Bug 1232822 (part 3) - Moz2Dify gfxFont::CalcXScale() and gfxFont::PostShapingFixup(). r=jfkthame.

This boils down to these two lines being equivalent:

  Size t = aContext->UserToDevice(Size(1.0, 0.0));
  Size t = aDrawTarget->GetTransform() * Size(1.0, 0.0);

The rest is just plumbing.

gfx/thebes/gfxFT2Fonts.cpp

@@ -55,8 +55,8 @@ gfxFT2Font::ShapeText(gfxContext     *aContext,
                             aVertical, aShapedText)) {
         // harfbuzz must have failed(?!), just render raw glyphs
         AddRange(aText, aOffset, aLength, aShapedText);
-        PostShapingFixup(aContext, aText, aOffset, aLength, aVertical,
-                         aShapedText);
+        PostShapingFixup(aContext->GetDrawTarget(), aText, aOffset, aLength,
+                         aVertical, aShapedText);
     }
 
     return true;

gfx/thebes/gfxFont.cpp

@@ -1642,10 +1642,10 @@ private:
 // the second draw occurs at a constant offset in device pixels.
 
 double
-gfxFont::CalcXScale(gfxContext *aContext)
+gfxFont::CalcXScale(DrawTarget* aDrawTarget)
 {
     // determine magnitude of a 1px x offset in device space
-    Size t = aContext->UserToDevice(Size(1.0, 0.0));
+    Size t = aDrawTarget->GetTransform() * Size(1.0, 0.0);
     if (t.width == 1.0 && t.height == 0.0) {
         // short-circuit the most common case to avoid sqrt() and division
         return 1.0;
@@ -1970,7 +1970,7 @@ gfxFont::Draw(gfxTextRun *aTextRun, uint32_t aStart, uint32_t aEnd,
     // Synthetic-bold strikes are each offset one device pixel in run direction.
     // (these values are only needed if IsSyntheticBold() is true)
     if (IsSyntheticBold()) {
-        double xscale = CalcXScale(aRunParams.context);
+        double xscale = CalcXScale(aRunParams.context->GetDrawTarget());
         fontParams.synBoldOnePixelOffset = aRunParams.direction * xscale;
         if (xscale != 0.0) {
             // use as many strikes as needed for the the increased advance
@@ -2577,26 +2577,26 @@ gfxFont::ShapeText(gfxContext      *aContext,
 
     NS_WARN_IF_FALSE(ok, "shaper failed, expect scrambled or missing text");
 
-    PostShapingFixup(aContext, aText, aOffset, aLength, aVertical,
-                     aShapedText);
+    PostShapingFixup(aContext->GetDrawTarget(), aText, aOffset, aLength,
+                     aVertical, aShapedText);
 
     return ok;
 }
 
 void
-gfxFont::PostShapingFixup(gfxContext      *aContext,
-                          const char16_t *aText,
-                          uint32_t         aOffset,
-                          uint32_t         aLength,
-                          bool             aVertical,
-                          gfxShapedText   *aShapedText)
+gfxFont::PostShapingFixup(DrawTarget*     aDrawTarget,
+                          const char16_t* aText,
+                          uint32_t        aOffset,
+                          uint32_t        aLength,
+                          bool            aVertical,
+                          gfxShapedText*  aShapedText)
 {
     if (IsSyntheticBold()) {
         const Metrics& metrics =
             GetMetrics(aVertical ? eVertical : eHorizontal);
         if (metrics.maxAdvance > metrics.aveCharWidth) {
             float synBoldOffset =
-                    GetSyntheticBoldOffset() * CalcXScale(aContext);
+                    GetSyntheticBoldOffset() * CalcXScale(aDrawTarget);
             aShapedText->AdjustAdvancesForSyntheticBold(synBoldOffset,
                                                         aOffset, aLength);
         }

gfx/thebes/gfxFont.h

@@ -1926,12 +1926,12 @@ protected:
     // Helper to adjust for synthetic bold and set character-type flags
     // in the shaped text; implementations of ShapeText should call this
     // after glyph shaping has been completed.
-    void PostShapingFixup(gfxContext      *aContext,
-                          const char16_t *aText,
-                          uint32_t         aOffset, // position within aShapedText
-                          uint32_t         aLength,
-                          bool             aVertical,
-                          gfxShapedText   *aShapedText);
+    void PostShapingFixup(DrawTarget*     aContext,
+                          const char16_t* aText,
+                          uint32_t        aOffset, // position within aShapedText
+                          uint32_t        aLength,
+                          bool            aVertical,
+                          gfxShapedText*  aShapedText);
 
     // Shape text directly into a range within a textrun, without using the
     // font's word cache. Intended for use when the font has layout features
@@ -2139,7 +2139,7 @@ protected:
     // the second draw occurs at a constant offset in device pixels.
     // This helper calculates the scale factor we need to apply to the
     // synthetic-bold offset.
-    static double CalcXScale(gfxContext *aContext);
+    static double CalcXScale(DrawTarget* aDrawTarget);
 };
 
 // proportion of ascent used for x-height, if unable to read value from font

gfx/thebes/gfxMacFont.cpp

@@ -142,8 +142,8 @@ gfxMacFont::ShapeText(gfxContext     *aContext,
         }
         if (mCoreTextShaper->ShapeText(aContext, aText, aOffset, aLength,
                                        aScript, aVertical, aShapedText)) {
-            PostShapingFixup(aContext, aText, aOffset, aLength, aVertical,
-                             aShapedText);
+            PostShapingFixup(aContext->GetDrawTarget(), aText, aOffset,
+                             aLength, aVertical, aShapedText);
             return true;
         }
     }