DrawTargetCapture.h

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef MOZILLA_GFX_DRAWTARGETCAPTURE_H_
#define MOZILLA_GFX_DRAWTARGETCAPTURE_H_

#include <vector>
#include <stack>

#include "2D.h"
#include "CaptureCommandList.h"

#include "Filters.h"

namespace mozilla {
namespace gfx {

class DrawingCommand;
class SourceSurfaceCapture;
class AlphaBoxBlur;

class DrawTargetCaptureImpl final : public DrawTargetCapture {
  friend class SourceSurfaceCapture;

 public:
  DrawTargetCaptureImpl(gfx::DrawTarget* aTarget, size_t aFlushBytes);
  DrawTargetCaptureImpl(BackendType aBackend, const IntSize& aSize,
                        SurfaceFormat aFormat);

  bool Init(const IntSize& aSize, DrawTarget* aRefDT);
  void InitForData(int32_t aStride, size_t aSurfaceAllocationSize);

  BackendType GetBackendType() const override {
    return mRefDT->GetBackendType();
  }
  DrawTargetType GetType() const override { return mRefDT->GetType(); }
  bool IsCaptureDT() const override { return true; }
  already_AddRefed<SourceSurface> Snapshot() override;
  already_AddRefed<SourceSurface> IntoLuminanceSource(
      LuminanceType aLuminanceType, float aOpacity) override;
  void SetPermitSubpixelAA(bool aPermitSubpixelAA) override;
  void DetachAllSnapshots() override;
  IntSize GetSize() const override { return mSize; }
  void Flush() override {}
  void DrawSurface(SourceSurface* aSurface, const Rect& aDest,
                   const Rect& aSource, const DrawSurfaceOptions& aSurfOptions,
                   const DrawOptions& aOptions) override;
  void DrawFilter(FilterNode* aNode, const Rect& aSourceRect,
                  const Point& aDestPoint,
                  const DrawOptions& aOptions = DrawOptions()) override;
  void DrawSurfaceWithShadow(SourceSurface* aSurface, const Point& aDest,
                             const DeviceColor& aColor, const Point& aOffset,
                             Float aSigma, CompositionOp aOperator) override;

  void ClearRect(const Rect& aRect) override;
  void MaskSurface(const Pattern& aSource, SourceSurface* aMask, Point aOffset,
                   const DrawOptions& aOptions = DrawOptions()) override;
  void CopySurface(SourceSurface* aSurface, const IntRect& aSourceRect,
                   const IntPoint& aDestination) override;
  void CopyRect(const IntRect& aSourceRect,
                const IntPoint& aDestination) override;

  void FillRect(const Rect& aRect, const Pattern& aPattern,
                const DrawOptions& aOptions = DrawOptions()) override;
  void FillRoundedRect(const RoundedRect& aRect, const Pattern& aPattern,
                       const DrawOptions& aOptions = DrawOptions()) override;
  void StrokeRect(const Rect& aRect, const Pattern& aPattern,
                  const StrokeOptions& aStrokeOptions = StrokeOptions(),
                  const DrawOptions& aOptions = DrawOptions()) override;
  void StrokeLine(const Point& aStart, const Point& aEnd,
                  const Pattern& aPattern,
                  const StrokeOptions& aStrokeOptions = StrokeOptions(),
                  const DrawOptions& aOptions = DrawOptions()) override;
  void Stroke(const Path* aPath, const Pattern& aPattern,
              const StrokeOptions& aStrokeOptions = StrokeOptions(),
              const DrawOptions& aOptions = DrawOptions()) override;
  void Fill(const Path* aPath, const Pattern& aPattern,
            const DrawOptions& aOptions = DrawOptions()) override;
  void FillGlyphs(ScaledFont* aFont, const GlyphBuffer& aBuffer,
                  const Pattern& aPattern,
                  const DrawOptions& aOptions = DrawOptions()) override;
  void StrokeGlyphs(ScaledFont* aFont, const GlyphBuffer& aBuffer,
                    const Pattern& aPattern,
                    const StrokeOptions& aStrokeOptions = StrokeOptions(),
                    const DrawOptions& aOptions = DrawOptions()) override;
  void Mask(const Pattern& aSource, const Pattern& aMask,
            const DrawOptions& aOptions = DrawOptions()) override;
  void PushClip(const Path* aPath) override;
  void PushClipRect(const Rect& aRect) override;
  void PopClip() override;
  void PushLayer(bool aOpaque, Float aOpacity, SourceSurface* aMask,
                 const Matrix& aMaskTransform, const IntRect& aBounds,
                 bool aCopyBackground) override;
  void PopLayer() override;
  void Blur(const AlphaBoxBlur& aBlur) override;
  void PadEdges(const IntRegion& aRegion) override;

  void SetTransform(const Matrix& aTransform) override;

  bool SupportsRegionClipping() const override {
    return mRefDT->SupportsRegionClipping();
  }

  already_AddRefed<SourceSurface> CreateSourceSurfaceFromData(
      unsigned char* aData, const IntSize& aSize, int32_t aStride,
      SurfaceFormat aFormat) const override {
    return mRefDT->CreateSourceSurfaceFromData(aData, aSize, aStride, aFormat);
  }
  already_AddRefed<SourceSurface> OptimizeSourceSurface(
      SourceSurface* aSurface) const override;

  already_AddRefed<SourceSurface> CreateSourceSurfaceFromNativeSurface(
      const NativeSurface& aSurface) const override {
    return mRefDT->CreateSourceSurfaceFromNativeSurface(aSurface);
  }

  already_AddRefed<DrawTarget> CreateSimilarDrawTarget(
      const IntSize& aSize, SurfaceFormat aFormat) const override;
  RefPtr<DrawTarget> CreateSimilarRasterTarget(
      const IntSize& aSize, SurfaceFormat aFormat) const override;
  RefPtr<DrawTarget> CreateClippedDrawTarget(const Rect& aBounds,
                                             SurfaceFormat aFormat) override;

  already_AddRefed<PathBuilder> CreatePathBuilder(
      FillRule aFillRule = FillRule::FILL_WINDING) const override;

  already_AddRefed<GradientStops> CreateGradientStops(
      GradientStop* aStops, uint32_t aNumStops,
      ExtendMode aExtendMode = ExtendMode::CLAMP) const override {
    return mRefDT->CreateGradientStops(aStops, aNumStops, aExtendMode);
  }
  already_AddRefed<FilterNode> CreateFilter(FilterType aType) override;

  void ReplayToDrawTarget(DrawTarget* aDT, const Matrix& aTransform);

  bool IsEmpty() const override;
  void Dump() override;

 protected:
  virtual ~DrawTargetCaptureImpl();

  void MarkChanged();

 private:
  void FlushCommandBuffer() {
    ReplayToDrawTarget(mRefDT, Matrix());
    mCommands.Clear();
  }

  // This storage system was used to minimize the amount of heap allocations
  // that are required while recording. It should be noted there's no
  // guarantees on the alignments of DrawingCommands allocated in this array.
  template <typename T>
  T* AppendToCommandList() {
    if (T::AffectsSnapshot) {
      MarkChanged();
    }
    if (mFlushBytes && mCommands.BufferWillAlloc<T>() &&
        mCommands.BufferCapacity() > mFlushBytes) {
      FlushCommandBuffer();
    }
    return mCommands.Append<T>();
  }
  template <typename T>
  T* ReuseOrAppendToCommandList() {
    if (T::AffectsSnapshot) {
      MarkChanged();
    }
    if (mFlushBytes && mCommands.BufferWillAlloc<T>() &&
        mCommands.BufferCapacity() > mFlushBytes) {
      FlushCommandBuffer();
    }
    return mCommands.ReuseOrAppend<T>();
  }

  RefPtr<DrawTarget> mRefDT;
  IntSize mSize;
  RefPtr<SourceSurfaceCapture> mSnapshot;

  // These are set if the draw target must be explicitly backed by data.
  int32_t mStride;
  size_t mSurfaceAllocationSize;

  struct PushedLayer {
    explicit PushedLayer(bool aOldPermitSubpixelAA)
        : mOldPermitSubpixelAA(aOldPermitSubpixelAA) {}
    bool mOldPermitSubpixelAA;
  };
  std::vector<PushedLayer> mPushedLayers;
  std::stack<IntRect> mCurrentClipBounds;

  CaptureCommandList mCommands;
  size_t mFlushBytes;
};

}  // namespace gfx
}  // namespace mozilla

#endif /* MOZILLA_GFX_DRAWTARGETCAPTURE_H_ */