Support for fake bold in Minikin builds

Part of the fix for bug 15436379 Fake bold doesn't fully work (Minikin)

This patch queries the Minikin layout for when fake bold is needed,
and applies that to both shaping and drawing paint.

Also simplifies refcounting (the lifetime of all MinikinFont objects
is subsumed by the enclosing FontCollection).

Note: the fake bold flag set by the user is ignored in this patch.

Fake italics would be possible using the same mechanism, but it's
slightly more complicated (fake and user-set textSkewX values would need
to be combined, and the latter restored after drawing).

Change-Id: Ica2c4604846cbb37e5a783778b18d8993c9d4563
diff --git a/core/jni/android/graphics/Canvas.cpp b/core/jni/android/graphics/Canvas.cpp
index 8b75e7d..3b44f97 100644
--- a/core/jni/android/graphics/Canvas.cpp
+++ b/core/jni/android/graphics/Canvas.cpp
@@ -776,13 +776,12 @@
                 : layout(layout), canvas(canvas), x(x), y(y), paint(paint), glyphs(glyphs),
                     pos(pos) { }
 
-        void operator()(SkTypeface* t, size_t start, size_t end) {
+        void operator()(size_t start, size_t end) {
             for (size_t i = start; i < end; i++) {
                 glyphs[i] = layout.getGlyphId(i);
                 pos[i].fX = x + layout.getX(i);
                 pos[i].fY = y + layout.getY(i);
             }
-            paint->setTypeface(t);
             canvas->drawPosText(glyphs + start, (end - start) << 1, pos + start, *paint);
         }
     private:
@@ -805,7 +804,7 @@
         paint->setTextAlign(SkPaint::kLeft_Align);
         paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
         DrawTextFunctor f(layout, canvas, x, y, paint, glyphs, pos);
-        MinikinUtils::forFontRun(layout, f);
+        MinikinUtils::forFontRun(layout, paint, f);
         doDrawTextDecorations(canvas, x, y, layout.getAdvance(), paint);
         paint->setTextAlign(align);
         delete[] glyphs;
diff --git a/core/jni/android/graphics/MinikinSkia.cpp b/core/jni/android/graphics/MinikinSkia.cpp
index 2b96f1b..a0796c6 100644
--- a/core/jni/android/graphics/MinikinSkia.cpp
+++ b/core/jni/android/graphics/MinikinSkia.cpp
@@ -43,13 +43,14 @@
     return !!glyph;
 }
 
-static void MinikinFontSkia_SetSkiaPaint(SkTypeface* typeface, SkPaint* skPaint, const MinikinPaint& paint) {
-    skPaint->setTypeface(typeface);
+static void MinikinFontSkia_SetSkiaPaint(const MinikinFont* font, SkPaint* skPaint, const MinikinPaint& paint) {
     skPaint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
     skPaint->setTextSize(paint.size);
     skPaint->setTextScaleX(paint.scaleX);
     skPaint->setTextSkewX(paint.skewX);
     MinikinFontSkia::unpackPaintFlags(skPaint, paint.paintFlags);
+    // Apply font fakery on top of user-supplied flags.
+    MinikinFontSkia::populateSkPaint(skPaint, font, paint.fakery);
 }
 
 float MinikinFontSkia::GetHorizontalAdvance(uint32_t glyph_id,
@@ -57,7 +58,7 @@
     SkPaint skPaint;
     uint16_t glyph16 = glyph_id;
     SkScalar skWidth;
-    MinikinFontSkia_SetSkiaPaint(mTypeface, &skPaint, paint);
+    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
     skPaint.getTextWidths(&glyph16, sizeof(glyph16), &skWidth, NULL);
 #ifdef VERBOSE
     ALOGD("width for typeface %d glyph %d = %f", mTypeface->uniqueID(), glyph_id, skWidth);
@@ -70,7 +71,7 @@
     SkPaint skPaint;
     uint16_t glyph16 = glyph_id;
     SkRect skBounds;
-    MinikinFontSkia_SetSkiaPaint(mTypeface, &skPaint, paint);
+    MinikinFontSkia_SetSkiaPaint(this, &skPaint, paint);
     skPaint.getTextWidths(&glyph16, sizeof(glyph16), NULL, &skBounds);
     bounds->mLeft = skBounds.fLeft;
     bounds->mTop = skBounds.fTop;
@@ -90,7 +91,7 @@
     }
 }
 
-SkTypeface *MinikinFontSkia::GetSkTypeface() {
+SkTypeface *MinikinFontSkia::GetSkTypeface() const {
     return mTypeface;
 }
 
@@ -115,4 +116,10 @@
     paint->setHinting(static_cast<SkPaint::Hinting>(paintFlags >> 16));
 }
 
+void MinikinFontSkia::populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery) {
+    paint->setTypeface(reinterpret_cast<const MinikinFontSkia*>(font)->GetSkTypeface());
+    paint->setFakeBoldText(fakery.isFakeBold());
+    // TODO: fake italics
+}
+
 }
diff --git a/core/jni/android/graphics/MinikinSkia.h b/core/jni/android/graphics/MinikinSkia.h
index 0452c57..ac4d2a0 100644
--- a/core/jni/android/graphics/MinikinSkia.h
+++ b/core/jni/android/graphics/MinikinSkia.h
@@ -36,10 +36,13 @@
 
     int32_t GetUniqueId() const;
 
-    SkTypeface *GetSkTypeface();
+    SkTypeface* GetSkTypeface() const;
 
     static uint32_t packPaintFlags(const SkPaint* paint);
     static void unpackPaintFlags(SkPaint* paint, uint32_t paintFlags);
+
+    // set typeface and fake bold/italic parameters
+    static void populateSkPaint(SkPaint* paint, const MinikinFont* font, FontFakery fakery);
 private:
     SkTypeface *mTypeface;
 };
diff --git a/core/jni/android/graphics/MinikinUtils.h b/core/jni/android/graphics/MinikinUtils.h
index ea7eb5d..47ab616 100644
--- a/core/jni/android/graphics/MinikinUtils.h
+++ b/core/jni/android/graphics/MinikinUtils.h
@@ -36,23 +36,24 @@
 
     static float xOffsetForTextAlign(SkPaint* paint, const Layout& layout);
 
-    // f is a functor of type void f(SkTypeface *, size_t start, size_t end);
+    // f is a functor of type void f(size_t start, size_t end);
     template <typename F>
-    static void forFontRun(const Layout& layout, F& f) {
-        SkTypeface* lastFace = NULL;
+    static void forFontRun(const Layout& layout, SkPaint* paint, F& f) {
+        MinikinFont* curFont = NULL;
         size_t start = 0;
         size_t nGlyphs = layout.nGlyphs();
         for (size_t i = 0; i < nGlyphs; i++) {
-            MinikinFontSkia* mfs = static_cast<MinikinFontSkia*>(layout.getFont(i));
-            SkTypeface* skFace = mfs->GetSkTypeface();
-            if (i > 0 && skFace != lastFace) {
-                f(lastFace, start, i);
+            MinikinFont* nextFont = layout.getFont(i);
+            if (i > 0 && nextFont != curFont) {
+                MinikinFontSkia::populateSkPaint(paint, curFont, layout.getFakery(start));
+                f(start, i);
                 start = i;
             }
-            lastFace = skFace;
+            curFont = nextFont;
         }
         if (nGlyphs > start) {
-            f(lastFace, start, nGlyphs);
+            MinikinFontSkia::populateSkPaint(paint, curFont, layout.getFakery(start));
+            f(start, nGlyphs);
         }
     }
 };
diff --git a/core/jni/android/graphics/Paint.cpp b/core/jni/android/graphics/Paint.cpp
index 24731ac..74f7085 100644
--- a/core/jni/android/graphics/Paint.cpp
+++ b/core/jni/android/graphics/Paint.cpp
@@ -439,8 +439,8 @@
 #ifdef USE_MINIKIN
         TypefaceImpl* typeface = GraphicsJNI::getNativeTypeface(env, jpaint);
         typeface = TypefaceImpl_resolveDefault(typeface);
-        MinikinFont* baseFont = typeface->fFontCollection->baseFont(typeface->fStyle);
-        paint->setTypeface(reinterpret_cast<MinikinFontSkia*>(baseFont)->GetSkTypeface());
+        FakedFont baseFont = typeface->fFontCollection->baseFontFaked(typeface->fStyle);
+        MinikinFontSkia::populateSkPaint(paint, baseFont.font, baseFont.fakery);
 #endif
         SkScalar spacing = paint->getFontMetrics(metrics);
         SkPaintOptionsAndroid paintOpts = paint->getPaintOptionsAndroid();
@@ -837,13 +837,12 @@
                 : layout(layout), path(path), x(x), y(y), paint(paint), glyphs(glyphs), pos(pos) {
         }
 
-        void operator()(SkTypeface* t, size_t start, size_t end) {
+        void operator()(size_t start, size_t end) {
             for (size_t i = start; i < end; i++) {
                 glyphs[i] = layout.getGlyphId(i);
                 pos[i].fX = x + layout.getX(i);
                 pos[i].fY = y + layout.getY(i);
             }
-            paint->setTypeface(t);
             if (start == 0) {
                 paint->getPosTextPath(glyphs + start, (end - start) << 1, pos + start, path);
             } else {
@@ -878,7 +877,7 @@
         paint->setTextAlign(SkPaint::kLeft_Align);
         paint->setTextEncoding(SkPaint::kGlyphID_TextEncoding);
         GetTextFunctor f(layout, path, x, y, paint, glyphs, pos);
-        MinikinUtils::forFontRun(layout, f);
+        MinikinUtils::forFontRun(layout, paint, f);
         paint->setTextAlign(align);
         delete[] glyphs;
         delete[] pos;
diff --git a/core/jni/android/graphics/TypefaceImpl.cpp b/core/jni/android/graphics/TypefaceImpl.cpp
index 27df7cf..1800d0c 100644
--- a/core/jni/android/graphics/TypefaceImpl.cpp
+++ b/core/jni/android/graphics/TypefaceImpl.cpp
@@ -173,7 +173,7 @@
     } else {
         const FontStyle defaultStyle;
         FontFamily* firstFamily = reinterpret_cast<FontFamily*>(families[0]);
-        MinikinFont* mf = firstFamily->getClosestMatch(defaultStyle);
+        MinikinFont* mf = firstFamily->getClosestMatch(defaultStyle).font;
         SkTypeface* skTypeface = reinterpret_cast<MinikinFontSkia*>(mf)->GetSkTypeface();
         // TODO: probably better to query more precise style from family, will be important
         // when we open up API to access 100..900 weights