/*
* Copyright 2010-2016 OpenXcom Developers.
*
* This file is part of OpenXcom.
*
* OpenXcom is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* OpenXcom 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with OpenXcom. If not, see <http://www.gnu.org/licenses/>.
*/
#include "WeightedOptions.h"
#include "../Engine/RNG.h"
namespace OpenXcom
{
/**
* Select a random choice from among the contents.
* This MUST be called on non-empty objects.
* Each time this is called, the returned value can be different.
* @return The key of the selected choice.
*/
std::string WeightedOptions::choose() const
{
if (_totalWeight == 0)
{
return "";
}
size_t var = RNG::generate(0, _totalWeight);
std::map<std::string, size_t>::const_iterator ii = _choices.begin();
for (; ii != _choices.end(); ++ii)
{
if (var <= ii->second)
break;
var -= ii->second;
}
// We always have a valid iterator here.
return ii->first;
}
/**
* Set an option's weight.
* If @a weight is set to 0, the option is removed from the list of choices.
* If @a id already exists, the new weight replaces the old one, otherwise
* @a id is added to the list of choices, with @a weight as the weight.
* @param id The option name.
* @param weight The option's new weight.
*/
void WeightedOptions::set(const std::string &id, size_t weight)
{
std::map<std::string, size_t>::iterator option = _choices.find(id);
if (option != _choices.end())
{
_totalWeight -= option->second;
if (0 != weight)
{
option->second = weight;
_totalWeight += weight;
}
else
{
_choices.erase(option);
}
}
else if (0 != weight)
{
_choices.insert(std::make_pair(id, weight));
_totalWeight += weight;
}
}
/**
* Add the weighted options from a YAML::Node to a WeightedOptions.
* The weight option list is not replaced, only values in @a nd will be added /
* changed.
* @param nd The YAML node (containing a map) with the new values.
*/
void WeightedOptions::load(const YAML::Node &nd)
{
for (YAML::const_iterator val = nd.begin(); val != nd.end(); ++val)
{
std::string id = val->first.as<std::string>();
size_t w = val->second.as<size_t>();
set(id, w);
}
}
/**
* Send the WeightedOption contents to a YAML::Emitter.
* @return YAML node.
*/
YAML::Node WeightedOptions::save() const
{
YAML::Node node;
for (std::map<std::string, size_t>::const_iterator ii = _choices.begin(); ii != _choices.end(); ++ii)
{
node[ii->first] = ii->second;
}
return node;
}
/**
* Get the list of strings associated with these weights.
* @return the list of strings in these weights.
*/
std::vector<std::string> WeightedOptions::getNames()
{
std::vector<std::string> names;
for (std::map<std::string, size_t>::const_iterator ii = _choices.begin(); ii != _choices.end(); ++ii)
{
names.push_back((*ii).first);
}
return names;
}
}
↑ V823 Decreased performance. Object may be created in-place in the '_choices' container. Consider replacing methods: 'insert' -> 'emplace'.