Add m-esr52 at 52.6.0

1 files changed, 1061 insertions, 0 deletions

diff --git a/layout/style/nsStyleTransformMatrix.cpp b/layout/style/nsStyleTransformMatrix.cpp
new file mode 100644
index 000000000..3cc166707
--- /dev/null
+++ b/layout/style/nsStyleTransformMatrix.cpp
@@ -0,0 +1,1061 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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/. */
+
+/*
+ * A class used for intermediate representations of the -moz-transform property.
+ */
+
+#include "nsStyleTransformMatrix.h"
+#include "nsCSSValue.h"
+#include "nsLayoutUtils.h"
+#include "nsPresContext.h"
+#include "nsRuleNode.h"
+#include "nsSVGUtils.h"
+#include "nsCSSKeywords.h"
+#include "mozilla/StyleAnimationValue.h"
+#include "gfxMatrix.h"
+#include "gfxQuaternion.h"
+
+using namespace mozilla;
+using namespace mozilla::gfx;
+
+namespace nsStyleTransformMatrix {
+
+/* Note on floating point precision: The transform matrix is an array
+ * of single precision 'float's, and so are most of the input values
+ * we get from the style system, but intermediate calculations
+ * involving angles need to be done in 'double'.
+ */
+
+
+// Define UNIFIED_CONTINUATIONS here and in nsDisplayList.cpp
+// to have the transform property try
+// to transform content with continuations as one unified block instead of
+// several smaller ones.  This is currently disabled because it doesn't work
+// correctly, since when the frames are initially being reflowed, their
+// continuations all compute their bounding rects independently of each other
+// and consequently get the wrong value.
+//#define UNIFIED_CONTINUATIONS
+
+void
+TransformReferenceBox::EnsureDimensionsAreCached()
+{
+  if (mIsCached) {
+    return;
+  }
+
+  MOZ_ASSERT(mFrame);
+
+  mIsCached = true;
+
+  if (mFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) {
+    if (!nsLayoutUtils::SVGTransformBoxEnabled()) {
+      mX = -mFrame->GetPosition().x;
+      mY = -mFrame->GetPosition().y;
+      Size contextSize = nsSVGUtils::GetContextSize(mFrame);
+      mWidth = nsPresContext::CSSPixelsToAppUnits(contextSize.width);
+      mHeight = nsPresContext::CSSPixelsToAppUnits(contextSize.height);
+    } else
+    if (mFrame->StyleDisplay()->mTransformBox ==
+          NS_STYLE_TRANSFORM_BOX_FILL_BOX) {
+      // Percentages in transforms resolve against the SVG bbox, and the
+      // transform is relative to the top-left of the SVG bbox.
+      gfxRect bbox = nsSVGUtils::GetBBox(const_cast<nsIFrame*>(mFrame));
+      nsRect bboxInAppUnits =
+        nsLayoutUtils::RoundGfxRectToAppRect(bbox,
+                                             mFrame->PresContext()->AppUnitsPerCSSPixel());
+      // The mRect of an SVG nsIFrame is its user space bounds *including*
+      // stroke and markers, whereas bboxInAppUnits is its user space bounds
+      // including fill only.  We need to note the offset of the reference box
+      // from the frame's mRect in mX/mY.
+      mX = bboxInAppUnits.x - mFrame->GetPosition().x;
+      mY = bboxInAppUnits.y - mFrame->GetPosition().y;
+      mWidth = bboxInAppUnits.width;
+      mHeight = bboxInAppUnits.height;
+    } else {
+      // The value 'border-box' is treated as 'view-box' for SVG content.
+      MOZ_ASSERT(mFrame->StyleDisplay()->mTransformBox ==
+                   NS_STYLE_TRANSFORM_BOX_VIEW_BOX ||
+                 mFrame->StyleDisplay()->mTransformBox ==
+                   NS_STYLE_TRANSFORM_BOX_BORDER_BOX,
+                 "Unexpected value for 'transform-box'");
+      // Percentages in transforms resolve against the width/height of the
+      // nearest viewport (or its viewBox if one is applied), and the
+      // transform is relative to {0,0} in current user space.
+      mX = -mFrame->GetPosition().x;
+      mY = -mFrame->GetPosition().y;
+      Size contextSize = nsSVGUtils::GetContextSize(mFrame);
+      mWidth = nsPresContext::CSSPixelsToAppUnits(contextSize.width);
+      mHeight = nsPresContext::CSSPixelsToAppUnits(contextSize.height);
+    }
+    return;
+  }
+
+  // If UNIFIED_CONTINUATIONS is not defined, this is simply the frame's
+  // bounding rectangle, translated to the origin.  Otherwise, it is the
+  // smallest rectangle containing a frame and all of its continuations.  For
+  // example, if there is a <span> element with several continuations split
+  // over several lines, this function will return the rectangle containing all
+  // of those continuations.
+
+  nsRect rect;
+
+#ifndef UNIFIED_CONTINUATIONS
+  rect = mFrame->GetRect();
+#else
+  // Iterate the continuation list, unioning together the bounding rects:
+  for (const nsIFrame *currFrame = mFrame->FirstContinuation();
+       currFrame != nullptr;
+       currFrame = currFrame->GetNextContinuation())
+  {
+    // Get the frame rect in local coordinates, then translate back to the
+    // original coordinates:
+    rect.UnionRect(result, nsRect(currFrame->GetOffsetTo(mFrame),
+                                  currFrame->GetSize()));
+  }
+#endif
+
+  mX = 0;
+  mY = 0;
+  mWidth = rect.Width();
+  mHeight = rect.Height();
+}
+
+void
+TransformReferenceBox::Init(const nsSize& aDimensions)
+{
+  MOZ_ASSERT(!mFrame && !mIsCached);
+
+  mX = 0;
+  mY = 0;
+  mWidth = aDimensions.width;
+  mHeight = aDimensions.height;
+  mIsCached = true;
+}
+
+float
+ProcessTranslatePart(const nsCSSValue& aValue,
+                     nsStyleContext* aContext,
+                     nsPresContext* aPresContext,
+                     RuleNodeCacheConditions& aConditions,
+                     TransformReferenceBox* aRefBox,
+                     TransformReferenceBox::DimensionGetter aDimensionGetter)
+{
+  nscoord offset = 0;
+  float percent = 0.0f;
+
+  if (aValue.GetUnit() == eCSSUnit_Percent) {
+    percent = aValue.GetPercentValue();
+  } else if (aValue.GetUnit() == eCSSUnit_Pixel ||
+             aValue.GetUnit() == eCSSUnit_Number) {
+    // Handle this here (even though nsRuleNode::CalcLength handles it
+    // fine) so that callers are allowed to pass a null style context
+    // and pres context to SetToTransformFunction if they know (as
+    // StyleAnimationValue does) that all lengths within the transform
+    // function have already been computed to pixels and percents.
+    //
+    // Raw numbers are treated as being pixels.
+    //
+    // Don't convert to aValue to AppUnits here to avoid precision issues.
+    return aValue.GetFloatValue();
+  } else if (aValue.IsCalcUnit()) {
+    nsRuleNode::ComputedCalc result =
+      nsRuleNode::SpecifiedCalcToComputedCalc(aValue, aContext, aPresContext,
+                                              aConditions);
+    percent = result.mPercent;
+    offset = result.mLength;
+  } else {
+    offset = nsRuleNode::CalcLength(aValue, aContext, aPresContext,
+                                    aConditions);
+  }
+
+  float translation = NSAppUnitsToFloatPixels(offset,
+                                              nsPresContext::AppUnitsPerCSSPixel());
+  // We want to avoid calling aDimensionGetter if there's no percentage to be
+  // resolved (for performance reasons - see TransformReferenceBox).
+  if (percent != 0.0f && aRefBox && !aRefBox->IsEmpty()) {
+    translation += percent *
+                     NSAppUnitsToFloatPixels((aRefBox->*aDimensionGetter)(),
+                                             nsPresContext::AppUnitsPerCSSPixel());
+  }
+  return translation;
+}
+
+/**
+ * Helper functions to process all the transformation function types.
+ *
+ * These take a matrix parameter to accumulate the current matrix.
+ */
+
+/* Helper function to process a matrix entry. */
+static void
+ProcessMatrix(Matrix4x4& aMatrix,
+              const nsCSSValue::Array* aData,
+              nsStyleContext* aContext,
+              nsPresContext* aPresContext,
+              RuleNodeCacheConditions& aConditions,
+              TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 7, "Invalid array!");
+
+  gfxMatrix result;
+
+  /* Take the first four elements out of the array as floats and store
+   * them.
+   */
+  result._11 = aData->Item(1).GetFloatValue();
+  result._12 = aData->Item(2).GetFloatValue();
+  result._21 = aData->Item(3).GetFloatValue();
+  result._22 = aData->Item(4).GetFloatValue();
+
+  /* The last two elements have their length parts stored in aDelta
+   * and their percent parts stored in aX[0] and aY[1].
+   */
+  result._31 = ProcessTranslatePart(aData->Item(5),
+                                   aContext, aPresContext, aConditions,
+                                   &aRefBox, &TransformReferenceBox::Width);
+  result._32 = ProcessTranslatePart(aData->Item(6),
+                                   aContext, aPresContext, aConditions,
+                                   &aRefBox, &TransformReferenceBox::Height);
+
+  aMatrix = result * aMatrix;
+}
+
+static void
+ProcessMatrix3D(Matrix4x4& aMatrix,
+                const nsCSSValue::Array* aData,
+                nsStyleContext* aContext,
+                nsPresContext* aPresContext,
+                RuleNodeCacheConditions& aConditions,
+                TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 17, "Invalid array!");
+
+  Matrix4x4 temp;
+
+  temp._11 = aData->Item(1).GetFloatValue();
+  temp._12 = aData->Item(2).GetFloatValue();
+  temp._13 = aData->Item(3).GetFloatValue();
+  temp._14 = aData->Item(4).GetFloatValue();
+  temp._21 = aData->Item(5).GetFloatValue();
+  temp._22 = aData->Item(6).GetFloatValue();
+  temp._23 = aData->Item(7).GetFloatValue();
+  temp._24 = aData->Item(8).GetFloatValue();
+  temp._31 = aData->Item(9).GetFloatValue();
+  temp._32 = aData->Item(10).GetFloatValue();
+  temp._33 = aData->Item(11).GetFloatValue();
+  temp._34 = aData->Item(12).GetFloatValue();
+  temp._44 = aData->Item(16).GetFloatValue();
+
+  temp._41 = ProcessTranslatePart(aData->Item(13),
+                                  aContext, aPresContext, aConditions,
+                                  &aRefBox, &TransformReferenceBox::Width);
+  temp._42 = ProcessTranslatePart(aData->Item(14),
+                                  aContext, aPresContext, aConditions,
+                                  &aRefBox, &TransformReferenceBox::Height);
+  temp._43 = ProcessTranslatePart(aData->Item(15),
+                                  aContext, aPresContext, aConditions,
+                                  nullptr);
+
+  aMatrix = temp * aMatrix;
+}
+
+/* Helper function to process two matrices that we need to interpolate between */
+void
+ProcessInterpolateMatrix(Matrix4x4& aMatrix,
+                         const nsCSSValue::Array* aData,
+                         nsStyleContext* aContext,
+                         nsPresContext* aPresContext,
+                         RuleNodeCacheConditions& aConditions,
+                         TransformReferenceBox& aRefBox,
+                         bool* aContains3dTransform)
+{
+  NS_PRECONDITION(aData->Count() == 4, "Invalid array!");
+
+  Matrix4x4 matrix1, matrix2;
+  if (aData->Item(1).GetUnit() == eCSSUnit_List) {
+    matrix1 = nsStyleTransformMatrix::ReadTransforms(aData->Item(1).GetListValue(),
+                             aContext, aPresContext,
+                             aConditions,
+                             aRefBox, nsPresContext::AppUnitsPerCSSPixel(),
+                             aContains3dTransform);
+  }
+  if (aData->Item(2).GetUnit() == eCSSUnit_List) {
+    matrix2 = ReadTransforms(aData->Item(2).GetListValue(),
+                             aContext, aPresContext,
+                             aConditions,
+                             aRefBox, nsPresContext::AppUnitsPerCSSPixel(),
+                             aContains3dTransform);
+  }
+  double progress = aData->Item(3).GetPercentValue();
+
+  aMatrix =
+    StyleAnimationValue::InterpolateTransformMatrix(matrix1, matrix2, progress)
+    * aMatrix;
+}
+
+/* Helper function to process a translatex function. */
+static void
+ProcessTranslateX(Matrix4x4& aMatrix,
+                  const nsCSSValue::Array* aData,
+                  nsStyleContext* aContext,
+                  nsPresContext* aPresContext,
+                  RuleNodeCacheConditions& aConditions,
+                  TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+
+  Point3D temp;
+
+  temp.x = ProcessTranslatePart(aData->Item(1),
+                                aContext, aPresContext, aConditions,
+                                &aRefBox, &TransformReferenceBox::Width);
+  aMatrix.PreTranslate(temp);
+}
+
+/* Helper function to process a translatey function. */
+static void
+ProcessTranslateY(Matrix4x4& aMatrix,
+                  const nsCSSValue::Array* aData,
+                  nsStyleContext* aContext,
+                  nsPresContext* aPresContext,
+                  RuleNodeCacheConditions& aConditions,
+                  TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+
+  Point3D temp;
+
+  temp.y = ProcessTranslatePart(aData->Item(1),
+                                aContext, aPresContext, aConditions,
+                                &aRefBox, &TransformReferenceBox::Height);
+  aMatrix.PreTranslate(temp);
+}
+
+static void
+ProcessTranslateZ(Matrix4x4& aMatrix,
+                  const nsCSSValue::Array* aData,
+                  nsStyleContext* aContext,
+                  nsPresContext* aPresContext,
+                  RuleNodeCacheConditions& aConditions)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+
+  Point3D temp;
+
+  temp.z = ProcessTranslatePart(aData->Item(1), aContext,
+                                aPresContext, aConditions,
+                                nullptr);
+  aMatrix.PreTranslate(temp);
+}
+
+/* Helper function to process a translate function. */
+static void
+ProcessTranslate(Matrix4x4& aMatrix,
+                 const nsCSSValue::Array* aData,
+                 nsStyleContext* aContext,
+                 nsPresContext* aPresContext,
+                 RuleNodeCacheConditions& aConditions,
+                 TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 2 || aData->Count() == 3, "Invalid array!");
+
+  Point3D temp;
+
+  temp.x = ProcessTranslatePart(aData->Item(1),
+                                aContext, aPresContext, aConditions,
+                                &aRefBox, &TransformReferenceBox::Width);
+
+  /* If we read in a Y component, set it appropriately */
+  if (aData->Count() == 3) {
+    temp.y = ProcessTranslatePart(aData->Item(2),
+                                  aContext, aPresContext, aConditions,
+                                  &aRefBox, &TransformReferenceBox::Height);
+  }
+  aMatrix.PreTranslate(temp);
+}
+
+static void
+ProcessTranslate3D(Matrix4x4& aMatrix,
+                   const nsCSSValue::Array* aData,
+                   nsStyleContext* aContext,
+                   nsPresContext* aPresContext,
+                   RuleNodeCacheConditions& aConditions,
+                   TransformReferenceBox& aRefBox)
+{
+  NS_PRECONDITION(aData->Count() == 4, "Invalid array!");
+
+  Point3D temp;
+
+  temp.x = ProcessTranslatePart(aData->Item(1),
+                                aContext, aPresContext, aConditions,
+                                &aRefBox, &TransformReferenceBox::Width);
+
+  temp.y = ProcessTranslatePart(aData->Item(2),
+                                aContext, aPresContext, aConditions,
+                                &aRefBox, &TransformReferenceBox::Height);
+
+  temp.z = ProcessTranslatePart(aData->Item(3),
+                                aContext, aPresContext, aConditions,
+                                nullptr);
+
+  aMatrix.PreTranslate(temp);
+}
+
+/* Helper function to set up a scale matrix. */
+static void
+ProcessScaleHelper(Matrix4x4& aMatrix,
+                   float aXScale,
+                   float aYScale,
+                   float aZScale)
+{
+  aMatrix.PreScale(aXScale, aYScale, aZScale);
+}
+
+/* Process a scalex function. */
+static void
+ProcessScaleX(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Bad array!");
+  ProcessScaleHelper(aMatrix, aData->Item(1).GetFloatValue(), 1.0f, 1.0f);
+}
+
+/* Process a scaley function. */
+static void
+ProcessScaleY(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Bad array!");
+  ProcessScaleHelper(aMatrix, 1.0f, aData->Item(1).GetFloatValue(), 1.0f);
+}
+
+static void
+ProcessScaleZ(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Bad array!");
+  ProcessScaleHelper(aMatrix, 1.0f, 1.0f, aData->Item(1).GetFloatValue());
+}
+
+static void
+ProcessScale3D(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 4, "Bad array!");
+  ProcessScaleHelper(aMatrix,
+                     aData->Item(1).GetFloatValue(),
+                     aData->Item(2).GetFloatValue(),
+                     aData->Item(3).GetFloatValue());
+}
+
+/* Process a scale function. */
+static void
+ProcessScale(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2 || aData->Count() == 3, "Bad array!");
+  /* We either have one element or two.  If we have one, it's for both X and Y.
+   * Otherwise it's one for each.
+   */
+  const nsCSSValue& scaleX = aData->Item(1);
+  const nsCSSValue& scaleY = (aData->Count() == 2 ? scaleX :
+                              aData->Item(2));
+
+  ProcessScaleHelper(aMatrix,
+                     scaleX.GetFloatValue(),
+                     scaleY.GetFloatValue(),
+                     1.0f);
+}
+
+/* Helper function that, given a set of angles, constructs the appropriate
+ * skew matrix.
+ */
+static void
+ProcessSkewHelper(Matrix4x4& aMatrix, double aXAngle, double aYAngle)
+{
+  aMatrix.SkewXY(aXAngle, aYAngle);
+}
+
+/* Function that converts a skewx transform into a matrix. */
+static void
+ProcessSkewX(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_ASSERTION(aData->Count() == 2, "Bad array!");
+  ProcessSkewHelper(aMatrix, aData->Item(1).GetAngleValueInRadians(), 0.0);
+}
+
+/* Function that converts a skewy transform into a matrix. */
+static void
+ProcessSkewY(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_ASSERTION(aData->Count() == 2, "Bad array!");
+  ProcessSkewHelper(aMatrix, 0.0, aData->Item(1).GetAngleValueInRadians());
+}
+
+/* Function that converts a skew transform into a matrix. */
+static void
+ProcessSkew(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_ASSERTION(aData->Count() == 2 || aData->Count() == 3, "Bad array!");
+
+  double xSkew = aData->Item(1).GetAngleValueInRadians();
+  double ySkew = (aData->Count() == 2
+                  ? 0.0 : aData->Item(2).GetAngleValueInRadians());
+
+  ProcessSkewHelper(aMatrix, xSkew, ySkew);
+}
+
+/* Function that converts a rotate transform into a matrix. */
+static void
+ProcessRotateZ(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+  double theta = aData->Item(1).GetAngleValueInRadians();
+  aMatrix.RotateZ(theta);
+}
+
+static void
+ProcessRotateX(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+  double theta = aData->Item(1).GetAngleValueInRadians();
+  aMatrix.RotateX(theta);
+}
+
+static void
+ProcessRotateY(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+  double theta = aData->Item(1).GetAngleValueInRadians();
+  aMatrix.RotateY(theta);
+}
+
+static void
+ProcessRotate3D(Matrix4x4& aMatrix, const nsCSSValue::Array* aData)
+{
+  NS_PRECONDITION(aData->Count() == 5, "Invalid array!");
+
+  double theta = aData->Item(4).GetAngleValueInRadians();
+  float x = aData->Item(1).GetFloatValue();
+  float y = aData->Item(2).GetFloatValue();
+  float z = aData->Item(3).GetFloatValue();
+
+  Matrix4x4 temp;
+  temp.SetRotateAxisAngle(x, y, z, theta);
+
+  aMatrix = temp * aMatrix;
+}
+
+static void
+ProcessPerspective(Matrix4x4& aMatrix,
+                   const nsCSSValue::Array* aData,
+                   nsStyleContext *aContext,
+                   nsPresContext *aPresContext,
+                   RuleNodeCacheConditions& aConditions)
+{
+  NS_PRECONDITION(aData->Count() == 2, "Invalid array!");
+
+  float depth = ProcessTranslatePart(aData->Item(1), aContext,
+                                     aPresContext, aConditions, nullptr);
+  ApplyPerspectiveToMatrix(aMatrix, depth);
+}
+
+
+/**
+ * SetToTransformFunction is essentially a giant switch statement that fans
+ * out to many smaller helper functions.
+ */
+static void
+MatrixForTransformFunction(Matrix4x4& aMatrix,
+                           const nsCSSValue::Array * aData,
+                           nsStyleContext* aContext,
+                           nsPresContext* aPresContext,
+                           RuleNodeCacheConditions& aConditions,
+                           TransformReferenceBox& aRefBox,
+                           bool* aContains3dTransform)
+{
+  MOZ_ASSERT(aContains3dTransform);
+  NS_PRECONDITION(aData, "Why did you want to get data from a null array?");
+  // It's OK if aContext and aPresContext are null if the caller already
+  // knows that all length units have been converted to pixels (as
+  // StyleAnimationValue does).
+
+
+  /* Get the keyword for the transform. */
+  switch (TransformFunctionOf(aData)) {
+  case eCSSKeyword_translatex:
+    ProcessTranslateX(aMatrix, aData, aContext, aPresContext,
+                      aConditions, aRefBox);
+    break;
+  case eCSSKeyword_translatey:
+    ProcessTranslateY(aMatrix, aData, aContext, aPresContext,
+                      aConditions, aRefBox);
+    break;
+  case eCSSKeyword_translatez:
+    *aContains3dTransform = true;
+    ProcessTranslateZ(aMatrix, aData, aContext, aPresContext,
+                      aConditions);
+    break;
+  case eCSSKeyword_translate:
+    ProcessTranslate(aMatrix, aData, aContext, aPresContext,
+                     aConditions, aRefBox);
+    break;
+  case eCSSKeyword_translate3d:
+    *aContains3dTransform = true;
+    ProcessTranslate3D(aMatrix, aData, aContext, aPresContext,
+                       aConditions, aRefBox);
+    break;
+  case eCSSKeyword_scalex:
+    ProcessScaleX(aMatrix, aData);
+    break;
+  case eCSSKeyword_scaley:
+    ProcessScaleY(aMatrix, aData);
+    break;
+  case eCSSKeyword_scalez:
+    *aContains3dTransform = true;
+    ProcessScaleZ(aMatrix, aData);
+    break;
+  case eCSSKeyword_scale:
+    ProcessScale(aMatrix, aData);
+    break;
+  case eCSSKeyword_scale3d:
+    *aContains3dTransform = true;
+    ProcessScale3D(aMatrix, aData);
+    break;
+  case eCSSKeyword_skewx:
+    ProcessSkewX(aMatrix, aData);
+    break;
+  case eCSSKeyword_skewy:
+    ProcessSkewY(aMatrix, aData);
+    break;
+  case eCSSKeyword_skew:
+    ProcessSkew(aMatrix, aData);
+    break;
+  case eCSSKeyword_rotatex:
+    *aContains3dTransform = true;
+    ProcessRotateX(aMatrix, aData);
+    break;
+  case eCSSKeyword_rotatey:
+    *aContains3dTransform = true;
+    ProcessRotateY(aMatrix, aData);
+    break;
+  case eCSSKeyword_rotatez:
+    *aContains3dTransform = true;
+    MOZ_FALLTHROUGH;
+  case eCSSKeyword_rotate:
+    ProcessRotateZ(aMatrix, aData);
+    break;
+  case eCSSKeyword_rotate3d:
+    *aContains3dTransform = true;
+    ProcessRotate3D(aMatrix, aData);
+    break;
+  case eCSSKeyword_matrix:
+    ProcessMatrix(aMatrix, aData, aContext, aPresContext,
+                  aConditions, aRefBox);
+    break;
+  case eCSSKeyword_matrix3d:
+    *aContains3dTransform = true;
+    ProcessMatrix3D(aMatrix, aData, aContext, aPresContext,
+                    aConditions, aRefBox);
+    break;
+  case eCSSKeyword_interpolatematrix:
+    ProcessInterpolateMatrix(aMatrix, aData, aContext, aPresContext,
+                             aConditions, aRefBox,
+                             aContains3dTransform);
+    break;
+  case eCSSKeyword_perspective:
+    *aContains3dTransform = true;
+    ProcessPerspective(aMatrix, aData, aContext, aPresContext,
+                       aConditions);
+    break;
+  default:
+    NS_NOTREACHED("Unknown transform function!");
+  }
+}
+
+/**
+ * Return the transform function, as an nsCSSKeyword, for the given
+ * nsCSSValue::Array from a transform list.
+ */
+nsCSSKeyword
+TransformFunctionOf(const nsCSSValue::Array* aData)
+{
+  MOZ_ASSERT(aData->Item(0).GetUnit() == eCSSUnit_Enumerated);
+  return aData->Item(0).GetKeywordValue();
+}
+
+void
+SetIdentityMatrix(nsCSSValue::Array* aMatrix)
+{
+  MOZ_ASSERT(aMatrix, "aMatrix should be non-null");
+
+  nsCSSKeyword tfunc = TransformFunctionOf(aMatrix);
+  MOZ_ASSERT(tfunc == eCSSKeyword_matrix ||
+             tfunc == eCSSKeyword_matrix3d,
+             "Only accept matrix and matrix3d");
+
+  if (tfunc == eCSSKeyword_matrix) {
+    MOZ_ASSERT(aMatrix->Count() == 7, "Invalid matrix");
+    Matrix m;
+    for (size_t i = 0; i < 6; ++i) {
+      aMatrix->Item(i + 1).SetFloatValue(m.components[i], eCSSUnit_Number);
+    }
+    return;
+  }
+
+  MOZ_ASSERT(aMatrix->Count() == 17, "Invalid matrix3d");
+  Matrix4x4 m;
+  for (size_t i = 0; i < 16; ++i) {
+    aMatrix->Item(i + 1).SetFloatValue(m.components[i], eCSSUnit_Number);
+  }
+}
+
+Matrix4x4
+ReadTransforms(const nsCSSValueList* aList,
+               nsStyleContext* aContext,
+               nsPresContext* aPresContext,
+               RuleNodeCacheConditions& aConditions,
+               TransformReferenceBox& aRefBox,
+               float aAppUnitsPerMatrixUnit,
+               bool* aContains3dTransform)
+{
+  Matrix4x4 result;
+
+  for (const nsCSSValueList* curr = aList; curr != nullptr; curr = curr->mNext) {
+    const nsCSSValue &currElem = curr->mValue;
+    if (currElem.GetUnit() != eCSSUnit_Function) {
+      NS_ASSERTION(currElem.GetUnit() == eCSSUnit_None &&
+                   !aList->mNext,
+                   "stream should either be a list of functions or a "
+                   "lone None");
+      continue;
+    }
+    NS_ASSERTION(currElem.GetArrayValue()->Count() >= 1,
+                 "Incoming function is too short!");
+
+    /* Read in a single transform matrix. */
+    MatrixForTransformFunction(result, currElem.GetArrayValue(), aContext,
+                               aPresContext, aConditions, aRefBox,
+                               aContains3dTransform);
+  }
+
+  float scale = float(nsPresContext::AppUnitsPerCSSPixel()) / aAppUnitsPerMatrixUnit;
+  result.PreScale(1/scale, 1/scale, 1/scale);
+  result.PostScale(scale, scale, scale);
+
+  return result;
+}
+
+/*
+ * The relevant section of the transitions specification:
+ * http://dev.w3.org/csswg/css3-transitions/#animation-of-property-types-
+ * defers all of the details to the 2-D and 3-D transforms specifications.
+ * For the 2-D transforms specification (all that's relevant for us, right
+ * now), the relevant section is:
+ * http://dev.w3.org/csswg/css3-2d-transforms/#animation
+ * This, in turn, refers to the unmatrix program in Graphics Gems,
+ * available from http://tog.acm.org/resources/GraphicsGems/ , and in
+ * particular as the file GraphicsGems/gemsii/unmatrix.c
+ * in http://tog.acm.org/resources/GraphicsGems/AllGems.tar.gz
+ *
+ * The unmatrix reference is for general 3-D transform matrices (any of the
+ * 16 components can have any value).
+ *
+ * For CSS 2-D transforms, we have a 2-D matrix with the bottom row constant:
+ *
+ * [ A C E ]
+ * [ B D F ]
+ * [ 0 0 1 ]
+ *
+ * For that case, I believe the algorithm in unmatrix reduces to:
+ *
+ *  (1) If A * D - B * C == 0, the matrix is singular.  Fail.
+ *
+ *  (2) Set translation components (Tx and Ty) to the translation parts of
+ *      the matrix (E and F) and then ignore them for the rest of the time.
+ *      (For us, E and F each actually consist of three constants:  a
+ *      length, a multiplier for the width, and a multiplier for the
+ *      height.  This actually requires its own decomposition, but I'll
+ *      keep that separate.)
+ *
+ *  (3) Let the X scale (Sx) be sqrt(A^2 + B^2).  Then divide both A and B
+ *      by it.
+ *
+ *  (4) Let the XY shear (K) be A * C + B * D.  From C, subtract A times
+ *      the XY shear.  From D, subtract B times the XY shear.
+ *
+ *  (5) Let the Y scale (Sy) be sqrt(C^2 + D^2).  Divide C, D, and the XY
+ *      shear (K) by it.
+ *
+ *  (6) At this point, A * D - B * C is either 1 or -1.  If it is -1,
+ *      negate the XY shear (K), the X scale (Sx), and A, B, C, and D.
+ *      (Alternatively, we could negate the XY shear (K) and the Y scale
+ *      (Sy).)
+ *
+ *  (7) Let the rotation be R = atan2(B, A).
+ *
+ * Then the resulting decomposed transformation is:
+ *
+ *   translate(Tx, Ty) rotate(R) skewX(atan(K)) scale(Sx, Sy)
+ *
+ * An interesting result of this is that all of the simple transform
+ * functions (i.e., all functions other than matrix()), in isolation,
+ * decompose back to themselves except for:
+ *   'skewY(φ)', which is 'matrix(1, tan(φ), 0, 1, 0, 0)', which decomposes
+ *   to 'rotate(φ) skewX(φ) scale(sec(φ), cos(φ))' since (ignoring the
+ *   alternate sign possibilities that would get fixed in step 6):
+ *     In step 3, the X scale factor is sqrt(1+tan²(φ)) = sqrt(sec²(φ)) = sec(φ).
+ *     Thus, after step 3, A = 1/sec(φ) = cos(φ) and B = tan(φ) / sec(φ) = sin(φ).
+ *     In step 4, the XY shear is sin(φ).
+ *     Thus, after step 4, C = -cos(φ)sin(φ) and D = 1 - sin²(φ) = cos²(φ).
+ *     Thus, in step 5, the Y scale is sqrt(cos²(φ)(sin²(φ) + cos²(φ)) = cos(φ).
+ *     Thus, after step 5, C = -sin(φ), D = cos(φ), and the XY shear is tan(φ).
+ *     Thus, in step 6, A * D - B * C = cos²(φ) + sin²(φ) = 1.
+ *     In step 7, the rotation is thus φ.
+ *
+ *   skew(θ, φ), which is matrix(1, tan(φ), tan(θ), 1, 0, 0), which decomposes
+ *   to 'rotate(φ) skewX(θ + φ) scale(sec(φ), cos(φ))' since (ignoring
+ *   the alternate sign possibilities that would get fixed in step 6):
+ *     In step 3, the X scale factor is sqrt(1+tan²(φ)) = sqrt(sec²(φ)) = sec(φ).
+ *     Thus, after step 3, A = 1/sec(φ) = cos(φ) and B = tan(φ) / sec(φ) = sin(φ).
+ *     In step 4, the XY shear is cos(φ)tan(θ) + sin(φ).
+ *     Thus, after step 4,
+ *     C = tan(θ) - cos(φ)(cos(φ)tan(θ) + sin(φ)) = tan(θ)sin²(φ) - cos(φ)sin(φ)
+ *     D = 1 - sin(φ)(cos(φ)tan(θ) + sin(φ)) = cos²(φ) - sin(φ)cos(φ)tan(θ)
+ *     Thus, in step 5, the Y scale is sqrt(C² + D²) =
+ *     sqrt(tan²(θ)(sin⁴(φ) + sin²(φ)cos²(φ)) -
+ *          2 tan(θ)(sin³(φ)cos(φ) + sin(φ)cos³(φ)) +
+ *          (sin²(φ)cos²(φ) + cos⁴(φ))) =
+ *     sqrt(tan²(θ)sin²(φ) - 2 tan(θ)sin(φ)cos(φ) + cos²(φ)) =
+ *     cos(φ) - tan(θ)sin(φ) (taking the negative of the obvious solution so
+ *     we avoid flipping in step 6).
+ *     After step 5, C = -sin(φ) and D = cos(φ), and the XY shear is
+ *     (cos(φ)tan(θ) + sin(φ)) / (cos(φ) - tan(θ)sin(φ)) =
+ *     (dividing both numerator and denominator by cos(φ))
+ *     (tan(θ) + tan(φ)) / (1 - tan(θ)tan(φ)) = tan(θ + φ).
+ *     (See http://en.wikipedia.org/wiki/List_of_trigonometric_identities .)
+ *     Thus, in step 6, A * D - B * C = cos²(φ) + sin²(φ) = 1.
+ *     In step 7, the rotation is thus φ.
+ *
+ *     To check this result, we can multiply things back together:
+ *
+ *     [ cos(φ) -sin(φ) ] [ 1 tan(θ + φ) ] [ sec(φ)    0   ]
+ *     [ sin(φ)  cos(φ) ] [ 0      1     ] [   0    cos(φ) ]
+ *
+ *     [ cos(φ)      cos(φ)tan(θ + φ) - sin(φ) ] [ sec(φ)    0   ]
+ *     [ sin(φ)      sin(φ)tan(θ + φ) + cos(φ) ] [   0    cos(φ) ]
+ *
+ *     but since tan(θ + φ) = (tan(θ) + tan(φ)) / (1 - tan(θ)tan(φ)),
+ *     cos(φ)tan(θ + φ) - sin(φ)
+ *      = cos(φ)(tan(θ) + tan(φ)) - sin(φ) + sin(φ)tan(θ)tan(φ)
+ *      = cos(φ)tan(θ) + sin(φ) - sin(φ) + sin(φ)tan(θ)tan(φ)
+ *      = cos(φ)tan(θ) + sin(φ)tan(θ)tan(φ)
+ *      = tan(θ) (cos(φ) + sin(φ)tan(φ))
+ *      = tan(θ) sec(φ) (cos²(φ) + sin²(φ))
+ *      = tan(θ) sec(φ)
+ *     and
+ *     sin(φ)tan(θ + φ) + cos(φ)
+ *      = sin(φ)(tan(θ) + tan(φ)) + cos(φ) - cos(φ)tan(θ)tan(φ)
+ *      = tan(θ) (sin(φ) - sin(φ)) + sin(φ)tan(φ) + cos(φ)
+ *      = sec(φ) (sin²(φ) + cos²(φ))
+ *      = sec(φ)
+ *     so the above is:
+ *     [ cos(φ)  tan(θ) sec(φ) ] [ sec(φ)    0   ]
+ *     [ sin(φ)     sec(φ)     ] [   0    cos(φ) ]
+ *
+ *     [    1   tan(θ) ]
+ *     [ tan(φ)    1   ]
+ */
+
+/*
+ * Decompose2DMatrix implements the above decomposition algorithm.
+ */
+
+bool
+Decompose2DMatrix(const Matrix& aMatrix,
+                  Point3D& aScale,
+                  ShearArray& aShear,
+                  gfxQuaternion& aRotate,
+                  Point3D& aTranslate)
+{
+  float A = aMatrix._11,
+        B = aMatrix._12,
+        C = aMatrix._21,
+        D = aMatrix._22;
+  if (A * D == B * C) {
+    // singular matrix
+    return false;
+  }
+
+  float scaleX = sqrt(A * A + B * B);
+  A /= scaleX;
+  B /= scaleX;
+
+  float XYshear = A * C + B * D;
+  C -= A * XYshear;
+  D -= B * XYshear;
+
+  float scaleY = sqrt(C * C + D * D);
+  C /= scaleY;
+  D /= scaleY;
+  XYshear /= scaleY;
+
+  // A*D - B*C should now be 1 or -1
+  NS_ASSERTION(0.99 < Abs(A*D - B*C) && Abs(A*D - B*C) < 1.01,
+               "determinant should now be 1 or -1");
+  if (A * D < B * C) {
+    A = -A;
+    B = -B;
+    C = -C;
+    D = -D;
+    XYshear = -XYshear;
+    scaleX = -scaleX;
+  }
+
+  float rotate = atan2f(B, A);
+  aRotate = gfxQuaternion(0, 0, sin(rotate/2), cos(rotate/2));
+  aShear[ShearType::XYSHEAR] = XYshear;
+  aScale.x = scaleX;
+  aScale.y = scaleY;
+  aTranslate.x = aMatrix._31;
+  aTranslate.y = aMatrix._32;
+  return true;
+}
+
+/**
+ * Implementation of the unmatrix algorithm, specified by:
+ *
+ * http://dev.w3.org/csswg/css3-2d-transforms/#unmatrix
+ *
+ * This, in turn, refers to the unmatrix program in Graphics Gems,
+ * available from http://tog.acm.org/resources/GraphicsGems/ , and in
+ * particular as the file GraphicsGems/gemsii/unmatrix.c
+ * in http://tog.acm.org/resources/GraphicsGems/AllGems.tar.gz
+ */
+bool
+Decompose3DMatrix(const Matrix4x4& aMatrix,
+                  Point3D& aScale,
+                  ShearArray& aShear,
+                  gfxQuaternion& aRotate,
+                  Point3D& aTranslate,
+                  Point4D& aPerspective)
+{
+  Matrix4x4 local = aMatrix;
+
+  if (local[3][3] == 0) {
+    return false;
+  }
+  /* Normalize the matrix */
+  local.Normalize();
+
+  /**
+   * perspective is used to solve for perspective, but it also provides
+   * an easy way to test for singularity of the upper 3x3 component.
+   */
+  Matrix4x4 perspective = local;
+  Point4D empty(0, 0, 0, 1);
+  perspective.SetTransposedVector(3, empty);
+
+  if (perspective.Determinant() == 0.0) {
+    return false;
+  }
+
+  /* First, isolate perspective. */
+  if (local[0][3] != 0 || local[1][3] != 0 ||
+      local[2][3] != 0) {
+    /* aPerspective is the right hand side of the equation. */
+    aPerspective = local.TransposedVector(3);
+
+    /**
+     * Solve the equation by inverting perspective and multiplying
+     * aPerspective by the inverse.
+     */
+    perspective.Invert();
+    aPerspective = perspective.TransposeTransform4D(aPerspective);
+
+    /* Clear the perspective partition */
+    local.SetTransposedVector(3, empty);
+  } else {
+    aPerspective = Point4D(0, 0, 0, 1);
+  }
+
+  /* Next take care of translation */
+  for (int i = 0; i < 3; i++) {
+    aTranslate[i] = local[3][i];
+    local[3][i] = 0;
+  }
+
+  /* Now get scale and shear. */
+
+  /* Compute X scale factor and normalize first row. */
+  aScale.x = local[0].Length();
+  local[0] /= aScale.x;
+
+  /* Compute XY shear factor and make 2nd local orthogonal to 1st. */
+  aShear[ShearType::XYSHEAR] = local[0].DotProduct(local[1]);
+  local[1] -= local[0] * aShear[ShearType::XYSHEAR];
+
+  /* Now, compute Y scale and normalize 2nd local. */
+  aScale.y = local[1].Length();
+  local[1] /= aScale.y;
+  aShear[ShearType::XYSHEAR] /= aScale.y;
+
+  /* Compute XZ and YZ shears, make 3rd local orthogonal */
+  aShear[ShearType::XZSHEAR] = local[0].DotProduct(local[2]);
+  local[2] -= local[0] * aShear[ShearType::XZSHEAR];
+  aShear[ShearType::YZSHEAR] = local[1].DotProduct(local[2]);
+  local[2] -= local[1] * aShear[ShearType::YZSHEAR];
+
+  /* Next, get Z scale and normalize 3rd local. */
+  aScale.z = local[2].Length();
+  local[2] /= aScale.z;
+
+  aShear[ShearType::XZSHEAR] /= aScale.z;
+  aShear[ShearType::YZSHEAR] /= aScale.z;
+
+  /**
+   * At this point, the matrix (in locals) is orthonormal.
+   * Check for a coordinate system flip.  If the determinant
+   * is -1, then negate the matrix and the scaling factors.
+   */
+  if (local[0].DotProduct(local[1].CrossProduct(local[2])) < 0) {
+    aScale *= -1;
+    for (int i = 0; i < 3; i++) {
+      local[i] *= -1;
+    }
+  }
+
+  /* Now, get the rotations out */
+  aRotate = gfxQuaternion(local);
+
+  return true;
+}
+
+Matrix
+CSSValueArrayTo2DMatrix(nsCSSValue::Array* aArray)
+{
+  MOZ_ASSERT(aArray &&
+             TransformFunctionOf(aArray) == eCSSKeyword_matrix &&
+             aArray->Count() == 7);
+  Matrix m(aArray->Item(1).GetFloatValue(),
+           aArray->Item(2).GetFloatValue(),
+           aArray->Item(3).GetFloatValue(),
+           aArray->Item(4).GetFloatValue(),
+           aArray->Item(5).GetFloatValue(),
+           aArray->Item(6).GetFloatValue());
+  return m;
+}
+
+Matrix4x4
+CSSValueArrayTo3DMatrix(nsCSSValue::Array* aArray)
+{
+  MOZ_ASSERT(aArray &&
+             TransformFunctionOf(aArray) == eCSSKeyword_matrix3d &&
+             aArray->Count() == 17);
+  gfx::Float array[16];
+  for (size_t i = 0; i < 16; ++i) {
+    array[i] = aArray->Item(i+1).GetFloatValue();
+  }
+  Matrix4x4 m(array);
+  return m;
+}
+
+} // namespace nsStyleTransformMatrix