Bug 1287552 - part 2 - fix transformed bitmaps with Skia and FreeType. r=gw280

MozReview-Commit-ID: BqiLfOfZZwR

--HG--
extra : rebase_source : 634873d2cc3069e06e2f9c3ea3dfa9e6c3f66961

gfx/skia/skia/src/ports/SkFontHost_FreeType.cpp

@@ -1163,7 +1163,6 @@ void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
             FT_Vector vector;
             vector.x = fFace->glyph->metrics.vertBearingX - fFace->glyph->metrics.horiBearingX;
             vector.y = -fFace->glyph->metrics.vertBearingY - fFace->glyph->metrics.horiBearingY;
-            FT_Vector_Transform(&vector, &fMatrix22);
             fFace->glyph->bitmap_left += SkFDot6Floor(vector.x);
             fFace->glyph->bitmap_top  += SkFDot6Floor(vector.y);
         }
@@ -1172,10 +1171,18 @@ void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
             glyph->fMaskFormat = SkMask::kARGB32_Format;
         }
 
-        glyph->fWidth   = SkToU16(fFace->glyph->bitmap.width);
-        glyph->fHeight  = SkToU16(fFace->glyph->bitmap.rows);
-        glyph->fTop     = -SkToS16(fFace->glyph->bitmap_top);
-        glyph->fLeft    = SkToS16(fFace->glyph->bitmap_left);
+        SkRect srcRect = SkRect::MakeXYWH(
+            SkIntToScalar(face->glyph->bitmap_left),
+            -SkIntToScalar(face->glyph->bitmap_top),
+            SkIntToScalar(face->glyph->bitmap.width),
+            SkIntToScalar(face->glyph->bitmap.rows));
+        SkRect destRect;
+        fMatrix22Scalar.mapRect(&destRect, srcRect);
+        SkIRect glyphRect = destRect.roundOut();
+        glyph->fWidth  = SkToU16(glyphRect.width());
+        glyph->fHeight = SkToU16(glyphRect.height());
+        glyph->fTop    = SkToS16(SkScalarRoundToInt(destRect.fTop));
+        glyph->fLeft   = SkToS16(SkScalarRoundToInt(destRect.fLeft));
         break;
 
       default:

gfx/skia/skia/src/ports/SkFontHost_FreeType_common.cpp

@@ -402,16 +402,12 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
                      SkMask::kARGB32_Format == maskFormat ||
                      SkMask::kLCD16_Format == maskFormat);
 
-            if (fRec.fFlags & SkScalerContext::kEmbolden_Flag &&
-                !(face->style_flags & FT_STYLE_FLAG_BOLD))
-            {
-                FT_GlyphSlot_Own_Bitmap(face->glyph);
-                FT_Bitmap_Embolden(face->glyph->library, &face->glyph->bitmap,
-                                   kBitmapEmboldenStrength, 0);
-            }
-
-            // If no scaling needed, directly copy glyph bitmap.
-            if (glyph.fWidth == face->glyph->bitmap.width &&
+            // If no skew or scaling needed, directly copy glyph bitmap.
+            bool skewed = fRec.fPreSkewX != 0 ||
+                          fRec.fPost2x2[0][1] != 0 ||
+                          fRec.fPost2x2[1][0] != 0;
+            if (!skewed &&
+                glyph.fWidth == face->glyph->bitmap.width &&
                 glyph.fHeight == face->glyph->bitmap.rows &&
                 glyph.fTop == -face->glyph->bitmap_top &&
                 glyph.fLeft == face->glyph->bitmap_left)
@@ -460,8 +456,22 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
             // Scale unscaledBitmap into dstBitmap.
             SkCanvas canvas(dstBitmap);
             canvas.clear(SK_ColorTRANSPARENT);
-            canvas.scale(SkIntToScalar(glyph.fWidth) / SkIntToScalar(face->glyph->bitmap.width),
-                         SkIntToScalar(glyph.fHeight) / SkIntToScalar(face->glyph->bitmap.rows));
+            if (skewed) {
+                // Apply any transforms with the bitmap placed at (0, 0).
+                SkMatrix matrix;
+                fRec.getSingleMatrix(&matrix);
+                SkRect srcRect = SkRect::MakeIWH(face->glyph->bitmap.width, face->glyph->bitmap.rows);
+                SkRect destRect;
+                matrix.mapRect(&destRect, srcRect);
+                matrix.postTranslate(-destRect.fLeft, -destRect.fTop);
+                // Rescale to the glyph's actual size.
+                matrix.postScale(SkIntToScalar(glyph.fWidth) / destRect.width(),
+                                 SkIntToScalar(glyph.fHeight) / destRect.height());
+                canvas.setMatrix(matrix);
+            } else {
+                canvas.scale(SkIntToScalar(glyph.fWidth) / SkIntToScalar(face->glyph->bitmap.width),
+                             SkIntToScalar(glyph.fHeight) / SkIntToScalar(face->glyph->bitmap.rows));
+            }
             SkPaint paint;
             paint.setFilterQuality(kMedium_SkFilterQuality);
             canvas.drawBitmap(unscaledBitmap, 0, 0, &paint);