/* -*- 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/. */

#include <cmath>
#include "DataSurfaceHelpers.h"
#include "FilterNodeSoftware.h"
#include "2D.h"
#include "Tools.h"
#include "Blur.h"
#include <map>
#include "FilterProcessing.h"
#include "Logging.h"
#include "mozilla/PodOperations.h"

// #define DEBUG_DUMP_SURFACES

#ifdef DEBUG_DUMP_SURFACES
#  include "gfxUtils.h"  // not part of Moz2D
#endif

namespace mozilla {
namespace gfx {

namespace {

/**
 * This class provides a way to get a pow() results in constant-time. It works
 * by caching 257 ((1 << sCacheIndexPrecisionBits) + 1) values for bases between
 * 0 and 1 and a fixed exponent.
 **/
class PowCache {
 public:
  PowCache() : mNumPowTablePreSquares(-1) {}

  void CacheForExponent(Float aExponent) {
    // Since we are in the world where we only care about
    // input and results in [0,1], there is no point in
    // dealing with non-positive exponents.
    if (aExponent <= 0) {
      mNumPowTablePreSquares = -1;
      return;
    }
    int numPreSquares = 0;
    while (numPreSquares < 5 && aExponent > (1 << (numPreSquares + 2))) {
      numPreSquares++;
    }
    mNumPowTablePreSquares = numPreSquares;
    for (size_t i = 0; i < sCacheSize; i++) {
      // sCacheSize is chosen in such a way that a takes values
      // from 0.0 to 1.0 inclusive.
      Float a = i / Float(1 << sCacheIndexPrecisionBits);
      MOZ_ASSERT(0.0f <= a && a <= 1.0f,
                 "We only want to cache for bases between 0 and 1.");

      for (int j = 0; j < mNumPowTablePreSquares; j++) {
        a = sqrt(a);
      }
      uint32_t cachedInt = pow(a, aExponent) * (1 << sOutputIntPrecisionBits);
      MOZ_ASSERT(cachedInt < (1 << (sizeof(mPowTable[i]) * 8)),
                 "mPowCache integer type too small");

      mPowTable[i] = cachedInt;
    }
  }

  // Only call Pow() if HasPowerTable() would return true, to avoid complicating
  // this code and having it just return (1 << sOutputIntPrecisionBits))
  uint16_t Pow(uint16_t aBase) {
    MOZ_ASSERT(HasPowerTable());
    // Results should be similar to what the following code would produce:
    // Float x = Float(aBase) / (1 << sInputIntPrecisionBits);
    // return uint16_t(pow(x, aExponent) * (1 << sOutputIntPrecisionBits));

    MOZ_ASSERT(aBase <= (1 << sInputIntPrecisionBits),
               "aBase needs to be between 0 and 1!");

    uint32_t a = aBase;
    for (int j = 0; j < mNumPowTablePreSquares; j++) {
      a = a * a >> sInputIntPrecisionBits;
    }
    uint32_t i = a >> (sInputIntPrecisionBits - sCacheIndexPrecisionBits);
    MOZ_ASSERT(i < sCacheSize, "out-of-bounds mPowTable access");
    return mPowTable[i];
  }

  static const int sInputIntPrecisionBits = 15;
  static const int sOutputIntPrecisionBits = 15;
  static const int sCacheIndexPrecisionBits = 8;

  inline bool HasPowerTable() const { return mNumPowTablePreSquares >= 0; }

 private:
  static const size_t sCacheSize = (1 << sCacheIndexPrecisionBits) + 1;

  int mNumPowTablePreSquares;
  uint16_t mPowTable[sCacheSize];
};

class PointLightSoftware {
 public:
  bool SetAttribute(uint32_t aIndex, Float) { return false; }
  bool SetAttribute(uint32_t aIndex, const Point3D&);
  void Prepare() {}
  Point3D GetVectorToLight(const Point3D& aTargetPoint);
  uint32_t GetColor(uint32_t aLightColor, const Point3D& aVectorToLight);

 private:
  Point3D mPosition;
};

class SpotLightSoftware {
 public:
  SpotLightSoftware();
  bool SetAttribute(uint32_t aIndex, Float);
  bool SetAttribute(uint32_t aIndex, const Point3D&);
  void Prepare();
  Point3D GetVectorToLight(const Point3D& aTargetPoint);
  uint32_t GetColor(uint32_t aLightColor, const Point3D& aVectorToLight);

 private:
  Point3D mPosition;
  Point3D mPointsAt;
  Point3D mVectorFromFocusPointToLight;
  Float mSpecularFocus;
  Float mLimitingConeAngle;
  Float mLimitingConeCos;
  PowCache mPowCache;
};

class DistantLightSoftware {
 public:
  DistantLightSoftware();
  bool SetAttribute(uint32_t aIndex, Float);
  bool SetAttribute(uint32_t aIndex, const Point3D&) { return false; }
  void Prepare();
  Point3D GetVectorToLight(const Point3D& aTargetPoint);
  uint32_t GetColor(uint32_t aLightColor, const Point3D& aVectorToLight);

 private:
  Float mAzimuth;
  Float mElevation;
  Point3D mVectorToLight;
};

class DiffuseLightingSoftware {
 public:
  DiffuseLightingSoftware();
  bool SetAttribute(uint32_t aIndex, Float);
  void Prepare() {}
  uint32_t LightPixel(const Point3D& aNormal, const Point3D& aVectorToLight,
                      uint32_t aColor);

 private:
  Float mDiffuseConstant;
};

class SpecularLightingSoftware {
 public:
  SpecularLightingSoftware();
  bool SetAttribute(uint32_t aIndex, Float);
  void Prepare();
  uint32_t LightPixel(const Point3D& aNormal, const Point3D& aVectorToLight,
                      uint32_t aColor);

 private:
  Float mSpecularConstant;
  Float mSpecularExponent;
  uint32_t mSpecularConstantInt;
  PowCache mPowCache;
};

}  // unnamed namespace

// from xpcom/ds/nsMathUtils.h
static int32_t NS_lround(double x) {
  return x >= 0.0 ? int32_t(x + 0.5) : int32_t(x - 0.5);
}

static already_AddRefed<DataSourceSurface> CloneAligned(
    DataSourceSurface* aSource) {
  return CreateDataSourceSurfaceByCloning(aSource);
}

static void FillRectWithPixel(DataSourceSurface* aSurface,
                              const IntRect& aFillRect, IntPoint aPixelPos) {
  MOZ_ASSERT(!aFillRect.Overflows());
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aFillRect),
             "aFillRect needs to be completely inside the surface");
  MOZ_ASSERT(SurfaceContainsPoint(aSurface, aPixelPos),
             "aPixelPos needs to be inside the surface");

  DataSourceSurface::ScopedMap surfMap(aSurface, DataSourceSurface::READ_WRITE);
  if (MOZ2D_WARN_IF(!surfMap.IsMapped())) {
    return;
  }
  uint8_t* sourcePixelData =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aPixelPos);
  uint8_t* data =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aFillRect.TopLeft());
  int bpp = BytesPerPixel(aSurface->GetFormat());

  // Fill the first row by hand.
  if (bpp == 4) {
    uint32_t sourcePixel = *(uint32_t*)sourcePixelData;
    for (int32_t x = 0; x < aFillRect.Width(); x++) {
      *((uint32_t*)data + x) = sourcePixel;
    }
  } else if (BytesPerPixel(aSurface->GetFormat()) == 1) {
    uint8_t sourcePixel = *sourcePixelData;
    memset(data, sourcePixel, aFillRect.Width());
  }

  // Copy the first row into the other rows.
  for (int32_t y = 1; y < aFillRect.Height(); y++) {
    PodCopy(data + y * surfMap.GetStride(), data, aFillRect.Width() * bpp);
  }
}

static void FillRectWithVerticallyRepeatingHorizontalStrip(
    DataSourceSurface* aSurface, const IntRect& aFillRect,
    const IntRect& aSampleRect) {
  MOZ_ASSERT(!aFillRect.Overflows());
  MOZ_ASSERT(!aSampleRect.Overflows());
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aFillRect),
             "aFillRect needs to be completely inside the surface");
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aSampleRect),
             "aSampleRect needs to be completely inside the surface");

  DataSourceSurface::ScopedMap surfMap(aSurface, DataSourceSurface::READ_WRITE);
  if (MOZ2D_WARN_IF(!surfMap.IsMapped())) {
    return;
  }

  uint8_t* sampleData =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aSampleRect.TopLeft());
  uint8_t* data =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aFillRect.TopLeft());
  if (BytesPerPixel(aSurface->GetFormat()) == 4) {
    for (int32_t y = 0; y < aFillRect.Height(); y++) {
      PodCopy((uint32_t*)data, (uint32_t*)sampleData, aFillRect.Width());
      data += surfMap.GetStride();
    }
  } else if (BytesPerPixel(aSurface->GetFormat()) == 1) {
    for (int32_t y = 0; y < aFillRect.Height(); y++) {
      PodCopy(data, sampleData, aFillRect.Width());
      data += surfMap.GetStride();
    }
  }
}

static void FillRectWithHorizontallyRepeatingVerticalStrip(
    DataSourceSurface* aSurface, const IntRect& aFillRect,
    const IntRect& aSampleRect) {
  MOZ_ASSERT(!aFillRect.Overflows());
  MOZ_ASSERT(!aSampleRect.Overflows());
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aFillRect),
             "aFillRect needs to be completely inside the surface");
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aSampleRect),
             "aSampleRect needs to be completely inside the surface");

  DataSourceSurface::ScopedMap surfMap(aSurface, DataSourceSurface::READ_WRITE);
  if (MOZ2D_WARN_IF(!surfMap.IsMapped())) {
    return;
  }

  uint8_t* sampleData =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aSampleRect.TopLeft());
  uint8_t* data =
      DataAtOffset(aSurface, surfMap.GetMappedSurface(), aFillRect.TopLeft());
  if (BytesPerPixel(aSurface->GetFormat()) == 4) {
    for (int32_t y = 0; y < aFillRect.Height(); y++) {
      int32_t sampleColor = *((uint32_t*)sampleData);
      for (int32_t x = 0; x < aFillRect.Width(); x++) {
        *((uint32_t*)data + x) = sampleColor;
      }
      data += surfMap.GetStride();
      sampleData += surfMap.GetStride();
    }
  } else if (BytesPerPixel(aSurface->GetFormat()) == 1) {
    for (int32_t y = 0; y < aFillRect.Height(); y++) {
      uint8_t sampleColor = *sampleData;
      memset(data, sampleColor, aFillRect.Width());
      data += surfMap.GetStride();
      sampleData += surfMap.GetStride();
    }
  }
}

static void DuplicateEdges(DataSourceSurface* aSurface,
                           const IntRect& aFromRect) {
  MOZ_ASSERT(!aFromRect.Overflows());
  MOZ_ASSERT(IntRect(IntPoint(), aSurface->GetSize()).Contains(aFromRect),
             "aFromRect needs to be completely inside the surface");

  IntSize size = aSurface->GetSize();
  IntRect fill;
  IntRect sampleRect;
  for (int32_t ix = 0; ix < 3; ix++) {
    switch (ix) {
      case 0:
        fill.SetRectX(0, aFromRect.X());
        sampleRect.SetRectX(fill.XMost(), 1);
        break;
      case 1:
        fill.SetRectX(aFromRect.X(), aFromRect.Width());
        sampleRect.SetRectX(fill.X(), fill.Width());
        break;
      case 2:
        fill.MoveToX(aFromRect.XMost());
        fill.SetRightEdge(size.width);
        sampleRect.SetRectX(fill.X() - 1, 1);
        break;
    }
    if (fill.Width() <= 0) {
      continue;
    }
    bool xIsMiddle = (ix == 1);
    for (int32_t iy = 0; iy < 3; iy++) {
      switch (iy) {
        case 0:
          fill.SetRectY(0, aFromRect.Y());
          sampleRect.SetRectY(fill.YMost(), 1);
          break;
        case 1:
          fill.SetRectY(aFromRect.Y(), aFromRect.Height());
          sampleRect.SetRectY(fill.Y(), fill.Height());
          break;
        case 2:
          fill.MoveToY(aFromRect.YMost());
          fill.SetBottomEdge(size.height);
          sampleRect.SetRectY(fill.Y() - 1, 1);
          break;
      }
      if (fill.Height() <= 0) {
        continue;
      }
      bool yIsMiddle = (iy == 1);
      if (!xIsMiddle && !yIsMiddle) {
        // Corner
        FillRectWithPixel(aSurface, fill, sampleRect.TopLeft());
      }
      if (xIsMiddle && !yIsMiddle) {
        // Top middle or bottom middle
        FillRectWithVerticallyRepeatingHorizontalStrip(aSurface, fill,
                                                       sampleRect);
      }
      if (!xIsMiddle && yIsMiddle) {
        // Left middle or right middle
        FillRectWithHorizontallyRepeatingVerticalStrip(aSurface, fill,
                                                       sampleRect);
      }
    }
  }
}

static IntPoint TileIndex(const IntRect& aFirstTileRect,
                          const IntPoint& aPoint) {
  return IntPoint(int32_t(floor(double(aPoint.x - aFirstTileRect.X()) /
                                aFirstTileRect.Width())),
                  int32_t(floor(double(aPoint.y - aFirstTileRect.Y()) /
                                aFirstTileRect.Height())));
}

static void TileSurface(DataSourceSurface* aSource, DataSourceSurface* aTarget,
                        const IntPoint& aOffset) {
  IntRect sourceRect(aOffset, aSource->GetSize());
  IntRect targetRect(IntPoint(0, 0), aTarget->GetSize());
  IntPoint startIndex = TileIndex(sourceRect, targetRect.TopLeft());
  IntPoint endIndex = TileIndex(sourceRect, targetRect.BottomRight());

  for (int32_t ix = startIndex.x; ix <= endIndex.x; ix++) {
    for (int32_t iy = startIndex.y; iy <= endIndex.y; iy++) {
      IntPoint destPoint(sourceRect.X() + ix * sourceRect.Width(),
                         sourceRect.Y() + iy * sourceRect.Height());
      IntRect destRect(destPoint, sourceRect.Size());
      destRect = destRect.Intersect(targetRect);
      IntRect srcRect = destRect - destPoint;
      CopyRect(aSource, aTarget, srcRect, destRect.TopLeft());
    }
  }
}

static already_AddRefed<DataSourceSurface> GetDataSurfaceInRect(
    SourceSurface* aSurface, const IntRect& aSurfaceRect,
    const IntRect& aDestRect, ConvolveMatrixEdgeMode aEdgeMode) {
  MOZ_ASSERT(aSurface ? aSurfaceRect.Size() == aSurface->GetSize()
                      : aSurfaceRect.IsEmpty());

  if (aSurfaceRect.Overflows() || aDestRect.Overflows()) {
    // We can't rely on the intersection calculations below to make sense when
    // XMost() or YMost() overflow. Bail out.
    return nullptr;
  }

  IntRect sourceRect = aSurfaceRect;

  if (sourceRect.IsEqualEdges(aDestRect)) {
    return aSurface ? aSurface->GetDataSurface() : nullptr;
  }

  IntRect intersect = sourceRect.Intersect(aDestRect);

  // create rects that are in surface local space.
  IntRect intersectInSourceSpace = intersect - sourceRect.TopLeft();
  IntRect intersectInDestSpace = intersect - aDestRect.TopLeft();
  SurfaceFormat format =
      aSurface ? aSurface->GetFormat() : SurfaceFormat(SurfaceFormat::B8G8R8A8);

  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(aDestRect.Size(), format, true);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  if (!aSurface) {
    return target.forget();
  }

  RefPtr<DataSourceSurface> dataSource = aSurface->GetDataSurface();
  MOZ_ASSERT(dataSource);

  if (aEdgeMode == EDGE_MODE_WRAP) {
    TileSurface(dataSource, target, intersectInDestSpace.TopLeft());
    return target.forget();
  }

  CopyRect(dataSource, target, intersectInSourceSpace,
           intersectInDestSpace.TopLeft());

  if (aEdgeMode == EDGE_MODE_DUPLICATE) {
    DuplicateEdges(target, intersectInDestSpace);
  }

  return target.forget();
}

/* static */
already_AddRefed<FilterNode> FilterNodeSoftware::Create(FilterType aType) {
  RefPtr<FilterNodeSoftware> filter;
  switch (aType) {
    case FilterType::BLEND:
      filter = new FilterNodeBlendSoftware();
      break;
    case FilterType::TRANSFORM:
      filter = new FilterNodeTransformSoftware();
      break;
    case FilterType::MORPHOLOGY:
      filter = new FilterNodeMorphologySoftware();
      break;
    case FilterType::COLOR_MATRIX:
      filter = new FilterNodeColorMatrixSoftware();
      break;
    case FilterType::FLOOD:
      filter = new FilterNodeFloodSoftware();
      break;
    case FilterType::TILE:
      filter = new FilterNodeTileSoftware();
      break;
    case FilterType::TABLE_TRANSFER:
      filter = new FilterNodeTableTransferSoftware();
      break;
    case FilterType::DISCRETE_TRANSFER:
      filter = new FilterNodeDiscreteTransferSoftware();
      break;
    case FilterType::LINEAR_TRANSFER:
      filter = new FilterNodeLinearTransferSoftware();
      break;
    case FilterType::GAMMA_TRANSFER:
      filter = new FilterNodeGammaTransferSoftware();
      break;
    case FilterType::CONVOLVE_MATRIX:
      filter = new FilterNodeConvolveMatrixSoftware();
      break;
    case FilterType::DISPLACEMENT_MAP:
      filter = new FilterNodeDisplacementMapSoftware();
      break;
    case FilterType::TURBULENCE:
      filter = new FilterNodeTurbulenceSoftware();
      break;
    case FilterType::ARITHMETIC_COMBINE:
      filter = new FilterNodeArithmeticCombineSoftware();
      break;
    case FilterType::COMPOSITE:
      filter = new FilterNodeCompositeSoftware();
      break;
    case FilterType::GAUSSIAN_BLUR:
      filter = new FilterNodeGaussianBlurSoftware();
      break;
    case FilterType::DIRECTIONAL_BLUR:
      filter = new FilterNodeDirectionalBlurSoftware();
      break;
    case FilterType::CROP:
      filter = new FilterNodeCropSoftware();
      break;
    case FilterType::PREMULTIPLY:
      filter = new FilterNodePremultiplySoftware();
      break;
    case FilterType::UNPREMULTIPLY:
      filter = new FilterNodeUnpremultiplySoftware();
      break;
    case FilterType::OPACITY:
      filter = new FilterNodeOpacitySoftware();
      break;
    case FilterType::POINT_DIFFUSE:
      filter = new FilterNodeLightingSoftware<PointLightSoftware,
                                              DiffuseLightingSoftware>(
          "FilterNodeLightingSoftware<PointLight, DiffuseLighting>");
      break;
    case FilterType::POINT_SPECULAR:
      filter = new FilterNodeLightingSoftware<PointLightSoftware,
                                              SpecularLightingSoftware>(
          "FilterNodeLightingSoftware<PointLight, SpecularLighting>");
      break;
    case FilterType::SPOT_DIFFUSE:
      filter = new FilterNodeLightingSoftware<SpotLightSoftware,
                                              DiffuseLightingSoftware>(
          "FilterNodeLightingSoftware<SpotLight, DiffuseLighting>");
      break;
    case FilterType::SPOT_SPECULAR:
      filter = new FilterNodeLightingSoftware<SpotLightSoftware,
                                              SpecularLightingSoftware>(
          "FilterNodeLightingSoftware<SpotLight, SpecularLighting>");
      break;
    case FilterType::DISTANT_DIFFUSE:
      filter = new FilterNodeLightingSoftware<DistantLightSoftware,
                                              DiffuseLightingSoftware>(
          "FilterNodeLightingSoftware<DistantLight, DiffuseLighting>");
      break;
    case FilterType::DISTANT_SPECULAR:
      filter = new FilterNodeLightingSoftware<DistantLightSoftware,
                                              SpecularLightingSoftware>(
          "FilterNodeLightingSoftware<DistantLight, SpecularLighting>");
      break;
  }
  return filter.forget();
}

void FilterNodeSoftware::Draw(DrawTarget* aDrawTarget, const Rect& aSourceRect,
                              const Point& aDestPoint,
                              const DrawOptions& aOptions) {
#ifdef DEBUG_DUMP_SURFACES
  printf("<style>section{margin:10px;}</style><pre>\nRendering filter %s...\n",
         GetName());
#endif

  Rect renderRect = aSourceRect;
  renderRect.RoundOut();
  IntRect renderIntRect;
  if (!renderRect.ToIntRect(&renderIntRect)) {
#ifdef DEBUG_DUMP_SURFACES
    printf("render rect overflowed, not painting anything\n");
    printf("</pre>\n");
#endif
    return;
  }

  IntRect outputRect = GetOutputRectInRect(renderIntRect);
  if (outputRect.Overflows()) {
#ifdef DEBUG_DUMP_SURFACES
    printf("output rect overflowed, not painting anything\n");
    printf("</pre>\n");
#endif
    return;
  }

  RefPtr<DataSourceSurface> result;
  if (!outputRect.IsEmpty()) {
    result = GetOutput(outputRect);
  }

  if (!result) {
    // Null results are allowed and treated as transparent. Don't draw anything.
#ifdef DEBUG_DUMP_SURFACES
    printf("output returned null\n");
    printf("</pre>\n");
#endif
    return;
  }

#ifdef DEBUG_DUMP_SURFACES
  printf("output from %s:\n", GetName());
  printf("<img src='");
  gfxUtils::DumpAsDataURI(result);
  printf("'>\n");
  printf("</pre>\n");
#endif

  Point sourceToDestOffset = aDestPoint - aSourceRect.TopLeft();
  Rect renderedSourceRect = Rect(outputRect).Intersect(aSourceRect);
  Rect renderedDestRect = renderedSourceRect + sourceToDestOffset;
  if (result->GetFormat() == SurfaceFormat::A8) {
    // Interpret the result as having implicitly black color channels.
    aDrawTarget->PushClipRect(renderedDestRect);
    aDrawTarget->MaskSurface(
        ColorPattern(DeviceColor::MaskOpaqueBlack()), result,
        Point(outputRect.TopLeft()) + sourceToDestOffset, aOptions);
    aDrawTarget->PopClip();
  } else {
    aDrawTarget->DrawSurface(result, renderedDestRect,
                             renderedSourceRect - Point(outputRect.TopLeft()),
                             DrawSurfaceOptions(), aOptions);
  }
}

already_AddRefed<DataSourceSurface> FilterNodeSoftware::GetOutput(
    const IntRect& aRect) {
  MOZ_ASSERT(GetOutputRectInRect(aRect).Contains(aRect));

  if (aRect.Overflows()) {
    return nullptr;
  }

  IntRect cachedRect;
  IntRect requestedRect;
  RefPtr<DataSourceSurface> cachedOutput;

  // Retrieve a cached surface if we have one and it can
  // satisfy this request, or else request a rect we will compute and cache
  if (!mCachedRect.Contains(aRect)) {
    RequestRect(aRect);
    requestedRect = mRequestedRect;
  } else {
    MOZ_ASSERT(mCachedOutput, "cached rect but no cached output?");
    cachedRect = mCachedRect;
    cachedOutput = mCachedOutput;
  }

  if (!cachedOutput) {
    // Compute the output
    cachedOutput = Render(requestedRect);

    // Update the cache for future requests
    mCachedOutput = cachedOutput;
    if (!mCachedOutput) {
      mCachedRect = IntRect();
      mRequestedRect = IntRect();
      return nullptr;
    }
    mCachedRect = requestedRect;
    mRequestedRect = IntRect();

    cachedRect = mCachedRect;
  }

  return GetDataSurfaceInRect(cachedOutput, cachedRect, aRect, EDGE_MODE_NONE);
}

void FilterNodeSoftware::RequestRect(const IntRect& aRect) {
  if (mRequestedRect.Contains(aRect)) {
    // Bail out now. Otherwise pathological filters can spend time exponential
    // in the number of primitives, e.g. if each primitive takes the
    // previous primitive as its two inputs.
    return;
  }
  mRequestedRect = mRequestedRect.Union(aRect);
  RequestFromInputsForRect(aRect);
}

IntRect FilterNodeSoftware::MapInputRectToSource(uint32_t aInputEnumIndex,
                                                 const IntRect& aRect,
                                                 const IntRect& aMax,
                                                 FilterNode* aSourceNode) {
  int32_t inputIndex = InputIndex(aInputEnumIndex);
  if (inputIndex < 0) {
    gfxDevCrash(LogReason::FilterInputError)
        << "Invalid input " << inputIndex << " vs. " << NumberOfSetInputs();
    return aMax;
  }
  if ((uint32_t)inputIndex < NumberOfSetInputs()) {
    RefPtr<FilterNodeSoftware> filter = mInputFilters[inputIndex];
    // If we have any input filters call into them to do the mapping,
    // otherwise we can assume an input surface will be used
    // and just return aRect.
    if (filter) {
      return filter->MapRectToSource(aRect, aMax, aSourceNode);
    }
  }
  // We have an input surface instead of a filter
  // so check if we're the target node.
  if (this == aSourceNode) {
    return aRect;
  }
  return IntRect();
}

void FilterNodeSoftware::RequestInputRect(uint32_t aInputEnumIndex,
                                          const IntRect& aRect) {
  if (aRect.Overflows()) {
    return;
  }

  int32_t inputIndex = InputIndex(aInputEnumIndex);
  if (inputIndex < 0 || (uint32_t)inputIndex >= NumberOfSetInputs()) {
    gfxDevCrash(LogReason::FilterInputError)
        << "Invalid input " << inputIndex << " vs. " << NumberOfSetInputs();
    return;
  }
  if (mInputSurfaces[inputIndex]) {
    return;
  }
  RefPtr<FilterNodeSoftware> filter = mInputFilters[inputIndex];
  MOZ_ASSERT(filter, "missing input");
  if (filter) {
    filter->RequestRect(filter->GetOutputRectInRect(aRect));
  }
}

SurfaceFormat FilterNodeSoftware::DesiredFormat(SurfaceFormat aCurrentFormat,
                                                FormatHint aFormatHint) {
  if (aCurrentFormat == SurfaceFormat::A8 && aFormatHint == CAN_HANDLE_A8) {
    return SurfaceFormat::A8;
  }
  return SurfaceFormat::B8G8R8A8;
}

already_AddRefed<DataSourceSurface>
FilterNodeSoftware::GetInputDataSourceSurface(
    uint32_t aInputEnumIndex, const IntRect& aRect, FormatHint aFormatHint,
    ConvolveMatrixEdgeMode aEdgeMode,
    const IntRect* aTransparencyPaddedSourceRect) {
  if (aRect.Overflows()) {
    return nullptr;
  }

#ifdef DEBUG_DUMP_SURFACES
  printf("<section><h1>GetInputDataSourceSurface with aRect: %s</h1>\n",
         ToString(aRect).c_str());
#endif
  int32_t inputIndex = InputIndex(aInputEnumIndex);
  if (inputIndex < 0 || (uint32_t)inputIndex >= NumberOfSetInputs()) {
    gfxDevCrash(LogReason::FilterInputData)
        << "Invalid data " << inputIndex << " vs. " << NumberOfSetInputs();
    return nullptr;
  }

  if (aRect.IsEmpty()) {
    return nullptr;
  }

  RefPtr<SourceSurface> surface;
  IntRect surfaceRect;

  if (mInputSurfaces[inputIndex]) {
    // Input from input surface
    surface = mInputSurfaces[inputIndex];
#ifdef DEBUG_DUMP_SURFACES
    printf("input from input surface:\n");
#endif
    surfaceRect = surface->GetRect();
  } else {
    // Input from input filter
    RefPtr<FilterNodeSoftware> filter = mInputFilters[inputIndex];
    MOZ_ASSERT(filter, "missing input");
    if (!filter) {
      return nullptr;
    }
#ifdef DEBUG_DUMP_SURFACES
    printf("getting input from input filter %s...\n", filter->GetName());
#endif
    IntRect inputFilterOutput = filter->GetOutputRectInRect(aRect);
    if (!inputFilterOutput.IsEmpty()) {
      surface = filter->GetOutput(inputFilterOutput);
    }
#ifdef DEBUG_DUMP_SURFACES
    printf("input from input filter %s:\n", filter->GetName());
#endif
    surfaceRect = inputFilterOutput;
    MOZ_ASSERT(!surface || surfaceRect.Size() == surface->GetSize());
  }

  if (surface && surface->GetFormat() == SurfaceFormat::UNKNOWN) {
#ifdef DEBUG_DUMP_SURFACES
    printf("wrong input format</section>\n\n");
#endif
    return nullptr;
  }

  if (!surfaceRect.IsEmpty() && !surface) {
#ifdef DEBUG_DUMP_SURFACES
    printf(" -- no input --</section>\n\n");
#endif
    return nullptr;
  }

  if (aTransparencyPaddedSourceRect &&
      !aTransparencyPaddedSourceRect->IsEmpty()) {
    IntRect srcRect = aTransparencyPaddedSourceRect->Intersect(aRect);
    surface =
        GetDataSurfaceInRect(surface, surfaceRect, srcRect, EDGE_MODE_NONE);
    if (surface) {
      surfaceRect = srcRect;
    } else {
      // Padding the surface with transparency failed, probably due to size
      // restrictions. Since |surface| is now null, set the surfaceRect to
      // empty so that we're consistent.
      surfaceRect.SetEmpty();
    }
  }

  RefPtr<DataSourceSurface> result =
      GetDataSurfaceInRect(surface, surfaceRect, aRect, aEdgeMode);

  if (result) {
    // TODO: This isn't safe since we don't have a guarantee
    // that future Maps will have the same stride
    DataSourceSurface::MappedSurface map;
    if (result->Map(DataSourceSurface::READ, &map)) {
      // Unmap immediately since CloneAligned hasn't been updated
      // to use the Map API yet. We can still read the stride/data
      // values as long as we don't try to dereference them.
      result->Unmap();
      if (map.mStride != GetAlignedStride<16>(map.mStride, 1) ||
          reinterpret_cast<uintptr_t>(map.mData) % 16 != 0) {
        // Align unaligned surface.
        result = CloneAligned(result);
      }
    } else {
      result = nullptr;
    }
  }

  if (!result) {
#ifdef DEBUG_DUMP_SURFACES
    printf(" -- no input --</section>\n\n");
#endif
    return nullptr;
  }

  SurfaceFormat currentFormat = result->GetFormat();
  if (DesiredFormat(currentFormat, aFormatHint) == SurfaceFormat::B8G8R8A8 &&
      currentFormat != SurfaceFormat::B8G8R8A8) {
    result = FilterProcessing::ConvertToB8G8R8A8(result);
  }

#ifdef DEBUG_DUMP_SURFACES
  printf("<img src='");
  gfxUtils::DumpAsDataURI(result);
  printf("'></section>");
#endif

  MOZ_ASSERT(!result || result->GetSize() == aRect.Size(),
             "wrong surface size");

  return result.forget();
}

IntRect FilterNodeSoftware::GetInputRectInRect(uint32_t aInputEnumIndex,
                                               const IntRect& aInRect) {
  if (aInRect.Overflows()) {
    return IntRect();
  }

  int32_t inputIndex = InputIndex(aInputEnumIndex);
  if (inputIndex < 0 || (uint32_t)inputIndex >= NumberOfSetInputs()) {
    gfxDevCrash(LogReason::FilterInputRect)
        << "Invalid rect " << inputIndex << " vs. " << NumberOfSetInputs();
    return IntRect();
  }
  if (mInputSurfaces[inputIndex]) {
    return aInRect.Intersect(mInputSurfaces[inputIndex]->GetRect());
  }
  RefPtr<FilterNodeSoftware> filter = mInputFilters[inputIndex];
  MOZ_ASSERT(filter, "missing input");
  if (!filter) {
    return IntRect();
  }
  return filter->GetOutputRectInRect(aInRect);
}

size_t FilterNodeSoftware::NumberOfSetInputs() {
  return std::max(mInputSurfaces.size(), mInputFilters.size());
}

void FilterNodeSoftware::AddInvalidationListener(
    FilterInvalidationListener* aListener) {
  MOZ_ASSERT(aListener, "null listener");
  mInvalidationListeners.push_back(aListener);
}

void FilterNodeSoftware::RemoveInvalidationListener(
    FilterInvalidationListener* aListener) {
  MOZ_ASSERT(aListener, "null listener");
  std::vector<FilterInvalidationListener*>::iterator it = std::find(
      mInvalidationListeners.begin(), mInvalidationListeners.end(), aListener);
  mInvalidationListeners.erase(it);
}

void FilterNodeSoftware::FilterInvalidated(FilterNodeSoftware* aFilter) {
  Invalidate();
}

void FilterNodeSoftware::Invalidate() {
  mCachedOutput = nullptr;
  mCachedRect = IntRect();
  for (std::vector<FilterInvalidationListener*>::iterator it =
           mInvalidationListeners.begin();
       it != mInvalidationListeners.end(); it++) {
    (*it)->FilterInvalidated(this);
  }
}

FilterNodeSoftware::FilterNodeSoftware() {}

FilterNodeSoftware::~FilterNodeSoftware() {
  MOZ_ASSERT(
      mInvalidationListeners.empty(),
      "All invalidation listeners should have unsubscribed themselves by now!");

  for (std::vector<RefPtr<FilterNodeSoftware> >::iterator it =
           mInputFilters.begin();
       it != mInputFilters.end(); it++) {
    if (*it) {
      (*it)->RemoveInvalidationListener(this);
    }
  }
}

void FilterNodeSoftware::SetInput(uint32_t aIndex, FilterNode* aFilter) {
  if (aFilter && aFilter->GetBackendType() != FILTER_BACKEND_SOFTWARE) {
    MOZ_ASSERT(false, "can only take software filters as inputs");
    return;
  }
  SetInput(aIndex, nullptr, static_cast<FilterNodeSoftware*>(aFilter));
}

void FilterNodeSoftware::SetInput(uint32_t aIndex, SourceSurface* aSurface) {
  SetInput(aIndex, aSurface, nullptr);
}

void FilterNodeSoftware::SetInput(uint32_t aInputEnumIndex,
                                  SourceSurface* aSurface,
                                  FilterNodeSoftware* aFilter) {
  int32_t inputIndex = InputIndex(aInputEnumIndex);
  if (inputIndex < 0) {
    gfxDevCrash(LogReason::FilterInputSet) << "Invalid set " << inputIndex;
    return;
  }
  if ((uint32_t)inputIndex >= NumberOfSetInputs()) {
    mInputSurfaces.resize(inputIndex + 1);
    mInputFilters.resize(inputIndex + 1);
  }
  mInputSurfaces[inputIndex] = aSurface;
  if (mInputFilters[inputIndex]) {
    mInputFilters[inputIndex]->RemoveInvalidationListener(this);
  }
  if (aFilter) {
    aFilter->AddInvalidationListener(this);
  }
  mInputFilters[inputIndex] = aFilter;
  if (!aSurface && !aFilter && (size_t)inputIndex == NumberOfSetInputs()) {
    mInputSurfaces.resize(inputIndex);
    mInputFilters.resize(inputIndex);
  }
  Invalidate();
}

FilterNodeBlendSoftware::FilterNodeBlendSoftware()
    : mBlendMode(BLEND_MODE_MULTIPLY) {}

int32_t FilterNodeBlendSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_BLEND_IN:
      return 0;
    case IN_BLEND_IN2:
      return 1;
    default:
      return -1;
  }
}

void FilterNodeBlendSoftware::SetAttribute(uint32_t aIndex,
                                           uint32_t aBlendMode) {
  MOZ_ASSERT(aIndex == ATT_BLEND_BLENDMODE);
  mBlendMode = static_cast<BlendMode>(aBlendMode);
  Invalidate();
}

static CompositionOp ToBlendOp(BlendMode aOp) {
  switch (aOp) {
    case BLEND_MODE_MULTIPLY:
      return CompositionOp::OP_MULTIPLY;
    case BLEND_MODE_SCREEN:
      return CompositionOp::OP_SCREEN;
    case BLEND_MODE_OVERLAY:
      return CompositionOp::OP_OVERLAY;
    case BLEND_MODE_DARKEN:
      return CompositionOp::OP_DARKEN;
    case BLEND_MODE_LIGHTEN:
      return CompositionOp::OP_LIGHTEN;
    case BLEND_MODE_COLOR_DODGE:
      return CompositionOp::OP_COLOR_DODGE;
    case BLEND_MODE_COLOR_BURN:
      return CompositionOp::OP_COLOR_BURN;
    case BLEND_MODE_HARD_LIGHT:
      return CompositionOp::OP_HARD_LIGHT;
    case BLEND_MODE_SOFT_LIGHT:
      return CompositionOp::OP_SOFT_LIGHT;
    case BLEND_MODE_DIFFERENCE:
      return CompositionOp::OP_DIFFERENCE;
    case BLEND_MODE_EXCLUSION:
      return CompositionOp::OP_EXCLUSION;
    case BLEND_MODE_HUE:
      return CompositionOp::OP_HUE;
    case BLEND_MODE_SATURATION:
      return CompositionOp::OP_SATURATION;
    case BLEND_MODE_COLOR:
      return CompositionOp::OP_COLOR;
    case BLEND_MODE_LUMINOSITY:
      return CompositionOp::OP_LUMINOSITY;
  }

  MOZ_ASSERT_UNREACHABLE("Unexpected BlendMode");
  return CompositionOp::OP_OVER;
}

already_AddRefed<DataSourceSurface> FilterNodeBlendSoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input1 =
      GetInputDataSourceSurface(IN_BLEND_IN, aRect, NEED_COLOR_CHANNELS);
  RefPtr<DataSourceSurface> input2 =
      GetInputDataSourceSurface(IN_BLEND_IN2, aRect, NEED_COLOR_CHANNELS);

  // Null inputs need to be treated as transparent.

  // First case: both are transparent.
  if (!input1 && !input2) {
    // Then the result is transparent, too.
    return nullptr;
  }

  // Second case: one of them is transparent. Return the non-transparent one.
  if (!input1 || !input2) {
    return input1 ? input1.forget() : input2.forget();
  }

  // Third case: both are non-transparent.
  // Apply normal filtering.
  RefPtr<DataSourceSurface> target =
      FilterProcessing::ApplyBlending(input1, input2, mBlendMode);
  if (target != nullptr) {
    return target.forget();
  }

  IntSize size = input1->GetSize();
  target = Factory::CreateDataSourceSurface(size, SurfaceFormat::B8G8R8A8);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  CopyRect(input1, target, IntRect(IntPoint(), size), IntPoint());

  // This needs to stay in scope until the draw target has been flushed.
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::READ_WRITE);
  if (MOZ2D_WARN_IF(!targetMap.IsMapped())) {
    return nullptr;
  }

  RefPtr<DrawTarget> dt = Factory::CreateDrawTargetForData(
      BackendType::SKIA, targetMap.GetData(), target->GetSize(),
      targetMap.GetStride(), target->GetFormat());

  if (!dt) {
    gfxWarning()
        << "FilterNodeBlendSoftware::Render failed in CreateDrawTargetForData";
    return nullptr;
  }

  Rect r(0, 0, size.width, size.height);
  dt->DrawSurface(input2, r, r, DrawSurfaceOptions(),
                  DrawOptions(1.0f, ToBlendOp(mBlendMode)));
  dt->Flush();
  return target.forget();
}

void FilterNodeBlendSoftware::RequestFromInputsForRect(const IntRect& aRect) {
  RequestInputRect(IN_BLEND_IN, aRect);
  RequestInputRect(IN_BLEND_IN2, aRect);
}

IntRect FilterNodeBlendSoftware::MapRectToSource(const IntRect& aRect,
                                                 const IntRect& aMax,
                                                 FilterNode* aSourceNode) {
  IntRect result = MapInputRectToSource(IN_BLEND_IN, aRect, aMax, aSourceNode);
  result.OrWith(MapInputRectToSource(IN_BLEND_IN2, aRect, aMax, aSourceNode));
  return result;
}

IntRect FilterNodeBlendSoftware::GetOutputRectInRect(const IntRect& aRect) {
  return GetInputRectInRect(IN_BLEND_IN, aRect)
      .Union(GetInputRectInRect(IN_BLEND_IN2, aRect))
      .Intersect(aRect);
}

FilterNodeTransformSoftware::FilterNodeTransformSoftware()
    : mSamplingFilter(SamplingFilter::GOOD) {}

int32_t FilterNodeTransformSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_TRANSFORM_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeTransformSoftware::SetAttribute(uint32_t aIndex,
                                               uint32_t aFilter) {
  MOZ_ASSERT(aIndex == ATT_TRANSFORM_FILTER);
  mSamplingFilter = static_cast<SamplingFilter>(aFilter);
  Invalidate();
}

void FilterNodeTransformSoftware::SetAttribute(uint32_t aIndex,
                                               const Matrix& aMatrix) {
  MOZ_ASSERT(aIndex == ATT_TRANSFORM_MATRIX);
  mMatrix = aMatrix;
  Invalidate();
}

IntRect FilterNodeTransformSoftware::SourceRectForOutputRect(
    const IntRect& aRect) {
  if (aRect.IsEmpty()) {
    return IntRect();
  }

  Matrix inverted(mMatrix);
  if (!inverted.Invert()) {
    return IntRect();
  }

  Rect neededRect = inverted.TransformBounds(Rect(aRect));
  neededRect.RoundOut();
  IntRect neededIntRect;
  if (!neededRect.ToIntRect(&neededIntRect)) {
    return IntRect();
  }
  return GetInputRectInRect(IN_TRANSFORM_IN, neededIntRect);
}

IntRect FilterNodeTransformSoftware::MapRectToSource(const IntRect& aRect,
                                                     const IntRect& aMax,
                                                     FilterNode* aSourceNode) {
  if (aRect.IsEmpty()) {
    return IntRect();
  }

  Matrix inverted(mMatrix);
  if (!inverted.Invert()) {
    return aMax;
  }

  Rect neededRect = inverted.TransformBounds(Rect(aRect));
  neededRect.RoundOut();
  IntRect neededIntRect;
  if (!neededRect.ToIntRect(&neededIntRect)) {
    return aMax;
  }
  return MapInputRectToSource(IN_TRANSFORM_IN, neededIntRect, aMax,
                              aSourceNode);
}

already_AddRefed<DataSourceSurface> FilterNodeTransformSoftware::Render(
    const IntRect& aRect) {
  IntRect srcRect = SourceRectForOutputRect(aRect);

  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_TRANSFORM_IN, srcRect);

  if (!input) {
    return nullptr;
  }

  Matrix transform = Matrix::Translation(srcRect.X(), srcRect.Y()) * mMatrix *
                     Matrix::Translation(-aRect.X(), -aRect.Y());
  if (transform.IsIdentity() && srcRect.Size() == aRect.Size()) {
    return input.forget();
  }

  RefPtr<DataSourceSurface> surf =
      Factory::CreateDataSourceSurface(aRect.Size(), input->GetFormat(), true);

  if (!surf) {
    return nullptr;
  }

  DataSourceSurface::MappedSurface mapping;
  if (!surf->Map(DataSourceSurface::MapType::WRITE, &mapping)) {
    gfxCriticalError()
        << "FilterNodeTransformSoftware::Render failed to map surface";
    return nullptr;
  }

  RefPtr<DrawTarget> dt = Factory::CreateDrawTargetForData(
      BackendType::SKIA, mapping.mData, surf->GetSize(), mapping.mStride,
      surf->GetFormat());
  if (!dt) {
    gfxWarning() << "FilterNodeTransformSoftware::Render failed in "
                    "CreateDrawTargetForData";
    return nullptr;
  }

  Rect r(0, 0, srcRect.Width(), srcRect.Height());
  dt->SetTransform(transform);
  dt->DrawSurface(input, r, r, DrawSurfaceOptions(mSamplingFilter));

  dt->Flush();
  surf->Unmap();
  return surf.forget();
}

void FilterNodeTransformSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_TRANSFORM_IN, SourceRectForOutputRect(aRect));
}

IntRect FilterNodeTransformSoftware::GetOutputRectInRect(const IntRect& aRect) {
  IntRect srcRect = SourceRectForOutputRect(aRect);
  if (srcRect.IsEmpty()) {
    return IntRect();
  }

  Rect outRect = mMatrix.TransformBounds(Rect(srcRect));
  outRect.RoundOut();
  IntRect outIntRect;
  if (!outRect.ToIntRect(&outIntRect)) {
    return IntRect();
  }
  return outIntRect.Intersect(aRect);
}

FilterNodeMorphologySoftware::FilterNodeMorphologySoftware()
    : mOperator(MORPHOLOGY_OPERATOR_ERODE) {}

int32_t FilterNodeMorphologySoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_MORPHOLOGY_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeMorphologySoftware::SetAttribute(uint32_t aIndex,
                                                const IntSize& aRadii) {
  MOZ_ASSERT(aIndex == ATT_MORPHOLOGY_RADII);
  mRadii.width = std::clamp(aRadii.width, 0, 100000);
  mRadii.height = std::clamp(aRadii.height, 0, 100000);
  Invalidate();
}

void FilterNodeMorphologySoftware::SetAttribute(uint32_t aIndex,
                                                uint32_t aOperator) {
  MOZ_ASSERT(aIndex == ATT_MORPHOLOGY_OPERATOR);
  mOperator = static_cast<MorphologyOperator>(aOperator);
  Invalidate();
}

static already_AddRefed<DataSourceSurface> ApplyMorphology(
    const IntRect& aSourceRect, DataSourceSurface* aInput,
    const IntRect& aDestRect, int32_t rx, int32_t ry,
    MorphologyOperator aOperator) {
  IntRect srcRect = aSourceRect - aDestRect.TopLeft();
  IntRect destRect = aDestRect - aDestRect.TopLeft();
  IntRect tmpRect(destRect.X(), srcRect.Y(), destRect.Width(),
                  srcRect.Height());
#ifdef DEBUG
  IntMargin margin = srcRect - destRect;
  MOZ_ASSERT(margin.top >= ry && margin.right >= rx && margin.bottom >= ry &&
                 margin.left >= rx,
             "insufficient margin");
#endif

  RefPtr<DataSourceSurface> tmp;
  if (rx == 0) {
    tmp = aInput;
  } else {
    tmp = Factory::CreateDataSourceSurface(tmpRect.Size(),
                                           SurfaceFormat::B8G8R8A8);
    if (MOZ2D_WARN_IF(!tmp)) {
      return nullptr;
    }

    DataSourceSurface::ScopedMap sourceMap(aInput, DataSourceSurface::READ);
    DataSourceSurface::ScopedMap tmpMap(tmp, DataSourceSurface::WRITE);
    if (MOZ2D_WARN_IF(!sourceMap.IsMapped() || !tmpMap.IsMapped())) {
      return nullptr;
    }
    const uint8_t* sourceData =
        DataAtOffset(aInput, sourceMap.GetMappedSurface(),
                     destRect.TopLeft() - srcRect.TopLeft());
    uint8_t* tmpData = DataAtOffset(tmp, tmpMap.GetMappedSurface(),
                                    destRect.TopLeft() - tmpRect.TopLeft());

    FilterProcessing::ApplyMorphologyHorizontal(
        sourceData, sourceMap.GetStride(), tmpData, tmpMap.GetStride(), tmpRect,
        rx, aOperator);
  }

  RefPtr<DataSourceSurface> dest;
  if (ry == 0) {
    dest = tmp;
  } else {
    dest = Factory::CreateDataSourceSurface(destRect.Size(),
                                            SurfaceFormat::B8G8R8A8);
    if (MOZ2D_WARN_IF(!dest)) {
      return nullptr;
    }

    DataSourceSurface::ScopedMap tmpMap(tmp, DataSourceSurface::READ);
    DataSourceSurface::ScopedMap destMap(dest, DataSourceSurface::WRITE);
    if (MOZ2D_WARN_IF(!tmpMap.IsMapped() || !destMap.IsMapped())) {
      return nullptr;
    }
    int32_t tmpStride = tmpMap.GetStride();
    const uint8_t* tmpData = DataAtOffset(
        tmp, tmpMap.GetMappedSurface(), destRect.TopLeft() - tmpRect.TopLeft());

    int32_t destStride = destMap.GetStride();
    uint8_t* destData = destMap.GetData();

    FilterProcessing::ApplyMorphologyVertical(
        tmpData, tmpStride, destData, destStride, destRect, ry, aOperator);
  }

  return dest.forget();
}

already_AddRefed<DataSourceSurface> FilterNodeMorphologySoftware::Render(
    const IntRect& aRect) {
  IntRect srcRect = aRect;
  srcRect.Inflate(mRadii);

  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_MORPHOLOGY_IN, srcRect, NEED_COLOR_CHANNELS);
  if (!input) {
    return nullptr;
  }

  int32_t rx = mRadii.width;
  int32_t ry = mRadii.height;

  if (rx == 0 && ry == 0) {
    return input.forget();
  }

  return ApplyMorphology(srcRect, input, aRect, rx, ry, mOperator);
}

void FilterNodeMorphologySoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  IntRect srcRect = aRect;
  srcRect.Inflate(mRadii);
  RequestInputRect(IN_MORPHOLOGY_IN, srcRect);
}

IntRect FilterNodeMorphologySoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  IntRect inflatedSourceRect = aRect;
  inflatedSourceRect.Inflate(mRadii);
  IntRect inputRect = GetInputRectInRect(IN_MORPHOLOGY_IN, inflatedSourceRect);
  if (mOperator == MORPHOLOGY_OPERATOR_ERODE) {
    inputRect.Deflate(mRadii);
  } else {
    inputRect.Inflate(mRadii);
  }
  return inputRect.Intersect(aRect);
}

int32_t FilterNodeColorMatrixSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_COLOR_MATRIX_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeColorMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                 const Matrix5x4& aMatrix) {
  MOZ_ASSERT(aIndex == ATT_COLOR_MATRIX_MATRIX);
  mMatrix = aMatrix;
  Invalidate();
}

void FilterNodeColorMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                 uint32_t aAlphaMode) {
  MOZ_ASSERT(aIndex == ATT_COLOR_MATRIX_ALPHA_MODE);
  mAlphaMode = (AlphaMode)aAlphaMode;
  Invalidate();
}

static already_AddRefed<DataSourceSurface> Premultiply(
    DataSourceSurface* aSurface) {
  if (aSurface->GetFormat() == SurfaceFormat::A8) {
    RefPtr<DataSourceSurface> surface(aSurface);
    return surface.forget();
  }

  IntSize size = aSurface->GetSize();
  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(size, SurfaceFormat::B8G8R8A8);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap inputMap(aSurface, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!inputMap.IsMapped() || !targetMap.IsMapped())) {
    return nullptr;
  }

  const uint8_t* inputData = inputMap.GetData();
  int32_t inputStride = inputMap.GetStride();
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  FilterProcessing::DoPremultiplicationCalculation(
      size, targetData, targetStride, inputData, inputStride);

  return target.forget();
}

static already_AddRefed<DataSourceSurface> Unpremultiply(
    DataSourceSurface* aSurface) {
  if (aSurface->GetFormat() == SurfaceFormat::A8) {
    RefPtr<DataSourceSurface> surface(aSurface);
    return surface.forget();
  }

  IntSize size = aSurface->GetSize();
  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(size, SurfaceFormat::B8G8R8A8);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap inputMap(aSurface, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!inputMap.IsMapped() || !targetMap.IsMapped())) {
    return nullptr;
  }

  uint8_t* inputData = inputMap.GetData();
  int32_t inputStride = inputMap.GetStride();
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  FilterProcessing::DoUnpremultiplicationCalculation(
      size, targetData, targetStride, inputData, inputStride);

  return target.forget();
}

static already_AddRefed<DataSourceSurface> Opacity(DataSourceSurface* aSurface,
                                                   Float aValue) {
  if (aValue == 1.0f) {
    RefPtr<DataSourceSurface> surface(aSurface);
    return surface.forget();
  }

  IntSize size = aSurface->GetSize();
  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(size, aSurface->GetFormat());
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap inputMap(aSurface, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!inputMap.IsMapped() || !targetMap.IsMapped())) {
    return nullptr;
  }

  uint8_t* inputData = inputMap.GetData();
  int32_t inputStride = inputMap.GetStride();
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  if (aSurface->GetFormat() == SurfaceFormat::A8) {
    FilterProcessing::DoOpacityCalculationA8(size, targetData, targetStride,
                                             inputData, inputStride, aValue);
  } else {
    MOZ_ASSERT(aSurface->GetFormat() == SurfaceFormat::B8G8R8A8);
    FilterProcessing::DoOpacityCalculation(size, targetData, targetStride,
                                           inputData, inputStride, aValue);
  }

  return target.forget();
}

already_AddRefed<DataSourceSurface> FilterNodeColorMatrixSoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_COLOR_MATRIX_IN, aRect, NEED_COLOR_CHANNELS);
  if (!input) {
    return nullptr;
  }

  if (mAlphaMode == ALPHA_MODE_PREMULTIPLIED) {
    input = Unpremultiply(input);
  }

  RefPtr<DataSourceSurface> result =
      FilterProcessing::ApplyColorMatrix(input, mMatrix);

  if (mAlphaMode == ALPHA_MODE_PREMULTIPLIED) {
    result = Premultiply(result);
  }

  return result.forget();
}

void FilterNodeColorMatrixSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_COLOR_MATRIX_IN, aRect);
}

IntRect FilterNodeColorMatrixSoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_COLOR_MATRIX_IN, aRect, aMax, aSourceNode);
}

IntRect FilterNodeColorMatrixSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  if (mMatrix._54 > 0.0f) {
    return aRect;
  }
  return GetInputRectInRect(IN_COLOR_MATRIX_IN, aRect);
}

void FilterNodeFloodSoftware::SetAttribute(uint32_t aIndex,
                                           const DeviceColor& aColor) {
  MOZ_ASSERT(aIndex == ATT_FLOOD_COLOR);
  mColor = aColor;
  Invalidate();
}

static uint32_t ColorToBGRA(const DeviceColor& aColor) {
  union {
    uint32_t color;
    uint8_t components[4];
  };
  components[B8G8R8A8_COMPONENT_BYTEOFFSET_R] =
      NS_lround(aColor.r * aColor.a * 255.0f);
  components[B8G8R8A8_COMPONENT_BYTEOFFSET_G] =
      NS_lround(aColor.g * aColor.a * 255.0f);
  components[B8G8R8A8_COMPONENT_BYTEOFFSET_B] =
      NS_lround(aColor.b * aColor.a * 255.0f);
  components[B8G8R8A8_COMPONENT_BYTEOFFSET_A] = NS_lround(aColor.a * 255.0f);
  return color;
}

static SurfaceFormat FormatForColor(DeviceColor aColor) {
  if (aColor.r == 0 && aColor.g == 0 && aColor.b == 0) {
    return SurfaceFormat::A8;
  }
  return SurfaceFormat::B8G8R8A8;
}

already_AddRefed<DataSourceSurface> FilterNodeFloodSoftware::Render(
    const IntRect& aRect) {
  SurfaceFormat format = FormatForColor(mColor);
  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(aRect.Size(), format);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!targetMap.IsMapped())) {
    return nullptr;
  }

  uint8_t* targetData = targetMap.GetData();
  int32_t stride = targetMap.GetStride();

  if (format == SurfaceFormat::B8G8R8A8) {
    uint32_t color = ColorToBGRA(mColor);
    for (int32_t y = 0; y < aRect.Height(); y++) {
      for (int32_t x = 0; x < aRect.Width(); x++) {
        *((uint32_t*)targetData + x) = color;
      }
      PodZero(&targetData[aRect.Width() * 4], stride - aRect.Width() * 4);
      targetData += stride;
    }
  } else if (format == SurfaceFormat::A8) {
    uint8_t alpha = NS_lround(mColor.a * 255.0f);
    for (int32_t y = 0; y < aRect.Height(); y++) {
      for (int32_t x = 0; x < aRect.Width(); x++) {
        targetData[x] = alpha;
      }
      PodZero(&targetData[aRect.Width()], stride - aRect.Width());
      targetData += stride;
    }
  } else {
    gfxDevCrash(LogReason::FilterInputFormat)
        << "Bad format in flood render " << (int)format;
    return nullptr;
  }

  return target.forget();
}

// Override GetOutput to get around caching. Rendering simple floods is
// comparatively fast.
already_AddRefed<DataSourceSurface> FilterNodeFloodSoftware::GetOutput(
    const IntRect& aRect) {
  return Render(aRect);
}

IntRect FilterNodeFloodSoftware::MapRectToSource(const IntRect& aRect,
                                                 const IntRect& aMax,
                                                 FilterNode* aSourceNode) {
  return IntRect();
}

IntRect FilterNodeFloodSoftware::GetOutputRectInRect(const IntRect& aRect) {
  if (mColor.a == 0.0f) {
    return IntRect();
  }
  return aRect;
}

int32_t FilterNodeTileSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_TILE_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeTileSoftware::SetAttribute(uint32_t aIndex,
                                          const IntRect& aSourceRect) {
  MOZ_ASSERT(aIndex == ATT_TILE_SOURCE_RECT);
  mSourceRect.SetRect(int32_t(aSourceRect.X()), int32_t(aSourceRect.Y()),
                      int32_t(aSourceRect.Width()),
                      int32_t(aSourceRect.Height()));
  Invalidate();
}

namespace {
struct CompareIntRects {
  bool operator()(const IntRect& a, const IntRect& b) const {
    if (a.X() != b.X()) {
      return a.X() < b.X();
    }
    if (a.Y() != b.Y()) {
      return a.Y() < b.Y();
    }
    if (a.Width() != b.Width()) {
      return a.Width() < b.Width();
    }
    return a.Height() < b.Height();
  }
};

}  // namespace

already_AddRefed<DataSourceSurface> FilterNodeTileSoftware::Render(
    const IntRect& aRect) {
  if (mSourceRect.IsEmpty()) {
    return nullptr;
  }

  if (mSourceRect.Contains(aRect)) {
    return GetInputDataSourceSurface(IN_TILE_IN, aRect);
  }

  RefPtr<DataSourceSurface> target;

  typedef std::map<IntRect, RefPtr<DataSourceSurface>, CompareIntRects>
      InputMap;
  InputMap inputs;

  IntPoint startIndex = TileIndex(mSourceRect, aRect.TopLeft());
  IntPoint endIndex = TileIndex(mSourceRect, aRect.BottomRight());
  for (int32_t ix = startIndex.x; ix <= endIndex.x; ix++) {
    for (int32_t iy = startIndex.y; iy <= endIndex.y; iy++) {
      IntPoint sourceToDestOffset(ix * mSourceRect.Width(),
                                  iy * mSourceRect.Height());
      IntRect destRect = aRect.Intersect(mSourceRect + sourceToDestOffset);
      IntRect srcRect = destRect - sourceToDestOffset;
      if (srcRect.IsEmpty()) {
        continue;
      }

      RefPtr<DataSourceSurface> input;
      InputMap::iterator it = inputs.find(srcRect);
      if (it == inputs.end()) {
        input = GetInputDataSourceSurface(IN_TILE_IN, srcRect);
        inputs[srcRect] = input;
      } else {
        input = it->second;
      }
      if (!input) {
        return nullptr;
      }
      if (!target) {
        // We delay creating the target until now because we want to use the
        // same format as our input filter, and we do not actually know the
        // input format before we call GetInputDataSourceSurface.
        target =
            Factory::CreateDataSourceSurface(aRect.Size(), input->GetFormat());
        if (MOZ2D_WARN_IF(!target)) {
          return nullptr;
        }
      }

      if (input->GetFormat() != target->GetFormat()) {
        // Different rectangles of the input can have different formats. If
        // that happens, just convert everything to B8G8R8A8.
        target = FilterProcessing::ConvertToB8G8R8A8(target);
        input = FilterProcessing::ConvertToB8G8R8A8(input);
        if (MOZ2D_WARN_IF(!target) || MOZ2D_WARN_IF(!input)) {
          return nullptr;
        }
      }

      CopyRect(input, target, srcRect - srcRect.TopLeft(),
               destRect.TopLeft() - aRect.TopLeft());
    }
  }

  return target.forget();
}

void FilterNodeTileSoftware::RequestFromInputsForRect(const IntRect& aRect) {
  // Do not request anything.
  // Source rects for the tile filter can be discontinuous with large gaps
  // between them. Requesting those from our input filter might cause it to
  // render the whole bounding box of all of them, which would be wasteful.
}

IntRect FilterNodeTileSoftware::GetOutputRectInRect(const IntRect& aRect) {
  return aRect;
}

FilterNodeComponentTransferSoftware::FilterNodeComponentTransferSoftware()
    : mDisableR(true), mDisableG(true), mDisableB(true), mDisableA(true) {}

void FilterNodeComponentTransferSoftware::SetAttribute(uint32_t aIndex,
                                                       bool aDisable) {
  switch (aIndex) {
    case ATT_TRANSFER_DISABLE_R:
      mDisableR = aDisable;
      break;
    case ATT_TRANSFER_DISABLE_G:
      mDisableG = aDisable;
      break;
    case ATT_TRANSFER_DISABLE_B:
      mDisableB = aDisable;
      break;
    case ATT_TRANSFER_DISABLE_A:
      mDisableA = aDisable;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeComponentTransferSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeComponentTransferSoftware::GenerateLookupTable(
    ptrdiff_t aComponent, uint8_t aTables[4][256], bool aDisabled) {
  if (aDisabled) {
    for (int32_t i = 0; i < 256; ++i) {
      aTables[aComponent][i] = i;
    }
  } else {
    FillLookupTable(aComponent, aTables[aComponent]);
  }
}

template <uint32_t BytesPerPixel>
static void TransferComponents(
    DataSourceSurface* aInput, DataSourceSurface* aTarget,
    const uint8_t aLookupTables[BytesPerPixel][256]) {
  MOZ_ASSERT(aInput->GetFormat() == aTarget->GetFormat(), "different formats");
  IntSize size = aInput->GetSize();

  DataSourceSurface::ScopedMap sourceMap(aInput, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(aTarget, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!sourceMap.IsMapped() || !targetMap.IsMapped())) {
    return;
  }

  uint8_t* sourceData = sourceMap.GetData();
  int32_t sourceStride = sourceMap.GetStride();
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  MOZ_ASSERT(sourceStride <= targetStride, "target smaller than source");

  for (int32_t y = 0; y < size.height; y++) {
    for (int32_t x = 0; x < size.width; x++) {
      uint32_t sourceIndex = y * sourceStride + x * BytesPerPixel;
      uint32_t targetIndex = y * targetStride + x * BytesPerPixel;
      for (uint32_t i = 0; i < BytesPerPixel; i++) {
        targetData[targetIndex + i] =
            aLookupTables[i][sourceData[sourceIndex + i]];
      }
    }

    // Zero padding to keep valgrind happy.
    PodZero(&targetData[y * targetStride + size.width * BytesPerPixel],
            targetStride - size.width * BytesPerPixel);
  }
}

static bool IsAllZero(const uint8_t aLookupTable[256]) {
  for (int32_t i = 0; i < 256; i++) {
    if (aLookupTable[i] != 0) {
      return false;
    }
  }
  return true;
}

already_AddRefed<DataSourceSurface> FilterNodeComponentTransferSoftware::Render(
    const IntRect& aRect) {
  if (mDisableR && mDisableG && mDisableB && mDisableA) {
    return GetInputDataSourceSurface(IN_TRANSFER_IN, aRect);
  }

  uint8_t lookupTables[4][256];
  GenerateLookupTable(B8G8R8A8_COMPONENT_BYTEOFFSET_R, lookupTables, mDisableR);
  GenerateLookupTable(B8G8R8A8_COMPONENT_BYTEOFFSET_G, lookupTables, mDisableG);
  GenerateLookupTable(B8G8R8A8_COMPONENT_BYTEOFFSET_B, lookupTables, mDisableB);
  GenerateLookupTable(B8G8R8A8_COMPONENT_BYTEOFFSET_A, lookupTables, mDisableA);

  bool needColorChannels =
      lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_R][0] != 0 ||
      lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_G][0] != 0 ||
      lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_B][0] != 0;

  FormatHint pref = needColorChannels ? NEED_COLOR_CHANNELS : CAN_HANDLE_A8;

  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_TRANSFER_IN, aRect, pref);
  if (!input) {
    return nullptr;
  }

  if (input->GetFormat() == SurfaceFormat::B8G8R8A8 && !needColorChannels) {
    bool colorChannelsBecomeBlack =
        IsAllZero(lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_R]) &&
        IsAllZero(lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_G]) &&
        IsAllZero(lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_B]);

    if (colorChannelsBecomeBlack) {
      input = FilterProcessing::ExtractAlpha(input);
    }
  }

  SurfaceFormat format = input->GetFormat();
  if (format == SurfaceFormat::A8 && mDisableA) {
    return input.forget();
  }

  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(aRect.Size(), format);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  if (format == SurfaceFormat::A8) {
    TransferComponents<1>(input, target,
                          &lookupTables[B8G8R8A8_COMPONENT_BYTEOFFSET_A]);
  } else {
    TransferComponents<4>(input, target, lookupTables);
  }

  return target.forget();
}

void FilterNodeComponentTransferSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_TRANSFER_IN, aRect);
}

IntRect FilterNodeComponentTransferSoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_TRANSFER_IN, aRect, aMax, aSourceNode);
}

IntRect FilterNodeComponentTransferSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  if (mDisableA) {
    return GetInputRectInRect(IN_TRANSFER_IN, aRect);
  }
  return aRect;
}

int32_t FilterNodeComponentTransferSoftware::InputIndex(
    uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_TRANSFER_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeTableTransferSoftware::SetAttribute(uint32_t aIndex,
                                                   const Float* aFloat,
                                                   uint32_t aSize) {
  std::vector<Float> table(aFloat, aFloat + aSize);
  switch (aIndex) {
    case ATT_TABLE_TRANSFER_TABLE_R:
      mTableR = table;
      break;
    case ATT_TABLE_TRANSFER_TABLE_G:
      mTableG = table;
      break;
    case ATT_TABLE_TRANSFER_TABLE_B:
      mTableB = table;
      break;
    case ATT_TABLE_TRANSFER_TABLE_A:
      mTableA = table;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeTableTransferSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeTableTransferSoftware::FillLookupTable(ptrdiff_t aComponent,
                                                      uint8_t aTable[256]) {
  switch (aComponent) {
    case B8G8R8A8_COMPONENT_BYTEOFFSET_R:
      FillLookupTableImpl(mTableR, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_G:
      FillLookupTableImpl(mTableG, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_B:
      FillLookupTableImpl(mTableB, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_A:
      FillLookupTableImpl(mTableA, aTable);
      break;
    default:
      MOZ_ASSERT(false, "unknown component");
      break;
  }
}

void FilterNodeTableTransferSoftware::FillLookupTableImpl(
    const std::vector<Float>& aTableValues, uint8_t aTable[256]) {
  uint32_t tvLength = aTableValues.size();
  if (tvLength < 2) {
    return;
  }

  for (size_t i = 0; i < 256; i++) {
    uint32_t k = (i * (tvLength - 1)) / 255;
    Float v1 = aTableValues[k];
    Float v2 = aTableValues[std::min(k + 1, tvLength - 1)];
    int32_t val = int32_t(255 * (v1 + (i / 255.0f - k / float(tvLength - 1)) *
                                          (tvLength - 1) * (v2 - v1)));
    aTable[i] = std::clamp(val, 0, 255);
  }
}

void FilterNodeDiscreteTransferSoftware::SetAttribute(uint32_t aIndex,
                                                      const Float* aFloat,
                                                      uint32_t aSize) {
  std::vector<Float> discrete(aFloat, aFloat + aSize);
  switch (aIndex) {
    case ATT_DISCRETE_TRANSFER_TABLE_R:
      mTableR = discrete;
      break;
    case ATT_DISCRETE_TRANSFER_TABLE_G:
      mTableG = discrete;
      break;
    case ATT_DISCRETE_TRANSFER_TABLE_B:
      mTableB = discrete;
      break;
    case ATT_DISCRETE_TRANSFER_TABLE_A:
      mTableA = discrete;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeDiscreteTransferSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeDiscreteTransferSoftware::FillLookupTable(ptrdiff_t aComponent,
                                                         uint8_t aTable[256]) {
  switch (aComponent) {
    case B8G8R8A8_COMPONENT_BYTEOFFSET_R:
      FillLookupTableImpl(mTableR, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_G:
      FillLookupTableImpl(mTableG, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_B:
      FillLookupTableImpl(mTableB, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_A:
      FillLookupTableImpl(mTableA, aTable);
      break;
    default:
      MOZ_ASSERT(false, "unknown component");
      break;
  }
}

void FilterNodeDiscreteTransferSoftware::FillLookupTableImpl(
    const std::vector<Float>& aTableValues, uint8_t aTable[256]) {
  uint32_t tvLength = aTableValues.size();
  if (tvLength < 1) {
    return;
  }

  for (size_t i = 0; i < 256; i++) {
    uint32_t k = (i * tvLength) / 255;
    k = std::min(k, tvLength - 1);
    Float v = aTableValues[k];
    int32_t val = NS_lround(255 * v);
    aTable[i] = std::clamp(val, 0, 255);
  }
}

FilterNodeLinearTransferSoftware::FilterNodeLinearTransferSoftware()
    : mSlopeR(0),
      mSlopeG(0),
      mSlopeB(0),
      mSlopeA(0),
      mInterceptR(0),
      mInterceptG(0),
      mInterceptB(0),
      mInterceptA(0) {}

void FilterNodeLinearTransferSoftware::SetAttribute(uint32_t aIndex,
                                                    Float aValue) {
  switch (aIndex) {
    case ATT_LINEAR_TRANSFER_SLOPE_R:
      mSlopeR = aValue;
      break;
    case ATT_LINEAR_TRANSFER_INTERCEPT_R:
      mInterceptR = aValue;
      break;
    case ATT_LINEAR_TRANSFER_SLOPE_G:
      mSlopeG = aValue;
      break;
    case ATT_LINEAR_TRANSFER_INTERCEPT_G:
      mInterceptG = aValue;
      break;
    case ATT_LINEAR_TRANSFER_SLOPE_B:
      mSlopeB = aValue;
      break;
    case ATT_LINEAR_TRANSFER_INTERCEPT_B:
      mInterceptB = aValue;
      break;
    case ATT_LINEAR_TRANSFER_SLOPE_A:
      mSlopeA = aValue;
      break;
    case ATT_LINEAR_TRANSFER_INTERCEPT_A:
      mInterceptA = aValue;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeLinearTransferSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeLinearTransferSoftware::FillLookupTable(ptrdiff_t aComponent,
                                                       uint8_t aTable[256]) {
  switch (aComponent) {
    case B8G8R8A8_COMPONENT_BYTEOFFSET_R:
      FillLookupTableImpl(mSlopeR, mInterceptR, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_G:
      FillLookupTableImpl(mSlopeG, mInterceptG, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_B:
      FillLookupTableImpl(mSlopeB, mInterceptB, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_A:
      FillLookupTableImpl(mSlopeA, mInterceptA, aTable);
      break;
    default:
      MOZ_ASSERT(false, "unknown component");
      break;
  }
}

void FilterNodeLinearTransferSoftware::FillLookupTableImpl(
    Float aSlope, Float aIntercept, uint8_t aTable[256]) {
  for (size_t i = 0; i < 256; i++) {
    int32_t val = NS_lround(aSlope * i + 255 * aIntercept);
    aTable[i] = std::clamp(val, 0, 255);
  }
}

FilterNodeGammaTransferSoftware::FilterNodeGammaTransferSoftware()
    : mAmplitudeR(0),
      mAmplitudeG(0),
      mAmplitudeB(0),
      mAmplitudeA(0),
      mExponentR(0),
      mExponentG(0),
      mExponentB(0),
      mExponentA(0),
      mOffsetR(0.0),
      mOffsetG(0.0),
      mOffsetB(0.0),
      mOffsetA(0.0) {}

void FilterNodeGammaTransferSoftware::SetAttribute(uint32_t aIndex,
                                                   Float aValue) {
  switch (aIndex) {
    case ATT_GAMMA_TRANSFER_AMPLITUDE_R:
      mAmplitudeR = aValue;
      break;
    case ATT_GAMMA_TRANSFER_EXPONENT_R:
      mExponentR = aValue;
      break;
    case ATT_GAMMA_TRANSFER_OFFSET_R:
      mOffsetR = aValue;
      break;
    case ATT_GAMMA_TRANSFER_AMPLITUDE_G:
      mAmplitudeG = aValue;
      break;
    case ATT_GAMMA_TRANSFER_EXPONENT_G:
      mExponentG = aValue;
      break;
    case ATT_GAMMA_TRANSFER_OFFSET_G:
      mOffsetG = aValue;
      break;
    case ATT_GAMMA_TRANSFER_AMPLITUDE_B:
      mAmplitudeB = aValue;
      break;
    case ATT_GAMMA_TRANSFER_EXPONENT_B:
      mExponentB = aValue;
      break;
    case ATT_GAMMA_TRANSFER_OFFSET_B:
      mOffsetB = aValue;
      break;
    case ATT_GAMMA_TRANSFER_AMPLITUDE_A:
      mAmplitudeA = aValue;
      break;
    case ATT_GAMMA_TRANSFER_EXPONENT_A:
      mExponentA = aValue;
      break;
    case ATT_GAMMA_TRANSFER_OFFSET_A:
      mOffsetA = aValue;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeGammaTransferSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeGammaTransferSoftware::FillLookupTable(ptrdiff_t aComponent,
                                                      uint8_t aTable[256]) {
  switch (aComponent) {
    case B8G8R8A8_COMPONENT_BYTEOFFSET_R:
      FillLookupTableImpl(mAmplitudeR, mExponentR, mOffsetR, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_G:
      FillLookupTableImpl(mAmplitudeG, mExponentG, mOffsetG, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_B:
      FillLookupTableImpl(mAmplitudeB, mExponentB, mOffsetB, aTable);
      break;
    case B8G8R8A8_COMPONENT_BYTEOFFSET_A:
      FillLookupTableImpl(mAmplitudeA, mExponentA, mOffsetA, aTable);
      break;
    default:
      MOZ_ASSERT(false, "unknown component");
      break;
  }
}

void FilterNodeGammaTransferSoftware::FillLookupTableImpl(Float aAmplitude,
                                                          Float aExponent,
                                                          Float aOffset,
                                                          uint8_t aTable[256]) {
  for (size_t i = 0; i < 256; i++) {
    int32_t val =
        NS_lround(255 * (aAmplitude * pow(i / 255.0f, aExponent) + aOffset));
    aTable[i] = std::clamp(val, 0, 255);
  }
}

FilterNodeConvolveMatrixSoftware::FilterNodeConvolveMatrixSoftware()
    : mDivisor(0),
      mBias(0),
      mEdgeMode(EDGE_MODE_DUPLICATE),
      mPreserveAlpha(false) {}

int32_t FilterNodeConvolveMatrixSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_CONVOLVE_MATRIX_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(
    uint32_t aIndex, const IntSize& aKernelSize) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_KERNEL_SIZE);
  mKernelSize = aKernelSize;
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                    const Float* aMatrix,
                                                    uint32_t aSize) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_KERNEL_MATRIX);
  mKernelMatrix = std::vector<Float>(aMatrix, aMatrix + aSize);
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                    Float aValue) {
  switch (aIndex) {
    case ATT_CONVOLVE_MATRIX_DIVISOR:
      mDivisor = aValue;
      break;
    case ATT_CONVOLVE_MATRIX_BIAS:
      mBias = aValue;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeConvolveMatrixSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(
    uint32_t aIndex, const Size& aKernelUnitLength) {
  switch (aIndex) {
    case ATT_CONVOLVE_MATRIX_KERNEL_UNIT_LENGTH:
      mKernelUnitLength = aKernelUnitLength;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeConvolveMatrixSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                    const IntPoint& aTarget) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_TARGET);
  mTarget = aTarget;
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(
    uint32_t aIndex, const IntRect& aRenderRect) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_RENDER_RECT);
  mRenderRect = aRenderRect;
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                    uint32_t aEdgeMode) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_EDGE_MODE);
  mEdgeMode = static_cast<ConvolveMatrixEdgeMode>(aEdgeMode);
  Invalidate();
}

void FilterNodeConvolveMatrixSoftware::SetAttribute(uint32_t aIndex,
                                                    bool aPreserveAlpha) {
  MOZ_ASSERT(aIndex == ATT_CONVOLVE_MATRIX_PRESERVE_ALPHA);
  mPreserveAlpha = aPreserveAlpha;
  Invalidate();
}

#ifdef DEBUG
static inline void DebugOnlyCheckColorSamplingAccess(
    const uint8_t* aSampleAddress, const uint8_t* aBoundsBegin,
    const uint8_t* aBoundsEnd) {
  MOZ_ASSERT(aSampleAddress >= aBoundsBegin, "accessing before start");
  MOZ_ASSERT(aSampleAddress < aBoundsEnd, "accessing after end");
}
#else
#  define DebugOnlyCheckColorSamplingAccess(address, boundsBegin, boundsEnd)
#endif

static inline uint8_t ColorComponentAtPoint(const uint8_t* aData,
                                            ptrdiff_t aStride,
                                            const uint8_t* aBoundsBegin,
                                            const uint8_t* aBoundsEnd,
                                            int32_t x, int32_t y, ptrdiff_t bpp,
                                            ptrdiff_t c) {
  DebugOnlyCheckColorSamplingAccess(&aData[y * aStride + bpp * x + c],
                                    aBoundsBegin, aBoundsEnd);
  return aData[y * aStride + bpp * x + c];
}

static inline int32_t ColorAtPoint(const uint8_t* aData, ptrdiff_t aStride,
                                   const uint8_t* aBoundsBegin,
                                   const uint8_t* aBoundsEnd, int32_t x,
                                   int32_t y) {
  DebugOnlyCheckColorSamplingAccess(aData + y * aStride + 4 * x, aBoundsBegin,
                                    aBoundsEnd);
  return *(uint32_t*)(aData + y * aStride + 4 * x);
}

// Accepts fractional x & y and does bilinear interpolation.
// Only call this if the pixel (floor(x)+1, floor(y)+1) is accessible.
static inline uint8_t ColorComponentAtPoint(
    const uint8_t* aData, ptrdiff_t aStride, const uint8_t* aBoundsBegin,
    const uint8_t* aBoundsEnd, Float x, Float y, ptrdiff_t bpp, ptrdiff_t c) {
  const uint32_t f = 256;
  const int32_t lx = floor(x);
  const int32_t ly = floor(y);
  const int32_t tux = uint32_t((x - lx) * f);
  const int32_t tlx = f - tux;
  const int32_t tuy = uint32_t((y - ly) * f);
  const int32_t tly = f - tuy;
  const uint8_t& cll = ColorComponentAtPoint(aData, aStride, aBoundsBegin,
                                             aBoundsEnd, lx, ly, bpp, c);
  const uint8_t& cul = ColorComponentAtPoint(aData, aStride, aBoundsBegin,
                                             aBoundsEnd, lx + 1, ly, bpp, c);
  const uint8_t& clu = ColorComponentAtPoint(aData, aStride, aBoundsBegin,
                                             aBoundsEnd, lx, ly + 1, bpp, c);
  const uint8_t& cuu = ColorComponentAtPoint(
      aData, aStride, aBoundsBegin, aBoundsEnd, lx + 1, ly + 1, bpp, c);
  return ((cll * tlx + cul * tux) * tly + (clu * tlx + cuu * tux) * tuy +
          f * f / 2) /
         (f * f);
}

static int32_t ClampToNonZero(int32_t a) { return a * (a >= 0); }

template <typename CoordType>
static void ConvolvePixel(const uint8_t* aSourceData, uint8_t* aTargetData,
                          int32_t aWidth, int32_t aHeight,
                          int32_t aSourceStride, int32_t aTargetStride,
                          const uint8_t* aSourceBegin,
                          const uint8_t* aSourceEnd, int32_t aX, int32_t aY,
                          const int32_t* aKernel, int32_t aBias, int32_t shiftL,
                          int32_t shiftR, bool aPreserveAlpha, int32_t aOrderX,
                          int32_t aOrderY, int32_t aTargetX, int32_t aTargetY,
                          CoordType aKernelUnitLengthX,
                          CoordType aKernelUnitLengthY) {
  int32_t sum[4] = {0, 0, 0, 0};
  int32_t offsets[4] = {
      B8G8R8A8_COMPONENT_BYTEOFFSET_R, B8G8R8A8_COMPONENT_BYTEOFFSET_G,
      B8G8R8A8_COMPONENT_BYTEOFFSET_B, B8G8R8A8_COMPONENT_BYTEOFFSET_A};
  int32_t channels = aPreserveAlpha ? 3 : 4;
  int32_t roundingAddition = shiftL == 0 ? 0 : 1 << (shiftL - 1);

  for (int32_t y = 0; y < aOrderY; y++) {
    CoordType sampleY = aY + (y - aTargetY) * aKernelUnitLengthY;
    for (int32_t x = 0; x < aOrderX; x++) {
      CoordType sampleX = aX + (x - aTargetX) * aKernelUnitLengthX;
      for (int32_t i = 0; i < channels; i++) {
        sum[i] +=
            aKernel[aOrderX * y + x] *
            ColorComponentAtPoint(aSourceData, aSourceStride, aSourceBegin,
                                  aSourceEnd, sampleX, sampleY, 4, offsets[i]);
      }
    }
  }
  for (int32_t i = 0; i < channels; i++) {
    int32_t clamped =
        umin(ClampToNonZero(sum[i] + aBias), 255 << shiftL >> shiftR);
    aTargetData[aY * aTargetStride + 4 * aX + offsets[i]] =
        (clamped + roundingAddition) << shiftR >> shiftL;
  }
  if (aPreserveAlpha) {
    aTargetData[aY * aTargetStride + 4 * aX + B8G8R8A8_COMPONENT_BYTEOFFSET_A] =
        aSourceData[aY * aSourceStride + 4 * aX +
                    B8G8R8A8_COMPONENT_BYTEOFFSET_A];
  }
}

already_AddRefed<DataSourceSurface> FilterNodeConvolveMatrixSoftware::Render(
    const IntRect& aRect) {
  if (mKernelUnitLength.width == floor(mKernelUnitLength.width) &&
      mKernelUnitLength.height == floor(mKernelUnitLength.height)) {
    return DoRender(aRect, (int32_t)mKernelUnitLength.width,
                    (int32_t)mKernelUnitLength.height);
  }
  return DoRender(aRect, mKernelUnitLength.width, mKernelUnitLength.height);
}

static std::vector<Float> ReversedVector(const std::vector<Float>& aVector) {
  size_t length = aVector.size();
  std::vector<Float> result(length, 0);
  for (size_t i = 0; i < length; i++) {
    result[length - 1 - i] = aVector[i];
  }
  return result;
}

static std::vector<Float> ScaledVector(const std::vector<Float>& aVector,
                                       Float aDivisor) {
  size_t length = aVector.size();
  std::vector<Float> result(length, 0);
  for (size_t i = 0; i < length; i++) {
    result[i] = aVector[i] / aDivisor;
  }
  return result;
}

static Float MaxVectorSum(const std::vector<Float>& aVector) {
  Float sum = 0;
  size_t length = aVector.size();
  for (size_t i = 0; i < length; i++) {
    if (aVector[i] > 0) {
      sum += aVector[i];
    }
  }
  return sum;
}

// Returns shiftL and shiftR in such a way that
// a << shiftL >> shiftR is roughly a * aFloat.
static void TranslateDoubleToShifts(double aDouble, int32_t& aShiftL,
                                    int32_t& aShiftR) {
  aShiftL = 0;
  aShiftR = 0;
  if (aDouble <= 0) {
    MOZ_CRASH("GFX: TranslateDoubleToShifts");
  }
  if (aDouble < 1) {
    while (1 << (aShiftR + 1) < 1 / aDouble) {
      aShiftR++;
    }
  } else {
    while (1 << (aShiftL + 1) < aDouble) {
      aShiftL++;
    }
  }
}

template <typename CoordType>
already_AddRefed<DataSourceSurface> FilterNodeConvolveMatrixSoftware::DoRender(
    const IntRect& aRect, CoordType aKernelUnitLengthX,
    CoordType aKernelUnitLengthY) {
  if (mKernelSize.width <= 0 || mKernelSize.height <= 0 ||
      mKernelMatrix.size() !=
          uint32_t(mKernelSize.width * mKernelSize.height) ||
      !IntRect(IntPoint(0, 0), mKernelSize).Contains(mTarget) ||
      mDivisor == 0) {
    return Factory::CreateDataSourceSurface(aRect.Size(),
                                            SurfaceFormat::B8G8R8A8, true);
  }

  IntRect srcRect = InflatedSourceRect(aRect);

  // Inflate the source rect by another pixel because the bilinear filtering in
  // ColorComponentAtPoint may want to access the margins.
  srcRect.Inflate(1);

  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_CONVOLVE_MATRIX_IN, srcRect,
                                NEED_COLOR_CHANNELS, mEdgeMode, &mRenderRect);

  if (!input) {
    return nullptr;
  }

  RefPtr<DataSourceSurface> target = Factory::CreateDataSourceSurface(
      aRect.Size(), SurfaceFormat::B8G8R8A8, true);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  IntPoint offset = aRect.TopLeft() - srcRect.TopLeft();

  DataSourceSurface::ScopedMap sourceMap(input, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!sourceMap.IsMapped() || !targetMap.IsMapped())) {
    return nullptr;
  }

  uint8_t* sourceData =
      DataAtOffset(input, sourceMap.GetMappedSurface(), offset);
  int32_t sourceStride = sourceMap.GetStride();
  uint8_t* sourceBegin = sourceMap.GetData();
  uint8_t* sourceEnd = sourceBegin + sourceStride * input->GetSize().height;
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  // Why exactly are we reversing the kernel?
  std::vector<Float> kernel = ReversedVector(mKernelMatrix);
  kernel = ScaledVector(kernel, mDivisor);
  Float maxResultAbs = std::max(MaxVectorSum(kernel) + mBias,
                                MaxVectorSum(ScaledVector(kernel, -1)) - mBias);
  maxResultAbs = std::max(maxResultAbs, 1.0f);

  double idealFactor = INT32_MAX / 2.0 / maxResultAbs / 255.0 * 0.999;
  MOZ_ASSERT(255.0 * maxResultAbs * idealFactor <= INT32_MAX / 2.0,
             "badly chosen float-to-int scale");
  int32_t shiftL, shiftR;
  TranslateDoubleToShifts(idealFactor, shiftL, shiftR);
  double factorFromShifts = Float(1 << shiftL) / Float(1 << shiftR);
  MOZ_ASSERT(255.0 * maxResultAbs * factorFromShifts <= INT32_MAX / 2.0,
             "badly chosen float-to-int scale");

  int32_t* intKernel = new int32_t[kernel.size()];
  for (size_t i = 0; i < kernel.size(); i++) {
    intKernel[i] = NS_lround(kernel[i] * factorFromShifts);
  }
  int32_t bias = NS_lround(mBias * 255 * factorFromShifts);

  for (int32_t y = 0; y < aRect.Height(); y++) {
    for (int32_t x = 0; x < aRect.Width(); x++) {
      ConvolvePixel(sourceData, targetData, aRect.Width(), aRect.Height(),
                    sourceStride, targetStride, sourceBegin, sourceEnd, x, y,
                    intKernel, bias, shiftL, shiftR, mPreserveAlpha,
                    mKernelSize.width, mKernelSize.height, mTarget.x, mTarget.y,
                    aKernelUnitLengthX, aKernelUnitLengthY);
    }
  }
  delete[] intKernel;

  return target.forget();
}

void FilterNodeConvolveMatrixSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_CONVOLVE_MATRIX_IN, InflatedSourceRect(aRect));
}

IntRect FilterNodeConvolveMatrixSoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_CONVOLVE_MATRIX_IN, InflatedSourceRect(aRect),
                              aMax, aSourceNode);
}

IntRect FilterNodeConvolveMatrixSoftware::InflatedSourceRect(
    const IntRect& aDestRect) {
  if (aDestRect.IsEmpty()) {
    return IntRect();
  }

  IntMargin margin;
  margin.left = static_cast<int32_t>(ceil(mTarget.x * mKernelUnitLength.width));
  margin.top = static_cast<int32_t>(ceil(mTarget.y * mKernelUnitLength.height));
  margin.right = static_cast<int32_t>(
      ceil((mKernelSize.width - mTarget.x - 1) * mKernelUnitLength.width));
  margin.bottom = static_cast<int32_t>(
      ceil((mKernelSize.height - mTarget.y - 1) * mKernelUnitLength.height));

  IntRect srcRect = aDestRect;
  srcRect.Inflate(margin);
  return srcRect;
}

IntRect FilterNodeConvolveMatrixSoftware::InflatedDestRect(
    const IntRect& aSourceRect) {
  if (aSourceRect.IsEmpty()) {
    return IntRect();
  }

  IntMargin margin;
  margin.left = static_cast<int32_t>(
      ceil((mKernelSize.width - mTarget.x - 1) * mKernelUnitLength.width));
  margin.top = static_cast<int32_t>(
      ceil((mKernelSize.height - mTarget.y - 1) * mKernelUnitLength.height));
  margin.right =
      static_cast<int32_t>(ceil(mTarget.x * mKernelUnitLength.width));
  margin.bottom =
      static_cast<int32_t>(ceil(mTarget.y * mKernelUnitLength.height));

  IntRect destRect = aSourceRect;
  destRect.Inflate(margin);
  return destRect;
}

IntRect FilterNodeConvolveMatrixSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  if (!mPreserveAlpha && mBias > 0) {
    // we transform transparent colors into non-transparent colors in this case
    return aRect;
  }
  IntRect srcRequest = InflatedSourceRect(aRect);
  IntRect srcOutput = GetInputRectInRect(IN_CONVOLVE_MATRIX_IN, srcRequest);
  return InflatedDestRect(srcOutput).Intersect(aRect);
}

FilterNodeDisplacementMapSoftware::FilterNodeDisplacementMapSoftware()
    : mScale(0.0f), mChannelX(COLOR_CHANNEL_R), mChannelY(COLOR_CHANNEL_G) {}

int32_t FilterNodeDisplacementMapSoftware::InputIndex(
    uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_DISPLACEMENT_MAP_IN:
      return 0;
    case IN_DISPLACEMENT_MAP_IN2:
      return 1;
    default:
      return -1;
  }
}

void FilterNodeDisplacementMapSoftware::SetAttribute(uint32_t aIndex,
                                                     Float aScale) {
  MOZ_ASSERT(aIndex == ATT_DISPLACEMENT_MAP_SCALE);
  mScale = aScale;
  Invalidate();
}

void FilterNodeDisplacementMapSoftware::SetAttribute(uint32_t aIndex,
                                                     uint32_t aValue) {
  switch (aIndex) {
    case ATT_DISPLACEMENT_MAP_X_CHANNEL:
      mChannelX = static_cast<ColorChannel>(aValue);
      break;
    case ATT_DISPLACEMENT_MAP_Y_CHANNEL:
      mChannelY = static_cast<ColorChannel>(aValue);
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeDisplacementMapSoftware::SetAttribute");
  }
  Invalidate();
}

already_AddRefed<DataSourceSurface> FilterNodeDisplacementMapSoftware::Render(
    const IntRect& aRect) {
  IntRect srcRect = InflatedSourceOrDestRect(aRect);
  RefPtr<DataSourceSurface> input = GetInputDataSourceSurface(
      IN_DISPLACEMENT_MAP_IN, srcRect, NEED_COLOR_CHANNELS);
  RefPtr<DataSourceSurface> map = GetInputDataSourceSurface(
      IN_DISPLACEMENT_MAP_IN2, aRect, NEED_COLOR_CHANNELS);
  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(aRect.Size(), SurfaceFormat::B8G8R8A8);
  if (MOZ2D_WARN_IF(!(input && map && target))) {
    return nullptr;
  }

  IntPoint offset = aRect.TopLeft() - srcRect.TopLeft();

  DataSourceSurface::ScopedMap inputMap(input, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap mapMap(map, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!(inputMap.IsMapped() && mapMap.IsMapped() &&
                      targetMap.IsMapped()))) {
    return nullptr;
  }

  uint8_t* sourceData =
      DataAtOffset(input, inputMap.GetMappedSurface(), offset);
  int32_t sourceStride = inputMap.GetStride();
  uint8_t* sourceBegin = inputMap.GetData();
  uint8_t* sourceEnd = sourceBegin + sourceStride * input->GetSize().height;
  uint8_t* mapData = mapMap.GetData();
  int32_t mapStride = mapMap.GetStride();
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  static const ptrdiff_t channelMap[4] = {
      B8G8R8A8_COMPONENT_BYTEOFFSET_R, B8G8R8A8_COMPONENT_BYTEOFFSET_G,
      B8G8R8A8_COMPONENT_BYTEOFFSET_B, B8G8R8A8_COMPONENT_BYTEOFFSET_A};
  uint16_t xChannel = channelMap[mChannelX];
  uint16_t yChannel = channelMap[mChannelY];

  float scaleOver255 = mScale / 255.0f;
  float scaleAdjustment = -0.5f * mScale;

  for (int32_t y = 0; y < aRect.Height(); y++) {
    for (int32_t x = 0; x < aRect.Width(); x++) {
      uint32_t mapIndex = y * mapStride + 4 * x;
      uint32_t targIndex = y * targetStride + 4 * x;
      int32_t sourceX =
          x + scaleOver255 * mapData[mapIndex + xChannel] + scaleAdjustment;
      int32_t sourceY =
          y + scaleOver255 * mapData[mapIndex + yChannel] + scaleAdjustment;
      *(uint32_t*)(targetData + targIndex) = ColorAtPoint(
          sourceData, sourceStride, sourceBegin, sourceEnd, sourceX, sourceY);
    }

    // Keep valgrind happy.
    PodZero(&targetData[y * targetStride + 4 * aRect.Width()],
            targetStride - 4 * aRect.Width());
  }

  return target.forget();
}

void FilterNodeDisplacementMapSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_DISPLACEMENT_MAP_IN, InflatedSourceOrDestRect(aRect));
  RequestInputRect(IN_DISPLACEMENT_MAP_IN2, aRect);
}

IntRect FilterNodeDisplacementMapSoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  IntRect result =
      MapInputRectToSource(IN_DISPLACEMENT_MAP_IN,
                           InflatedSourceOrDestRect(aRect), aMax, aSourceNode);
  result.OrWith(
      MapInputRectToSource(IN_DISPLACEMENT_MAP_IN2, aRect, aMax, aSourceNode));
  return result;
}

IntRect FilterNodeDisplacementMapSoftware::InflatedSourceOrDestRect(
    const IntRect& aDestOrSourceRect) {
  IntRect sourceOrDestRect = aDestOrSourceRect;
  sourceOrDestRect.Inflate(ceil(fabs(mScale) / 2));
  return sourceOrDestRect;
}

IntRect FilterNodeDisplacementMapSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  IntRect srcRequest = InflatedSourceOrDestRect(aRect);
  IntRect srcOutput = GetInputRectInRect(IN_DISPLACEMENT_MAP_IN, srcRequest);
  return InflatedSourceOrDestRect(srcOutput).Intersect(aRect);
}

FilterNodeTurbulenceSoftware::FilterNodeTurbulenceSoftware()
    : mNumOctaves(0),
      mSeed(0),
      mStitchable(false),
      mType(TURBULENCE_TYPE_TURBULENCE) {}

int32_t FilterNodeTurbulenceSoftware::InputIndex(uint32_t aInputEnumIndex) {
  return -1;
}

void FilterNodeTurbulenceSoftware::SetAttribute(uint32_t aIndex,
                                                const Size& aBaseFrequency) {
  switch (aIndex) {
    case ATT_TURBULENCE_BASE_FREQUENCY:
      mBaseFrequency = aBaseFrequency;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeTurbulenceSoftware::SetAttribute");
      break;
  }
  Invalidate();
}

void FilterNodeTurbulenceSoftware::SetAttribute(uint32_t aIndex,
                                                const IntRect& aRect) {
  switch (aIndex) {
    case ATT_TURBULENCE_RECT:
      mRenderRect = aRect;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeTurbulenceSoftware::SetAttribute");
      break;
  }
  Invalidate();
}

void FilterNodeTurbulenceSoftware::SetAttribute(uint32_t aIndex,
                                                bool aStitchable) {
  MOZ_ASSERT(aIndex == ATT_TURBULENCE_STITCHABLE);
  mStitchable = aStitchable;
  Invalidate();
}

void FilterNodeTurbulenceSoftware::SetAttribute(uint32_t aIndex,
                                                uint32_t aValue) {
  switch (aIndex) {
    case ATT_TURBULENCE_NUM_OCTAVES:
      mNumOctaves = aValue;
      break;
    case ATT_TURBULENCE_SEED:
      mSeed = aValue;
      break;
    case ATT_TURBULENCE_TYPE:
      mType = static_cast<TurbulenceType>(aValue);
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeTurbulenceSoftware::SetAttribute");
      break;
  }
  Invalidate();
}

already_AddRefed<DataSourceSurface> FilterNodeTurbulenceSoftware::Render(
    const IntRect& aRect) {
  return FilterProcessing::RenderTurbulence(
      aRect.Size(), aRect.TopLeft(), mBaseFrequency, mSeed, mNumOctaves, mType,
      mStitchable, Rect(mRenderRect));
}

IntRect FilterNodeTurbulenceSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  return aRect.Intersect(mRenderRect);
}

IntRect FilterNodeTurbulenceSoftware::MapRectToSource(const IntRect& aRect,
                                                      const IntRect& aMax,
                                                      FilterNode* aSourceNode) {
  return IntRect();
}

FilterNodeArithmeticCombineSoftware::FilterNodeArithmeticCombineSoftware()
    : mK1(0), mK2(0), mK3(0), mK4(0) {}

int32_t FilterNodeArithmeticCombineSoftware::InputIndex(
    uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_ARITHMETIC_COMBINE_IN:
      return 0;
    case IN_ARITHMETIC_COMBINE_IN2:
      return 1;
    default:
      return -1;
  }
}

void FilterNodeArithmeticCombineSoftware::SetAttribute(uint32_t aIndex,
                                                       const Float* aFloat,
                                                       uint32_t aSize) {
  MOZ_ASSERT(aIndex == ATT_ARITHMETIC_COMBINE_COEFFICIENTS);
  MOZ_RELEASE_ASSERT(aSize == 4);

  mK1 = aFloat[0];
  mK2 = aFloat[1];
  mK3 = aFloat[2];
  mK4 = aFloat[3];

  Invalidate();
}

already_AddRefed<DataSourceSurface> FilterNodeArithmeticCombineSoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input1 = GetInputDataSourceSurface(
      IN_ARITHMETIC_COMBINE_IN, aRect, NEED_COLOR_CHANNELS);
  RefPtr<DataSourceSurface> input2 = GetInputDataSourceSurface(
      IN_ARITHMETIC_COMBINE_IN2, aRect, NEED_COLOR_CHANNELS);
  if (!input1 && !input2) {
    return nullptr;
  }

  // If one input is null, treat it as transparent by adjusting the factors.
  Float k1 = mK1, k2 = mK2, k3 = mK3, k4 = mK4;
  if (!input1) {
    k1 = 0.0f;
    k2 = 0.0f;
    input1 = input2;
  }

  if (!input2) {
    k1 = 0.0f;
    k3 = 0.0f;
    input2 = input1;
  }

  return FilterProcessing::ApplyArithmeticCombine(input1, input2, k1, k2, k3,
                                                  k4);
}

void FilterNodeArithmeticCombineSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_ARITHMETIC_COMBINE_IN, aRect);
  RequestInputRect(IN_ARITHMETIC_COMBINE_IN2, aRect);
}

IntRect FilterNodeArithmeticCombineSoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  IntRect result =
      MapInputRectToSource(IN_ARITHMETIC_COMBINE_IN, aRect, aMax, aSourceNode);
  result.OrWith(MapInputRectToSource(IN_ARITHMETIC_COMBINE_IN2, aRect, aMax,
                                     aSourceNode));
  return result;
}

IntRect FilterNodeArithmeticCombineSoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  if (mK4 > 0.0f) {
    return aRect;
  }
  IntRect rectFrom1 =
      GetInputRectInRect(IN_ARITHMETIC_COMBINE_IN, aRect).Intersect(aRect);
  IntRect rectFrom2 =
      GetInputRectInRect(IN_ARITHMETIC_COMBINE_IN2, aRect).Intersect(aRect);
  IntRect result;
  if (mK1 > 0.0f) {
    result = rectFrom1.Intersect(rectFrom2);
  }
  if (mK2 > 0.0f) {
    result = result.Union(rectFrom1);
  }
  if (mK3 > 0.0f) {
    result = result.Union(rectFrom2);
  }
  return result;
}

FilterNodeCompositeSoftware::FilterNodeCompositeSoftware()
    : mOperator(COMPOSITE_OPERATOR_OVER) {}

int32_t FilterNodeCompositeSoftware::InputIndex(uint32_t aInputEnumIndex) {
  return aInputEnumIndex - IN_COMPOSITE_IN_START;
}

void FilterNodeCompositeSoftware::SetAttribute(uint32_t aIndex,
                                               uint32_t aCompositeOperator) {
  MOZ_ASSERT(aIndex == ATT_COMPOSITE_OPERATOR);
  mOperator = static_cast<CompositeOperator>(aCompositeOperator);
  Invalidate();
}

already_AddRefed<DataSourceSurface> FilterNodeCompositeSoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> start = GetInputDataSourceSurface(
      IN_COMPOSITE_IN_START, aRect, NEED_COLOR_CHANNELS);
  RefPtr<DataSourceSurface> dest = Factory::CreateDataSourceSurface(
      aRect.Size(), SurfaceFormat::B8G8R8A8, true);
  if (MOZ2D_WARN_IF(!dest)) {
    return nullptr;
  }

  if (start) {
    CopyRect(start, dest, aRect - aRect.TopLeft(), IntPoint());
  }

  for (size_t inputIndex = 1; inputIndex < NumberOfSetInputs(); inputIndex++) {
    RefPtr<DataSourceSurface> input = GetInputDataSourceSurface(
        IN_COMPOSITE_IN_START + inputIndex, aRect, NEED_COLOR_CHANNELS);
    if (input) {
      FilterProcessing::ApplyComposition(input, dest, mOperator);
    } else {
      // We need to treat input as transparent. Depending on the composite
      // operator, different things happen to dest.
      switch (mOperator) {
        case COMPOSITE_OPERATOR_OVER:
        case COMPOSITE_OPERATOR_ATOP:
        case COMPOSITE_OPERATOR_XOR:
        case COMPOSITE_OPERATOR_LIGHTER:
          // dest is unchanged.
          break;
        case COMPOSITE_OPERATOR_OUT:
          // dest is now transparent, but it can become non-transparent again
          // when compositing additional inputs.
          ClearDataSourceSurface(dest);
          break;
        case COMPOSITE_OPERATOR_IN:
          // Transparency always wins. We're completely transparent now and
          // no additional input can get rid of that transparency.
          return nullptr;
      }
    }
  }
  return dest.forget();
}

void FilterNodeCompositeSoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  for (size_t inputIndex = 0; inputIndex < NumberOfSetInputs(); inputIndex++) {
    RequestInputRect(IN_COMPOSITE_IN_START + inputIndex, aRect);
  }
}

IntRect FilterNodeCompositeSoftware::MapRectToSource(const IntRect& aRect,
                                                     const IntRect& aMax,
                                                     FilterNode* aSourceNode) {
  IntRect result;
  for (size_t inputIndex = 0; inputIndex < NumberOfSetInputs(); inputIndex++) {
    result.OrWith(MapInputRectToSource(IN_COMPOSITE_IN_START + inputIndex,
                                       aRect, aMax, aSourceNode));
  }
  return result;
}

IntRect FilterNodeCompositeSoftware::GetOutputRectInRect(const IntRect& aRect) {
  IntRect rect;
  for (size_t inputIndex = 0; inputIndex < NumberOfSetInputs(); inputIndex++) {
    IntRect inputRect =
        GetInputRectInRect(IN_COMPOSITE_IN_START + inputIndex, aRect);
    if (mOperator == COMPOSITE_OPERATOR_IN && inputIndex > 0) {
      rect = rect.Intersect(inputRect);
    } else {
      rect = rect.Union(inputRect);
    }
  }
  return rect;
}

int32_t FilterNodeBlurXYSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_GAUSSIAN_BLUR_IN:
      return 0;
    default:
      return -1;
  }
}

already_AddRefed<DataSourceSurface> FilterNodeBlurXYSoftware::Render(
    const IntRect& aRect) {
  Size sigmaXY = StdDeviationXY();
  IntSize d =
      GaussianBlur::CalculateBlurRadius(Point(sigmaXY.width, sigmaXY.height));

  if (d.width == 0 && d.height == 0) {
    return GetInputDataSourceSurface(IN_GAUSSIAN_BLUR_IN, aRect);
  }

  IntRect srcRect = InflatedSourceOrDestRect(aRect);
  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_GAUSSIAN_BLUR_IN, srcRect);
  if (!input) {
    return nullptr;
  }

  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(srcRect.Size(), input->GetFormat());
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }
  CopyRect(input, target, IntRect(IntPoint(), input->GetSize()), IntPoint());

  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::READ_WRITE);
  if (MOZ2D_WARN_IF(!targetMap.IsMapped())) {
    return nullptr;
  }
  GaussianBlur blur(Point(sigmaXY.width, sigmaXY.height));
  blur.Blur(targetMap.GetData(), targetMap.GetStride(), target->GetSize(),
            target->GetFormat());

  return GetDataSurfaceInRect(target, srcRect, aRect, EDGE_MODE_NONE);
}

void FilterNodeBlurXYSoftware::RequestFromInputsForRect(const IntRect& aRect) {
  RequestInputRect(IN_GAUSSIAN_BLUR_IN, InflatedSourceOrDestRect(aRect));
}

IntRect FilterNodeBlurXYSoftware::MapRectToSource(const IntRect& aRect,
                                                  const IntRect& aMax,
                                                  FilterNode* aSourceNode) {
  return MapInputRectToSource(
      IN_GAUSSIAN_BLUR_IN, InflatedSourceOrDestRect(aRect), aMax, aSourceNode);
}

IntRect FilterNodeBlurXYSoftware::InflatedSourceOrDestRect(
    const IntRect& aDestRect) {
  Size sigmaXY = StdDeviationXY();
  IntSize d =
      GaussianBlur::CalculateBlurRadius(Point(sigmaXY.width, sigmaXY.height));
  IntRect srcRect = aDestRect;
  srcRect.Inflate(d);
  return srcRect;
}

IntRect FilterNodeBlurXYSoftware::GetOutputRectInRect(const IntRect& aRect) {
  IntRect srcRequest = InflatedSourceOrDestRect(aRect);
  IntRect srcOutput = GetInputRectInRect(IN_GAUSSIAN_BLUR_IN, srcRequest);
  return InflatedSourceOrDestRect(srcOutput).Intersect(aRect);
}

FilterNodeGaussianBlurSoftware::FilterNodeGaussianBlurSoftware()
    : mStdDeviation(0) {}

static float ClampStdDeviation(float aStdDeviation) {
  // Cap software blur radius for performance reasons.
  return std::clamp(aStdDeviation, 0.f, 100.f);
}

void FilterNodeGaussianBlurSoftware::SetAttribute(uint32_t aIndex,
                                                  float aStdDeviation) {
  switch (aIndex) {
    case ATT_GAUSSIAN_BLUR_STD_DEVIATION:
      mStdDeviation = ClampStdDeviation(aStdDeviation);
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeGaussianBlurSoftware::SetAttribute");
  }
  Invalidate();
}

Size FilterNodeGaussianBlurSoftware::StdDeviationXY() {
  return Size(mStdDeviation, mStdDeviation);
}

FilterNodeDirectionalBlurSoftware::FilterNodeDirectionalBlurSoftware()
    : mStdDeviation(0.0), mBlurDirection(BLUR_DIRECTION_X) {}

void FilterNodeDirectionalBlurSoftware::SetAttribute(uint32_t aIndex,
                                                     Float aStdDeviation) {
  switch (aIndex) {
    case ATT_DIRECTIONAL_BLUR_STD_DEVIATION:
      mStdDeviation = ClampStdDeviation(aStdDeviation);
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeDirectionalBlurSoftware::SetAttribute");
  }
  Invalidate();
}

void FilterNodeDirectionalBlurSoftware::SetAttribute(uint32_t aIndex,
                                                     uint32_t aBlurDirection) {
  switch (aIndex) {
    case ATT_DIRECTIONAL_BLUR_DIRECTION:
      mBlurDirection = (BlurDirection)aBlurDirection;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeDirectionalBlurSoftware::SetAttribute");
  }
  Invalidate();
}

Size FilterNodeDirectionalBlurSoftware::StdDeviationXY() {
  float sigmaX = mBlurDirection == BLUR_DIRECTION_X ? mStdDeviation : 0;
  float sigmaY = mBlurDirection == BLUR_DIRECTION_Y ? mStdDeviation : 0;
  return Size(sigmaX, sigmaY);
}

int32_t FilterNodeCropSoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_CROP_IN:
      return 0;
    default:
      return -1;
  }
}

void FilterNodeCropSoftware::SetAttribute(uint32_t aIndex,
                                          const Rect& aSourceRect) {
  MOZ_ASSERT(aIndex == ATT_CROP_RECT);
  Rect srcRect = aSourceRect;
  srcRect.Round();
  if (!srcRect.ToIntRect(&mCropRect)) {
    mCropRect = IntRect();
  }
  Invalidate();
}

already_AddRefed<DataSourceSurface> FilterNodeCropSoftware::Render(
    const IntRect& aRect) {
  return GetInputDataSourceSurface(IN_CROP_IN, aRect.Intersect(mCropRect));
}

void FilterNodeCropSoftware::RequestFromInputsForRect(const IntRect& aRect) {
  RequestInputRect(IN_CROP_IN, aRect.Intersect(mCropRect));
}

IntRect FilterNodeCropSoftware::MapRectToSource(const IntRect& aRect,
                                                const IntRect& aMax,
                                                FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_CROP_IN, aRect.Intersect(mCropRect), aMax,
                              aSourceNode);
}

IntRect FilterNodeCropSoftware::GetOutputRectInRect(const IntRect& aRect) {
  return GetInputRectInRect(IN_CROP_IN, aRect).Intersect(mCropRect);
}

int32_t FilterNodePremultiplySoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_PREMULTIPLY_IN:
      return 0;
    default:
      return -1;
  }
}

already_AddRefed<DataSourceSurface> FilterNodePremultiplySoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_PREMULTIPLY_IN, aRect);
  return input ? Premultiply(input) : nullptr;
}

void FilterNodePremultiplySoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_PREMULTIPLY_IN, aRect);
}

IntRect FilterNodePremultiplySoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_PREMULTIPLY_IN, aRect, aMax, aSourceNode);
}

IntRect FilterNodePremultiplySoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  return GetInputRectInRect(IN_PREMULTIPLY_IN, aRect);
}

int32_t FilterNodeUnpremultiplySoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_UNPREMULTIPLY_IN:
      return 0;
    default:
      return -1;
  }
}

already_AddRefed<DataSourceSurface> FilterNodeUnpremultiplySoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_UNPREMULTIPLY_IN, aRect);
  return input ? Unpremultiply(input) : nullptr;
}

void FilterNodeUnpremultiplySoftware::RequestFromInputsForRect(
    const IntRect& aRect) {
  RequestInputRect(IN_UNPREMULTIPLY_IN, aRect);
}

IntRect FilterNodeUnpremultiplySoftware::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_UNPREMULTIPLY_IN, aRect, aMax, aSourceNode);
}

IntRect FilterNodeUnpremultiplySoftware::GetOutputRectInRect(
    const IntRect& aRect) {
  return GetInputRectInRect(IN_UNPREMULTIPLY_IN, aRect);
}

void FilterNodeOpacitySoftware::SetAttribute(uint32_t aIndex, Float aValue) {
  MOZ_ASSERT(aIndex == ATT_OPACITY_VALUE);
  mValue = aValue;
  Invalidate();
}

int32_t FilterNodeOpacitySoftware::InputIndex(uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_OPACITY_IN:
      return 0;
    default:
      return -1;
  }
}

already_AddRefed<DataSourceSurface> FilterNodeOpacitySoftware::Render(
    const IntRect& aRect) {
  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_OPACITY_IN, aRect);
  return input ? Opacity(input, mValue) : nullptr;
}

void FilterNodeOpacitySoftware::RequestFromInputsForRect(const IntRect& aRect) {
  RequestInputRect(IN_OPACITY_IN, aRect);
}

IntRect FilterNodeOpacitySoftware::MapRectToSource(const IntRect& aRect,
                                                   const IntRect& aMax,
                                                   FilterNode* aSourceNode) {
  return MapInputRectToSource(IN_OPACITY_IN, aRect, aMax, aSourceNode);
}

IntRect FilterNodeOpacitySoftware::GetOutputRectInRect(const IntRect& aRect) {
  return GetInputRectInRect(IN_OPACITY_IN, aRect);
}

bool PointLightSoftware::SetAttribute(uint32_t aIndex, const Point3D& aPoint) {
  switch (aIndex) {
    case ATT_POINT_LIGHT_POSITION:
      mPosition = aPoint;
      break;
    default:
      return false;
  }
  return true;
}

SpotLightSoftware::SpotLightSoftware()
    : mSpecularFocus(0), mLimitingConeAngle(0), mLimitingConeCos(1) {}

bool SpotLightSoftware::SetAttribute(uint32_t aIndex, const Point3D& aPoint) {
  switch (aIndex) {
    case ATT_SPOT_LIGHT_POSITION:
      mPosition = aPoint;
      break;
    case ATT_SPOT_LIGHT_POINTS_AT:
      mPointsAt = aPoint;
      break;
    default:
      return false;
  }
  return true;
}

bool SpotLightSoftware::SetAttribute(uint32_t aIndex, Float aValue) {
  switch (aIndex) {
    case ATT_SPOT_LIGHT_LIMITING_CONE_ANGLE:
      mLimitingConeAngle = aValue;
      break;
    case ATT_SPOT_LIGHT_FOCUS:
      mSpecularFocus = aValue;
      break;
    default:
      return false;
  }
  return true;
}

DistantLightSoftware::DistantLightSoftware() : mAzimuth(0), mElevation(0) {}

bool DistantLightSoftware::SetAttribute(uint32_t aIndex, Float aValue) {
  switch (aIndex) {
    case ATT_DISTANT_LIGHT_AZIMUTH:
      mAzimuth = aValue;
      break;
    case ATT_DISTANT_LIGHT_ELEVATION:
      mElevation = aValue;
      break;
    default:
      return false;
  }
  return true;
}

static inline Point3D Normalized(const Point3D& vec) {
  Point3D copy(vec);
  copy.Normalize();
  return copy;
}

template <typename LightType, typename LightingType>
FilterNodeLightingSoftware<LightType, LightingType>::FilterNodeLightingSoftware(
    const char* aTypeName)
    : mSurfaceScale(0)
#if defined(MOZILLA_INTERNAL_API) && defined(NS_BUILD_REFCNT_LOGGING)
      ,
      mTypeName(aTypeName)
#endif
{
}

template <typename LightType, typename LightingType>
int32_t FilterNodeLightingSoftware<LightType, LightingType>::InputIndex(
    uint32_t aInputEnumIndex) {
  switch (aInputEnumIndex) {
    case IN_LIGHTING_IN:
      return 0;
    default:
      return -1;
  }
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<LightType, LightingType>::SetAttribute(
    uint32_t aIndex, const Point3D& aPoint) {
  if (mLight.SetAttribute(aIndex, aPoint)) {
    Invalidate();
    return;
  }
  MOZ_CRASH("GFX: FilterNodeLightingSoftware::SetAttribute point");
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<LightType, LightingType>::SetAttribute(
    uint32_t aIndex, Float aValue) {
  if (mLight.SetAttribute(aIndex, aValue) ||
      mLighting.SetAttribute(aIndex, aValue)) {
    Invalidate();
    return;
  }
  switch (aIndex) {
    case ATT_LIGHTING_SURFACE_SCALE:
      mSurfaceScale = std::fpclassify(aValue) == FP_SUBNORMAL ? 0.0 : aValue;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeLightingSoftware::SetAttribute float");
  }
  Invalidate();
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<LightType, LightingType>::SetAttribute(
    uint32_t aIndex, const Size& aKernelUnitLength) {
  switch (aIndex) {
    case ATT_LIGHTING_KERNEL_UNIT_LENGTH:
      mKernelUnitLength = aKernelUnitLength;
      break;
    default:
      MOZ_CRASH("GFX: FilterNodeLightingSoftware::SetAttribute size");
  }
  Invalidate();
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<LightType, LightingType>::SetAttribute(
    uint32_t aIndex, const DeviceColor& aColor) {
  MOZ_ASSERT(aIndex == ATT_LIGHTING_COLOR);
  mColor = aColor;
  Invalidate();
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<LightType, LightingType>::SetAttribute(
    uint32_t aIndex, const IntRect& aRenderRect) {
  MOZ_ASSERT(aIndex == ATT_LIGHTING_RENDER_RECT);
  mRenderRect = aRenderRect;
  Invalidate();
}

template <typename LightType, typename LightingType>
IntRect
FilterNodeLightingSoftware<LightType, LightingType>::GetOutputRectInRect(
    const IntRect& aRect) {
  return aRect;
}

Point3D PointLightSoftware::GetVectorToLight(const Point3D& aTargetPoint) {
  return Normalized(mPosition - aTargetPoint);
}

uint32_t PointLightSoftware::GetColor(uint32_t aLightColor,
                                      const Point3D& aVectorToLight) {
  return aLightColor;
}

void SpotLightSoftware::Prepare() {
  mVectorFromFocusPointToLight = Normalized(mPointsAt - mPosition);
  mLimitingConeCos =
      std::max<double>(cos(mLimitingConeAngle * M_PI / 180.0), 0.0);
  mPowCache.CacheForExponent(mSpecularFocus);
}

Point3D SpotLightSoftware::GetVectorToLight(const Point3D& aTargetPoint) {
  return Normalized(mPosition - aTargetPoint);
}

uint32_t SpotLightSoftware::GetColor(uint32_t aLightColor,
                                     const Point3D& aVectorToLight) {
  union {
    uint32_t color;
    uint8_t colorC[4];
  };

  Float dot = -aVectorToLight.DotProduct(mVectorFromFocusPointToLight);
  if (!mPowCache.HasPowerTable()) {
    dot *= (dot >= mLimitingConeCos);
    color = aLightColor;
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_R] *= dot;
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_G] *= dot;
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_B] *= dot;
  } else {
    color = aLightColor;
    uint16_t doti = dot * (dot >= 0) * (1 << PowCache::sInputIntPrecisionBits);
    uint32_t tmp = mPowCache.Pow(doti) * (dot >= mLimitingConeCos);
    MOZ_ASSERT(tmp <= (1 << PowCache::sOutputIntPrecisionBits),
               "pow() result must not exceed 1.0");
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_R] =
        uint8_t((colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_R] * tmp) >>
                PowCache::sOutputIntPrecisionBits);
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_G] =
        uint8_t((colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_G] * tmp) >>
                PowCache::sOutputIntPrecisionBits);
    colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_B] =
        uint8_t((colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_B] * tmp) >>
                PowCache::sOutputIntPrecisionBits);
  }
  colorC[B8G8R8A8_COMPONENT_BYTEOFFSET_A] = 255;
  return color;
}

void DistantLightSoftware::Prepare() {
  const double radPerDeg = M_PI / 180.0;
  mVectorToLight.x = cos(mAzimuth * radPerDeg) * cos(mElevation * radPerDeg);
  mVectorToLight.y = sin(mAzimuth * radPerDeg) * cos(mElevation * radPerDeg);
  mVectorToLight.z = sin(mElevation * radPerDeg);
}

Point3D DistantLightSoftware::GetVectorToLight(const Point3D& aTargetPoint) {
  return mVectorToLight;
}

uint32_t DistantLightSoftware::GetColor(uint32_t aLightColor,
                                        const Point3D& aVectorToLight) {
  return aLightColor;
}

template <typename CoordType>
static Point3D GenerateNormal(const uint8_t* data, int32_t stride,
                              uint8_t* boundsBegin, uint8_t* boundsEnd,
                              int32_t x, int32_t y, float surfaceScale,
                              CoordType dx, CoordType dy) {
  const uint8_t* index = data + y * stride + x;

  CoordType zero = 0;

  // See this for source of constants:
  //   http://www.w3.org/TR/SVG11/filters.html#feDiffuseLightingElement
  int16_t normalX = -1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, -dx, -dy, 1, 0) +
                    1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, dx, -dy, 1, 0) +
                    -2 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, -dx, zero, 1, 0) +
                    2 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, dx, zero, 1, 0) +
                    -1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, -dx, dy, 1, 0) +
                    1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, dx, dy, 1, 0);

  int16_t normalY = -1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, -dx, -dy, 1, 0) +
                    -2 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, zero, -dy, 1, 0) +
                    -1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                               boundsEnd, dx, -dy, 1, 0) +
                    1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, -dx, dy, 1, 0) +
                    2 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, zero, dy, 1, 0) +
                    1 * ColorComponentAtPoint(index, stride, boundsBegin,
                                              boundsEnd, dx, dy, 1, 0);

  Point3D normal;
  normal.x = -surfaceScale * normalX / 4.0f;
  normal.y = -surfaceScale * normalY / 4.0f;
  normal.z = 255;
  return Normalized(normal);
}

template <typename LightType, typename LightingType>
already_AddRefed<DataSourceSurface>
FilterNodeLightingSoftware<LightType, LightingType>::Render(
    const IntRect& aRect) {
  if (mKernelUnitLength.width == floor(mKernelUnitLength.width) &&
      mKernelUnitLength.height == floor(mKernelUnitLength.height)) {
    return DoRender(aRect, (int32_t)mKernelUnitLength.width,
                    (int32_t)mKernelUnitLength.height);
  }
  return DoRender(aRect, mKernelUnitLength.width, mKernelUnitLength.height);
}

template <typename LightType, typename LightingType>
void FilterNodeLightingSoftware<
    LightType, LightingType>::RequestFromInputsForRect(const IntRect& aRect) {
  IntRect srcRect = aRect;
  srcRect.Inflate(ceil(mKernelUnitLength.width),
                  ceil(mKernelUnitLength.height));
  RequestInputRect(IN_LIGHTING_IN, srcRect);
}

template <typename LightType, typename LightingType>
IntRect FilterNodeLightingSoftware<LightType, LightingType>::MapRectToSource(
    const IntRect& aRect, const IntRect& aMax, FilterNode* aSourceNode) {
  IntRect srcRect = aRect;
  srcRect.Inflate(ceil(mKernelUnitLength.width),
                  ceil(mKernelUnitLength.height));
  return MapInputRectToSource(IN_LIGHTING_IN, srcRect, aMax, aSourceNode);
}

template <typename LightType, typename LightingType>
template <typename CoordType>
already_AddRefed<DataSourceSurface>
FilterNodeLightingSoftware<LightType, LightingType>::DoRender(
    const IntRect& aRect, CoordType aKernelUnitLengthX,
    CoordType aKernelUnitLengthY) {
  MOZ_ASSERT(aKernelUnitLengthX > 0,
             "aKernelUnitLengthX can be a negative or zero value");
  MOZ_ASSERT(aKernelUnitLengthY > 0,
             "aKernelUnitLengthY can be a negative or zero value");

  IntRect srcRect = aRect;
  IntSize size = aRect.Size();
  srcRect.Inflate(ceil(float(aKernelUnitLengthX)),
                  ceil(float(aKernelUnitLengthY)));

  // Inflate the source rect by another pixel because the bilinear filtering in
  // ColorComponentAtPoint may want to access the margins.
  srcRect.Inflate(1);

  IntRect srcRectInRenderRect = srcRect.Intersect(mRenderRect);

  RefPtr<DataSourceSurface> input =
      GetInputDataSourceSurface(IN_LIGHTING_IN, srcRect, CAN_HANDLE_A8,
                                EDGE_MODE_DUPLICATE, &srcRectInRenderRect);

  if (!input) {
    return nullptr;
  }

  if (input->GetFormat() != SurfaceFormat::A8) {
    input = FilterProcessing::ExtractAlpha(input);
  }

  RefPtr<DataSourceSurface> target =
      Factory::CreateDataSourceSurface(size, SurfaceFormat::B8G8R8A8);
  if (MOZ2D_WARN_IF(!target)) {
    return nullptr;
  }

  IntPoint offset = aRect.TopLeft() - srcRect.TopLeft();

  DataSourceSurface::ScopedMap sourceMap(input, DataSourceSurface::READ);
  DataSourceSurface::ScopedMap targetMap(target, DataSourceSurface::WRITE);
  if (MOZ2D_WARN_IF(!(sourceMap.IsMapped() && targetMap.IsMapped()))) {
    return nullptr;
  }

  uint8_t* sourceData =
      DataAtOffset(input, sourceMap.GetMappedSurface(), offset);
  int32_t sourceStride = sourceMap.GetStride();
  uint8_t* sourceBegin = sourceMap.GetData();
  uint8_t* sourceEnd = sourceBegin + sourceStride * input->GetSize().height;
  uint8_t* targetData = targetMap.GetData();
  int32_t targetStride = targetMap.GetStride();

  uint32_t lightColor = ColorToBGRA(mColor);
  mLight.Prepare();
  mLighting.Prepare();

  for (int32_t y = 0; y < size.height; y++) {
    for (int32_t x = 0; x < size.width; x++) {
      int32_t sourceIndex = y * sourceStride + x;
      int32_t targetIndex = y * targetStride + 4 * x;

      Point3D normal =
          GenerateNormal(sourceData, sourceStride, sourceBegin, sourceEnd, x, y,
                         mSurfaceScale, aKernelUnitLengthX, aKernelUnitLengthY);

      IntPoint pointInFilterSpace(aRect.X() + x, aRect.Y() + y);
      Float Z = mSurfaceScale * sourceData[sourceIndex] / 255.0f;
      Point3D pt(pointInFilterSpace.x, pointInFilterSpace.y, Z);
      Point3D rayDir = mLight.GetVectorToLight(pt);
      uint32_t color = mLight.GetColor(lightColor, rayDir);

      *(uint32_t*)(targetData + targetIndex) =
          mLighting.LightPixel(normal, rayDir, color);
    }

    // Zero padding to keep valgrind happy.
    PodZero(&targetData[y * targetStride + 4 * size.width],
            targetStride - 4 * size.width);
  }

  return target.forget();
}

DiffuseLightingSoftware::DiffuseLightingSoftware() : mDiffuseConstant(0) {}

bool DiffuseLightingSoftware::SetAttribute(uint32_t aIndex, Float aValue) {
  switch (aIndex) {
    case ATT_DIFFUSE_LIGHTING_DIFFUSE_CONSTANT:
      mDiffuseConstant = aValue;
      break;
    default:
      return false;
  }
  return true;
}

uint32_t DiffuseLightingSoftware::LightPixel(const Point3D& aNormal,
                                             const Point3D& aVectorToLight,
                                             uint32_t aColor) {
  Float dotNL = std::max(0.0f, aNormal.DotProduct(aVectorToLight));
  Float diffuseNL = mDiffuseConstant * dotNL;

  union {
    uint32_t bgra;
    uint8_t components[4];
  } color = {aColor};
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_B] = umin(
      uint32_t(diffuseNL * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_B]),
      255U);
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_G] = umin(
      uint32_t(diffuseNL * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_G]),
      255U);
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_R] = umin(
      uint32_t(diffuseNL * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_R]),
      255U);
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_A] = 255;
  return color.bgra;
}

SpecularLightingSoftware::SpecularLightingSoftware()
    : mSpecularConstant(0), mSpecularExponent(0), mSpecularConstantInt(0) {}

bool SpecularLightingSoftware::SetAttribute(uint32_t aIndex, Float aValue) {
  switch (aIndex) {
    case ATT_SPECULAR_LIGHTING_SPECULAR_CONSTANT:
      mSpecularConstant = std::clamp(aValue, 0.0f, 255.0f);
      break;
    case ATT_SPECULAR_LIGHTING_SPECULAR_EXPONENT:
      mSpecularExponent = std::clamp(aValue, 1.0f, 128.0f);
      break;
    default:
      return false;
  }
  return true;
}

void SpecularLightingSoftware::Prepare() {
  mPowCache.CacheForExponent(mSpecularExponent);
  mSpecularConstantInt = uint32_t(mSpecularConstant * (1 << 8));
}

uint32_t SpecularLightingSoftware::LightPixel(const Point3D& aNormal,
                                              const Point3D& aVectorToLight,
                                              uint32_t aColor) {
  Point3D vectorToEye(0, 0, 1);
  Point3D halfwayVector = aVectorToLight + vectorToEye;
  Float halfwayLength = halfwayVector.Length();
  if (halfwayLength > 0) {
    halfwayVector /= halfwayLength;
  }
  Float dotNH = aNormal.DotProduct(halfwayVector);
  uint16_t dotNHi =
      uint16_t(dotNH * (dotNH >= 0) * (1 << PowCache::sInputIntPrecisionBits));
  // The exponent for specular is in [1,128] range, so we don't need to check
  // and optimize for the "default power table" scenario here.
  MOZ_ASSERT(mPowCache.HasPowerTable());
  uint32_t specularNHi =
      uint32_t(mSpecularConstantInt) * mPowCache.Pow(dotNHi) >> 8;

  union {
    uint32_t bgra;
    uint8_t components[4];
  } color = {aColor};
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_B] =
      umin((specularNHi * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_B]) >>
               PowCache::sOutputIntPrecisionBits,
           255U);
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_G] =
      umin((specularNHi * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_G]) >>
               PowCache::sOutputIntPrecisionBits,
           255U);
  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_R] =
      umin((specularNHi * color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_R]) >>
               PowCache::sOutputIntPrecisionBits,
           255U);

  color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_A] =
      umax(color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_B],
           umax(color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_G],
                color.components[B8G8R8A8_COMPONENT_BYTEOFFSET_R]));
  return color.bgra;
}

}  // namespace gfx
}  // namespace mozilla
