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#pragma once
#include <mbgl/style/function/convert.hpp>
#include <mbgl/style/function/exponential_stops.hpp>
#include <mbgl/style/function/interval_stops.hpp>
#include <mbgl/style/function/categorical_stops.hpp>
#include <mbgl/style/function/identity_stops.hpp>
#include <mbgl/util/interpolate.hpp>
#include <mbgl/util/variant.hpp>
#include <string>
namespace mbgl {
namespace style {
template <class T>
class SourceFunction {
public:
using Stops = std::conditional_t<
util::Interpolatable<T>::value,
variant<
ExponentialStops<T>,
IntervalStops<T>,
CategoricalStops<T>,
IdentityStops<T>>,
variant<
IntervalStops<T>,
CategoricalStops<T>,
IdentityStops<T>>>;
SourceFunction(std::string property_, Stops stops_, optional<T> defaultValue_ = {})
: property(std::move(property_)),
stops(std::move(stops_)),
defaultValue(std::move(defaultValue_)),
expression(stops.match([&] (const auto& s) {
return expression::Convert::toExpression(property, s, defaultValue);
}))
{}
template <class Feature>
T evaluate(const Feature& feature, T finalDefaultValue) const {
auto result = expression->evaluate<T>(expression::EvaluationParameters { optional<float>(), &feature });
if (!result) {
return finalDefaultValue;
}
return *result;
}
friend bool operator==(const SourceFunction& lhs,
const SourceFunction& rhs) {
return std::tie(lhs.property, lhs.stops, lhs.defaultValue)
== std::tie(rhs.property, rhs.stops, rhs.defaultValue);
}
bool useIntegerZoom = false;
// retained for compatibility with pre-expression function API
std::string property;
Stops stops;
optional<T> defaultValue;
private:
std::shared_ptr<expression::Expression> expression;
};
} // namespace style
} // namespace mbgl
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