Add Truetype and Type 1 font embedding support

Sorry this is such a large CL.  It was very exploratory for me to make this
work.

- Add an interface to SkFontHost to retrieve font information and provide NULL implementations on all platforms except Linux.
- Segment large Type 1 fonts into fonts with shared resources with 255 glyphs each.
- Convert the various Type 1 formats to the form PDF wants.
- Update font as we draw text instead of as part of the graphical state.
- Remove built-in font support, we can't really use it.

Other changes I can pull out to a separate CL if you like.

- Add SkTScopedPtr class.
- Fix double free of resources.
- Fix bug in resource unique-ifying code.
- Don't print anything for any empty clip path.
- Fix copy paste error - MiterLimit.
- Fix sign extension bug in SkPDFString
- Fix FlateTest rename that was missed on a previous commit.

Review URL: http://codereview.appspot.com/4082042

git-svn-id: http://skia.googlecode.com/svn/trunk@728 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/include/pdf/SkPDFFont.h b/include/pdf/SkPDFFont.h
index 82357ef..d020163 100644
--- a/include/pdf/SkPDFFont.h
+++ b/include/pdf/SkPDFFont.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2010 The Android Open Source Project
+ * Copyright (C) 2011 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -22,6 +22,7 @@
 #include "SkThread.h"
 
 class SkPaint;
+class SkPDFTypefaceInfo;
 
 /** \class SkPDFFont
     A PDF Object class representing a font.  The font may have resources
@@ -40,53 +41,95 @@
      */
     uint32_t fontID();
 
-    /** Returns true if this font supports glyph IDs above 255.
+    /** Return true if this font has an encoding for the passed glyph id.
+     */
+    bool hasGlyph(uint16_t glyphID);
+
+    /** Returns true if this font encoding supports glyph IDs above 255.
      */
     bool multiByteGlyphs();
 
-    /** Covert the specified text to glyph IDs, taking into consideration
-     *  PDF encodings and return the number of glyphs IDs written.
+    /** Convert the input glyph IDs into the font encoding.  If the font has
+     *  more glyphs than can be encoded (like a type 1 font with more than
+     *  255 glyphs) this method only converts up to the first out of range
+     *  glyph ID.
+     *  @param glyphIDs       The input text as glyph IDs.
+     *  @param numGlyphs      The number of input glyphs.
+     *  @param encodedValues  The method writes its result to this parameter.
+     *                        multiByteGlyphs() reveals the output format.
+     *  @param encodedLength  The size of encodedValues (in bytes), which is
+     *                        overwritten with how much of encodedValues is
+     *                        used.
+     *  @return               Returns the number of glyphs consumed.
      */
-    int textToPDFGlyphs(const void* text, size_t byteLength,
-                        const SkPaint& paint, uint16_t* glyphs,
-                        size_t glyphsLength) const;
+    size_t glyphsToPDFFontEncoding(const uint16_t* glyphIDs, size_t numGlyphs,
+                                   void* encodedValues, size_t* encodedLength);
 
-    /** Get the font resource for the passed font ID. The reference count of
-     *  the object is incremented and it is the caller's responsibility to
-     *  unreference it when done.  This is needed to accommodate the weak
-     *  reference pattern used when the returned object is new and has no
-     *  other references.
-     *  @param paint  The SkPaint to emulate.
+    /** Get the font resource for the passed font ID and glyphID. The
+     *  reference count of the object is incremented and it is the caller's
+     *  responsibility to unreference it when done.  This is needed to
+     *  accommodate the weak reference pattern used when the returned object
+     *  is new and has no other references.
+     *  @param fontID  The fontId to find.
+     *  @param glyphID Specify which section of a large font is of interest.
      */
-    static SkPDFFont* getFontResouceByID(uint32_t fontID);
+    static SkPDFFont* getFontResource(uint32_t fontID, uint16_t glyphID);
 
 private:
     uint32_t fFontID;
+#ifdef SK_DEBUG
+    bool fDescendant;
+#endif
     bool fMultiByteGlyphs;
 
+    // The glyph IDs accessible with this font.  For Type1 (non CID) fonts,
+    // this will be a subset if the font has more than 255 glyphs.
+    uint16_t fFirstGlyphID;
+    uint16_t fLastGlyphID;
+    // The font info is only kept around after construction for large
+    // Type1 (non CID) fonts that need multiple "fonts" to access all glyphs.
+    SkRefPtr<SkPDFTypefaceInfo> fFontInfo;
     SkTDArray<SkPDFObject*> fResources;
+    SkRefPtr<SkPDFDict> fDescriptor;
 
     class FontRec {
     public:
         SkPDFFont* fFont;
         uint32_t fFontID;
+        uint16_t fGlyphID;
 
+        // A fGlyphID of 0 with no fFont always matches.
         bool operator==(const FontRec& b) const;
-        FontRec(SkPDFFont* font, uint32_t fontID);
+        FontRec(SkPDFFont* font, uint32_t fontID, uint16_t fGlyphID);
     };
 
     // This should be made a hash table if performance is a problem.
     static SkTDArray<FontRec>& canonicalFonts();
     static SkMutex& canonicalFontsMutex();
 
-    SkPDFFont(uint32_t fontID, bool multiByteGlyphs);
+    /** Construct a new font dictionary and support objects.
+     *  @param fontInfo       Information about the to create.
+     *  @param fontID         The font ID of the font.
+     *  @param glyphID        The glyph ID the caller is interested in. This
+     *                        is important only for Type1 fonts, which have
+     *                        more than 255 glyphs.
+     *  @param descendantFont If this is the descendant (true) or root
+     *                        (Type 0 font - false) font dictionary.  Only True
+     *                        Type and CID encoded fonts will use a true value.
+     *  @param fontDescriptor If the font descriptor has already have generated
+     *                        for this font, pass it in here, otherwise pass
+     *                        NULL.
+     */
+    SkPDFFont(class SkPDFTypefaceInfo* fontInfo, uint32_t fontID,
+              uint16_t glyphID, bool descendantFont, SkPDFDict* fontDescriptor);
 
-    void populateBuiltinFont(const char fontName[]);
-    void populateFont(const char subType[], const char fontName[],
-                      int firstChar, int lastChar, int widths[],
-                      SkPDFObject* fontDescriptor);
+    void populateType0Font();
+    void populateCIDFont();
+    bool populateType1Font(uint16_t firstGlyphID, uint16_t lastGlyphID);
+    void populateType3Font();
+    bool addFontDescriptor(int defaultWidth);
 
-    static int find(uint32_t fontID);
+    static bool find(uint32_t fontID, uint16_t glyphID, int* index);
 };
 
 #endif