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Diffstat (limited to 'include/mbgl/style/conversion/function.hpp')
-rw-r--r-- | include/mbgl/style/conversion/function.hpp | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/include/mbgl/style/conversion/function.hpp b/include/mbgl/style/conversion/function.hpp new file mode 100644 index 0000000000..f14b5089be --- /dev/null +++ b/include/mbgl/style/conversion/function.hpp @@ -0,0 +1,69 @@ +#pragma once + +#include <mbgl/style/function.hpp> +#include <mbgl/style/conversion.hpp> +#include <mbgl/style/conversion/constant.hpp> + +namespace mbgl { +namespace style { +namespace conversion { + +template <class T> +struct Converter<Function<T>> { + template <class V> + Result<Function<T>> operator()(const V& value) const { + if (!isObject(value)) { + return Error { "function must be an object" }; + } + + auto stopsValue = objectMember(value, "stops"); + if (!stopsValue) { + return Error { "function value must specify stops" }; + } + + if (!isArray(*stopsValue)) { + return Error { "function stops must be an array" }; + } + + std::vector<std::pair<float, T>> stops; + for (std::size_t i = 0; i < arrayLength(*stopsValue); ++i) { + const auto& stopValue = arrayMember(*stopsValue, i); + + if (!isArray(stopValue)) { + return Error { "function stop must be an array" }; + } + + if (arrayLength(stopValue) != 2) { + return Error { "function stop must have two elements" }; + } + + optional<float> z = toNumber(arrayMember(stopValue, 0)); + if (!z) { + return Error { "function stop zoom level must be a number" }; + } + + Result<T> v = convert<T>(arrayMember(stopValue, 1)); + if (!v) { + return v.error(); + } + + stops.emplace_back(*z, *v); + } + + auto baseValue = objectMember(value, "base"); + if (!baseValue) { + return Function<T>(stops, 1.0f); + } + + optional<float> base = toNumber(*baseValue); + if (!base) { + return Error { "function base must be a number"}; + } + + return Function<T>(stops, *base); + } +}; + +} // namespace conversion +} // namespace style +} // namespace mbgl |