SkPDF: in-place font subsetting

src/pdf/SkPDFMakeToUnicodeCmap.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkPDFMakeToUnicodeCmap.h"
 #include "SkPDFUtils.h"
 #include "SkUtils.h"
@@ skipping 131 matching lines @@
 // overlap, but succeeding maps supersede preceding maps."
 //
 // In case of searching text in PDF, bfrange will have higher precedence so
 // typing char id 0x0014 in search box will get glyph id 0x0004 first.  However,
 // the spec does not mention how will this kind of conflict being resolved.
 //
 // For the worst case (having 65536 continuous unicode and we use every other
 // one of them), the possible savings by aggressive optimization is 416KB
 // pre-compressed and does not provide enough motivation for implementation.
 void SkPDFAppendCmapSections(const SkTDArray<SkUnichar>& glyphToUnicode,
-                             const SkPDFGlyphSet* subset,
+                             const SkBitSet* subset,
                              SkDynamicMemoryWStream* cmap,
                              bool multiByteGlyphs,
                              SkGlyphID firstGlyphID,
                              SkGlyphID lastGlyphID) {
     if (glyphToUnicode.isEmpty()) {
         return;
     }
     int glyphOffset = 0;
     if (!multiByteGlyphs) {
         glyphOffset = firstGlyphID - 1;
@@ skipping 42 matching lines @@
     }
 
     // The spec requires all bfchar entries for a font must come before bfrange
     // entries.
     append_bfchar_section(bfcharEntries, cmap);
     append_bfrange_section(bfrangeEntries, cmap);
 }
 
 sk_sp<SkPDFStream> SkPDFMakeToUnicodeCmap(
         const SkTDArray<SkUnichar>& glyphToUnicode,
-        const SkPDFGlyphSet* subset,
+        const SkBitSet* subset,
         bool multiByteGlyphs,
         SkGlyphID firstGlyphID,
         SkGlyphID lastGlyphID) {
     SkDynamicMemoryWStream cmap;
     if (multiByteGlyphs) {
         append_tounicode_header(&cmap, firstGlyphID, lastGlyphID);
     } else {
         append_tounicode_header(&cmap, 1, lastGlyphID - firstGlyphID + 1);
     }
     SkPDFAppendCmapSections(glyphToUnicode, subset, &cmap, multiByteGlyphs,
                             firstGlyphID, lastGlyphID);
     append_cmap_footer(&cmap);
     return sk_make_sp<SkPDFStream>(
             std::unique_ptr<SkStreamAsset>(cmap.detachAsStream()));
 }