53 lines
1.7 KiB
C++
53 lines
1.7 KiB
C++
#pragma once
|
|
|
|
#include <mbgl/style/expression/expression.hpp>
|
|
#include <mbgl/style/expression/value.hpp>
|
|
#include <mbgl/style/expression/is_constant.hpp>
|
|
|
|
namespace mbgl {
|
|
namespace style {
|
|
|
|
template <class T>
|
|
class SourceFunction {
|
|
public:
|
|
// The second parameter should be used only for conversions from legacy functions.
|
|
SourceFunction(std::unique_ptr<expression::Expression> expression_, optional<T> defaultValue_ = {})
|
|
: isExpression(defaultValue_),
|
|
expression(std::move(expression_)),
|
|
defaultValue(std::move(defaultValue_)) {
|
|
assert(expression::isZoomConstant(*expression));
|
|
assert(!expression::isFeatureConstant(*expression));
|
|
}
|
|
|
|
template <class Feature>
|
|
T evaluate(const Feature& feature, T finalDefaultValue) const {
|
|
const expression::EvaluationResult result = expression->evaluate(expression::EvaluationContext(&feature));
|
|
if (result) {
|
|
const optional<T> typed = expression::fromExpressionValue<T>(*result);
|
|
return typed ? *typed : defaultValue ? *defaultValue : finalDefaultValue;
|
|
}
|
|
return defaultValue ? *defaultValue : finalDefaultValue;
|
|
}
|
|
|
|
std::vector<optional<T>> possibleOutputs() const {
|
|
return expression::fromExpressionValues<T>(expression->possibleOutputs());
|
|
}
|
|
|
|
friend bool operator==(const SourceFunction& lhs,
|
|
const SourceFunction& rhs) {
|
|
return *lhs.expression == *rhs.expression;
|
|
}
|
|
|
|
bool useIntegerZoom = false;
|
|
bool isExpression;
|
|
|
|
const expression::Expression& getExpression() const { return *expression; }
|
|
|
|
private:
|
|
std::shared_ptr<const expression::Expression> expression;
|
|
optional<T> defaultValue;
|
|
};
|
|
|
|
} // namespace style
|
|
} // namespace mbgl
|