Load FreeType glyph bitmap before emboldening.

If a bitmap glyph was loaded with FT_LOAD_BITMAP_METRICS_ONLY then the
glyph must be re-loaded without this flag before accessing the bitmap.

BUG=chromium:725975

Change-Id: If5e5a6844e9c32238560135e141fea7f77ad7fac
Reviewed-on: https://skia-review.googlesource.com/20830
Reviewed-by: Herb Derby <herb@google.com>
Reviewed-by: Florin Malita <fmalita@chromium.org>
Commit-Queue: Ben Wagner <bungeman@google.com>

1 files changed, 9 insertions, 7 deletions

diff --git a/src/ports/SkFontHost_FreeType.cpp b/src/ports/SkFontHost_FreeType.cpp
index b87af6ff04..0d61d5f426 100644
--- a/src/ports/SkFontHost_FreeType.cpp
+++ b/src/ports/SkFontHost_FreeType.cpp
@@ -496,7 +496,7 @@ private:
     void updateGlyphIfLCD(SkGlyph* glyph);
     // Caller must lock gFTMutex before calling this function.
     // update FreeType2 glyph slot with glyph emboldened
-    void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph);
+    void emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph, SkGlyphID gid);
     bool shouldSubpixelBitmap(const SkGlyph&, const SkMatrix&);
 };
 
@@ -1107,7 +1107,7 @@ bool SkScalerContext_FreeType::getCBoxForLetter(char letter, FT_BBox* bbox) {
     if (FT_Load_Glyph(fFace, glyph_id, fLoadGlyphFlags) != 0) {
         return false;
     }
-    emboldenIfNeeded(fFace, fFace->glyph);
+    emboldenIfNeeded(fFace, fFace->glyph, SkTo<SkGlyphID>(glyph_id));
     FT_Outline_Get_CBox(&fFace->glyph->outline, bbox);
     return true;
 }
@@ -1159,7 +1159,7 @@ void SkScalerContext_FreeType::generateMetrics(SkGlyph* glyph) {
         glyph->zeroMetrics();
         return;
     }
-    emboldenIfNeeded(fFace, fFace->glyph);
+    emboldenIfNeeded(fFace, fFace->glyph, glyph->getGlyphID());
 
     switch ( fFace->glyph->format ) {
       case FT_GLYPH_FORMAT_OUTLINE:
@@ -1269,7 +1269,7 @@ void SkScalerContext_FreeType::generateImage(const SkGlyph& glyph) {
         return;
     }
 
-    emboldenIfNeeded(fFace, fFace->glyph);
+    emboldenIfNeeded(fFace, fFace->glyph, glyph.getGlyphID());
     SkMatrix* bitmapMatrix = &fMatrix22Scalar;
     SkMatrix subpixelBitmapMatrix;
     if (this->shouldSubpixelBitmap(glyph, *bitmapMatrix)) {
@@ -1304,7 +1304,7 @@ void SkScalerContext_FreeType::generatePath(SkGlyphID glyphID, SkPath* path) {
         path->reset();
         return;
     }
-    emboldenIfNeeded(fFace, fFace->glyph);
+    emboldenIfNeeded(fFace, fFace->glyph, glyphID);
 
     generateGlyphPath(fFace, path);
 
@@ -1460,8 +1460,7 @@ void SkScalerContext_FreeType::generateFontMetrics(SkPaint::FontMetrics* metrics
 
 ///////////////////////////////////////////////////////////////////////////////
 
-void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)
-{
+void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph, SkGlyphID gid) {
     // check to see if the embolden bit is set
     if (0 == (fRec.fFlags & SkScalerContext::kEmbolden_Flag)) {
         return;
@@ -1475,6 +1474,9 @@ void SkScalerContext_FreeType::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph
             FT_Outline_Embolden(&glyph->outline, strength);
             break;
         case FT_GLYPH_FORMAT_BITMAP:
+            if (!fFace->glyph->bitmap.buffer) {
+                FT_Load_Glyph(fFace, gid, fLoadGlyphFlags);
+            }
             FT_GlyphSlot_Own_Bitmap(glyph);
             FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
             break;