add portable and canonical font support for DM

src/fonts/SkTestScalerContext.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkTestScalerContext_DEFINED
 #define SkTestScalerContext_DEFINED
 
 #include "SkPaint.h"
 #include "SkPath.h"
+#include "SkRefCnt.h"
 #include "SkTDArray.h"
 #include "SkTypeface.h"
 
-SkTypeface* CreateTestTypeface(SkPaint::FontMetrics (*funct)(SkTDArray<SkPath*>& pathArray,
-                               SkTDArray<SkFixed>& widthArray),
-                               SkTypeface::Style style);
+class SkTestFont;
+
+struct SkTestFontData {
+    const SkScalar* fPoints;
+    const unsigned char* fVerbs;
+    const unsigned* fCharCodes;
+    const size_t fCharCodesCount;
+    const SkFixed* fWidths;
+    const SkPaint::FontMetrics& fMetrics;
+    const char* fName;
+    SkTypeface::Style fStyle;
+    SkTestFont* fFontCache;
+};
+
+class SkTestFont : public SkRefCnt {
+public:
+    SK_DECLARE_INST_COUNT(SkTestFont)
+
+    SkTestFont(const SkTestFontData& );
+    virtual ~SkTestFont();
+    int codeToIndex(SkUnichar charCode) const;
+    void init(const SkScalar* pts, const unsigned char* verbs);
+#ifdef SK_DEBUG  // detect missing test font data
+    mutable unsigned char fDebugBits[16];
+    mutable SkUnichar fDebugOverage[8];
+    const char* fDebugName;
+    SkTypeface::Style fDebugStyle;
+    const char* debugFontName() const { return fName; }
+#endif
+private:
+    const unsigned* fCharCodes;
+    const size_t fCharCodesCount;
+    const SkFixed* fWidths;
+    const SkPaint::FontMetrics& fMetrics;
+    const char* fName;
+    SkPath** fPaths;
+    friend class SkTestTypeface;
+    typedef SkRefCnt INHERITED;
+};
+
+
+class SkTestTypeface : public SkTypeface {
+public:
+    SkTestTypeface(SkTestFont* , SkTypeface::Style style);
+    virtual ~SkTestTypeface() {
+        SkSafeUnref(fTestFont);
+    }
+    void getAdvance(SkGlyph* glyph);
+    void getFontMetrics(SkPaint::FontMetrics* metrics);
+    void getMetrics(SkGlyph* glyph);
+    void getPath(const SkGlyph& glyph, SkPath* path);
+protected:
+    virtual SkScalerContext* onCreateScalerContext(const SkDescriptor* desc) const SK_OVERRIDE;
+    virtual void onFilterRec(SkScalerContextRec* rec) const SK_OVERRIDE;
+    virtual SkAdvancedTypefaceMetrics* onGetAdvancedTypefaceMetrics(
+                                    SkAdvancedTypefaceMetrics::PerGlyphInfo ,
+                                    const uint32_t* glyphIDs,
+                                    uint32_t glyphIDsCount) const SK_OVERRIDE;
+
+    virtual SkStream* onOpenStream(int* ttcIndex) const SK_OVERRIDE {
+        SkASSERT(0);  // don't expect to get here
+        return NULL;
+    }
+
+    virtual void onGetFontDescriptor(SkFontDescriptor* desc, bool* isLocal) const SK_OVERRIDE;
+
+    virtual int onCharsToGlyphs(const void* chars, Encoding encoding,
+                                uint16_t glyphs[], int glyphCount) const SK_OVERRIDE;
+
+    virtual int onCountGlyphs() const SK_OVERRIDE {
+        return (int) fTestFont->fCharCodesCount;
+    }
+
+    virtual int onGetUPEM() const SK_OVERRIDE {
+        SkASSERT(0);  // don't expect to get here
+        return 1;
+    }
+
+    virtual SkTypeface::LocalizedStrings* onCreateFamilyNameIterator() const SK_OVERRIDE;
+
+    virtual int onGetTableTags(SkFontTableTag tags[]) const SK_OVERRIDE {
+        return 0;
+    }
+
+    virtual size_t onGetTableData(SkFontTableTag tag, size_t offset,
+                                  size_t length, void* data) const SK_OVERRIDE {
+        return 0;
+    }
+private:
+    SkTestFont* fTestFont;
+    friend class SkTestScalerContext;
+};
+
+SkTypeface* CreateTestTypeface(const char* name, SkTypeface::Style style);
 
 #endif