Bug 1546894 - Keep track of current and begin points in path objects in case we'll create a builder from them. r=lsalzman

Because of the way the canvas 2D implementation juggles between path builders and paths, we have to keep track of current and first points in the path, in case a builder is created out of it.

Differential Revision: https://phabricator.services.mozilla.com/D33757

--HG--
extra : source : c79b3af2395894b449731fccdd9eb006b4d0189e

gfx/2d/2D.h

@@ -587,10 +587,31 @@ class PathSink : public RefCounted<PathSink> {
   /** Add an arc to the current figure */
   virtual void Arc(const Point& aOrigin, float aRadius, float aStartAngle,
                    float aEndAngle, bool aAntiClockwise = false) = 0;
+
+  virtual Point CurrentPoint() const {
+    return mCurrentPoint;
+  }
+
+  virtual Point BeginPoint() const {
+    return mBeginPoint;
+  }
+
+  virtual void SetCurrentPoint(const Point& aPoint) {
+    mCurrentPoint = aPoint;
+  }
+
+  virtual void SetBeginPoint(const Point& aPoint) {
+    mBeginPoint = aPoint;
+  }
+
+protected:
   /** Point the current subpath is at - or where the next subpath will start
    * if there is no active subpath.
    */
-  virtual Point CurrentPoint() const = 0;
+  Point mCurrentPoint;
+
+  /** Position of the previous MoveTo operation. */
+  Point mBeginPoint;
 };
 
 class PathBuilder;

gfx/2d/Path.cpp

@@ -75,7 +75,7 @@ void FlattenedPath::MoveTo(const Point& aPoint) {
   op.mPoint = aPoint;
   mPathOps.push_back(op);
 
-  mLastMove = aPoint;
+  mBeginPoint = aPoint;
 }
 
 void FlattenedPath::LineTo(const Point& aPoint) {
@@ -109,7 +109,7 @@ void FlattenedPath::QuadraticBezierTo(const Point& aCP1, const Point& aCP2) {
 
 void FlattenedPath::Close() {
   MOZ_ASSERT(!mCalculatedLength);
-  LineTo(mLastMove);
+  LineTo(mBeginPoint);
 }
 
 void FlattenedPath::Arc(const Point& aOrigin, float aRadius, float aStartAngle,

gfx/2d/PathAnalysis.h

@@ -45,7 +45,6 @@ class FlattenedPath : public PathSink {
  private:
   Float mCachedLength;
   bool mCalculatedLength;
-  Point mLastMove;
 
   std::vector<FlatPathOp> mPathOps;
 };

gfx/2d/PathCairo.cpp

@@ -102,18 +102,18 @@ void PathBuilderCairo::Arc(const Point& aOrigin, float aRadius,
               aAntiClockwise);
 }
 
-Point PathBuilderCairo::CurrentPoint() const { return mCurrentPoint; }
-
 already_AddRefed<Path> PathBuilderCairo::Finish() {
-  return MakeAndAddRef<PathCairo>(mFillRule, mPathData, mCurrentPoint);
+  return MakeAndAddRef<PathCairo>(mFillRule, mPathData, mCurrentPoint, mBeginPoint);
 }
 
 PathCairo::PathCairo(FillRule aFillRule,
                      std::vector<cairo_path_data_t>& aPathData,
-                     const Point& aCurrentPoint)
+                     const Point& aCurrentPoint,
+                     const Point& aBeginPoint)
     : mFillRule(aFillRule),
       mContainingContext(nullptr),
-      mCurrentPoint(aCurrentPoint) {
+      mCurrentPoint(aCurrentPoint),
+      mBeginPoint(aBeginPoint) {
   mPathData.swap(aPathData);
 }
 
@@ -143,6 +143,7 @@ already_AddRefed<PathBuilder> PathCairo::CopyToBuilder(
 
   builder->mPathData = mPathData;
   builder->mCurrentPoint = mCurrentPoint;
+  builder->mBeginPoint = mBeginPoint;
 
   return builder.forget();
 }
@@ -153,6 +154,7 @@ already_AddRefed<PathBuilder> PathCairo::TransformedCopyToBuilder(
 
   AppendPathToBuilder(builder, &aTransform);
   builder->mCurrentPoint = aTransform.TransformPoint(mCurrentPoint);
+  builder->mBeginPoint = aTransform.TransformPoint(mBeginPoint);
 
   return builder.forget();
 }

gfx/2d/PathCairo.h

@@ -30,7 +30,6 @@ class PathBuilderCairo : public PathBuilder {
   void Close() override;
   void Arc(const Point& aOrigin, float aRadius, float aStartAngle,
            float aEndAngle, bool aAntiClockwise = false) override;
-  Point CurrentPoint() const override;
   already_AddRefed<Path> Finish() override;
 
   BackendType GetBackendType() const override { return BackendType::CAIRO; }
@@ -40,10 +39,6 @@ class PathBuilderCairo : public PathBuilder {
 
   FillRule mFillRule;
   std::vector<cairo_path_data_t> mPathData;
-  // It's easiest to track this here, parsing the path data to find the current
-  // point is a little tricky.
-  Point mCurrentPoint;
-  Point mBeginPoint;
 };
 
 class PathCairo : public Path {
@@ -51,7 +46,7 @@ class PathCairo : public Path {
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(PathCairo, override)
 
   PathCairo(FillRule aFillRule, std::vector<cairo_path_data_t>& aPathData,
-            const Point& aCurrentPoint);
+            const Point& aCurrentPoint, const Point& aBeginPoint);
   explicit PathCairo(cairo_t* aContext);
   virtual ~PathCairo();
 
@@ -91,6 +86,7 @@ class PathCairo : public Path {
   mutable cairo_t* mContainingContext;
   mutable Matrix mContainingTransform;
   Point mCurrentPoint;
+  Point mBeginPoint;
 };
 
 }  // namespace gfx

gfx/2d/PathCapture.cpp

@@ -17,7 +17,7 @@ void PathBuilderCapture::MoveTo(const Point& aPoint) {
   op.mP1 = aPoint;
   mPathOps.push_back(op);
   mCurrentPoint = aPoint;
-  mFirstPoint = aPoint;
+  mBeginPoint = aPoint;
 }
 
 void PathBuilderCapture::LineTo(const Point& aPoint) {
@@ -68,16 +68,16 @@ void PathBuilderCapture::Close() {
   PathOp op;
   op.mType = PathOp::OP_CLOSE;
   mPathOps.push_back(op);
-  mCurrentPoint = mFirstPoint;
+  mCurrentPoint = mBeginPoint;
 }
 
-Point PathBuilderCapture::CurrentPoint() const { return mCurrentPoint; }
-
 already_AddRefed<Path> PathBuilderCapture::Finish() {
+  Point currentPoint = mCurrentPoint;
+  Point beginPoint = mBeginPoint;
   mCurrentPoint = Point(0.0, 0.0);
-  mFirstPoint = Point(0.0, 0.0);
+  mBeginPoint = Point(0.0, 0.0);
   return MakeAndAddRef<PathCapture>(std::move(mPathOps), mFillRule, mDT,
-                                    mCurrentPoint);
+                                    currentPoint, beginPoint);
 }
 
 already_AddRefed<PathBuilder> PathCapture::CopyToBuilder(
@@ -85,6 +85,7 @@ already_AddRefed<PathBuilder> PathCapture::CopyToBuilder(
   RefPtr<PathBuilderCapture> capture = new PathBuilderCapture(aFillRule, mDT);
   capture->mPathOps = mPathOps;
   capture->mCurrentPoint = mCurrentPoint;
+  capture->mBeginPoint = mBeginPoint;
   return capture.forget();
 }
 
@@ -136,6 +137,7 @@ already_AddRefed<PathBuilder> PathCapture::TransformedCopyToBuilder(
     }
   }
   capture->mCurrentPoint = aTransform.TransformPoint(mCurrentPoint);
+  capture->mBeginPoint = aTransform.TransformPoint(mBeginPoint);
   return capture.forget();
 }
 bool PathCapture::ContainsPoint(const Point& aPoint,

gfx/2d/PathCapture.h

@@ -45,11 +45,6 @@ class PathBuilderCapture : public PathBuilder {
    */
   virtual void Close() override;
 
-  /* Point the current subpath is at - or where the next subpath will start
-   * if there is no active subpath.
-   */
-  virtual Point CurrentPoint() const override;
-
   virtual already_AddRefed<Path> Finish() override;
 
   virtual BackendType GetBackendType() const override {
@@ -61,8 +56,6 @@ class PathBuilderCapture : public PathBuilder {
 
   FillRule mFillRule;
   std::vector<PathOp> mPathOps;
-  Point mCurrentPoint;
-  Point mFirstPoint;
   RefPtr<DrawTarget> mDT;
 };
 
@@ -71,11 +64,13 @@ class PathCapture : public Path {
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(PathCapture, override)
 
   PathCapture(const std::vector<PathOp> aOps, FillRule aFillRule,
-              DrawTarget* aDT, const Point& aCurrentPoint)
+              DrawTarget* aDT, const Point& aCurrentPoint,
+              const Point& aBeginPoint)
       : mPathOps(aOps),
         mFillRule(aFillRule),
         mDT(aDT),
-        mCurrentPoint(aCurrentPoint) {}
+        mCurrentPoint(aCurrentPoint),
+        mBeginPoint(aBeginPoint) {}
 
   virtual BackendType GetBackendType() const override {
     return BackendType::CAPTURE;
@@ -110,6 +105,7 @@ class PathCapture : public Path {
   FillRule mFillRule;
   RefPtr<DrawTarget> mDT;
   Point mCurrentPoint;
+  Point mBeginPoint;
 };
 
 }  // namespace gfx

gfx/2d/PathD2D.cpp

@@ -223,8 +223,6 @@ void PathBuilderD2D::Arc(const Point& aOrigin, Float aRadius, Float aStartAngle,
   mCurrentPoint = endPoint;
 }
 
-Point PathBuilderD2D::CurrentPoint() const { return mCurrentPoint; }
-
 void PathBuilderD2D::EnsureActive(const Point& aPoint) {
   if (!mFigureActive) {
     mSink->BeginFigure(D2DPoint(aPoint), D2D1_FIGURE_BEGIN_FILLED);

gfx/2d/PathD2D.h

@@ -36,7 +36,6 @@ class PathBuilderD2D : public PathBuilder {
   virtual void Close();
   virtual void Arc(const Point& aOrigin, Float aRadius, Float aStartAngle,
                    Float aEndAngle, bool aAntiClockwise = false);
-  virtual Point CurrentPoint() const;
 
   virtual already_AddRefed<Path> Finish();
 
@@ -55,8 +54,6 @@ class PathBuilderD2D : public PathBuilder {
   RefPtr<ID2D1PathGeometry> mGeometry;
 
   bool mFigureActive;
-  Point mCurrentPoint;
-  Point mBeginPoint;
   FillRule mFillRule;
   BackendType mBackendType;
 };

gfx/2d/PathRecording.cpp

@@ -57,13 +57,9 @@ void PathBuilderRecording::Close() {
   mPathBuilder->Close();
 }
 
-Point PathBuilderRecording::CurrentPoint() const {
-  return mPathBuilder->CurrentPoint();
-}
-
 already_AddRefed<Path> PathBuilderRecording::Finish() {
   RefPtr<Path> path = mPathBuilder->Finish();
-  return MakeAndAddRef<PathRecording>(path, mPathOps, mFillRule);
+  return MakeAndAddRef<PathRecording>(path, mPathOps, mFillRule, mCurrentPoint, mBeginPoint);
 }
 
 PathRecording::~PathRecording() {
@@ -79,6 +75,8 @@ already_AddRefed<PathBuilder> PathRecording::CopyToBuilder(
   RefPtr<PathBuilderRecording> recording =
       new PathBuilderRecording(pathBuilder, aFillRule);
   recording->mPathOps = mPathOps;
+  recording->SetCurrentPoint(mCurrentPoint);
+  recording->SetBeginPoint(mBeginPoint);
   return recording.forget();
 }
 
@@ -104,6 +102,10 @@ already_AddRefed<PathBuilder> PathRecording::TransformedCopyToBuilder(
     }
     recording->mPathOps.push_back(newPathOp);
   }
+
+  recording->SetCurrentPoint(aTransform.TransformPoint(mCurrentPoint));
+  recording->SetBeginPoint(aTransform.TransformPoint(mBeginPoint));
+
   return recording.forget();
 }
 

gfx/2d/PathRecording.h

@@ -53,7 +53,21 @@ class PathBuilderRecording : public PathBuilder {
   /* Point the current subpath is at - or where the next subpath will start
    * if there is no active subpath.
    */
-  virtual Point CurrentPoint() const override;
+  virtual Point CurrentPoint() const override {
+    return mPathBuilder->CurrentPoint();
+  }
+
+  virtual Point BeginPoint() const override {
+    return mPathBuilder->BeginPoint();
+  }
+
+  virtual void SetCurrentPoint(const Point& aPoint) override {
+    mPathBuilder->SetCurrentPoint(aPoint);
+  }
+
+  virtual void SetBeginPoint(const Point& aPoint) override {
+    mPathBuilder->SetBeginPoint(aPoint);
+  }
 
   virtual already_AddRefed<Path> Finish() override;
 
@@ -73,8 +87,10 @@ class PathRecording : public Path {
  public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(PathRecording, override)
 
-  PathRecording(Path* aPath, const std::vector<PathOp> aOps, FillRule aFillRule)
-      : mPath(aPath), mPathOps(aOps), mFillRule(aFillRule) {}
+  PathRecording(Path* aPath, const std::vector<PathOp> aOps, FillRule aFillRule,
+                const Point& aCurrentPoint, const Point& aBeginPoint)
+      : mPath(aPath), mPathOps(aOps), mFillRule(aFillRule),
+        mCurrentPoint(aCurrentPoint), mBeginPoint(aBeginPoint) {}
 
   ~PathRecording();
 
@@ -122,6 +138,8 @@ class PathRecording : public Path {
   RefPtr<Path> mPath;
   std::vector<PathOp> mPathOps;
   FillRule mFillRule;
+  Point mCurrentPoint;
+  Point mBeginPoint;
 
   // Event recorders that have this path in their event stream.
   std::vector<RefPtr<DrawEventRecorderPrivate>> mStoredRecorders;

gfx/2d/PathSkia.cpp

@@ -37,7 +37,7 @@ void PathBuilderSkia::SetFillRule(FillRule aFillRule) {
 void PathBuilderSkia::MoveTo(const Point& aPoint) {
   mPath.moveTo(SkFloatToScalar(aPoint.x), SkFloatToScalar(aPoint.y));
   mCurrentPoint = aPoint;
-  mFirstPoint = aPoint;
+  mBeginPoint = aPoint;
 }
 
 void PathBuilderSkia::LineTo(const Point& aPoint) {
@@ -71,7 +71,7 @@ void PathBuilderSkia::QuadraticBezierTo(const Point& aCP1, const Point& aCP2) {
 
 void PathBuilderSkia::Close() {
   mPath.close();
-  mCurrentPoint = mFirstPoint;
+  mCurrentPoint = mBeginPoint;
 }
 
 void PathBuilderSkia::Arc(const Point& aOrigin, float aRadius,
@@ -81,12 +81,12 @@ void PathBuilderSkia::Arc(const Point& aOrigin, float aRadius,
               aAntiClockwise);
 }
 
-Point PathBuilderSkia::CurrentPoint() const { return mCurrentPoint; }
-
 already_AddRefed<Path> PathBuilderSkia::Finish() {
+  RefPtr<Path> path = MakeAndAddRef<PathSkia>(mPath, mFillRule,
+                                              mCurrentPoint, mBeginPoint);
   mCurrentPoint = Point(0.0, 0.0);
-  mFirstPoint = Point(0.0, 0.0);
-  return MakeAndAddRef<PathSkia>(mPath, mFillRule);
+  mBeginPoint = Point(0.0, 0.0);
+  return path.forget();
 }
 
 void PathBuilderSkia::AppendPath(const SkPath& aPath) { mPath.addPath(aPath); }
@@ -98,7 +98,13 @@ already_AddRefed<PathBuilder> PathSkia::CopyToBuilder(
 
 already_AddRefed<PathBuilder> PathSkia::TransformedCopyToBuilder(
     const Matrix& aTransform, FillRule aFillRule) const {
-  return MakeAndAddRef<PathBuilderSkia>(aTransform, mPath, aFillRule);
+  RefPtr<PathBuilderSkia> builder = MakeAndAddRef<PathBuilderSkia>(
+    aTransform, mPath, aFillRule);
+
+  builder->mCurrentPoint = aTransform.TransformPoint(mCurrentPoint);
+  builder->mBeginPoint = aTransform.TransformPoint(mBeginPoint);
+
+  return builder.forget();
 }
 
 static bool SkPathContainsPoint(const SkPath& aPath, const Point& aPoint,

gfx/2d/PathSkia.h

@@ -31,7 +31,6 @@ class PathBuilderSkia : public PathBuilder {
   void Close() override;
   void Arc(const Point& aOrigin, float aRadius, float aStartAngle,
            float aEndAngle, bool aAntiClockwise = false) override;
-  Point CurrentPoint() const override;
   already_AddRefed<Path> Finish() override;
 
   void AppendPath(const SkPath& aPath);
@@ -39,11 +38,11 @@ class PathBuilderSkia : public PathBuilder {
   BackendType GetBackendType() const override { return BackendType::SKIA; }
 
  private:
+  friend class PathSkia;
+
   void SetFillRule(FillRule aFillRule);
 
   SkPath mPath;
-  Point mCurrentPoint;
-  Point mFirstPoint;
   FillRule mFillRule;
 };
 
@@ -51,7 +50,13 @@ class PathSkia : public Path {
  public:
   MOZ_DECLARE_REFCOUNTED_VIRTUAL_TYPENAME(PathSkia, override)
 
-  PathSkia(SkPath& aPath, FillRule aFillRule) : mFillRule(aFillRule) {
+  PathSkia(SkPath& aPath,
+           FillRule aFillRule,
+           Point aCurrentPoint = Point(),
+           Point aBeginPoint = Point())
+  : mFillRule(aFillRule)
+  , mCurrentPoint(aCurrentPoint)
+  , mBeginPoint(aBeginPoint) {
     mPath.swap(aPath);
   }
 
@@ -85,6 +90,8 @@ class PathSkia : public Path {
 
   SkPath mPath;
   FillRule mFillRule;
+  Point mCurrentPoint;
+  Point mBeginPoint;
 };
 
 }  // namespace gfx

widget/gtk/nsNativeThemeGTK.cpp

@@ -809,6 +809,7 @@ class SystemCairoClipper : public ClipExporter {
 
   void MoveTo(const Point& aPoint) override {
     cairo_move_to(mContext, aPoint.x / mScaleFactor, aPoint.y / mScaleFactor);
+    mBeginPoint = aPoint;
     mCurrentPoint = aPoint;
   }
 
@@ -842,15 +843,15 @@ class SystemCairoClipper : public ClipExporter {
                 aAntiClockwise);
   }
 
-  void Close() override { cairo_close_path(mContext); }
+  void Close() override {
+    cairo_close_path(mContext);
+    mCurrentPoint = mBeginPoint;
+  }
 
   void EndClip() override { cairo_clip(mContext); }
 
-  Point CurrentPoint() const override { return mCurrentPoint; }
-
  private:
   cairo_t* mContext;
-  Point mCurrentPoint;
   gint mScaleFactor;
 };