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/*
Copyright (C) 2012, 2013, 2014 Johan Mattsson
This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 3 of the
License, or (at your option) any later version.
This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
*/
namespace BirdFont {
public class HeadTable : Table {
public int16 xmin = int16.MIN;
public int16 ymin = int16.MIN;
public int16 xmax = int16.MAX;
public int16 ymax = int16.MAX;
uint32 adjusted_checksum = 0;
uint16 mac_style;
uint16 lowest_PPEM;
int16 font_direction_hint;
public int16 loca_offset_size = 1; // 0 for int16 1 for int32
int16 glyph_data_format;
Fixed version;
Fixed font_revision;
uint32 magic_number;
uint16 flags;
uint64 created;
uint64 modified;
public static uint16 units_per_em;
public static double UNITS;
const uint8 BASELINE_AT_ZERO = 1 << 0;
const uint8 LSB_AT_ZERO = 1 << 1;
const uint8 SIZE_SPECIFIC_INSTRUCTIONS = 1 << 2;
const uint8 FORCE_PPEM_INTEGER_VALUES = 1 << 3;
GlyfTable glyf_table;
public HeadTable (GlyfTable gt) {
glyf_table = gt;
id = "head";
init ();
}
/** Set default value for unit. */
public static void init () {
units_per_em = 1024;
UNITS = 10 * (units_per_em / 1000.0);
}
public uint32 get_adjusted_checksum () {
return adjusted_checksum;
}
/** Get the units per em for generated fonts, not for fonts parsed
* with this library.
*/
public double get_units_per_em () {
return units_per_em * 10;
}
public override void parse (FontData dis) throws GLib.Error {
return_if_fail (offset > 0 && length > 0);
dis.seek (offset);
font_data = new FontData ();
version = dis.read_fixed ();
if (!version.equals (1, 0)) {
warning (@"Expecting head version 1.0 got $(version.get_string ())\n");
}
font_revision = dis.read_fixed ();
adjusted_checksum = dis.read_ulong ();
magic_number = dis.read_ulong ();
if (magic_number != 0x5F0F3CF5) {
warning (@"Magic number is invalid ($(magic_number)).");
return;
}
flags = dis.read_ushort ();
if ((flags & BASELINE_AT_ZERO) > 0) {
printd ("Flag BASELINE_AT_ZERO has been set.\n");
}
if ((flags & LSB_AT_ZERO) > 0) {
printd ("Flags LSB_AT_ZERO has been set.\n");
}
units_per_em = dis.read_ushort ();
created = dis.read_udate ();
modified = dis.read_udate ();
xmin = dis.read_short ();
ymin = dis.read_short ();
xmax = dis.read_short ();
ymax = dis.read_short ();
printd (@"font boundaries:\n");
printd (@"xmin: $xmin\n");
printd (@"ymin: $ymin\n");
printd (@"xmax: $xmax\n");
printd (@"ymax: $ymax\n");
mac_style = dis.read_ushort ();
lowest_PPEM = dis.read_ushort ();
font_direction_hint = dis.read_short ();
loca_offset_size = dis.read_short ();
glyph_data_format = dis.read_short ();
if (glyph_data_format != 0) {
warning (@"Unknown glyph data format. Expecting 0 got $glyph_data_format.");
}
printd (@"Version: $(version.get_string ())\n");
printd (@"flags: $flags\n");
printd (@"font_revision: $(font_revision.get_string ())\n");
printd (@"flags: $flags\n");
printd (@"Units per em: $units_per_em\n");
printd (@"lowest_PPEM: $lowest_PPEM\n");
printd (@"font_direction_hint: $font_direction_hint\n");
printd (@"loca_offset_size: $loca_offset_size\n");
printd (@"glyph_data_format: $glyph_data_format\n");
// Some deprecated values follow here ...
}
public uint32 get_font_checksum () {
return adjusted_checksum;
}
public void set_check_sum_adjustment (uint32 csa) {
this.adjusted_checksum = csa;
}
public uint32 get_checksum_position () {
return 8;
}
public void process () throws GLib.Error {
FontData font_data = new FontData ();
Fixed version = 1 << 16;
Fixed font_revision = 1 << 16;
uint64 time = (uint64) Math.rint (GLib.get_real_time () / 1000000.0);
const uint64 time_diff = 60 * 60 * 24 * (365 * (1970 - 1904) + 17); // FIXME: add leap seconds
font_data.add_fixed (version);
font_data.add_fixed (font_revision);
// Zero on the first run and updated by directory tables checksum calculation
// for the entire font.
font_data.add_u32 (adjusted_checksum);
font_data.add_u32 (0x5F0F3CF5); // magic number
// FIXME: delete LSB_AT_ZERO?
// flags
font_data.add_u16 (BASELINE_AT_ZERO | LSB_AT_ZERO | FORCE_PPEM_INTEGER_VALUES);
font_data.add_u16 (units_per_em); // units per em (should be a power of two for ttf fonts)
font_data.add_u64 (time + time_diff); // creation time since 1901-01-01
font_data.add_u64 (time + time_diff); // modified time since 1901-01-01
xmin = glyf_table.xmin;
ymin = glyf_table.ymin;
xmax = glyf_table.xmax;
ymax = glyf_table.ymax;
printd (@"font boundaries:\n");
printd (@"xmin: $xmin\n");
printd (@"ymin: $ymin\n");
printd (@"xmax: $xmax\n");
printd (@"ymax: $ymax\n");
font_data.add_short (xmin);
font_data.add_short (ymin);
font_data.add_short (xmax);
font_data.add_short (ymax);
font_data.add_u16 (0); // mac style
font_data.add_u16 (8); // smallest recommended size in pixels, ppem
font_data.add_16 (2); // deprecated direction hint
font_data.add_16 (loca_offset_size); // long offset
font_data.add_16 (0); // Use current glyph data format
font_data.pad ();
this.font_data = font_data;
}
}
}
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