skia2/include/effects/SkBlurDrawLooper.h
senorblanco@chromium.org 038aff623d Patch by Mike Lawther (mikelawther@chromium.org).
The HTML5 canvas client of BlurDrawLooper needs the option to not apply the
canvas transform to the blur offset.

see
http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-elemen...
- "The shadowOffsetX and shadowOffsetY attributes specify the distance that the
shadow will be offset in the positive horizontal and positive vertical distance
respectively. Their values are in coordinate space units. They are not affected
by the current transformation matrix."

This patch is part of fixing
http://code.google.com/p/chromium/issues/detail?id=64647.

Review URL:  http://codereview.appspot.com/3391041/



git-svn-id: http://skia.googlecode.com/svn/trunk@631 2bbb7eff-a529-9590-31e7-b0007b416f81
2010-12-06 23:45:58 +00:00

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2.4 KiB
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/*
* Copyright (C) 2008 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef SkBlurDrawLooper_DEFINED
#define SkBlurDrawLooper_DEFINED
#include "SkDrawLooper.h"
#include "SkColor.h"
class SkMaskFilter;
/** \class SkBlurDrawLooper
This class draws a shadow of the object (possibly offset), and then draws
the original object in its original position.
should there be an option to just draw the shadow/blur layer? webkit?
*/
class SkBlurDrawLooper : public SkDrawLooper {
public:
enum BlurFlags {
kNone_BlurFlag = 0x00,
/**
The blur layer's dx/dy/radius aren't affected by the canvas
transform.
*/
kIgnoreTransform_BlurFlag = 0x01,
/** mask for all blur flags */
kAll_BlurFlag = 0x01
};
SkBlurDrawLooper(SkScalar radius, SkScalar dx, SkScalar dy, SkColor color,
uint32_t flags = kNone_BlurFlag);
virtual ~SkBlurDrawLooper();
// overrides from SkDrawLooper
virtual void init(SkCanvas*, SkPaint*);
virtual bool next();
virtual void restore();
static SkFlattenable* CreateProc(SkFlattenableReadBuffer& buffer) {
return SkNEW_ARGS(SkBlurDrawLooper, (buffer));
}
protected:
SkBlurDrawLooper(SkFlattenableReadBuffer&);
// overrides from SkFlattenable
virtual void flatten(SkFlattenableWriteBuffer& );
virtual Factory getFactory() { return CreateProc; }
private:
SkCanvas* fCanvas;
SkPaint* fPaint;
SkMaskFilter* fBlur;
SkScalar fDx, fDy;
SkColor fBlurColor;
SkColor fSavedColor; // remember the original
int fSaveCount;
uint32_t fBlurFlags;
enum State {
kBeforeEdge,
kAfterEdge,
kDone
};
State fState;
typedef SkDrawLooper INHERITED;
};
#endif