/*
	Copyright (C) 2012, 2013 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 OffsetTable : OtfTable {
	DirectoryTable directory_table;
		
	public uint16 num_tables = 0;
	uint16 search_range = 0;
	uint16 entry_selector = 0;
	uint16 range_shift = 0;
	
	public OffsetTable (DirectoryTable t) {
		id = "Offset table";
		directory_table = t;
	}
		
	public override void parse (FontData dis) throws Error {
		Fixed version;
		
		dis.seek (offset);
		
		version = dis.read_fixed ();
		num_tables = dis.read_ushort ();
		search_range = dis.read_ushort ();
		entry_selector = dis.read_ushort ();
		range_shift = dis.read_ushort ();
		
		printd (@"Font file version $(version.get_string ())\n");
		printd (@"Number of tables $num_tables\n");		
	}
	
	public void process () throws GLib.Error {
		FontData fd = new FontData ();
		Fixed version = 0x00010000; // sfnt version 1.0 for TTF CFF else use OTTO

		
		num_tables = (uint16) directory_table.get_tables ().size - 2; // number of tables, skip DirectoryTable and OffsetTable
		
		search_range = max_pow_2_less_than_i (num_tables) * 16;
		entry_selector = max_log_2_less_than_i (num_tables);
		range_shift = 16 * num_tables - search_range;

		fd.add_fixed (version); 
		fd.add_u16 (num_tables);
		fd.add_u16 (search_range);
		fd.add_u16 (entry_selector);
		fd.add_u16 (range_shift);
		
		// skip padding for offset table 
		
		this.font_data = fd;
	}
}

}