fs2open.github.com/code/options/Option.cpp

//Provides an API to create and interface with built-in game options
//through scripting. Includes methods for instantly persisting value changes
//or saving changes to persist upon restart of the game.

#include "Option.h"
#include "OptionsManager.h"
#include "parse/parselo.h"
#include <utility>

namespace {


} // namespace

namespace options {

namespace internal {

json_t* string_serializer(const SCP_string& value) { return json_pack("s", value.c_str()); }
SCP_string string_deserializer(const json_t* value) {
	const char* s;

	json_error_t err;
	if (json_unpack_ex((json_t*)value, &err, 0, "s", &s) != 0) {
		throw json_exception(err);
	}

	return SCP_string(s);
}
template<>
void set_defaults<SCP_string>(Option<SCP_string>& opt) {
	opt.setDeserializer(string_deserializer);
	opt.setSerializer(string_serializer);
}

float float_deserializer(const json_t* value)
{
	double f;

	json_error_t err;
	if (json_unpack_ex((json_t*)value, &err, 0, "f", &f) != 0) {
		throw json_exception(err);
	}

	return (float)f;
}
json_t* float_serializer(float value) { return json_pack("f", value); }
SCP_string float_display(float value)
{
	SCP_string out;
	sprintf(out, "%.1f", value);
	return out;
}
template<>
void set_defaults<float>(Option<float>& opt) {
	opt.setDeserializer(float_deserializer);
	opt.setSerializer(float_serializer);
	opt.setDisplayFunc(float_display);

	opt.setType(OptionType::Range);
}

int int_deserializer(const json_t* value)
{
	int i;

	json_error_t err;
	if (json_unpack_ex((json_t*)value, &err, 0, "i", &i) != 0) {
		throw json_exception(err);
	}

	return i;
}
json_t* int_serializer(int value) { return json_pack("i", value); }
SCP_string int_display(int value)
{
	SCP_string out;
	sprintf(out, "%d", value);
	return out;
}
template<>
void set_defaults<int>(Option<int>& opt) {
	opt.setDeserializer(int_deserializer);
	opt.setSerializer(int_serializer);
	opt.setDisplayFunc(int_display);

	opt.setType(OptionType::Range);
}

bool boolean_deserializer(const json_t* value)
{
	int b;

	json_error_t err;
	if (json_unpack_ex((json_t*)value, &err, 0, "b", &b) != 0) {
		throw json_exception(err);
	}

	return b != 0;
}
json_t* boolean_serializer(bool value) { return json_pack("b", value ? 1 : 0); }
SCP_string boolean_display(bool value) { return value ? XSTR("On", 1285) : XSTR("Off", 1286); }
template<>
void set_defaults<bool>(Option<bool>& opt) {
	opt.setDeserializer(boolean_deserializer);
	opt.setSerializer(boolean_serializer);
	opt.setDisplayFunc(boolean_display);
	opt.setValueEnumerator(VectorEnumerator<bool>({false, true}));
}

} // namespace internal

ValueDescription::ValueDescription(SCP_string _display, SCP_string _serialized)
    : display(std::move(_display)), serialized(std::move(_serialized))
{
}

OptionBase::~OptionBase() = default;
OptionBase::OptionBase(SCP_string config_key, SCP_string title, SCP_string description)
    : _config_key(std::move(config_key)), _title(std::move(title)), _description(std::move(description))
{
	_parent = OptionsManager::instance();
}

//Return the option value from the config
std::optional<std::unique_ptr<json_t>> OptionBase::getConfigValue() const { return _parent->getValueFromConfig(_config_key); }

//Return the option expert_level value
ExpertLevel OptionBase::getExpertLevel() const { return _expert_level; }

//Set the option expert_level value
void OptionBase::setExpertLevel(ExpertLevel expert_level) { _expert_level = expert_level; }

//Set option preset value
void OptionBase::setPreset(PresetKind preset, const SCP_string& value) { _preset_values.emplace(preset, value); }

//Return the option category
const SCP_string OptionBase::getCategory() const { return XSTR(_category.first, _category.second); }

//Set the option category
void OptionBase::setCategory(const std::pair<const char*, int>& category)
{
	_category = category;
}

//Return unique built-in key for the option
const SCP_string& OptionBase::getConfigKey() const {
	return _config_key;
}

//Return option title
const SCP_string& OptionBase::getTitle() const {
	return _title;
}

//Return option description
const SCP_string& OptionBase::getDescription() const {
	return _description;
}

//Return option importance, used for sorting
int OptionBase::getImportance() const {
	return _importance;
}

//Set option importance, used for sorting
void OptionBase::setImportance(int importance) {
	_importance = importance;
}

//Get option min/max range values
std::pair<float, float> OptionBase::getRangeValues() const {
	return std::make_pair(_min, _max);
}

//Set option min/max range values
void OptionBase::setRangeValues(float min, float max)
{
	_min = min;
	_max = max;
}

bool operator<(const OptionBase& lhs, const OptionBase& rhs) {
	auto val = stricmp(lhs._category.first, rhs._category.first);
	if (val < 0)
		return true;
	if (val > 0)
		return false;
	return lhs._importance > rhs._importance; // Importance is sorted from highest to lowest
}
bool operator>(const OptionBase& lhs, const OptionBase& rhs) {
	return rhs < lhs;
}
bool operator<=(const OptionBase& lhs, const OptionBase& rhs) {
	return !(rhs < lhs);
}
bool operator>=(const OptionBase& lhs, const OptionBase& rhs) {
	return !(lhs < rhs);
}

//Return current flags for this option
const flagset<OptionFlags>& OptionBase::getFlags() const {
	return _flags;
}

//Set flags for this option
void OptionBase::setFlags(const flagset<OptionFlags>& flags) {
	_flags = flags;
}

bool OptionBase::getIsOnce() const {
	return _is_once;
}

void OptionBase::setIsOnce(bool is_once) {
	_is_once = is_once;
}

//persists any changes made to this specific option and returns whether or not it was successful
bool OptionBase::persistChanges() const { return _parent->persistOptionChanges(this); }

} // namespace options