third_party/ots/src/vorg.cc

   1 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "vorg.h"
   6
   7 #include <vector>
   8
   9 // VORG - Vertical Origin Table
  10 // http://www.microsoft.com/typography/otspec/vorg.htm
  11
  12 #define TABLE_NAME "VORG"
  13
  14 #define DROP_THIS_TABLE(...) \
  15   do { \
  16     OTS_FAILURE_MSG_(font->file, TABLE_NAME ": " __VA_ARGS__); \
  17     OTS_FAILURE_MSG("Table discarded"); \
  18     delete font->vorg; \
  19     font->vorg = 0; \
  20   } while (0)
  21
  22 namespace ots {
  23
  24 bool ots_vorg_parse(Font *font, const uint8_t *data, size_t length) {
  25   Buffer table(data, length);
  26   font->vorg = new OpenTypeVORG;
  27   OpenTypeVORG * const vorg = font->vorg;
  28
  29   uint16_t num_recs;
  30   if (!table.ReadU16(&vorg->major_version) ||
  31       !table.ReadU16(&vorg->minor_version) ||
  32       !table.ReadS16(&vorg->default_vert_origin_y) ||
  33       !table.ReadU16(&num_recs)) {
  34     return OTS_FAILURE_MSG("Failed to read header");
  35   }
  36   if (vorg->major_version != 1) {
  37     DROP_THIS_TABLE("bad major version: %u", vorg->major_version);
  38     return true;
  39   }
  40   if (vorg->minor_version != 0) {
  41     DROP_THIS_TABLE("bad minor version: %u", vorg->minor_version);
  42     return true;
  43   }
  44
  45   // num_recs might be zero (e.g., DFHSMinchoPro5-W3-Demo.otf).
  46   if (!num_recs) {
  47     return true;
  48   }
  49
  50   uint16_t last_glyph_index = 0;
  51   vorg->metrics.reserve(num_recs);
  52   for (unsigned i = 0; i < num_recs; ++i) {
  53     OpenTypeVORGMetrics rec;
  54
  55     if (!table.ReadU16(&rec.glyph_index) ||
  56         !table.ReadS16(&rec.vert_origin_y)) {
  57       return OTS_FAILURE_MSG("Failed to read record %d", i);
  58     }
  59     if ((i != 0) && (rec.glyph_index <= last_glyph_index)) {
  60       DROP_THIS_TABLE("the table is not sorted");
  61       return true;
  62     }
  63     last_glyph_index = rec.glyph_index;
  64
  65     vorg->metrics.push_back(rec);
  66   }
  67
  68   return true;
  69 }
  70
  71 bool ots_vorg_should_serialise(Font *font) {
  72   if (!font->cff) return false;  // this table is not for fonts with TT glyphs.
  73   return font->vorg != NULL;
  74 }
  75
  76 bool ots_vorg_serialise(OTSStream *out, Font *font) {
  77   OpenTypeVORG * const vorg = font->vorg;
  78
  79   const uint16_t num_metrics = static_cast<uint16_t>(vorg->metrics.size());
  80   if (num_metrics != vorg->metrics.size() ||
  81       !out->WriteU16(vorg->major_version) ||
  82       !out->WriteU16(vorg->minor_version) ||
  83       !out->WriteS16(vorg->default_vert_origin_y) ||
  84       !out->WriteU16(num_metrics)) {
  85     return OTS_FAILURE_MSG("Failed to write table header");
  86   }
  87
  88   for (uint16_t i = 0; i < num_metrics; ++i) {
  89     const OpenTypeVORGMetrics& rec = vorg->metrics[i];
  90     if (!out->WriteU16(rec.glyph_index) ||
  91         !out->WriteS16(rec.vert_origin_y)) {
  92       return OTS_FAILURE_MSG("Failed to write record %d", i);
  93     }
  94   }
  95
  96   return true;
  97 }
  98
  99 void ots_vorg_reuse(Font *font, Font *other) {
 100   font->vorg = other->vorg;
 101   font->vorg_reused = true;
 102 }
 103
 104 void ots_vorg_free(Font *font) {
 105   delete font->vorg;
 106 }
 107
 108 }  // namespace ots
 109
 110 #undef TABLE_NAME
 111 #undef DROP_THIS_TABLE