Adding upstream version 86.0.1.upstream/86.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 859 insertions, 0 deletions

diff --git a/dom/svg/SVGContentUtils.cpp b/dom/svg/SVGContentUtils.cpp
new file mode 100644
index 0000000000..9f07fa42c8
--- /dev/null
+++ b/dom/svg/SVGContentUtils.cpp
@@ -0,0 +1,859 @@
+/* -*- 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/. */
+
+// Main header first:
+// This is also necessary to ensure our definition of M_SQRT1_2 is picked up
+#include "SVGContentUtils.h"
+
+// Keep others in (case-insensitive) order:
+#include "gfx2DGlue.h"
+#include "gfxMatrix.h"
+#include "gfxPlatform.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/dom/SVGSVGElement.h"
+#include "mozilla/PresShell.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/SVGContextPaint.h"
+#include "mozilla/SVGUtils.h"
+#include "mozilla/TextUtils.h"
+#include "nsComputedDOMStyle.h"
+#include "nsContainerFrame.h"
+#include "nsFontMetrics.h"
+#include "nsIFrame.h"
+#include "nsIScriptError.h"
+#include "nsLayoutUtils.h"
+#include "nsMathUtils.h"
+#include "nsWhitespaceTokenizer.h"
+#include "SVGAnimatedPreserveAspectRatio.h"
+#include "SVGGeometryProperty.h"
+#include "nsContentUtils.h"
+#include "mozilla/gfx/2D.h"
+#include "mozilla/gfx/Types.h"
+#include "mozilla/FloatingPoint.h"
+#include "mozilla/ComputedStyle.h"
+#include "SVGPathDataParser.h"
+#include "SVGPathData.h"
+#include "SVGPathElement.h"
+
+using namespace mozilla;
+using namespace mozilla::dom;
+using namespace mozilla::dom::SVGPreserveAspectRatio_Binding;
+using namespace mozilla::gfx;
+
+static bool ParseNumber(RangedPtr<const char16_t>& aIter,
+                        const RangedPtr<const char16_t>& aEnd, double& aValue) {
+  int32_t sign;
+  if (!SVGContentUtils::ParseOptionalSign(aIter, aEnd, sign)) {
+    return false;
+  }
+
+  // Absolute value of the integer part of the mantissa.
+  double intPart = 0.0;
+
+  bool gotDot = *aIter == '.';
+
+  if (!gotDot) {
+    if (!mozilla::IsAsciiDigit(*aIter)) {
+      return false;
+    }
+    do {
+      intPart = 10.0 * intPart + mozilla::AsciiAlphanumericToNumber(*aIter);
+      ++aIter;
+    } while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
+
+    if (aIter != aEnd) {
+      gotDot = *aIter == '.';
+    }
+  }
+
+  // Fractional part of the mantissa.
+  double fracPart = 0.0;
+
+  if (gotDot) {
+    ++aIter;
+    if (aIter == aEnd || !mozilla::IsAsciiDigit(*aIter)) {
+      return false;
+    }
+
+    // Power of ten by which we need to divide the fraction
+    double divisor = 1.0;
+
+    do {
+      fracPart = 10.0 * fracPart + mozilla::AsciiAlphanumericToNumber(*aIter);
+      divisor *= 10.0;
+      ++aIter;
+    } while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
+
+    fracPart /= divisor;
+  }
+
+  bool gotE = false;
+  int32_t exponent = 0;
+  int32_t expSign;
+
+  if (aIter != aEnd && (*aIter == 'e' || *aIter == 'E')) {
+    RangedPtr<const char16_t> expIter(aIter);
+
+    ++expIter;
+    if (expIter != aEnd) {
+      expSign = *expIter == '-' ? -1 : 1;
+      if (*expIter == '-' || *expIter == '+') {
+        ++expIter;
+      }
+      if (expIter != aEnd && mozilla::IsAsciiDigit(*expIter)) {
+        // At this point we're sure this is an exponent
+        // and not the start of a unit such as em or ex.
+        gotE = true;
+      }
+    }
+
+    if (gotE) {
+      aIter = expIter;
+      do {
+        exponent = 10.0 * exponent + mozilla::AsciiAlphanumericToNumber(*aIter);
+        ++aIter;
+      } while (aIter != aEnd && mozilla::IsAsciiDigit(*aIter));
+    }
+  }
+
+  // Assemble the number
+  aValue = sign * (intPart + fracPart);
+  if (gotE) {
+    aValue *= pow(10.0, expSign * exponent);
+  }
+  return true;
+}
+
+namespace mozilla {
+
+SVGSVGElement* SVGContentUtils::GetOuterSVGElement(SVGElement* aSVGElement) {
+  Element* element = nullptr;
+  Element* ancestor = aSVGElement->GetParentElementCrossingShadowRoot();
+
+  while (ancestor && ancestor->IsSVGElement() &&
+         !ancestor->IsSVGElement(nsGkAtoms::foreignObject)) {
+    element = ancestor;
+    ancestor = element->GetParentElementCrossingShadowRoot();
+  }
+
+  if (element && element->IsSVGElement(nsGkAtoms::svg)) {
+    return static_cast<SVGSVGElement*>(element);
+  }
+  return nullptr;
+}
+
+enum DashState {
+  eDashedStroke,
+  eContinuousStroke,  //< all dashes, no gaps
+  eNoStroke           //< all gaps, no dashes
+};
+
+static DashState GetStrokeDashData(
+    SVGContentUtils::AutoStrokeOptions* aStrokeOptions, SVGElement* aElement,
+    const nsStyleSVG* aStyleSVG, SVGContextPaint* aContextPaint) {
+  size_t dashArrayLength;
+  Float totalLengthOfDashes = 0.0, totalLengthOfGaps = 0.0;
+  Float pathScale = 1.0;
+
+  if (aStyleSVG->mStrokeDasharray.IsContextValue()) {
+    if (!aContextPaint) {
+      return eContinuousStroke;
+    }
+    const FallibleTArray<Float>& dashSrc = aContextPaint->GetStrokeDashArray();
+    dashArrayLength = dashSrc.Length();
+    if (dashArrayLength <= 0) {
+      return eContinuousStroke;
+    }
+    Float* dashPattern = aStrokeOptions->InitDashPattern(dashArrayLength);
+    if (!dashPattern) {
+      return eContinuousStroke;
+    }
+    for (size_t i = 0; i < dashArrayLength; i++) {
+      if (dashSrc[i] < 0.0) {
+        return eContinuousStroke;  // invalid
+      }
+      dashPattern[i] = Float(dashSrc[i]);
+      (i % 2 ? totalLengthOfGaps : totalLengthOfDashes) += dashSrc[i];
+    }
+  } else {
+    const auto dasharray = aStyleSVG->mStrokeDasharray.AsValues().AsSpan();
+    dashArrayLength = dasharray.Length();
+    if (dashArrayLength <= 0) {
+      return eContinuousStroke;
+    }
+    if (aElement->IsNodeOfType(nsINode::eSHAPE)) {
+      pathScale =
+          static_cast<SVGGeometryElement*>(aElement)->GetPathLengthScale(
+              SVGGeometryElement::eForStroking);
+      if (pathScale <= 0) {
+        return eContinuousStroke;
+      }
+    }
+    Float* dashPattern = aStrokeOptions->InitDashPattern(dashArrayLength);
+    if (!dashPattern) {
+      return eContinuousStroke;
+    }
+    for (uint32_t i = 0; i < dashArrayLength; i++) {
+      Float dashLength =
+          SVGContentUtils::CoordToFloat(aElement, dasharray[i]) * pathScale;
+      if (dashLength < 0.0) {
+        return eContinuousStroke;  // invalid
+      }
+      dashPattern[i] = dashLength;
+      (i % 2 ? totalLengthOfGaps : totalLengthOfDashes) += dashLength;
+    }
+  }
+
+  // Now that aStrokeOptions.mDashPattern is fully initialized (we didn't
+  // return early above) we can safely set mDashLength:
+  aStrokeOptions->mDashLength = dashArrayLength;
+
+  if ((dashArrayLength % 2) == 1) {
+    // If we have a dash pattern with an odd number of lengths the pattern
+    // repeats a second time, per the SVG spec., and as implemented by Moz2D.
+    // When deciding whether to return eNoStroke or eContinuousStroke below we
+    // need to take into account that in the repeat pattern the dashes become
+    // gaps, and the gaps become dashes.
+    Float origTotalLengthOfDashes = totalLengthOfDashes;
+    totalLengthOfDashes += totalLengthOfGaps;
+    totalLengthOfGaps += origTotalLengthOfDashes;
+  }
+
+  // Stroking using dashes is much slower than stroking a continuous line
+  // (see bug 609361 comment 40), and much, much slower than not stroking the
+  // line at all. Here we check for cases when the dash pattern causes the
+  // stroke to essentially be continuous or to be nonexistent in which case
+  // we can avoid expensive stroking operations (the underlying platform
+  // graphics libraries don't seem to optimize for this).
+  if (totalLengthOfGaps <= 0) {
+    return eContinuousStroke;
+  }
+  // We can only return eNoStroke if the value of stroke-linecap isn't
+  // adding caps to zero length dashes.
+  if (totalLengthOfDashes <= 0 &&
+      aStyleSVG->mStrokeLinecap == StyleStrokeLinecap::Butt) {
+    return eNoStroke;
+  }
+
+  if (aStyleSVG->mStrokeDashoffset.IsContextValue()) {
+    aStrokeOptions->mDashOffset =
+        Float(aContextPaint ? aContextPaint->GetStrokeDashOffset() : 0);
+  } else {
+    aStrokeOptions->mDashOffset =
+        SVGContentUtils::CoordToFloat(
+            aElement, aStyleSVG->mStrokeDashoffset.AsLengthPercentage()) *
+        pathScale;
+  }
+
+  return eDashedStroke;
+}
+
+void SVGContentUtils::GetStrokeOptions(AutoStrokeOptions* aStrokeOptions,
+                                       SVGElement* aElement,
+                                       const ComputedStyle* aComputedStyle,
+                                       SVGContextPaint* aContextPaint,
+                                       StrokeOptionFlags aFlags) {
+  auto doCompute = [&](const ComputedStyle* computedStyle) {
+    const nsStyleSVG* styleSVG = computedStyle->StyleSVG();
+
+    bool checkedDashAndStrokeIsDashed = false;
+    if (aFlags != eIgnoreStrokeDashing) {
+      DashState dashState =
+          GetStrokeDashData(aStrokeOptions, aElement, styleSVG, aContextPaint);
+
+      if (dashState == eNoStroke) {
+        // Hopefully this will shortcircuit any stroke operations:
+        aStrokeOptions->mLineWidth = 0;
+        return;
+      }
+      if (dashState == eContinuousStroke && aStrokeOptions->mDashPattern) {
+        // Prevent our caller from wasting time looking at a pattern without
+        // gaps:
+        aStrokeOptions->DiscardDashPattern();
+      }
+      checkedDashAndStrokeIsDashed = (dashState == eDashedStroke);
+    }
+
+    aStrokeOptions->mLineWidth =
+        GetStrokeWidth(aElement, computedStyle, aContextPaint);
+
+    aStrokeOptions->mMiterLimit = Float(styleSVG->mStrokeMiterlimit);
+
+    switch (styleSVG->mStrokeLinejoin) {
+      case StyleStrokeLinejoin::Miter:
+        aStrokeOptions->mLineJoin = JoinStyle::MITER_OR_BEVEL;
+        break;
+      case StyleStrokeLinejoin::Round:
+        aStrokeOptions->mLineJoin = JoinStyle::ROUND;
+        break;
+      case StyleStrokeLinejoin::Bevel:
+        aStrokeOptions->mLineJoin = JoinStyle::BEVEL;
+        break;
+    }
+
+    if (ShapeTypeHasNoCorners(aElement) && !checkedDashAndStrokeIsDashed) {
+      // Note: if aFlags == eIgnoreStrokeDashing then we may be returning the
+      // wrong linecap value here, since the actual linecap used on render in
+      // this case depends on whether the stroke is dashed or not.
+      aStrokeOptions->mLineCap = CapStyle::BUTT;
+    } else {
+      switch (styleSVG->mStrokeLinecap) {
+        case StyleStrokeLinecap::Butt:
+          aStrokeOptions->mLineCap = CapStyle::BUTT;
+          break;
+        case StyleStrokeLinecap::Round:
+          aStrokeOptions->mLineCap = CapStyle::ROUND;
+          break;
+        case StyleStrokeLinecap::Square:
+          aStrokeOptions->mLineCap = CapStyle::SQUARE;
+          break;
+      }
+    }
+  };
+
+  if (aComputedStyle) {
+    doCompute(aComputedStyle);
+  } else {
+    SVGGeometryProperty::DoForComputedStyle(aElement, doCompute);
+  }
+}
+
+Float SVGContentUtils::GetStrokeWidth(SVGElement* aElement,
+                                      const ComputedStyle* aComputedStyle,
+                                      SVGContextPaint* aContextPaint) {
+  Float res = 0.0;
+
+  auto doCompute = [&](ComputedStyle const* computedStyle) {
+    const nsStyleSVG* styleSVG = computedStyle->StyleSVG();
+
+    if (styleSVG->mStrokeWidth.IsContextValue()) {
+      res = aContextPaint ? aContextPaint->GetStrokeWidth() : 1.0;
+    } else {
+      res = SVGContentUtils::CoordToFloat(
+          aElement, styleSVG->mStrokeWidth.AsLengthPercentage());
+    }
+  };
+
+  if (aComputedStyle) {
+    doCompute(aComputedStyle);
+  } else {
+    SVGGeometryProperty::DoForComputedStyle(aElement, doCompute);
+  }
+
+  return res;
+}
+
+float SVGContentUtils::GetFontSize(Element* aElement) {
+  if (!aElement) {
+    return 1.0f;
+  }
+
+  nsPresContext* pc = nsContentUtils::GetContextForContent(aElement);
+  if (!pc) {
+    return 1.0f;
+  }
+
+  if (auto* f = aElement->GetPrimaryFrame()) {
+    return GetFontSize(f->Style(), pc);
+  }
+
+  if (RefPtr<ComputedStyle> style =
+          nsComputedDOMStyle::GetComputedStyleNoFlush(aElement, nullptr)) {
+    return GetFontSize(style, pc);
+  }
+
+  // ReportToConsole
+  NS_WARNING("Couldn't get ComputedStyle for content in GetFontStyle");
+  return 1.0f;
+}
+
+float SVGContentUtils::GetFontSize(nsIFrame* aFrame) {
+  MOZ_ASSERT(aFrame, "NULL frame in GetFontSize");
+  return GetFontSize(aFrame->Style(), aFrame->PresContext());
+}
+
+float SVGContentUtils::GetFontSize(ComputedStyle* aComputedStyle,
+                                   nsPresContext* aPresContext) {
+  MOZ_ASSERT(aComputedStyle);
+  MOZ_ASSERT(aPresContext);
+
+  return aComputedStyle->StyleFont()->mSize.ToCSSPixels() /
+         aPresContext->EffectiveTextZoom();
+}
+
+float SVGContentUtils::GetFontXHeight(Element* aElement) {
+  if (!aElement) {
+    return 1.0f;
+  }
+
+  nsPresContext* pc = nsContentUtils::GetContextForContent(aElement);
+  if (!pc) {
+    return 1.0f;
+  }
+
+  if (auto* f = aElement->GetPrimaryFrame()) {
+    return GetFontXHeight(f->Style(), pc);
+  }
+
+  if (RefPtr<ComputedStyle> style =
+          nsComputedDOMStyle::GetComputedStyleNoFlush(aElement, nullptr)) {
+    return GetFontXHeight(style, pc);
+  }
+
+  // ReportToConsole
+  NS_WARNING("Couldn't get ComputedStyle for content in GetFontStyle");
+  return 1.0f;
+}
+
+float SVGContentUtils::GetFontXHeight(nsIFrame* aFrame) {
+  MOZ_ASSERT(aFrame, "NULL frame in GetFontXHeight");
+  return GetFontXHeight(aFrame->Style(), aFrame->PresContext());
+}
+
+float SVGContentUtils::GetFontXHeight(ComputedStyle* aComputedStyle,
+                                      nsPresContext* aPresContext) {
+  MOZ_ASSERT(aComputedStyle && aPresContext);
+
+  RefPtr<nsFontMetrics> fontMetrics =
+      nsLayoutUtils::GetFontMetricsForComputedStyle(aComputedStyle,
+                                                    aPresContext);
+
+  if (!fontMetrics) {
+    // ReportToConsole
+    NS_WARNING("no FontMetrics in GetFontXHeight()");
+    return 1.0f;
+  }
+
+  nscoord xHeight = fontMetrics->XHeight();
+  return nsPresContext::AppUnitsToFloatCSSPixels(xHeight) /
+         aPresContext->EffectiveTextZoom();
+}
+nsresult SVGContentUtils::ReportToConsole(Document* doc, const char* aWarning,
+                                          const nsTArray<nsString>& aParams) {
+  return nsContentUtils::ReportToConsole(nsIScriptError::warningFlag, "SVG"_ns,
+                                         doc, nsContentUtils::eSVG_PROPERTIES,
+                                         aWarning, aParams);
+}
+
+bool SVGContentUtils::EstablishesViewport(nsIContent* aContent) {
+  // Although SVG 1.1 states that <image> is an element that establishes a
+  // viewport, this is really only for the document it references, not
+  // for any child content, which is what this function is used for.
+  return aContent &&
+         aContent->IsAnyOfSVGElements(nsGkAtoms::svg, nsGkAtoms::foreignObject,
+                                      nsGkAtoms::symbol);
+}
+
+SVGViewportElement* SVGContentUtils::GetNearestViewportElement(
+    const nsIContent* aContent) {
+  nsIContent* element = aContent->GetFlattenedTreeParent();
+
+  while (element && element->IsSVGElement()) {
+    if (EstablishesViewport(element)) {
+      if (element->IsSVGElement(nsGkAtoms::foreignObject)) {
+        return nullptr;
+      }
+      MOZ_ASSERT(element->IsAnyOfSVGElements(nsGkAtoms::svg, nsGkAtoms::symbol),
+                 "upcoming static_cast is only valid for "
+                 "SVGViewportElement subclasses");
+      return static_cast<SVGViewportElement*>(element);
+    }
+    element = element->GetFlattenedTreeParent();
+  }
+  return nullptr;
+}
+
+static gfx::Matrix GetCTMInternal(SVGElement* aElement, bool aScreenCTM,
+                                  bool aHaveRecursed) {
+  auto getLocalTransformHelper =
+      [](SVGElement const* e, bool shouldIncludeChildToUserSpace) -> gfxMatrix {
+    gfxMatrix ret;
+
+    if (auto* f = e->GetPrimaryFrame()) {
+      ret = SVGUtils::GetTransformMatrixInUserSpace(f);
+    } else {
+      // FIXME: Ideally we should also return the correct matrix
+      // for display:none, but currently transform related code relies
+      // heavily on the present of a frame.
+      // For now we just fall back to |PrependLocalTransformsTo| which
+      // doesn't account for CSS transform.
+      ret = e->PrependLocalTransformsTo({}, eUserSpaceToParent);
+    }
+
+    if (shouldIncludeChildToUserSpace) {
+      ret = e->PrependLocalTransformsTo({}, eChildToUserSpace) * ret;
+    }
+
+    return ret;
+  };
+
+  gfxMatrix matrix = getLocalTransformHelper(aElement, aHaveRecursed);
+
+  SVGElement* element = aElement;
+  nsIContent* ancestor = aElement->GetFlattenedTreeParent();
+
+  while (ancestor && ancestor->IsSVGElement() &&
+         !ancestor->IsSVGElement(nsGkAtoms::foreignObject)) {
+    element = static_cast<SVGElement*>(ancestor);
+    matrix *= getLocalTransformHelper(element, true);
+    if (!aScreenCTM && SVGContentUtils::EstablishesViewport(element)) {
+      if (!element->NodeInfo()->Equals(nsGkAtoms::svg, kNameSpaceID_SVG) &&
+          !element->NodeInfo()->Equals(nsGkAtoms::symbol, kNameSpaceID_SVG)) {
+        NS_ERROR("New (SVG > 1.1) SVG viewport establishing element?");
+        return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0);  // singular
+      }
+      // XXX spec seems to say x,y translation should be undone for IsInnerSVG
+      return gfx::ToMatrix(matrix);
+    }
+    ancestor = ancestor->GetFlattenedTreeParent();
+  }
+  if (!aScreenCTM) {
+    // didn't find a nearestViewportElement
+    return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0);  // singular
+  }
+  if (!element->IsSVGElement(nsGkAtoms::svg)) {
+    // Not a valid SVG fragment
+    return gfx::Matrix(0.0, 0.0, 0.0, 0.0, 0.0, 0.0);  // singular
+  }
+  if (element == aElement && !aHaveRecursed) {
+    // We get here when getScreenCTM() is called on an outer-<svg>.
+    // Consistency with other elements would have us include only the
+    // eFromUserSpace transforms, but we include the eAllTransforms
+    // transforms in this case since that's what we've been doing for
+    // a while, and it keeps us consistent with WebKit and Opera (if not
+    // really with the ambiguous spec).
+    matrix = getLocalTransformHelper(aElement, true);
+  }
+
+  if (auto* f = element->GetPrimaryFrame()) {
+    if (f->IsSVGOuterSVGFrame()) {
+      nsMargin bp = f->GetUsedBorderAndPadding();
+      matrix.PostTranslate(
+          NSAppUnitsToFloatPixels(bp.left, AppUnitsPerCSSPixel()),
+          NSAppUnitsToFloatPixels(bp.top, AppUnitsPerCSSPixel()));
+    }
+  }
+
+  if (!ancestor || !ancestor->IsElement()) {
+    return gfx::ToMatrix(matrix);
+  }
+  if (ancestor->IsSVGElement()) {
+    return gfx::ToMatrix(matrix) *
+           GetCTMInternal(static_cast<SVGElement*>(ancestor), true, true);
+  }
+
+  // XXX this does not take into account CSS transform, or that the non-SVG
+  // content that we've hit may itself be inside an SVG foreignObject higher up
+  Document* currentDoc = aElement->GetComposedDoc();
+  float x = 0.0f, y = 0.0f;
+  if (currentDoc &&
+      element->NodeInfo()->Equals(nsGkAtoms::svg, kNameSpaceID_SVG)) {
+    PresShell* presShell = currentDoc->GetPresShell();
+    if (presShell) {
+      nsIFrame* frame = element->GetPrimaryFrame();
+      nsIFrame* ancestorFrame = presShell->GetRootFrame();
+      if (frame && ancestorFrame) {
+        nsPoint point = frame->GetOffsetTo(ancestorFrame);
+        x = nsPresContext::AppUnitsToFloatCSSPixels(point.x);
+        y = nsPresContext::AppUnitsToFloatCSSPixels(point.y);
+      }
+    }
+  }
+  return ToMatrix(matrix).PostTranslate(x, y);
+}
+
+gfx::Matrix SVGContentUtils::GetCTM(SVGElement* aElement, bool aScreenCTM) {
+  return GetCTMInternal(aElement, aScreenCTM, false);
+}
+
+void SVGContentUtils::RectilinearGetStrokeBounds(
+    const Rect& aRect, const Matrix& aToBoundsSpace,
+    const Matrix& aToNonScalingStrokeSpace, float aStrokeWidth, Rect* aBounds) {
+  MOZ_ASSERT(aToBoundsSpace.IsRectilinear(),
+             "aToBoundsSpace must be rectilinear");
+  MOZ_ASSERT(aToNonScalingStrokeSpace.IsRectilinear(),
+             "aToNonScalingStrokeSpace must be rectilinear");
+
+  Matrix nonScalingToSource = aToNonScalingStrokeSpace.Inverse();
+  Matrix nonScalingToBounds = nonScalingToSource * aToBoundsSpace;
+
+  *aBounds = aToBoundsSpace.TransformBounds(aRect);
+
+  // Compute the amounts dx and dy that nonScalingToBounds scales a half-width
+  // stroke in the x and y directions, and then inflate aBounds by those amounts
+  // so that when aBounds is transformed back to non-scaling-stroke space
+  // it will map onto the correct stroked bounds.
+
+  Float dx = 0.0f;
+  Float dy = 0.0f;
+  // nonScalingToBounds is rectilinear, so either _12 and _21 are zero or _11
+  // and _22 are zero, and in each case the non-zero entries (from among _11,
+  // _12, _21, _22) simply scale the stroke width in the x and y directions.
+  if (FuzzyEqual(nonScalingToBounds._12, 0) &&
+      FuzzyEqual(nonScalingToBounds._21, 0)) {
+    dx = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._11);
+    dy = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._22);
+  } else {
+    dx = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._21);
+    dy = (aStrokeWidth / 2.0f) * std::abs(nonScalingToBounds._12);
+  }
+
+  aBounds->Inflate(dx, dy);
+}
+
+double SVGContentUtils::ComputeNormalizedHypotenuse(double aWidth,
+                                                    double aHeight) {
+  return NS_hypot(aWidth, aHeight) / M_SQRT2;
+}
+
+float SVGContentUtils::AngleBisect(float a1, float a2) {
+  float delta = std::fmod(a2 - a1, static_cast<float>(2 * M_PI));
+  if (delta < 0) {
+    delta += static_cast<float>(2 * M_PI);
+  }
+  /* delta is now the angle from a1 around to a2, in the range [0, 2*M_PI) */
+  float r = a1 + delta / 2;
+  if (delta >= M_PI) {
+    /* the arc from a2 to a1 is smaller, so use the ray on that side */
+    r += static_cast<float>(M_PI);
+  }
+  return r;
+}
+
+gfx::Matrix SVGContentUtils::GetViewBoxTransform(
+    float aViewportWidth, float aViewportHeight, float aViewboxX,
+    float aViewboxY, float aViewboxWidth, float aViewboxHeight,
+    const SVGAnimatedPreserveAspectRatio& aPreserveAspectRatio) {
+  return GetViewBoxTransform(aViewportWidth, aViewportHeight, aViewboxX,
+                             aViewboxY, aViewboxWidth, aViewboxHeight,
+                             aPreserveAspectRatio.GetAnimValue());
+}
+
+gfx::Matrix SVGContentUtils::GetViewBoxTransform(
+    float aViewportWidth, float aViewportHeight, float aViewboxX,
+    float aViewboxY, float aViewboxWidth, float aViewboxHeight,
+    const SVGPreserveAspectRatio& aPreserveAspectRatio) {
+  NS_ASSERTION(aViewportWidth >= 0, "viewport width must be nonnegative!");
+  NS_ASSERTION(aViewportHeight >= 0, "viewport height must be nonnegative!");
+  NS_ASSERTION(aViewboxWidth > 0, "viewBox width must be greater than zero!");
+  NS_ASSERTION(aViewboxHeight > 0, "viewBox height must be greater than zero!");
+
+  uint16_t align = aPreserveAspectRatio.GetAlign();
+  uint16_t meetOrSlice = aPreserveAspectRatio.GetMeetOrSlice();
+
+  // default to the defaults
+  if (align == SVG_PRESERVEASPECTRATIO_UNKNOWN)
+    align = SVG_PRESERVEASPECTRATIO_XMIDYMID;
+  if (meetOrSlice == SVG_MEETORSLICE_UNKNOWN)
+    meetOrSlice = SVG_MEETORSLICE_MEET;
+
+  float a, d, e, f;
+  a = aViewportWidth / aViewboxWidth;
+  d = aViewportHeight / aViewboxHeight;
+  e = 0.0f;
+  f = 0.0f;
+
+  if (align != SVG_PRESERVEASPECTRATIO_NONE && a != d) {
+    if ((meetOrSlice == SVG_MEETORSLICE_MEET && a < d) ||
+        (meetOrSlice == SVG_MEETORSLICE_SLICE && d < a)) {
+      d = a;
+      switch (align) {
+        case SVG_PRESERVEASPECTRATIO_XMINYMIN:
+        case SVG_PRESERVEASPECTRATIO_XMIDYMIN:
+        case SVG_PRESERVEASPECTRATIO_XMAXYMIN:
+          break;
+        case SVG_PRESERVEASPECTRATIO_XMINYMID:
+        case SVG_PRESERVEASPECTRATIO_XMIDYMID:
+        case SVG_PRESERVEASPECTRATIO_XMAXYMID:
+          f = (aViewportHeight - a * aViewboxHeight) / 2.0f;
+          break;
+        case SVG_PRESERVEASPECTRATIO_XMINYMAX:
+        case SVG_PRESERVEASPECTRATIO_XMIDYMAX:
+        case SVG_PRESERVEASPECTRATIO_XMAXYMAX:
+          f = aViewportHeight - a * aViewboxHeight;
+          break;
+        default:
+          MOZ_ASSERT_UNREACHABLE("Unknown value for align");
+      }
+    } else if ((meetOrSlice == SVG_MEETORSLICE_MEET && d < a) ||
+               (meetOrSlice == SVG_MEETORSLICE_SLICE && a < d)) {
+      a = d;
+      switch (align) {
+        case SVG_PRESERVEASPECTRATIO_XMINYMIN:
+        case SVG_PRESERVEASPECTRATIO_XMINYMID:
+        case SVG_PRESERVEASPECTRATIO_XMINYMAX:
+          break;
+        case SVG_PRESERVEASPECTRATIO_XMIDYMIN:
+        case SVG_PRESERVEASPECTRATIO_XMIDYMID:
+        case SVG_PRESERVEASPECTRATIO_XMIDYMAX:
+          e = (aViewportWidth - a * aViewboxWidth) / 2.0f;
+          break;
+        case SVG_PRESERVEASPECTRATIO_XMAXYMIN:
+        case SVG_PRESERVEASPECTRATIO_XMAXYMID:
+        case SVG_PRESERVEASPECTRATIO_XMAXYMAX:
+          e = aViewportWidth - a * aViewboxWidth;
+          break;
+        default:
+          MOZ_ASSERT_UNREACHABLE("Unknown value for align");
+      }
+    } else
+      MOZ_ASSERT_UNREACHABLE("Unknown value for meetOrSlice");
+  }
+
+  if (aViewboxX) e += -a * aViewboxX;
+  if (aViewboxY) f += -d * aViewboxY;
+
+  return gfx::Matrix(a, 0.0f, 0.0f, d, e, f);
+}
+
+template <class floatType>
+bool SVGContentUtils::ParseNumber(RangedPtr<const char16_t>& aIter,
+                                  const RangedPtr<const char16_t>& aEnd,
+                                  floatType& aValue) {
+  RangedPtr<const char16_t> iter(aIter);
+
+  double value;
+  if (!::ParseNumber(iter, aEnd, value)) {
+    return false;
+  }
+  floatType floatValue = floatType(value);
+  if (!IsFinite(floatValue)) {
+    return false;
+  }
+  aValue = floatValue;
+  aIter = iter;
+  return true;
+}
+
+template bool SVGContentUtils::ParseNumber<float>(
+    RangedPtr<const char16_t>& aIter, const RangedPtr<const char16_t>& aEnd,
+    float& aValue);
+
+template bool SVGContentUtils::ParseNumber<double>(
+    RangedPtr<const char16_t>& aIter, const RangedPtr<const char16_t>& aEnd,
+    double& aValue);
+
+RangedPtr<const char16_t> SVGContentUtils::GetStartRangedPtr(
+    const nsAString& aString) {
+  return RangedPtr<const char16_t>(aString.Data(), aString.Length());
+}
+
+RangedPtr<const char16_t> SVGContentUtils::GetEndRangedPtr(
+    const nsAString& aString) {
+  return RangedPtr<const char16_t>(aString.Data() + aString.Length(),
+                                   aString.Data(), aString.Length());
+}
+
+template <class floatType>
+bool SVGContentUtils::ParseNumber(const nsAString& aString, floatType& aValue) {
+  RangedPtr<const char16_t> iter = GetStartRangedPtr(aString);
+  const RangedPtr<const char16_t> end = GetEndRangedPtr(aString);
+
+  return ParseNumber(iter, end, aValue) && iter == end;
+}
+
+template bool SVGContentUtils::ParseNumber<float>(const nsAString& aString,
+                                                  float& aValue);
+template bool SVGContentUtils::ParseNumber<double>(const nsAString& aString,
+                                                   double& aValue);
+
+/* static */
+bool SVGContentUtils::ParseInteger(RangedPtr<const char16_t>& aIter,
+                                   const RangedPtr<const char16_t>& aEnd,
+                                   int32_t& aValue) {
+  RangedPtr<const char16_t> iter(aIter);
+
+  int32_t sign;
+  if (!ParseOptionalSign(iter, aEnd, sign)) {
+    return false;
+  }
+
+  if (!mozilla::IsAsciiDigit(*iter)) {
+    return false;
+  }
+
+  int64_t value = 0;
+
+  do {
+    if (value <= std::numeric_limits<int32_t>::max()) {
+      value = 10 * value + mozilla::AsciiAlphanumericToNumber(*iter);
+    }
+    ++iter;
+  } while (iter != aEnd && mozilla::IsAsciiDigit(*iter));
+
+  aIter = iter;
+  aValue = int32_t(clamped(sign * value,
+                           int64_t(std::numeric_limits<int32_t>::min()),
+                           int64_t(std::numeric_limits<int32_t>::max())));
+  return true;
+}
+
+/* static */
+bool SVGContentUtils::ParseInteger(const nsAString& aString, int32_t& aValue) {
+  RangedPtr<const char16_t> iter = GetStartRangedPtr(aString);
+  const RangedPtr<const char16_t> end = GetEndRangedPtr(aString);
+
+  return ParseInteger(iter, end, aValue) && iter == end;
+}
+
+float SVGContentUtils::CoordToFloat(SVGElement* aContent,
+                                    const LengthPercentage& aLength,
+                                    uint8_t aCtxType) {
+  float result = aLength.ResolveToCSSPixelsWith([&] {
+    SVGViewportElement* ctx = aContent->GetCtx();
+    return CSSCoord(ctx ? ctx->GetLength(aCtxType) : 0.0f);
+  });
+  if (aLength.IsCalc()) {
+    const auto& calc = aLength.AsCalc();
+    if (calc.clamping_mode == StyleAllowedNumericType::NonNegative) {
+      result = std::max(result, 0.0f);
+    } else {
+      MOZ_ASSERT(calc.clamping_mode == StyleAllowedNumericType::All);
+    }
+  }
+  return result;
+}
+
+already_AddRefed<gfx::Path> SVGContentUtils::GetPath(
+    const nsAString& aPathString) {
+  SVGPathData pathData;
+  SVGPathDataParser parser(aPathString, &pathData);
+  if (!parser.Parse()) {
+    return nullptr;
+  }
+
+  RefPtr<DrawTarget> drawTarget =
+      gfxPlatform::GetPlatform()->ScreenReferenceDrawTarget();
+  RefPtr<PathBuilder> builder =
+      drawTarget->CreatePathBuilder(FillRule::FILL_WINDING);
+
+  return pathData.BuildPath(builder, StyleStrokeLinecap::Butt, 1);
+}
+
+bool SVGContentUtils::ShapeTypeHasNoCorners(const nsIContent* aContent) {
+  return aContent &&
+         aContent->IsAnyOfSVGElements(nsGkAtoms::circle, nsGkAtoms::ellipse);
+}
+
+nsDependentSubstring SVGContentUtils::GetAndEnsureOneToken(
+    const nsAString& aString, bool& aSuccess) {
+  nsWhitespaceTokenizerTemplate<nsContentUtils::IsHTMLWhitespace> tokenizer(
+      aString);
+
+  aSuccess = false;
+  if (!tokenizer.hasMoreTokens()) {
+    return {};
+  }
+  auto token = tokenizer.nextToken();
+  if (tokenizer.hasMoreTokens()) {
+    return {};
+  }
+
+  aSuccess = true;
+  return token;
+}
+
+}  // namespace mozilla