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Diffstat (limited to 'include/mbgl/style/function/convert.hpp')
| -rw-r--r-- | include/mbgl/style/function/convert.hpp | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/include/mbgl/style/function/convert.hpp b/include/mbgl/style/function/convert.hpp new file mode 100644 index 0000000000..9f7b7ed1f8 --- /dev/null +++ b/include/mbgl/style/function/convert.hpp @@ -0,0 +1,351 @@ +#pragma once + +#include <mbgl/style/expression/array_assertion.hpp> +#include <mbgl/style/expression/assertion.hpp> +#include <mbgl/style/expression/case.hpp> +#include <mbgl/style/expression/coalesce.hpp> +#include <mbgl/style/expression/compound_expression.hpp> +#include <mbgl/style/expression/coercion.hpp> +#include <mbgl/style/expression/interpolate.hpp> +#include <mbgl/style/expression/expression.hpp> +#include <mbgl/style/expression/literal.hpp> +#include <mbgl/style/expression/match.hpp> +#include <mbgl/style/expression/step.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/composite_exponential_stops.hpp> +#include <mbgl/style/function/composite_interval_stops.hpp> +#include <mbgl/style/function/composite_categorical_stops.hpp> +#include <mbgl/style/function/identity_stops.hpp> + +#include <mbgl/util/enum.hpp> +#include <mbgl/style/types.hpp> + +#include <string> + + +namespace mbgl { +namespace style { +namespace expression { + +namespace detail { + +class ErrorExpression : public Expression { +public: + ErrorExpression(std::string message_) : Expression(type::Error), message(std::move(message_)) {} + void eachChild(const std::function<void(const Expression&)>&) const override {} + + bool operator==(const Expression& e) const override { + return dynamic_cast<const ErrorExpression*>(&e); + } + + EvaluationResult evaluate(const EvaluationContext&) const override { + return EvaluationError{message}; + } + +private: + std::string message; +}; + +} // namespace detail + + +// Create expressions representing 'classic' (i.e. stop-based) style functions + +struct Convert { + template <typename T> + static std::unique_ptr<Literal> makeLiteral(const T& value) { + return std::make_unique<Literal>(Value(toExpressionValue(value))); + } + + static std::unique_ptr<Expression> makeGet(type::Type type, const std::string& property) { + ParsingContext ctx; + std::vector<std::unique_ptr<Expression>> getArgs; + getArgs.push_back(makeLiteral(property)); + ParseResult get = createCompoundExpression("get", std::move(getArgs), ctx); + assert(get); + assert(ctx.getErrors().size() == 0); + + std::vector<std::unique_ptr<Expression>> assertionArgs; + assertionArgs.push_back(std::move(*get)); + + return std::make_unique<Assertion>(type, std::move(assertionArgs)); + } + + static std::unique_ptr<Expression> makeZoom() { + ParsingContext ctx; + ParseResult zoom = createCompoundExpression("zoom", std::vector<std::unique_ptr<Expression>>(), ctx); + assert(zoom); + assert(ctx.getErrors().size() == 0); + return std::move(*zoom); + } + + static std::unique_ptr<Expression> makeError(std::string message) { + return std::make_unique<detail::ErrorExpression>(message); + } + + template <typename OutputType> + static ParseResult makeInterpolate(type::Type type, + std::unique_ptr<Expression> input, + std::map<double, std::unique_ptr<Expression>> convertedStops, + typename Interpolate<OutputType>::Interpolator interpolator) + { + ParseResult curve = ParseResult(std::make_unique<Interpolate<OutputType>>( + std::move(type), + std::move(interpolator), + std::move(input), + std::move(convertedStops) + )); + assert(curve); + return std::move(*curve); + } + + template <typename Key> + static ParseResult makeMatch(type::Type type, + std::unique_ptr<Expression> input, + std::map<CategoricalValue, std::unique_ptr<Expression>> stops) { + // match expression + typename Match<Key>::Branches branches; + for(auto it = stops.begin(); it != stops.end(); it++) { + assert(it->first.template is<Key>()); + Key key = it->first.template get<Key>(); + branches.emplace( + std::move(key), + std::move(it->second) + ); + } + + return ParseResult(std::make_unique<Match<Key>>(std::move(type), + std::move(input), + std::move(branches), + makeError("No matching label"))); + } + + static ParseResult makeCase(type::Type type, + std::unique_ptr<Expression> input, + std::map<CategoricalValue, std::unique_ptr<Expression>> stops) { + // case expression + std::vector<typename Case::Branch> branches; + + auto it = stops.find(true); + std::unique_ptr<Expression> true_case = it == stops.end() ? + makeError("No matching label") : + std::move(it->second); + + it = stops.find(false); + std::unique_ptr<Expression> false_case = it == stops.end() ? + makeError("No matching label") : + std::move(it->second); + + branches.push_back(std::make_pair(std::move(input), std::move(true_case))); + return ParseResult(std::make_unique<Case>(std::move(type), std::move(branches), std::move(false_case))); + } + + template <typename T> + static ParseResult fromCategoricalStops(std::map<CategoricalValue, T> stops, const std::string& property) { + assert(stops.size() > 0); + + std::map<CategoricalValue, std::unique_ptr<Expression>> convertedStops; + for(const std::pair<CategoricalValue, T>& stop : stops) { + convertedStops.emplace( + stop.first, + makeLiteral(stop.second) + ); + } + + type::Type type = valueTypeToExpressionType<T>(); + + const CategoricalValue& firstKey = stops.begin()->first; + return firstKey.match( + [&](bool) { + return makeCase(type, makeGet(type::Boolean, property), std::move(convertedStops)); + }, + [&](const std::string&) { + return makeMatch<std::string>(type, makeGet(type::String, property), std::move(convertedStops)); + }, + [&](int64_t) { + return makeMatch<int64_t>(type, makeGet(type::Number, property), std::move(convertedStops)); + } + ); + } + + template <typename T> + static std::map<double, std::unique_ptr<Expression>> convertStops(const std::map<float, T>& stops) { + std::map<double, std::unique_ptr<Expression>> convertedStops; + for(const auto& stop : stops) { + convertedStops.emplace( + stop.first, + makeLiteral(stop.second) + ); + } + return convertedStops; + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const ExponentialStops<T>& stops) + { + ParseResult e = makeInterpolate<typename ValueConverter<T>::ExpressionType>( + valueTypeToExpressionType<T>(), + makeZoom(), + convertStops(stops.stops), + ExponentialInterpolator(stops.base)); + assert(e); + return std::move(*e); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const IntervalStops<T>& stops) + { + ParseResult e(std::make_unique<Step>(valueTypeToExpressionType<T>(), + makeZoom(), + convertStops(stops.stops))); + assert(e); + return std::move(*e); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const ExponentialStops<T>& stops) + { + ParseResult e = makeInterpolate<typename ValueConverter<T>::ExpressionType>(valueTypeToExpressionType<T>(), + makeGet(type::Number, property), + convertStops(stops.stops), + ExponentialInterpolator(stops.base)); + assert(e); + return std::move(*e); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const IntervalStops<T>& stops) + { + std::unique_ptr<Expression> get = makeGet(type::Number, property); + ParseResult e(std::make_unique<Step>(valueTypeToExpressionType<T>(), + std::move(get), + convertStops(stops.stops))); + assert(e); + return std::move(*e); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const CategoricalStops<T>& stops) + { + ParseResult expr = fromCategoricalStops(stops.stops, property); + assert(expr); + return std::move(*expr); + } + + // interpolatable zoom curve + template <typename T> + static typename std::enable_if_t<util::Interpolatable<T>::value, + ParseResult> makeZoomCurve(std::map<double, std::unique_ptr<Expression>> stops) { + return makeInterpolate<typename ValueConverter<T>::ExpressionType>(valueTypeToExpressionType<T>(), + makeZoom(), + std::move(stops), + ExponentialInterpolator(1.0)); + } + + // non-interpolatable zoom curve + template <typename T> + static typename std::enable_if_t<!util::Interpolatable<T>::value, + ParseResult> makeZoomCurve(std::map<double, std::unique_ptr<Expression>> stops) { + return ParseResult(std::make_unique<Step>(valueTypeToExpressionType<T>(), makeZoom(), std::move(stops))); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const CompositeExponentialStops<T>& stops) + { + std::map<double, std::unique_ptr<Expression>> outerStops; + for (const std::pair<float, std::map<float, T>>& stop : stops.stops) { + std::unique_ptr<Expression> get = makeGet(type::Number, property); + ParseResult innerInterpolate = makeInterpolate<typename ValueConverter<T>::ExpressionType>(valueTypeToExpressionType<T>(), + std::move(get), + convertStops(stop.second), + ExponentialInterpolator(stops.base)); + assert(innerInterpolate); + outerStops.emplace(stop.first, std::move(*innerInterpolate)); + } + + ParseResult zoomCurve = makeZoomCurve<T>(std::move(outerStops)); + assert(zoomCurve); + return std::move(*zoomCurve); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const CompositeIntervalStops<T>& stops) + { + std::map<double, std::unique_ptr<Expression>> outerStops; + for (const std::pair<float, std::map<float, T>>& stop : stops.stops) { + std::unique_ptr<Expression> get = makeGet(type::Number, property); + ParseResult innerInterpolate(std::make_unique<Step>(valueTypeToExpressionType<T>(), + std::move(get), + convertStops(stop.second))); + assert(innerInterpolate); + outerStops.emplace(stop.first, std::move(*innerInterpolate)); + } + + ParseResult zoomCurve = makeZoomCurve<T>(std::move(outerStops)); + assert(zoomCurve); + return std::move(*zoomCurve); + } + + template <typename T> + static std::unique_ptr<Expression> toExpression(const std::string& property, + const CompositeCategoricalStops<T>& stops) + { + std::map<double, std::unique_ptr<Expression>> outerStops; + for (const std::pair<float, std::map<CategoricalValue, T>>& stop : stops.stops) { + ParseResult innerInterpolate = fromCategoricalStops(stop.second, property); + assert(innerInterpolate); + outerStops.emplace(stop.first, std::move(*innerInterpolate)); + } + + ParseResult zoomCurve = makeZoomCurve<T>(std::move(outerStops)); + assert(zoomCurve); + return std::move(*zoomCurve); + } + + + static std::unique_ptr<Expression> fromIdentityFunction(type::Type type, const std::string& property) + { + std::unique_ptr<Expression> input = type.match( + [&] (const type::StringType&) { + return makeGet(type::String, property); + }, + [&] (const type::NumberType&) { + return makeGet(type::Number, property); + }, + [&] (const type::BooleanType&) { + return makeGet(type::Boolean, property); + }, + [&] (const type::ColorType&) { + std::vector<std::unique_ptr<Expression>> args; + args.push_back(makeGet(type::String, property)); + return std::make_unique<Coercion>(type::Color, std::move(args)); + }, + [&] (const type::Array& arr) { + std::vector<std::unique_ptr<Expression>> getArgs; + getArgs.push_back(makeLiteral(property)); + ParsingContext ctx; + ParseResult get = createCompoundExpression("get", std::move(getArgs), ctx); + assert(get); + assert(ctx.getErrors().size() == 0); + return std::make_unique<ArrayAssertion>(arr, std::move(*get)); + }, + [&] (const auto&) -> std::unique_ptr<Expression> { + return makeLiteral(Null); + } + ); + + return input; + } +}; + +} // namespace expression +} // namespace style +} // namespace mbgl |