chromium/third_party/skia/include/core/SkImageFilter.h

/*
 * Copyright 2011 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkImageFilter_DEFINED
#define SkImageFilter_DEFINED

#include "include/core/SkFlattenable.h"
#include "include/core/SkRect.h"
#include "include/core/SkRefCnt.h"
#include "include/private/base/SkAPI.h"

#include <cstddef>

class SkColorFilter;
class SkMatrix;
struct SkDeserialProcs;

/**
 *  Base class for image filters. If one is installed in the paint, then all drawing occurs as
 *  usual, but it is as if the drawing happened into an offscreen (before the xfermode is applied).
 *  This offscreen bitmap will then be handed to the imagefilter, who in turn creates a new bitmap
 *  which is what will finally be drawn to the device (using the original xfermode).
 *
 *  The local space of image filters matches the local space of the drawn geometry. For instance if
 *  there is rotation on the canvas, the blur will be computed along those rotated axes and not in
 *  the device space. In order to achieve this result, the actual drawing of the geometry may happen
 *  in an unrotated coordinate system so that the filtered image can be computed more easily, and
 *  then it will be post transformed to match what would have been produced if the geometry were
 *  drawn with the total canvas matrix to begin with.
 */
class SK_API SkImageFilter : public SkFlattenable { … };

#endif