yusukes@chromium.org | d257d18 | 2009-11-04 04:56:32 +0000 | [diff] [blame] | 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 "vdmx.h" |
| 6 | |
| 7 | // VDMX - Vertical Device Metrics |
| 8 | // http://www.microsoft.com/opentype/otspec/vdmx.htm |
| 9 | |
| 10 | #define DROP_THIS_TABLE \ |
| 11 | do { delete file->vdmx; file->vdmx = 0; } while (0) |
| 12 | |
| 13 | namespace ots { |
| 14 | |
| 15 | bool ots_vdmx_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| 16 | Buffer table(data, length); |
| 17 | file->vdmx = new OpenTypeVDMX; |
| 18 | OpenTypeVDMX * const vdmx = file->vdmx; |
| 19 | |
| 20 | if (!table.ReadU16(&vdmx->version) || |
| 21 | !table.ReadU16(&vdmx->num_recs) || |
| 22 | !table.ReadU16(&vdmx->num_ratios)) { |
| 23 | return OTS_FAILURE(); |
| 24 | } |
| 25 | |
| 26 | if (vdmx->version > 1) { |
| 27 | OTS_WARNING("bad version: %u", vdmx->version); |
| 28 | DROP_THIS_TABLE; |
| 29 | return true; // continue transcoding |
| 30 | } |
| 31 | |
| 32 | vdmx->rat_ranges.reserve(vdmx->num_ratios); |
| 33 | for (unsigned i = 0; i < vdmx->num_ratios; ++i) { |
| 34 | OpenTypeVDMXRatioRecord rec; |
| 35 | |
| 36 | if (!table.ReadU8(&rec.charset) || |
| 37 | !table.ReadU8(&rec.x_ratio) || |
| 38 | !table.ReadU8(&rec.y_start_ratio) || |
| 39 | !table.ReadU8(&rec.y_end_ratio)) { |
| 40 | return OTS_FAILURE(); |
| 41 | } |
| 42 | |
| 43 | if (rec.charset > 1) { |
| 44 | OTS_WARNING("bad charset: %u", rec.charset); |
| 45 | DROP_THIS_TABLE; |
| 46 | return true; |
| 47 | } |
yusukes@chromium.org | a4099a3 | 2009-11-12 01:43:51 +0000 | [diff] [blame] | 48 | |
| 49 | if (rec.y_start_ratio > rec.y_end_ratio) { |
yusukes@chromium.org | d257d18 | 2009-11-04 04:56:32 +0000 | [diff] [blame] | 50 | OTS_WARNING("bad y ratio"); |
| 51 | DROP_THIS_TABLE; |
| 52 | return true; |
| 53 | } |
| 54 | |
| 55 | // All values set to zero signal the default grouping to use; |
| 56 | // if present, this must be the last Ratio group in the table. |
| 57 | if ((i < vdmx->num_ratios - 1u) && |
| 58 | (rec.x_ratio == 0) && |
| 59 | (rec.y_start_ratio == 0) && |
| 60 | (rec.y_end_ratio == 0)) { |
| 61 | // workaround for fonts which have 2 or more {0, 0, 0} terminators. |
| 62 | OTS_WARNING("superfluous terminator found"); |
| 63 | DROP_THIS_TABLE; |
yusukes@chromium.org | a4099a3 | 2009-11-12 01:43:51 +0000 | [diff] [blame] | 64 | return true; |
yusukes@chromium.org | d257d18 | 2009-11-04 04:56:32 +0000 | [diff] [blame] | 65 | } |
| 66 | |
| 67 | vdmx->rat_ranges.push_back(rec); |
| 68 | } |
| 69 | |
| 70 | vdmx->offsets.reserve(vdmx->num_ratios); |
| 71 | const size_t current_offset = table.offset(); |
| 72 | // current_offset is less than (2 bytes * 3) + (4 bytes * USHRT_MAX) = 256k. |
| 73 | for (unsigned i = 0; i < vdmx->num_ratios; ++i) { |
| 74 | uint16_t offset; |
| 75 | if (!table.ReadU16(&offset)) { |
| 76 | return OTS_FAILURE(); |
| 77 | } |
| 78 | if (current_offset + offset >= length) { // thus doesn't overflow. |
| 79 | return OTS_FAILURE(); |
| 80 | } |
| 81 | |
| 82 | vdmx->offsets.push_back(offset); |
| 83 | } |
| 84 | |
| 85 | vdmx->groups.reserve(vdmx->num_recs); |
| 86 | for (unsigned i = 0; i < vdmx->num_recs; ++i) { |
| 87 | OpenTypeVDMXGroup group; |
| 88 | if (!table.ReadU16(&group.recs) || |
| 89 | !table.ReadU8(&group.startsz) || |
| 90 | !table.ReadU8(&group.endsz)) { |
| 91 | return OTS_FAILURE(); |
| 92 | } |
| 93 | group.entries.reserve(group.recs); |
| 94 | for (unsigned j = 0; j < group.recs; ++j) { |
| 95 | OpenTypeVDMXVTable vt; |
| 96 | if (!table.ReadU16(&vt.y_pel_height) || |
| 97 | !table.ReadS16(&vt.y_max) || |
| 98 | !table.ReadS16(&vt.y_min)) { |
| 99 | return OTS_FAILURE(); |
| 100 | } |
| 101 | if (vt.y_max < vt.y_min) { |
| 102 | OTS_WARNING("bad y min/max"); |
| 103 | DROP_THIS_TABLE; |
| 104 | return true; |
| 105 | } |
| 106 | |
| 107 | // This table must appear in sorted order (sorted by yPelHeight), |
| 108 | // but need not be continuous. |
| 109 | if ((j != 0) && (group.entries[j - 1].y_pel_height >= vt.y_pel_height)) { |
| 110 | OTS_WARNING("the table is not sorted"); |
| 111 | DROP_THIS_TABLE; |
| 112 | return true; |
| 113 | } |
| 114 | |
| 115 | group.entries.push_back(vt); |
| 116 | } |
| 117 | vdmx->groups.push_back(group); |
| 118 | } |
| 119 | |
| 120 | return true; |
| 121 | } |
| 122 | |
| 123 | bool ots_vdmx_should_serialise(OpenTypeFile *file) { |
| 124 | if (!file->glyf) return false; // this table is not for CFF fonts. |
agl@chromium.org | 2beaf1d | 2011-01-21 17:19:34 +0000 | [diff] [blame] | 125 | return file->vdmx != NULL; |
yusukes@chromium.org | d257d18 | 2009-11-04 04:56:32 +0000 | [diff] [blame] | 126 | } |
| 127 | |
| 128 | bool ots_vdmx_serialise(OTSStream *out, OpenTypeFile *file) { |
| 129 | OpenTypeVDMX * const vdmx = file->vdmx; |
| 130 | |
| 131 | if (!out->WriteU16(vdmx->version) || |
| 132 | !out->WriteU16(vdmx->num_recs) || |
| 133 | !out->WriteU16(vdmx->num_ratios)) { |
| 134 | return OTS_FAILURE(); |
| 135 | } |
| 136 | |
| 137 | for (unsigned i = 0; i < vdmx->rat_ranges.size(); ++i) { |
| 138 | const OpenTypeVDMXRatioRecord& rec = vdmx->rat_ranges[i]; |
| 139 | if (!out->Write(&rec.charset, 1) || |
| 140 | !out->Write(&rec.x_ratio, 1) || |
| 141 | !out->Write(&rec.y_start_ratio, 1) || |
| 142 | !out->Write(&rec.y_end_ratio, 1)) { |
| 143 | return OTS_FAILURE(); |
| 144 | } |
| 145 | } |
| 146 | |
| 147 | for (unsigned i = 0; i < vdmx->offsets.size(); ++i) { |
| 148 | if (!out->WriteU16(vdmx->offsets[i])) { |
| 149 | return OTS_FAILURE(); |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | for (unsigned i = 0; i < vdmx->groups.size(); ++i) { |
| 154 | const OpenTypeVDMXGroup& group = vdmx->groups[i]; |
| 155 | if (!out->WriteU16(group.recs) || |
| 156 | !out->Write(&group.startsz, 1) || |
| 157 | !out->Write(&group.endsz, 1)) { |
| 158 | return OTS_FAILURE(); |
| 159 | } |
| 160 | for (unsigned j = 0; j < group.entries.size(); ++j) { |
| 161 | const OpenTypeVDMXVTable& vt = group.entries[j]; |
| 162 | if (!out->WriteU16(vt.y_pel_height) || |
| 163 | !out->WriteS16(vt.y_max) || |
| 164 | !out->WriteS16(vt.y_min)) { |
| 165 | return OTS_FAILURE(); |
| 166 | } |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | return true; |
| 171 | } |
| 172 | |
| 173 | void ots_vdmx_free(OpenTypeFile *file) { |
| 174 | delete file->vdmx; |
| 175 | } |
| 176 | |
| 177 | } // namespace ots |