The Tor Browser / file revision

 // 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/typography/otspec/os2.htm

 #define TABLE_NAME "OS/2"

 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_MSG("Failed toi read basic os2 elements");

   }

   if (os2->version > 4) {

     return OTS_FAILURE_MSG("os2 version too high %d", os2->version);

   }

   // 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_MSG("Failed to read panose in os2 table");

     }

   }

   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_MSG("Failed to read more basic os2 fields");

   }

   // 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_MSG("Head table missing from font as needed by os2 table");

   }

   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_MSG("OS2 version %d incompatible with selection %d", os2->version, os2->selection);

   }

   // mask reserved bits. use only 0..9 bits.

   os2->selection &= 0x3ff;

   if (os2->first_char_index > os2->last_char_index) {

     return OTS_FAILURE_MSG("first char index %d > last char index %d in os2", os2->first_char_index, os2->last_char_index);

   }

   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_MSG("Failed to read codepage ranges");

   }

   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_MSG("Failed to read os2 version 2 information");

   }

   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 != NULL;

 }

 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_MSG("Failed to write basic OS2 information");

   }

   for (unsigned i = 0; i < 10; ++i) {

     if (!out->Write(&os2->panose[i], 1)) {

       return OTS_FAILURE_MSG("Failed to write os2 panose information");

     }

   }

   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_MSG("Failed to write os2 version 1 information");

   }

   if (os2->version < 1) {

     return true;

   }

   if (!out->WriteU32(os2->code_page_range_1) ||

       !out->WriteU32(os2->code_page_range_2)) {

     return OTS_FAILURE_MSG("Failed to write codepage ranges");

   }

   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_MSG("Failed to write os2 version 2 information");

   }

   return true;

 }

 void ots_os2_free(OpenTypeFile *file) {

   delete file->os2;

 }

 }  // namespace ots