| // Copyright (c) 2009 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "head.h" |
| |
| #include <cstring> |
| |
| // head - Font Header |
| // http://www.microsoft.com/opentype/otspec/head.htm |
| |
| namespace ots { |
| |
| bool ots_head_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { |
| Buffer table(data, length); |
| file->head = new OpenTypeHEAD; |
| |
| uint32_t version = 0; |
| if (!table.ReadU32(&version) || |
| !table.ReadU32(&file->head->revision)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (version >> 16 != 1) { |
| return OTS_FAILURE(); |
| } |
| |
| // Skip the checksum adjustment |
| if (!table.Skip(4)) { |
| return OTS_FAILURE(); |
| } |
| |
| uint32_t magic; |
| if (!table.ReadTag(&magic) || |
| std::memcmp(&magic, "\x5F\x0F\x3C\xF5", 4)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (!table.ReadU16(&file->head->flags)) { |
| return OTS_FAILURE(); |
| } |
| |
| // We allow bits 0..4, 11..13 |
| file->head->flags &= 0x381f; |
| |
| if (!table.ReadU16(&file->head->ppem)) { |
| return OTS_FAILURE(); |
| } |
| |
| // ppem must be in range |
| if (file->head->ppem < 16 || |
| file->head->ppem > 16384) { |
| return OTS_FAILURE(); |
| } |
| |
| // ppem must be a power of two |
| #if 0 |
| // We don't call ots_failure() for now since lots of TrueType fonts are |
| // not following this rule. Putting OTS_WARNING here is too noisy. |
| if ((file->head->ppem - 1) & file->head->ppem) { |
| return OTS_FAILURE(); |
| } |
| #endif |
| |
| if (!table.ReadR64(&file->head->created) || |
| !table.ReadR64(&file->head->modified)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (!table.ReadS16(&file->head->xmin) || |
| !table.ReadS16(&file->head->ymin) || |
| !table.ReadS16(&file->head->xmax) || |
| !table.ReadS16(&file->head->ymax)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (file->head->xmin > file->head->xmax) { |
| return OTS_FAILURE(); |
| } |
| if (file->head->ymin > file->head->ymax) { |
| return OTS_FAILURE(); |
| } |
| |
| if (!table.ReadU16(&file->head->mac_style)) { |
| return OTS_FAILURE(); |
| } |
| |
| // We allow bits 0..6 |
| file->head->mac_style &= 0x7f; |
| |
| if (!table.ReadU16(&file->head->min_ppem)) { |
| return OTS_FAILURE(); |
| } |
| |
| // We don't care about the font direction hint |
| if (!table.Skip(2)) { |
| return OTS_FAILURE(); |
| } |
| |
| if (!table.ReadS16(&file->head->index_to_loc_format)) { |
| return OTS_FAILURE(); |
| } |
| if (file->head->index_to_loc_format < 0 || |
| file->head->index_to_loc_format > 1) { |
| return OTS_FAILURE(); |
| } |
| |
| int16_t glyph_data_format; |
| if (!table.ReadS16(&glyph_data_format) || |
| glyph_data_format) { |
| return OTS_FAILURE(); |
| } |
| |
| return true; |
| } |
| |
| bool ots_head_should_serialise(OpenTypeFile *file) { |
| return file->head != NULL; |
| } |
| |
| bool ots_head_serialise(OTSStream *out, OpenTypeFile *file) { |
| if (!out->WriteU32(0x00010000) || |
| !out->WriteU32(file->head->revision) || |
| !out->WriteU32(0) || // check sum not filled in yet |
| !out->WriteU32(0x5F0F3CF5) || |
| !out->WriteU16(file->head->flags) || |
| !out->WriteU16(file->head->ppem) || |
| !out->WriteR64(file->head->created) || |
| !out->WriteR64(file->head->modified) || |
| !out->WriteS16(file->head->xmin) || |
| !out->WriteS16(file->head->ymin) || |
| !out->WriteS16(file->head->xmax) || |
| !out->WriteS16(file->head->ymax) || |
| !out->WriteU16(file->head->mac_style) || |
| !out->WriteU16(file->head->min_ppem) || |
| !out->WriteS16(2) || |
| !out->WriteS16(file->head->index_to_loc_format) || |
| !out->WriteS16(0)) { |
| return OTS_FAILURE(); |
| } |
| |
| return true; |
| } |
| |
| void ots_head_free(OpenTypeFile *file) { |
| delete file->head; |
| } |
| |
| } // namespace |