Bug 939534 - Convert the SVG textPath code from gfxPath to Moz2D Path. r=heycam

layout/svg/nsSVGGlyphFrame.cpp

@@ -9,6 +9,7 @@
 
 // Keep others in (case-insensitive) order:
 #include "DOMSVGPoint.h"
+#include "gfx2DGlue.h"
 #include "gfxContext.h"
 #include "gfxMatrix.h"
 #include "gfxPlatform.h"
@@ -22,6 +23,7 @@
 #include "nsSVGIntegrationUtils.h"
 #include "nsSVGPaintServerFrame.h"
 #include "mozilla/dom/SVGRect.h"
+#include "mozilla/gfx/2D.h"
 #include "nsSVGTextPathFrame.h"
 #include "nsSVGUtils.h"
 #include "nsTextFragment.h"
@@ -750,13 +752,11 @@ nsSVGGlyphFrame::GetCharacterPositions(nsTArray<CharacterPosition>* aCharacterPo
     if (!aCharacterPositions->SetLength(strLength))
       return false;
 
-    nsRefPtr<gfxPath> data = new gfxPath(path);
-
     gfxFloat pathScale = textPath->GetOffsetScale();
 
     CharacterPosition *cp = aCharacterPositions->Elements();
 
-    gfxFloat length = data->GetLength();
+    Float length = path->ComputeLength();
 
     for (uint32_t i = 0; i < strLength; i++) {
       gfxFloat halfAdvance =
@@ -777,15 +777,15 @@ nsSVGGlyphFrame::GetCharacterPositions(nsTArray<CharacterPosition>* aCharacterPo
                     pos.x + halfAdvance <= length);
 
       if (cp[i].draw) {
-
-        // add y (normal)
-        // add rotation
-        // move point back along tangent
-        gfxPoint pt = data->FindPoint(gfxPoint(pos.x + halfAdvance, pos.y),
-                                      &(cp[i].angle));
-        cp[i].pos =
-          pt - gfxPoint(cos(cp[i].angle), sin(cp[i].angle)) * halfAdvance;
-        cp[i].angle += angle;
+        Point tangent; // Unit vector tangent to the point we find.
+        Point pt = path->ComputePointAtLength(Float(pos.x + halfAdvance),
+                                              &tangent);
+        Point normal(-tangent.y, tangent.x); // Unit vector normal to the point.
+        Point offsetFromPath = normal * pos.y;
+        cp[i].pos = ThebesPoint(pt + offsetFromPath) -
+                      ThebesPoint(tangent) * halfAdvance;
+        double glyphRotation = atan2(tangent.y, tangent.x);
+        cp[i].angle = glyphRotation + angle;
       }
       pos.x += 2 * halfAdvance;
     }

layout/svg/nsSVGTextFrame2.cpp

@@ -4785,8 +4785,7 @@ nsSVGTextFrame2::DoTextPathLayout()
 
     // Get the path itself.
     RefPtr<Path> path = GetTextPath(textPathFrame);
-    nsRefPtr<gfxPath> data = new gfxPath(path);
-    if (!data) {
+    if (!path) {
       it.AdvancePastCurrentTextPathFrame();
       continue;
     }
@@ -4794,7 +4793,7 @@ nsSVGTextFrame2::DoTextPathLayout()
     nsIContent* textPath = textPathFrame->GetContent();
 
     gfxFloat offset = GetStartOffset(textPathFrame);
-    gfxFloat pathLength = data->GetLength();
+    Float pathLength = path->ComputeLength();
 
     // Loop for each text frame in the text path.
     do {
@@ -4808,19 +4807,22 @@ nsSVGTextFrame2::DoTextPathLayout()
       mPositions[i].mHidden = midx < 0 || midx > pathLength;
 
       // Position the character on the path at the right angle.
-      double angle;
-      gfxPoint pt =
-        data->FindPoint(gfxPoint(midx, mPositions[i].mPosition.y), &angle);
-      gfxPoint direction = gfxPoint(cos(angle), sin(angle)) * sign;
-      mPositions[i].mPosition = pt - direction * halfAdvance;
-      mPositions[i].mAngle += angle;
+      Point tangent; // Unit vector tangent to the point we find.
+      Point pt = path->ComputePointAtLength(Float(midx), &tangent);
+      double glyphRotation = atan2(tangent.y, tangent.x);
+      Point normal(-tangent.y, tangent.x); // Unit vector normal to the point.
+      Point offsetFromPath = normal * mPositions[i].mPosition.y;
+      pt += offsetFromPath;
+      Point direction = tangent * sign;
+      mPositions[i].mPosition = ThebesPoint(pt) - ThebesPoint(direction) * halfAdvance;
+      mPositions[i].mAngle += glyphRotation;
 
       // Position any characters for a partial ligature.
       for (uint32_t j = i + 1;
            j < mPositions.Length() && mPositions[j].mClusterOrLigatureGroupMiddle;
            j++) {
         gfxPoint partialAdvance =
-          direction * it.GetGlyphPartialAdvance(j - i, context) /
+          ThebesPoint(direction) * it.GetGlyphPartialAdvance(j - i, context) /
                                                          mFontSizeScaleFactor;
         mPositions[j].mPosition = mPositions[i].mPosition + partialAdvance;
         mPositions[j].mAngle = mPositions[i].mAngle;

layout/svg/nsSVGTextFrame2.h

@@ -21,7 +21,6 @@ class nsDisplaySVGText;
 class nsRenderingContext;
 class nsSVGTextFrame2;
 class nsTextFrame;
-class gfxPath;
 
 typedef nsSVGDisplayContainerFrame nsSVGTextFrame2Base;
 

layout/svg/nsSVGTextPathFrame.cpp

@@ -8,7 +8,6 @@
 
 // Keep others in (case-insensitive) order:
 #include "gfx2DGlue.h"
-#include "gfxPath.h"
 #include "nsContentUtils.h"
 #include "nsSVGEffects.h"
 #include "nsSVGLength2.h"

layout/svg/nsSVGTextPathFrame.h

@@ -17,7 +17,6 @@
 #include "nsQueryFrame.h"
 #include "nsSVGTSpanFrame.h"
 
-class gfxPath;
 class nsIAtom;
 class nsIContent;
 class nsIFrame;