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Diffstat (limited to 'src/os2.cc')
-rw-r--r-- | src/os2.cc | 290 |
1 files changed, 290 insertions, 0 deletions
diff --git a/src/os2.cc b/src/os2.cc new file mode 100644 index 0000000..983482e --- /dev/null +++ b/src/os2.cc @@ -0,0 +1,290 @@ +// 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 "os2.h" + +#include "head.h" + +// OS/2 - OS/2 and Windows Metrics +// http://www.microsoft.com/opentype/otspec/os2.htm + +namespace ots { + +bool ots_os2_parse(OpenTypeFile *file, const uint8_t *data, size_t length) { + Buffer table(data, length); + + OpenTypeOS2 *os2 = new OpenTypeOS2; + file->os2 = os2; + + if (!table.ReadU16(&os2->version) || + !table.ReadS16(&os2->avg_char_width) || + !table.ReadU16(&os2->weight_class) || + !table.ReadU16(&os2->width_class) || + !table.ReadU16(&os2->type) || + !table.ReadS16(&os2->subscript_x_size) || + !table.ReadS16(&os2->subscript_y_size) || + !table.ReadS16(&os2->subscript_x_offset) || + !table.ReadS16(&os2->subscript_y_offset) || + !table.ReadS16(&os2->superscript_x_size) || + !table.ReadS16(&os2->superscript_y_size) || + !table.ReadS16(&os2->superscript_x_offset) || + !table.ReadS16(&os2->superscript_y_offset) || + !table.ReadS16(&os2->strikeout_size) || + !table.ReadS16(&os2->strikeout_position) || + !table.ReadS16(&os2->family_class)) { + return OTS_FAILURE(); + } + + if (os2->version > 4) { + return OTS_FAILURE(); + } + + // Some linux fonts (e.g., Kedage-t.ttf and LucidaSansDemiOblique.ttf) have + // weird weight/width classes. Overwrite them with FW_NORMAL/1/9. + if (os2->weight_class < 100 || + os2->weight_class > 900 || + os2->weight_class % 100) { + OTS_WARNING("bad weight: %u", os2->weight_class); + os2->weight_class = 400; // FW_NORMAL + } + if (os2->width_class < 1) { + OTS_WARNING("bad width: %u", os2->width_class); + os2->width_class = 1; + } else if (os2->width_class > 9) { + OTS_WARNING("bad width: %u", os2->width_class); + os2->width_class = 9; + } + + // lowest 3 bits of fsType are exclusive. + if (os2->type & 0x2) { + // mask bits 2 & 3. + os2->type &= 0xfff3u; + } else if (os2->type & 0x4) { + // mask bits 1 & 3. + os2->type &= 0xfff4u; + } else if (os2->type & 0x8) { + // mask bits 1 & 2. + os2->type &= 0xfff9u; + } + + // mask reserved bits. use only 0..3, 8, 9 bits. + os2->type &= 0x30f; + + if (os2->subscript_x_size < 0) { + OTS_WARNING("bad subscript_x_size: %d", os2->subscript_x_size); + os2->subscript_x_size = 0; + } + if (os2->subscript_y_size < 0) { + OTS_WARNING("bad subscript_y_size: %d", os2->subscript_y_size); + os2->subscript_y_size = 0; + } + if (os2->superscript_x_size < 0) { + OTS_WARNING("bad superscript_x_size: %d", os2->superscript_x_size); + os2->superscript_x_size = 0; + } + if (os2->superscript_y_size < 0) { + OTS_WARNING("bad superscript_y_size: %d", os2->superscript_y_size); + os2->superscript_y_size = 0; + } + if (os2->strikeout_size < 0) { + OTS_WARNING("bad strikeout_size: %d", os2->strikeout_size); + os2->strikeout_size = 0; + } + + for (unsigned i = 0; i < 10; ++i) { + if (!table.ReadU8(&os2->panose[i])) { + return OTS_FAILURE(); + } + } + + if (!table.ReadU32(&os2->unicode_range_1) || + !table.ReadU32(&os2->unicode_range_2) || + !table.ReadU32(&os2->unicode_range_3) || + !table.ReadU32(&os2->unicode_range_4) || + !table.ReadU32(&os2->vendor_id) || + !table.ReadU16(&os2->selection) || + !table.ReadU16(&os2->first_char_index) || + !table.ReadU16(&os2->last_char_index) || + !table.ReadS16(&os2->typo_ascender) || + !table.ReadS16(&os2->typo_descender) || + !table.ReadS16(&os2->typo_linegap) || + !table.ReadU16(&os2->win_ascent) || + !table.ReadU16(&os2->win_descent)) { + return OTS_FAILURE(); + } + + // If bit 6 is set, then bits 0 and 5 must be clear. + if (os2->selection & 0x40) { + os2->selection &= 0xffdeu; + } + + // the settings of bits 0 and 1 must be reflected in the macStyle bits + // in the 'head' table. + if (!file->head) { + return OTS_FAILURE(); + } + if ((os2->selection & 0x1) && + !(file->head->mac_style & 0x2)) { + OTS_WARNING("adjusting Mac style (italic)"); + file->head->mac_style |= 0x2; + } + if ((os2->selection & 0x2) && + !(file->head->mac_style & 0x4)) { + OTS_WARNING("adjusting Mac style (underscore)"); + file->head->mac_style |= 0x4; + } + + // While bit 6 on implies that bits 0 and 1 of macStyle are clear, + // the reverse is not true. + if ((os2->selection & 0x40) && + (file->head->mac_style & 0x3)) { + OTS_WARNING("adjusting Mac style (regular)"); + file->head->mac_style &= 0xfffcu; + } + + if ((os2->version < 4) && + (os2->selection & 0x300)) { + // bit 8 and 9 must be unset in OS/2 table versions less than 4. + return OTS_FAILURE(); + } + + // mask reserved bits. use only 0..9 bits. + os2->selection &= 0x3ff; + + if (os2->first_char_index > os2->last_char_index) { + return OTS_FAILURE(); + } + if (os2->typo_linegap < 0) { + OTS_WARNING("bad linegap: %d", os2->typo_linegap); + os2->typo_linegap = 0; + } + + if (os2->version < 1) { + // http://www.microsoft.com/typography/otspec/os2ver0.htm + return true; + } + + if (length < offsetof(OpenTypeOS2, code_page_range_2)) { + OTS_WARNING("bad version number: %u", os2->version); + // Some fonts (e.g., kredit1.ttf and quinquef.ttf) have weird version + // numbers. Fix them. + os2->version = 0; + return true; + } + + if (!table.ReadU32(&os2->code_page_range_1) || + !table.ReadU32(&os2->code_page_range_2)) { + return OTS_FAILURE(); + } + + if (os2->version < 2) { + // http://www.microsoft.com/typography/otspec/os2ver1.htm + return true; + } + + if (length < offsetof(OpenTypeOS2, max_context)) { + OTS_WARNING("bad version number: %u", os2->version); + // some Japanese fonts (e.g., mona.ttf) have weird version number. + // fix them. + os2->version = 1; + return true; + } + + if (!table.ReadS16(&os2->x_height) || + !table.ReadS16(&os2->cap_height) || + !table.ReadU16(&os2->default_char) || + !table.ReadU16(&os2->break_char) || + !table.ReadU16(&os2->max_context)) { + return OTS_FAILURE(); + } + + if (os2->x_height < 0) { + OTS_WARNING("bad x_height: %d", os2->x_height); + os2->x_height = 0; + } + if (os2->cap_height < 0) { + OTS_WARNING("bad cap_height: %d", os2->cap_height); + os2->cap_height = 0; + } + + return true; +} + +bool ots_os2_should_serialise(OpenTypeFile *file) { + return file->os2; +} + +bool ots_os2_serialise(OTSStream *out, OpenTypeFile *file) { + const OpenTypeOS2 *os2 = file->os2; + + if (!out->WriteU16(os2->version) || + !out->WriteS16(os2->avg_char_width) || + !out->WriteU16(os2->weight_class) || + !out->WriteU16(os2->width_class) || + !out->WriteU16(os2->type) || + !out->WriteS16(os2->subscript_x_size) || + !out->WriteS16(os2->subscript_y_size) || + !out->WriteS16(os2->subscript_x_offset) || + !out->WriteS16(os2->subscript_y_offset) || + !out->WriteS16(os2->superscript_x_size) || + !out->WriteS16(os2->superscript_y_size) || + !out->WriteS16(os2->superscript_x_offset) || + !out->WriteS16(os2->superscript_y_offset) || + !out->WriteS16(os2->strikeout_size) || + !out->WriteS16(os2->strikeout_position) || + !out->WriteS16(os2->family_class)) { + return OTS_FAILURE(); + } + + for (unsigned i = 0; i < 10; ++i) { + if (!out->Write(&os2->panose[i], 1)) { + return OTS_FAILURE(); + } + } + + if (!out->WriteU32(os2->unicode_range_1) || + !out->WriteU32(os2->unicode_range_2) || + !out->WriteU32(os2->unicode_range_3) || + !out->WriteU32(os2->unicode_range_4) || + !out->WriteU32(os2->vendor_id) || + !out->WriteU16(os2->selection) || + !out->WriteU16(os2->first_char_index) || + !out->WriteU16(os2->last_char_index) || + !out->WriteS16(os2->typo_ascender) || + !out->WriteS16(os2->typo_descender) || + !out->WriteS16(os2->typo_linegap) || + !out->WriteU16(os2->win_ascent) || + !out->WriteU16(os2->win_descent)) { + return OTS_FAILURE(); + } + + if (os2->version < 1) { + return true; + } + + if (!out->WriteU32(os2->code_page_range_1) || + !out->WriteU32(os2->code_page_range_2)) { + return OTS_FAILURE(); + } + + if (os2->version < 2) { + return true; + } + + if (!out->WriteS16(os2->x_height) || + !out->WriteS16(os2->cap_height) || + !out->WriteU16(os2->default_char) || + !out->WriteU16(os2->break_char) || + !out->WriteU16(os2->max_context)) { + return OTS_FAILURE(); + } + + return true; +} + +void ots_os2_free(OpenTypeFile *file) { + delete file->os2; +} + +} // namespace ots |