FloatTag.php

<?php
 
/*
 *
 *  ____            _        _   __  __ _                  __  __ ____
 * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
 * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
 * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
 * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
 *
 * This program 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.
 *
 * @author PocketMine Team
 * @link http://www.pocketmine.net/
 *
 *
*/
 
declare(strict_types=1);
 
namespace pocketmine\nbt\tag;
 
use pocketmine\nbt\NBT;
use pocketmine\nbt\NbtStreamReader;
use pocketmine\nbt\NbtStreamWriter;
use pocketmine\utils\Binary;
use function func_num_args;
 
final class FloatTag extends ImmutableTag{
    private $value;
 
    public function __construct(float $value){
        self::restrictArgCount(__METHOD__, func_num_args(), 1);
        $this->value = $value;
    }
 
    protected function getTypeName() : string{
        return "Float";
    }
 
    public function getType() : int{
        return NBT::TAG_Float;
    }
 
    public static function read(NbtStreamReader $reader) : self{
        return new self($reader->readFloat());
    }
 
    public function write(NbtStreamWriter $writer) : void{
        $writer->writeFloat($this->value);
    }
 
    public function getValue() : float{
        return $this->value;
    }
 
    protected function stringifyValue(int $indentation) : string{
        return (string) $this->value;
    }
 
    public function equals(Tag $that) : bool{
        //the values of TAG_Float are represented in 32 bits (single precision), so we don't want extra precision given
        //by 64-bit in-memory representation to break comparison (e.g. 0.3 != decode(encode(0.3)))
        //this intentionally truncates our value so that it compares as valid
        return $that instanceof $this && Binary::writeFloat($this->value) === Binary::writeFloat($that->value);
    }
}