Bug 1915971 - Simplify PrependLocalTransformsTo. r=longsonr

emilio · emilio · commit 748004681d7d · 2024-09-02T11:05:34.000Z
Now that there's only one transform kind seems worth doing this. Differential Revision: https://phabricator.services.mozilla.com/D220733
diff --git a/dom/svg/SVGContentUtils.cpp b/dom/svg/SVGContentUtils.cpp
@@ -496,15 +496,12 @@ static gfx::Matrix GetCTMInternal(SVGElement* aElement, CTMType aCTMType,
   auto getLocalTransformHelper =
       [](SVGElement const* e, bool shouldIncludeChildToUserSpace) -> gfxMatrix {
     gfxMatrix ret;
-
     if (auto* f = e->GetPrimaryFrame()) {
       ret = SVGUtils::GetTransformMatrixInUserSpace(f);
     }
-
     if (shouldIncludeChildToUserSpace) {
-      ret = e->PrependLocalTransformsTo({}, eChildToUserSpace) * ret;
+      ret = e->ChildToUserSpaceTransform() * ret;
     }
-
     return ret;
   };
 
diff --git a/dom/svg/SVGContentUtils.h b/dom/svg/SVGContentUtils.h
@@ -41,26 +41,6 @@ class SVGViewportElement;
 
 #define SVG_ZERO_LENGTH_PATH_FIX_FACTOR 512
 
-/**
- * SVGTransformTypes controls the transforms that PrependLocalTransformsTo
- * applies.
- *
- * If aWhich is eAllTransforms, then all the transforms from the coordinate
- * space established by this element for its children to the coordinate
- * space established by this element's parent element for this element, are
- * included.
- *
- * If aWhich is eChildToUserSpace, then only the transforms from the
- * coordinate space established by this element for its childre to this
- * elements userspace are included. This includes any offsets due to e.g.
- * 'x'/'y' attributes, and any transform due to a 'viewBox' attribute, but
- * does not include any transforms due to the 'transform' attribute.
- */
-enum SVGTransformTypes {
-  eAllTransforms,
-  eChildToUserSpace
-};
-
 /**
  * Functions generally used by SVG Content classes. Functions here
  * should not generally depend on layout methods/classes e.g. SVGUtils
diff --git a/dom/svg/SVGElement.cpp b/dom/svg/SVGElement.cpp
@@ -1564,10 +1564,7 @@ SVGViewportElement* SVGElement::GetCtx() const {
 }
 
 /* virtual */
-gfxMatrix SVGElement::PrependLocalTransformsTo(const gfxMatrix& aMatrix,
-                                               SVGTransformTypes aWhich) const {
-  return aMatrix;
-}
+gfxMatrix SVGElement::ChildToUserSpaceTransform() const { return {}; }
 
 SVGElement::LengthAttributesInfo SVGElement::GetLengthInfo() {
   return LengthAttributesInfo(nullptr, nullptr, 0);
diff --git a/dom/svg/SVGElement.h b/dom/svg/SVGElement.h
@@ -135,23 +135,12 @@ class SVGElement : public SVGElementBase  // nsIContent
   mozilla::dom::SVGViewportElement* GetCtx() const;
 
   /**
-   * Returns aMatrix pre-multiplied by (explicit or implicit) transforms that
-   * are introduced by attributes on this element.
-   *
-   * If aWhich is eAllTransforms, then all the transforms from the coordinate
-   * space established by this element for its children to the coordinate
-   * space established by this element's parent element for this element, are
-   * included.
-   *
-   * If aWhich is eChildToUserSpace, then only the transforms from the
-   * coordinate space established by this element for its childre to this
-   * elements userspace are included. This includes any offsets due to e.g.
-   * 'x'/'y' attributes, and any transform due to a 'viewBox' attribute, but
-   * does not include any transforms due to the 'transform' attribute.
+   * Returns the transforms from the coordinate space established by this
+   * element for its children to this element's userspace. This includes any
+   * offsets due to e.g. 'x'/'y' attributes, and any transform due to a
+   * 'viewBox' attribute.
    */
-  virtual gfxMatrix PrependLocalTransformsTo(
-      const gfxMatrix& aMatrix,
-      SVGTransformTypes aWhich = eAllTransforms) const;
+  virtual gfxMatrix ChildToUserSpaceTransform() const;
 
   // Setter for to set the current <animateMotion> transformation
   // Only visible for SVGGraphicElement, so it's a no-op here, and that
diff --git a/dom/svg/SVGForeignObjectElement.cpp b/dom/svg/SVGForeignObjectElement.cpp
@@ -68,23 +68,16 @@ already_AddRefed<DOMSVGAnimatedLength> SVGForeignObjectElement::Height() {
 //----------------------------------------------------------------------
 // SVGElement methods
 
-/* virtual */
-gfxMatrix SVGForeignObjectElement::PrependLocalTransformsTo(
-    const gfxMatrix& aMatrix, SVGTransformTypes aWhich) const {
+gfxMatrix SVGForeignObjectElement::ChildToUserSpaceTransform() const {
   // our 'x' and 'y' attributes:
   float x, y;
-
   if (!SVGGeometryProperty::ResolveAll<SVGT::X, SVGT::Y>(this, &x, &y)) {
     // This function might be called for element in display:none subtree
     // (e.g. getScreenCTM), we fall back to use SVG attributes.
     const_cast<SVGForeignObjectElement*>(this)->GetAnimatedLengthValues(
         &x, &y, nullptr);
   }
-
-  gfxMatrix toUserSpace = gfxMatrix::Translation(x, y);
-  MOZ_ASSERT(aWhich == eAllTransforms || aWhich == eChildToUserSpace,
-             "Unknown TransformTypes");
-  return toUserSpace * aMatrix;
+  return gfxMatrix::Translation(x, y);
 }
 
 /* virtual */
diff --git a/dom/svg/SVGForeignObjectElement.h b/dom/svg/SVGForeignObjectElement.h
@@ -32,9 +32,7 @@ class SVGForeignObjectElement final : public SVGGraphicsElement {
 
  public:
   // SVGElement specializations:
-  gfxMatrix PrependLocalTransformsTo(
-      const gfxMatrix& aMatrix,
-      SVGTransformTypes aWhich = eAllTransforms) const override;
+  gfxMatrix ChildToUserSpaceTransform() const override;
   bool HasValidDimensions() const override;
 
   // nsIContent interface
diff --git a/dom/svg/SVGSVGElement.h b/dom/svg/SVGSVGElement.h
@@ -9,6 +9,7 @@
 
 #include "SVGAnimatedEnumeration.h"
 #include "SVGViewportElement.h"
+#include "mozilla/SVGImageContext.h"
 
 nsresult NS_NewSVGSVGElement(
     nsIContent** aResult, already_AddRefed<mozilla::dom::NodeInfo>&& aNodeInfo,
diff --git a/dom/svg/SVGUseElement.cpp b/dom/svg/SVGUseElement.cpp
@@ -604,18 +604,12 @@ void SVGUseElement::UnlinkSource() {
 // SVGElement methods
 
 /* virtual */
-gfxMatrix SVGUseElement::PrependLocalTransformsTo(
-    const gfxMatrix& aMatrix, SVGTransformTypes aWhich) const {
-  // our 'x' and 'y' attributes:
+gfxMatrix SVGUseElement::ChildToUserSpaceTransform() const {
   float x, y;
   if (!SVGGeometryProperty::ResolveAll<SVGT::X, SVGT::Y>(this, &x, &y)) {
     const_cast<SVGUseElement*>(this)->GetAnimatedLengthValues(&x, &y, nullptr);
   }
-
-  gfxMatrix childToUser = gfxMatrix::Translation(x, y);
-  MOZ_ASSERT(aWhich == eChildToUserSpace || aWhich == eAllTransforms,
-             "Unknown TransformTypes");
-  return childToUser * aMatrix;
+  return gfxMatrix::Translation(x, y);
 }
 
 /* virtual */
diff --git a/dom/svg/SVGUseElement.h b/dom/svg/SVGUseElement.h
@@ -64,9 +64,7 @@ class SVGUseElement final : public SVGUseElementBase,
   NS_DECL_NSIMUTATIONOBSERVER_NODEWILLBEDESTROYED
 
   // SVGElement specializations:
-  gfxMatrix PrependLocalTransformsTo(
-      const gfxMatrix& aMatrix,
-      SVGTransformTypes aWhich = eAllTransforms) const override;
+  gfxMatrix ChildToUserSpaceTransform() const override;
   bool HasValidDimensions() const override;
 
   // nsIContent interface
diff --git a/dom/svg/SVGViewportElement.cpp b/dom/svg/SVGViewportElement.cpp
@@ -237,31 +237,23 @@ float SVGViewportElement::GetLength(uint8_t aCtxType) const {
 // SVGElement methods
 
 /* virtual */
-gfxMatrix SVGViewportElement::PrependLocalTransformsTo(
-    const gfxMatrix& aMatrix, SVGTransformTypes aWhich) const {
-  gfxMatrix childToUser;
-
+gfxMatrix SVGViewportElement::ChildToUserSpaceTransform() const {
+  auto viewBox = GetViewBoxTransform();
   if (IsInner()) {
     float x, y;
     const_cast<SVGViewportElement*>(this)->GetAnimatedLengthValues(&x, &y,
                                                                    nullptr);
-    childToUser = ThebesMatrix(GetViewBoxTransform().PostTranslate(x, y));
-  } else if (IsRootSVGSVGElement()) {
+    return ThebesMatrix(viewBox.PostTranslate(x, y));
+  }
+  if (IsRootSVGSVGElement()) {
     const auto* svg = static_cast<const SVGSVGElement*>(this);
     const SVGPoint& translate = svg->GetCurrentTranslate();
     float scale = svg->CurrentScale();
-    childToUser =
-        ThebesMatrix(GetViewBoxTransform()
-                         .PostScale(scale, scale)
-                         .PostTranslate(translate.GetX(), translate.GetY()));
-  } else {
-    // outer-<svg>, but inline in some other content:
-    childToUser = ThebesMatrix(GetViewBoxTransform());
+    return ThebesMatrix(viewBox.PostScale(scale, scale)
+                            .PostTranslate(translate.GetX(), translate.GetY()));
   }
-
-  MOZ_ASSERT(aWhich == eAllTransforms || aWhich == eChildToUserSpace,
-             "Unknown TransformTypes");
-  return childToUser * aMatrix;
+  // outer-<svg>, but inline in some other content:
+  return ThebesMatrix(viewBox);
 }
 
 /* virtual */
diff --git a/dom/svg/SVGViewportElement.h b/dom/svg/SVGViewportElement.h
@@ -8,9 +8,6 @@
 #define DOM_SVG_SVGVIEWPORTELEMENT_H_
 
 #include "mozilla/Attributes.h"
-#include "mozilla/SVGImageContext.h"
-#include "mozilla/UniquePtr.h"
-#include "mozilla/dom/FromParser.h"
 #include "nsIContentInlines.h"
 #include "SVGAnimatedEnumeration.h"
 #include "SVGAnimatedLength.h"
@@ -45,9 +42,7 @@ class SVGViewportElement : public SVGGraphicsElement {
   NS_IMETHOD_(bool) IsAttributeMapped(const nsAtom* aAttribute) const override;
 
   // SVGElement specializations:
-  gfxMatrix PrependLocalTransformsTo(
-      const gfxMatrix& aMatrix,
-      SVGTransformTypes aWhich = eAllTransforms) const override;
+  gfxMatrix ChildToUserSpaceTransform() const override;
 
   bool HasValidDimensions() const override;
 
diff --git a/layout/svg/ISVGDisplayableFrame.h b/layout/svg/ISVGDisplayableFrame.h
@@ -125,7 +125,7 @@ class ISVGDisplayableFrame : public nsQueryFrame {
    * SVG defines an element's bbox to be the element's fill bounds in the
    * userspace established by that element. By allowing callers to pass in the
    * transform from the userspace established by this element to the userspace
-   * established by an an ancestor, this method allows callers to obtain this
+   * established by an ancestor, this method allows callers to obtain this
    * element's fill bounds in the userspace established by that ancestor
    * instead. In that case, since we return the bounds in a different userspace
    * (the ancestor's), the bounds we return are not this element's bbox, but
diff --git a/layout/svg/SVGContainerFrame.cpp b/layout/svg/SVGContainerFrame.cpp
@@ -217,7 +217,7 @@ void SVGDisplayContainerFrame::PaintSVG(gfxContext& aContext,
 
   gfxMatrix matrix = aTransform;
   if (auto* svg = SVGElement::FromNode(GetContent())) {
-    matrix = svg->PrependLocalTransformsTo(matrix, eChildToUserSpace);
+    matrix = svg->ChildToUserSpaceTransform() * matrix;
     if (matrix.IsSingular()) {
       return;
     }
@@ -250,7 +250,7 @@ nsIFrame* SVGDisplayContainerFrame::GetFrameForPoint(const gfxPoint& aPoint) {
   // for its children (e.g. take account of any 'viewBox' attribute):
   gfxPoint point = aPoint;
   if (const auto* svg = SVGElement::FromNode(GetContent())) {
-    gfxMatrix m = svg->PrependLocalTransformsTo({}, eChildToUserSpace);
+    gfxMatrix m = svg->ChildToUserSpaceTransform();
     if (!m.IsIdentity()) {
       if (!m.Invert()) {
         return nullptr;
@@ -399,7 +399,7 @@ SVGBBox SVGDisplayContainerFrame::GetBBoxContribution(
     }
     gfxMatrix transform = gfx::ThebesMatrix(aToBBoxUserspace);
     if (svg) {
-      transform = svg->PrependLocalTransformsTo({}, eChildToUserSpace) *
+      transform = svg->ChildToUserSpaceTransform() *
                   SVGUtils::GetTransformMatrixInUserSpace(kid) * transform;
     }
     // We need to include zero width/height vertical/horizontal lines, so we
@@ -414,13 +414,10 @@ SVGBBox SVGDisplayContainerFrame::GetBBoxContribution(
 gfxMatrix SVGDisplayContainerFrame::GetCanvasTM() {
   if (!mCanvasTM) {
     NS_ASSERTION(GetParent(), "null parent");
-
     auto* parent = static_cast<SVGContainerFrame*>(GetParent());
     auto* content = static_cast<SVGElement*>(GetContent());
-
-    gfxMatrix tm = content->PrependLocalTransformsTo(parent->GetCanvasTM());
-
-    mCanvasTM = MakeUnique<gfxMatrix>(tm);
+    mCanvasTM = MakeUnique<gfxMatrix>(content->ChildToUserSpaceTransform() *
+                                      parent->GetCanvasTM());
   }
 
   return *mCanvasTM;
diff --git a/layout/svg/SVGForeignObjectFrame.cpp b/layout/svg/SVGForeignObjectFrame.cpp
@@ -366,13 +366,10 @@ SVGBBox SVGForeignObjectFrame::GetBBoxContribution(
 gfxMatrix SVGForeignObjectFrame::GetCanvasTM() {
   if (!mCanvasTM) {
     NS_ASSERTION(GetParent(), "null parent");
-
     auto* parent = static_cast<SVGContainerFrame*>(GetParent());
     auto* content = static_cast<SVGForeignObjectElement*>(GetContent());
-
-    gfxMatrix tm = content->PrependLocalTransformsTo(parent->GetCanvasTM());
-
-    mCanvasTM = MakeUnique<gfxMatrix>(tm);
+    mCanvasTM = MakeUnique<gfxMatrix>(content->ChildToUserSpaceTransform() *
+                                      parent->GetCanvasTM());
   }
   return *mCanvasTM;
 }
diff --git a/layout/svg/SVGGeometryFrame.cpp b/layout/svg/SVGGeometryFrame.cpp
@@ -530,8 +530,7 @@ gfxMatrix SVGGeometryFrame::GetCanvasTM() {
 
   auto* parent = static_cast<SVGContainerFrame*>(GetParent());
   auto* content = static_cast<SVGGraphicsElement*>(GetContent());
-
-  return content->PrependLocalTransformsTo(parent->GetCanvasTM());
+  return content->ChildToUserSpaceTransform() * parent->GetCanvasTM();
 }
 
 void SVGGeometryFrame::Render(gfxContext* aContext, uint32_t aRenderComponents,
diff --git a/layout/svg/SVGOuterSVGFrame.cpp b/layout/svg/SVGOuterSVGFrame.cpp
@@ -634,7 +634,7 @@ SVGBBox SVGOuterSVGFrame::GetBBoxContribution(
           !PrincipalChildList().FirstChild()->GetNextSibling(),
       "We should have a single, anonymous, child");
   // We must defer to our child so that we don't include our
-  // content->PrependLocalTransformsTo() transforms.
+  // content->ChildToUserSpaceTransform() transform.
   auto* anonKid = static_cast<SVGOuterSVGAnonChildFrame*>(
       PrincipalChildList().FirstChild());
   return anonKid->GetBBoxContribution(aToBBoxUserspace, aFlags);
@@ -649,8 +649,8 @@ gfxMatrix SVGOuterSVGFrame::GetCanvasTM() {
     float devPxPerCSSPx = 1.0f / nsPresContext::AppUnitsToFloatCSSPixels(
                                      PresContext()->AppUnitsPerDevPixel());
 
-    gfxMatrix tm = content->PrependLocalTransformsTo(
-        gfxMatrix::Scaling(devPxPerCSSPx, devPxPerCSSPx));
+    gfxMatrix tm = content->ChildToUserSpaceTransform().PostScale(
+        devPxPerCSSPx, devPxPerCSSPx);
     mCanvasTM = MakeUnique<gfxMatrix>(tm);
   }
   return *mCanvasTM;
@@ -797,9 +797,9 @@ bool SVGOuterSVGFrame::HasChildrenOnlyTransform(Matrix* aTransform) const {
     return false;
   }
   if (aTransform) {
-    // Outer-<svg> doesn't use x/y, so we can pass eChildToUserSpace here.
-    *aTransform = gfx::ToMatrix(
-        content->PrependLocalTransformsTo(gfxMatrix(), eChildToUserSpace));
+    // Outer-<svg> doesn't use x/y, so we can use the child-to-user-space
+    // transform here.
+    *aTransform = gfx::ToMatrix(content->ChildToUserSpaceTransform());
     if (aTransform->HasNonTranslation()) {
       // The nsDisplayTransform code will apply this transform to our inner kid,
       // including to its frame position.  We don't want our frame position to
diff --git a/layout/svg/SVGSwitchFrame.cpp b/layout/svg/SVGSwitchFrame.cpp
@@ -229,9 +229,9 @@ SVGBBox SVGSwitchFrame::GetBBoxContribution(const Matrix& aToBBoxUserspace,
     nsIContent* content = kid->GetContent();
     gfxMatrix transform = ThebesMatrix(aToBBoxUserspace);
     if (content->IsSVGElement()) {
-      transform = static_cast<SVGElement*>(content)->PrependLocalTransformsTo(
-                      {}, eChildToUserSpace) *
-                  SVGUtils::GetTransformMatrixInUserSpace(kid) * transform;
+      transform =
+          static_cast<SVGElement*>(content)->ChildToUserSpaceTransform() *
+          SVGUtils::GetTransformMatrixInUserSpace(kid) * transform;
     }
     return svgKid->GetBBoxContribution(ToMatrix(transform), aFlags);
   }
@@ -241,7 +241,6 @@ SVGBBox SVGSwitchFrame::GetBBoxContribution(const Matrix& aToBBoxUserspace,
 nsIFrame* SVGSwitchFrame::GetActiveChildFrame() {
   auto* activeChild =
       static_cast<dom::SVGSwitchElement*>(GetContent())->GetActiveChild();
-
   return activeChild ? activeChild->GetPrimaryFrame() : nullptr;
 }
 
diff --git a/layout/svg/SVGUtils.cpp b/layout/svg/SVGUtils.cpp
@@ -347,7 +347,7 @@ gfxMatrix SVGUtils::GetCanvasTM(nsIFrame* aFrame) {
   auto* parent = static_cast<SVGContainerFrame*>(aFrame->GetParent());
   auto* content = static_cast<SVGElement*>(aFrame->GetContent());
 
-  return content->PrependLocalTransformsTo(parent->GetCanvasTM());
+  return content->ChildToUserSpaceTransform() * parent->GetCanvasTM();
 }
 
 bool SVGUtils::GetParentSVGTransforms(const nsIFrame* aFrame,
@@ -888,8 +888,8 @@ gfxRect SVGUtils::GetBBox(nsIFrame* aFrame, uint32_t aFlags,
     // NOTE: When changing this to apply to other frame types, make sure to
     // also update SVGUtils::FrameSpaceInCSSPxToUserSpaceOffset.
     MOZ_ASSERT(aFrame->GetContent()->IsSVGElement(), "bad cast");
-    SVGElement* element = static_cast<SVGElement*>(aFrame->GetContent());
-    matrix = element->PrependLocalTransformsTo(matrix, eChildToUserSpace);
+    auto* element = static_cast<SVGElement*>(aFrame->GetContent());
+    matrix = element->ChildToUserSpaceTransform() * matrix;
   }
   gfxRect bbox =
       svg->GetBBoxContribution(ToMatrix(matrix), aFlags).ToThebesRect();
@@ -966,9 +966,8 @@ gfxPoint SVGUtils::FrameSpaceInCSSPxToUserSpaceOffset(const nsIFrame* aFrame) {
   // For foreignObject frames, SVGUtils::GetBBox applies their local
   // transform, so we need to do the same here.
   if (aFrame->IsSVGForeignObjectFrame()) {
-    gfxMatrix transform =
-        static_cast<SVGElement*>(aFrame->GetContent())
-            ->PrependLocalTransformsTo(gfxMatrix(), eChildToUserSpace);
+    gfxMatrix transform = static_cast<SVGElement*>(aFrame->GetContent())
+                              ->ChildToUserSpaceTransform();
     NS_ASSERTION(!transform.HasNonTranslation(),
                  "we're relying on this being an offset-only transform");
     return transform.GetTranslation();
@@ -1462,9 +1461,9 @@ bool SVGUtils::GetSVGGlyphExtents(const Element* aElement,
     return false;
   }
 
-  gfxMatrix transform(aSVGToAppSpace);
+  gfxMatrix transform = aSVGToAppSpace;
   if (auto* svg = SVGElement::FromNode(frame->GetContent())) {
-    transform = svg->PrependLocalTransformsTo(aSVGToAppSpace);
+    transform = svg->ChildToUserSpaceTransform() * transform;
   }
 
   *aResult =
