Rotate emoji with FreeType.

src/ports/SkFontHost_FreeType_common.cpp

Index: src/ports/SkFontHost_FreeType_common.cpp
diff --git a/src/ports/SkFontHost_FreeType_common.cpp b/src/ports/SkFontHost_FreeType_common.cpp
index 245ded1283572362da007c6837caf4e9d9486e0a..947c717a06aa173868a8d07399885e7c8a93ad4a 100644
--- a/src/ports/SkFontHost_FreeType_common.cpp
+++ b/src/ports/SkFontHost_FreeType_common.cpp
@@ -334,7 +334,11 @@ inline SkColorType SkColorType_for_SkMaskFormat(SkMask::Format format) {
     }
 }
 
-void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGlyph& glyph) {
+void SkScalerContext_FreeType_Base::generateGlyphImage(
+    FT_Face face,
+    const SkGlyph& glyph,
+    const SkMatrix& bitmapTransform)
+{
     const bool doBGR = SkToBool(fRec.fFlags & SkScalerContext::kLCD_BGROrder_Flag);
     const bool doVert = SkToBool(fRec.fFlags & SkScalerContext::kLCD_Vertical_Flag);
 
@@ -411,11 +415,7 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
             }
 
             // If no scaling needed, directly copy glyph bitmap.
-            if (glyph.fWidth == face->glyph->bitmap.width &&
-                glyph.fHeight == face->glyph->bitmap.rows &&
-                glyph.fTop == -face->glyph->bitmap_top &&
-                glyph.fLeft == face->glyph->bitmap_left)
-            {
+            if (bitmapTransform.isIdentity()) {
                 SkMask dstMask;
                 glyph.toMask(&dstMask);
                 copyFTBitmap(face->glyph->bitmap, dstMask);
@@ -459,9 +459,15 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
 
             // Scale unscaledBitmap into dstBitmap.
             SkCanvas canvas(dstBitmap);
+#ifdef SK_SHOW_TEXT_BLIT_COVERAGE
+            canvas.clear(0x33FF0000);
+#else
             canvas.clear(SK_ColorTRANSPARENT);
-            canvas.scale(SkIntToScalar(glyph.fWidth) / SkIntToScalar(face->glyph->bitmap.width),
-                         SkIntToScalar(glyph.fHeight) / SkIntToScalar(face->glyph->bitmap.rows));
+#endif
+            canvas.translate(-glyph.fLeft, -glyph.fTop);
+            canvas.concat(bitmapTransform);

[bungeman-skia, 2016/07/11 22:18:42]

For the no-skew case everything is the same except right here. Now the transform
is directly computed and applied. Before the ratio of the rounded out bounds
were used to back form an approximation of a scale. This accounts for the
changes to existing gms.

+            canvas.translate(face->glyph->bitmap_left, -face->glyph->bitmap_top);
+
             SkPaint paint;
             paint.setFilterQuality(kMedium_SkFilterQuality);
             canvas.drawBitmap(unscaledBitmap, 0, 0, &paint);