1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
#pragma once
#include <mbgl/style/expression/is_constant.hpp>
#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::unique_ptr<expression::Expression> expression_)
: expression(std::move(expression_))
{
assert(expression::isZoomConstant(*expression));
assert(!expression::isFeatureConstant(*expression));
}
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 IdentityStops<T>&) {
return expression::Convert::fromIdentityFunction(expression::valueTypeToExpressionType<T>(), property);
}, [&] (const auto& s) {
return expression::Convert::toExpression(property, s);
}))
{}
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;
const expression::Expression& getExpression() const { return *expression; }
// 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
|
