gfx/ots/src/loca.cc@6474c204b198 (annotated)
gfx/ots/src/loca.cc
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
| michael@0 | 1 | // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| michael@0 | 2 | // Use of this source code is governed by a BSD-style license that can be |
| michael@0 | 3 | // found in the LICENSE file. |
| michael@0 | 4 | |
| michael@0 | 5 | #include "loca.h" |
| michael@0 | 6 | |
| michael@0 | 7 | #include "head.h" |
| michael@0 | 8 | #include "maxp.h" |
| michael@0 | 9 | |
| michael@0 | 10 | // loca - Index to Location |
| michael@0 | 11 | // http://www.microsoft.com/typography/otspec/loca.htm |
| michael@0 | 12 | |
| michael@0 | 13 | #define TABLE_NAME "loca" |
| michael@0 | 14 | |
| michael@0 | 15 | namespace ots { |
| michael@0 | 16 | |
| michael@0 | 17 | bool ots_loca_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| michael@0 | 18 | Buffer table(data, length); |
| michael@0 | 19 | |
| michael@0 | 20 | // We can't do anything useful in validating this data except to ensure that |
| michael@0 | 21 | // the values are monotonically increasing. |
| michael@0 | 22 | |
| michael@0 | 23 | OpenTypeLOCA *loca = new OpenTypeLOCA; |
| michael@0 | 24 | file->loca = loca; |
| michael@0 | 25 | |
| michael@0 | 26 | if (!file->maxp || !file->head) { |
| michael@0 | 27 | return OTS_FAILURE_MSG("maxp or head tables missing from font, needed by loca"); |
| michael@0 | 28 | } |
| michael@0 | 29 | |
| michael@0 | 30 | const unsigned num_glyphs = file->maxp->num_glyphs; |
| michael@0 | 31 | unsigned last_offset = 0; |
| michael@0 | 32 | loca->offsets.resize(num_glyphs + 1); |
| michael@0 | 33 | // maxp->num_glyphs is uint16_t, thus the addition never overflows. |
| michael@0 | 34 | |
| michael@0 | 35 | if (file->head->index_to_loc_format == 0) { |
| michael@0 | 36 | // Note that the <= here (and below) is correct. There is one more offset |
| michael@0 | 37 | // than the number of glyphs in order to give the length of the final |
| michael@0 | 38 | // glyph. |
| michael@0 | 39 | for (unsigned i = 0; i <= num_glyphs; ++i) { |
| michael@0 | 40 | uint16_t offset = 0; |
| michael@0 | 41 | if (!table.ReadU16(&offset)) { |
| michael@0 | 42 | return OTS_FAILURE_MSG("Failed to read offset for glyph %d", i); |
| michael@0 | 43 | } |
| michael@0 | 44 | if (offset < last_offset) { |
| michael@0 | 45 | return OTS_FAILURE_MSG("Out of order offset %d < %d for glyph %d", offset, last_offset, i); |
| michael@0 | 46 | } |
| michael@0 | 47 | last_offset = offset; |
| michael@0 | 48 | loca->offsets[i] = offset * 2; |
| michael@0 | 49 | } |
| michael@0 | 50 | } else { |
| michael@0 | 51 | for (unsigned i = 0; i <= num_glyphs; ++i) { |
| michael@0 | 52 | uint32_t offset = 0; |
| michael@0 | 53 | if (!table.ReadU32(&offset)) { |
| michael@0 | 54 | return OTS_FAILURE_MSG("Failed to read offset for glyph %d", i); |
| michael@0 | 55 | } |
| michael@0 | 56 | if (offset < last_offset) { |
| michael@0 | 57 | return OTS_FAILURE_MSG("Out of order offset %d < %d for glyph %d", offset, last_offset, i); |
| michael@0 | 58 | } |
| michael@0 | 59 | last_offset = offset; |
| michael@0 | 60 | loca->offsets[i] = offset; |
| michael@0 | 61 | } |
| michael@0 | 62 | } |
| michael@0 | 63 | |
| michael@0 | 64 | return true; |
| michael@0 | 65 | } |
| michael@0 | 66 | |
| michael@0 | 67 | bool ots_loca_should_serialise(OpenTypeFile *file) { |
| michael@0 | 68 | return file->loca != NULL; |
| michael@0 | 69 | } |
| michael@0 | 70 | |
| michael@0 | 71 | bool ots_loca_serialise(OTSStream *out, OpenTypeFile *file) { |
| michael@0 | 72 | const OpenTypeLOCA *loca = file->loca; |
| michael@0 | 73 | const OpenTypeHEAD *head = file->head; |
| michael@0 | 74 | |
| michael@0 | 75 | if (!head) { |
| michael@0 | 76 | return OTS_FAILURE_MSG("Missing head table in font needed by loca"); |
| michael@0 | 77 | } |
| michael@0 | 78 | |
| michael@0 | 79 | if (head->index_to_loc_format == 0) { |
| michael@0 | 80 | for (unsigned i = 0; i < loca->offsets.size(); ++i) { |
| michael@0 | 81 | if (!out->WriteU16(loca->offsets[i] >> 1)) { |
| michael@0 | 82 | return OTS_FAILURE_MSG("Failed to write glyph offset for glyph %d", i); |
| michael@0 | 83 | } |
| michael@0 | 84 | } |
| michael@0 | 85 | } else { |
| michael@0 | 86 | for (unsigned i = 0; i < loca->offsets.size(); ++i) { |
| michael@0 | 87 | if (!out->WriteU32(loca->offsets[i])) { |
| michael@0 | 88 | return OTS_FAILURE_MSG("Failed to write glyph offset for glyph %d", i); |
| michael@0 | 89 | } |
| michael@0 | 90 | } |
| michael@0 | 91 | } |
| michael@0 | 92 | |
| michael@0 | 93 | return true; |
| michael@0 | 94 | } |
| michael@0 | 95 | |
| michael@0 | 96 | void ots_loca_free(OpenTypeFile *file) { |
| michael@0 | 97 | delete file->loca; |
| michael@0 | 98 | } |
| michael@0 | 99 | |
| michael@0 | 100 | } // namespace ots |
