refactor emboldenGlyph

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 065a83a41c2d4c3546363d311ec501cdb57b40ab..df7d8a44be2e6dba8aaa630d01f7fe21ab211e4f 100644
--- a/src/ports/SkFontHost_FreeType_common.cpp
+++ b/src/ports/SkFontHost_FreeType_common.cpp
@@ -344,11 +344,6 @@ void SkScalerContext_FreeType_Base::generateGlyphImage(FT_Face face, const SkGly
             FT_BBox     bbox;
             FT_Bitmap   target;
 
-            if (fRec.fFlags & SkScalerContext::kEmbolden_Flag &&
-                !(face->style_flags & FT_STYLE_FLAG_BOLD)) {
-                emboldenOutline(face, outline);
-            }
-
             int dx = 0, dy = 0;
             if (fRec.fFlags & SkScalerContext::kSubpixelPositioning_Flag) {
                 dx = SkFixedToFDot6(glyph.getSubXFixed());
@@ -547,10 +542,6 @@ static int cubic_proc(const FT_Vector* pt0, const FT_Vector* pt1,
 void SkScalerContext_FreeType_Base::generateGlyphPath(FT_Face face,
                                                       SkPath* path)
 {
-    if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {

[bungeman-skia, 2013/12/16 16:33:36]

I am of two minds about removing this from here and moving it up to
SkFontHost_FreeType. On the one hand this changes the behavior of this method
such that it no longer respects the kEmbolden flag. On the other hand it seems
wrong for this method to respect such flags as the patch (or image, above) must
have the same emboldening as the metrics and the metrics are not calculated
here.

On the other hand it seems like this would change behavior. Fortunately, that
isn't an issue, because the kEmbolden flag is only ever set if
SK_USE_FREETYPE_EMBOLDEN is defined at build time, and no one does that (as far
as I'm aware).

[zheng.xu, 2013/12/17 10:02:51]

Moving this to SkFontHost_FreeType changes the behavior of the function
SkScalerContext_FreeType_Base::generateGlyphPath. But this protected function is
not the interface function of SkScalerContext. 

Only the inherited class need to take care of this change. The related changes
has been already applied by this patch sets. The behavior of the interface
function SkScalerContext_FreeType::generatePath still keeps unchanged.

-        emboldenOutline(face, &face->glyph->outline);
-    }
-
     FT_Outline_Funcs    funcs;
 
     funcs.move_to   = move_proc;
@@ -577,3 +568,20 @@ void SkScalerContext_FreeType_Base::emboldenOutline(FT_Face face, FT_Outline* ou
                / 24;
     FT_Outline_Embolden(outline, strength);
 }
+
+void SkScalerContext_FreeType_Base::emboldenIfNeeded(FT_Face face, FT_GlyphSlot glyph)

[bungeman-skia, 2013/12/16 16:33:36]

Having this here seems a bit silly if it's only called from SkFontHost_FreeType.
Since all of the path/image/metrics must use the same embolden (otherwise
something will end up incorrect) and since the metrics aren't handled here, I'd
say just move this over to SkFontHost_FreeType.cpp where it can also be inlined.

[zheng.xu, 2013/12/17 10:02:51]

Done.

+{
+    if (fRec.fFlags & SkScalerContext::kEmbolden_Flag) {
+        switch ( glyph->format ) {
+            case FT_GLYPH_FORMAT_OUTLINE:
+                emboldenOutline(face, &glyph->outline);
+                break;
+            case FT_GLYPH_FORMAT_BITMAP:
+                FT_GlyphSlot_Own_Bitmap(glyph);
+                FT_Bitmap_Embolden(glyph->library, &glyph->bitmap, kBitmapEmboldenStrength, 0);
+                break;
+            default:
+                SkDEBUGFAIL("unknown glyph format");
+        }
+    }
+}