Implement a resize image filter. This is needed for the "filterRes" feature in SVG filter effects, …

Implement a resize image filter. This is needed for the "filterRes" feature in SVG filter effects, which specifies the required size for intermediate processing buffers. In order to make this work, we need to render the primitive at the given resolution (doable at the callsite in Blink), and then to resize the result to the actual on-screen size. The latter is where this filter comes in.

It simply applies a scaling factor (and the current CTM) to its input, and draws its input bitmap at that size.

R=reed@google.com

Committed: https://code.google.com/p/skia/source/detail?r=13077
Reverted: https://code.google.com/p/skia/source/detail?r=13078

BUG=

Committed: https://code.google.com/p/skia/source/detail?r=13082

[Stephen White, 2014-01-13 21:52:13]

reed@: PTAL. Thanks!

[reed1, 2014-01-13 22:02:57]

'filterRes' is expressed as a target size, not a scale-factor, correct?

Using SkSize for your parameter, that suggests (to me at least) we are
specifying a size. If your intention is to scale/transform the image by some
relative amount, then I think a different type would be clearer: SkScalar sx, sy
is my first thought, since that will look just like what we pass to canvas and
matrix for 'scaling'.

https://codereview.chromium.org/136863006/diff/30001/include/effects/SkResize...
File include/effects/SkResizeImageFilter.h (right):

https://codereview.chromium.org/136863006/diff/30001/include/effects/SkResize...
include/effects/SkResizeImageFilter.h:30: SkResizeImageFilter(const SkSize&
scale, SkPaint::FilterLevel filterLevel, SkImageFilter* input = NULL);
nit: col width > 100. You could drop 'filterLevel', as skia doesn't need to name
parameters that just rename their type.

https://codereview.chromium.org/136863006/diff/30001/src/effects/SkResizeImag...
File src/effects/SkResizeImageFilter.cpp (right):

https://codereview.chromium.org/136863006/diff/30001/src/effects/SkResizeImag...
src/effects/SkResizeImageFilter.cpp:72: canvas.drawBitmapRectToRect(src,
&srcRect, dstRect, &paint);
can you instead call canvas.concat(dstMatrix) followed by drawBitmap?

[Stephen White, 2014-01-14 21:45:42]

I removed the CTM application from the scale, since the source bitmap is already
transformed by the CTM. I've also modified the GM to more closely match what
Blink does in this case.

https://codereview.chromium.org/136863006/diff/30001/include/effects/SkResize...
File include/effects/SkResizeImageFilter.h (right):

https://codereview.chromium.org/136863006/diff/30001/include/effects/SkResize...
include/effects/SkResizeImageFilter.h:30: SkResizeImageFilter(const SkSize&
scale, SkPaint::FilterLevel filterLevel, SkImageFilter* input = NULL);
On 2014/01/13 22:02:57, reed1 wrote:
> nit: col width > 100. You could drop 'filterLevel', as skia doesn't need to
name
> parameters that just rename their type.

Unfortunately that wasn't enough after I split the SkSize. :) Fixed.

https://codereview.chromium.org/136863006/diff/30001/src/effects/SkResizeImag...
File src/effects/SkResizeImageFilter.cpp (right):

https://codereview.chromium.org/136863006/diff/30001/src/effects/SkResizeImag...
src/effects/SkResizeImageFilter.cpp:72: canvas.drawBitmapRectToRect(src,
&srcRect, dstRect, &paint);
On 2014/01/13 22:02:57, reed1 wrote:
> can you instead call canvas.concat(dstMatrix) followed by drawBitmap?

Done.

[reed1, 2014-01-14 21:55:19]

lgtm

[Stephen White, 2014-01-14 22:20:54]

Committed patchset #8 manually as r13077 (presubmit successful).

[Stephen White, 2014-01-15 04:49:24]

Committed patchset #9 manually as r13082 (presubmit successful).