chromium/third_party/skia/src/core/SkCanvasPriv.h

/*
 * Copyright 2014 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#ifndef SkCanvasPriv_DEFINED
#define SkCanvasPriv_DEFINED

#include "include/core/SkCanvas.h"
#include "include/core/SkPaint.h"
#include "include/core/SkScalar.h"
#include "include/private/base/SkDebug.h"
#include "include/private/base/SkNoncopyable.h"

#include <cstddef>

class SkDevice;
class SkImageFilter;
class SkMatrix;
class SkReadBuffer;
struct SkRect;
class SkWriteBuffer;

class SkAutoCanvasMatrixPaint : SkNoncopyable { … };

class SkCanvasPriv { … };

/**
 *  This constant is trying to balance the speed of ref'ing a subpicture into a parent picture,
 *  against the playback cost of recursing into the subpicture to get at its actual ops.
 *
 *  For now we pick a conservatively small value, though measurement (and other heuristics like
 *  the type of ops contained) may justify changing this value.
 */
constexpr int kMaxPictureOpsToUnrollInsteadOfRef = …;

/**
 *  We implement ImageFilters and MaskFilters for a given draw by creating a layer, then applying
 *  the filter to the pixels of that layer (its backing surface/image), and then we call restore()
 *  to blend that layer to the main canvas.
 *
 *  If the paint has neither an image filter nor a mask filter, there will be no layer and paint()
 *  returns the original without modification.
 *
 * NOTE: This works by assuming all sources of color and shading are represented by the SkPaint.
 * Operations like drawImageRect must convert to an equivalent drawRect call if there's a mask
 * filter, or otherwise ensure there are no mask filters (e.g. drawAtlas).
 */
class AutoLayerForImageFilter { … };

#endif