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comparison: gfx/ots/src/gasp.cc
gfx/ots/src/gasp.cc
- changeset 0
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| -1:000000000000 | 0:4e6f4246598a |
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| 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 "gasp.h" | |
| 6 | |
| 7 // gasp - Grid-fitting And Scan-conversion Procedure | |
| 8 // http://www.microsoft.com/typography/otspec/gasp.htm | |
| 9 | |
| 10 #define TABLE_NAME "gasp" | |
| 11 | |
| 12 #define DROP_THIS_TABLE \ | |
| 13 do { \ | |
| 14 delete file->gasp; \ | |
| 15 file->gasp = 0; \ | |
| 16 OTS_FAILURE_MSG("Table discarded"); \ | |
| 17 } while (0) | |
| 18 | |
| 19 namespace ots { | |
| 20 | |
| 21 bool ots_gasp_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { | |
| 22 Buffer table(data, length); | |
| 23 | |
| 24 OpenTypeGASP *gasp = new OpenTypeGASP; | |
| 25 file->gasp = gasp; | |
| 26 | |
| 27 uint16_t num_ranges = 0; | |
| 28 if (!table.ReadU16(&gasp->version) || | |
| 29 !table.ReadU16(&num_ranges)) { | |
| 30 return OTS_FAILURE_MSG("Failed to read table header"); | |
| 31 } | |
| 32 | |
| 33 if (gasp->version > 1) { | |
| 34 // Lots of Linux fonts have bad version numbers... | |
| 35 OTS_WARNING("bad version: %u", gasp->version); | |
| 36 DROP_THIS_TABLE; | |
| 37 return true; | |
| 38 } | |
| 39 | |
| 40 if (num_ranges == 0) { | |
| 41 OTS_WARNING("num_ranges is zero"); | |
| 42 DROP_THIS_TABLE; | |
| 43 return true; | |
| 44 } | |
| 45 | |
| 46 gasp->gasp_ranges.reserve(num_ranges); | |
| 47 for (unsigned i = 0; i < num_ranges; ++i) { | |
| 48 uint16_t max_ppem = 0; | |
| 49 uint16_t behavior = 0; | |
| 50 if (!table.ReadU16(&max_ppem) || | |
| 51 !table.ReadU16(&behavior)) { | |
| 52 return OTS_FAILURE_MSG("Failed to read subrange %d", i); | |
| 53 } | |
| 54 if ((i > 0) && (gasp->gasp_ranges[i - 1].first >= max_ppem)) { | |
| 55 // The records in the gaspRange[] array must be sorted in order of | |
| 56 // increasing rangeMaxPPEM value. | |
| 57 OTS_WARNING("ranges are not sorted"); | |
| 58 DROP_THIS_TABLE; | |
| 59 return true; | |
| 60 } | |
| 61 if ((i == num_ranges - 1u) && // never underflow. | |
| 62 (max_ppem != 0xffffu)) { | |
| 63 OTS_WARNING("The last record should be 0xFFFF as a sentinel value " | |
| 64 "for rangeMaxPPEM"); | |
| 65 DROP_THIS_TABLE; | |
| 66 return true; | |
| 67 } | |
| 68 | |
| 69 if (behavior >> 8) { | |
| 70 OTS_WARNING("undefined bits are used: %x", behavior); | |
| 71 // mask undefined bits. | |
| 72 behavior &= 0x000fu; | |
| 73 } | |
| 74 | |
| 75 if (gasp->version == 0 && (behavior >> 2) != 0) { | |
| 76 OTS_WARNING("changed the version number to 1"); | |
| 77 gasp->version = 1; | |
| 78 } | |
| 79 | |
| 80 gasp->gasp_ranges.push_back(std::make_pair(max_ppem, behavior)); | |
| 81 } | |
| 82 | |
| 83 return true; | |
| 84 } | |
| 85 | |
| 86 bool ots_gasp_should_serialise(OpenTypeFile *file) { | |
| 87 return file->gasp != NULL; | |
| 88 } | |
| 89 | |
| 90 bool ots_gasp_serialise(OTSStream *out, OpenTypeFile *file) { | |
| 91 const OpenTypeGASP *gasp = file->gasp; | |
| 92 | |
| 93 if (!out->WriteU16(gasp->version) || | |
| 94 !out->WriteU16(gasp->gasp_ranges.size())) { | |
| 95 return OTS_FAILURE_MSG("failed to write gasp header"); | |
| 96 } | |
| 97 | |
| 98 for (unsigned i = 0; i < gasp->gasp_ranges.size(); ++i) { | |
| 99 if (!out->WriteU16(gasp->gasp_ranges[i].first) || | |
| 100 !out->WriteU16(gasp->gasp_ranges[i].second)) { | |
| 101 return OTS_FAILURE_MSG("Failed to write gasp subtable %d", i); | |
| 102 } | |
| 103 } | |
| 104 | |
| 105 return true; | |
| 106 } | |
| 107 | |
| 108 void ots_gasp_free(OpenTypeFile *file) { | |
| 109 delete file->gasp; | |
| 110 } | |
| 111 | |
| 112 } // namespace ots |
