundaries.
By implementing the onFilterBounds() traversal, and using it in
saveLayer() when a filter is present, we can clip the layer to the
expanded clip rect. Note that this requires that the traversal be
performed in reverse as compared to computeFastBounds(). (It's also
done in device space, unlike computeFastBounds()).
New test imagefiltersclipped tests pixel-moving filters when clipped
by various clip rects.
New test imageblurtiled tests tiled (compositor-style) rendering of
blurred text. There should be no artifacts at the tile boundaries.
BUG=337831
R=reed@google.com
Review URL: https://codereview.chromium.org/23011012
git-svn-id: http://skia.googlecode.com/svn/trunk@13323 2bbb7eff-a529-9590-31e7-b0007b416f81
Eliminates SkFlattenable{Read,Write}Buffer, promoting SkOrdered{Read,Write}Buffer
a step each in the hierarchy.
What used to be this:
SkFlattenableWriteBuffer -> SkOrderedWriteBuffer
SkFlattenableReadBuffer -> SkOrderedReadBuffer
SkFlattenableReadBuffer -> SkValidatingReadBuffer
is now
SkWriteBuffer
SkReadBuffer -> SkValidatingReadBuffer
Benefits:
- code is simpler, names are less wordy
- the generic SkFlattenableFooBuffer code in SkPaint was incorrect; removed
- write buffers are completely devirtualized, important for record speed
This refactoring was mostly mechanical. You aren't going to find anything
interesting in files with less than 10 lines changed.
BUG=skia:
R=reed@google.com, scroggo@google.com, djsollen@google.com, mtklein@google.com
Author: mtklein@chromium.org
Review URL: https://codereview.chromium.org/134163010
git-svn-id: http://skia.googlecode.com/svn/trunk@13245 2bbb7eff-a529-9590-31e7-b0007b416f81
This patch adds the parameter to the filterImageGPU() signature, plumbs through the code on the GPU side, and implements support for it in SkXfermodeImageFilter for both raster and GPU.
Of the remaining filters with GPU implementations, Blur, Morphology, Bicubic and Displacement work fine; they're commutative wrt offset and can simply pass it up the chain. Blend is not, but will be removed shortly anyway (has been replaced with SkXfermodeImageFilter in Blink).
R=reed@google.com, bsalomon@google.com
Author: senorblanco@chromium.org
Review URL: https://chromiumcodereview.appspot.com/15995026
git-svn-id: http://skia.googlecode.com/svn/trunk@9977 2bbb7eff-a529-9590-31e7-b0007b416f81
This fixes the bicubic image filter GM on the GPU, which otherwise draws garbage outside the filtered region. It also moves us closer to unifying the signatures of SkImageFilter::onFilterImage() and SkImageFilter::filterImageGPU().
Review URL: https://codereview.appspot.com/7180048
git-svn-id: http://skia.googlecode.com/svn/trunk@7467 2bbb7eff-a529-9590-31e7-b0007b416f81
