[ot] Start implementing cmap table

src/Makefile.am

@@ -35,6 +35,7 @@ HBSOURCES =  \
 	hb-object-private.hh \
 	hb-open-file-private.hh \
 	hb-open-type-private.hh \
+	hb-ot-cmap-table.hh \
 	hb-ot-head-table.hh \
 	hb-ot-hhea-table.hh \
 	hb-ot-hmtx-table.hh \

src/hb-ot-cmap-table.hh

+/*
+ * Copyright © 2014  Google, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Google Author(s): Behdad Esfahbod
+ */
+
+#ifndef HB_OT_CMAP_TABLE_HH
+#define HB_OT_CMAP_TABLE_HH
+
+#include "hb-open-type-private.hh"
+
+
+namespace OT {
+
+
+/*
+ * cmap -- Character To Glyph Index Mapping Table
+ */
+
+#define HB_OT_TAG_cmap HB_TAG('c','m','a','p')
+
+
+struct CmapSubtableFormat4
+{
+  friend struct CmapSubtable;
+
+  private:
+  inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
+  {
+    return false;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) {
+    TRACE_SANITIZE (this);
+    return TRACE_RETURN (c->check_struct (this) &&
+			 c->check_range (this, length) &&
+			 16 + 4 * (unsigned int) segCountX2 < length);
+  }
+
+  protected:
+  USHORT	format;		/* Format number is set to 4. */
+  USHORT	length;		/* This is the length in bytes of the
+				 * subtable. */
+  USHORT	language;	/* Ignore. */
+  USHORT	segCountX2;	/* 2 x segCount. */
+  USHORT	searchRange;	/* 2 * (2**floor(log2(segCount))) */
+  USHORT	entrySelector;	/* log2(searchRange/2) */
+  USHORT	rangeShift;	/* 2 x segCount - searchRange */
+
+  USHORT	values[VAR];
+#if 0
+  USHORT	endCount[segCount];	/* End characterCode for each segment,
+					 * last=0xFFFF. */
+  USHORT	reservedPad;		/* Set to 0. */
+  USHORT	startCount[segCount];	/* Start character code for each segment. */
+  SHORT		idDelta[segCount];	/* Delta for all character codes in segment. */
+  USHORT	idRangeOffset[segCount];/* Offsets into glyphIdArray or 0 */
+  USHORT	glyphIdArray[VAR];	/* Glyph index array (arbitrary length) */
+#endif
+
+  public:
+  DEFINE_SIZE_ARRAY (14, values);
+};
+
+struct CmapSubtable
+{
+  inline bool get_glyph (hb_codepoint_t codepoint, hb_codepoint_t *glyph) const
+  {
+    switch (u.format) {
+    case 4: return u.format4.get_glyph(codepoint, glyph);
+    default:return false;
+    }
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) {
+    TRACE_SANITIZE (this);
+    if (!u.format.sanitize (c)) return TRACE_RETURN (false);
+    switch (u.format) {
+    case 4: return TRACE_RETURN (u.format4.sanitize (c));
+    default:return TRACE_RETURN (true);
+    }
+  }
+
+  protected:
+  union {
+  USHORT		format;		/* Format identifier */
+  CmapSubtableFormat4	format4;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, format);
+};
+
+
+struct EncodingRecord
+{
+  int cmp (const EncodingRecord &other) const
+  {
+    int ret;
+    ret = other.platformID.cmp (platformID);
+    if (ret) return ret;
+    ret = other.encodingID.cmp (encodingID);
+    if (ret) return ret;
+    return 0;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c, void *base) {
+    TRACE_SANITIZE (this);
+    return TRACE_RETURN (c->check_struct (this) &&
+			 subtable.sanitize (c, base));
+  }
+
+  USHORT	platformID;	/* Platform ID. */
+  USHORT	encodingID;	/* Platform-specific encoding ID. */
+  LongOffsetTo<CmapSubtable>
+		subtable;	/* Byte offset from beginning of table to the subtable for this encoding. */
+  public:
+  DEFINE_SIZE_STATIC (8);
+};
+
+struct cmap
+{
+  static const hb_tag_t tableTag	= HB_OT_TAG_cmap;
+
+  inline unsigned int find_subtable (unsigned int platform_id,
+				     unsigned int encoding_id) const
+  {
+    EncodingRecord key;
+    key.platformID.set (platform_id);
+    key.encodingID.set (encoding_id);
+
+    return encodingRecord.search (key);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) {
+    TRACE_SANITIZE (this);
+    return TRACE_RETURN (c->check_struct (this) &&
+			 likely (version == 0) &&
+			 encodingRecord.sanitize (c, this));
+  }
+
+  USHORT			version;	/* Table version number (0). */
+  ArrayOf<EncodingRecord>	encodingRecord;	/* Encoding tables. */
+  public:
+  DEFINE_SIZE_ARRAY (4, encodingRecord);
+};
+
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_CMAP_TABLE_HH */

src/hb-ot-font.cc

@@ -30,6 +30,7 @@
 
 #include "hb-font-private.hh"
 
+#include "hb-ot-cmap-table.hh"
 #include "hb-ot-hhea-table.hh"
 #include "hb-ot-hmtx-table.hh"