[core] Runtime style layer API

1 files changed, 21 insertions, 0 deletions

diff --git a/include/mbgl/style/types.hpp b/include/mbgl/style/types.hpp
index 9b03ab8a2d..a852a09a14 100644
--- a/include/mbgl/style/types.hpp
+++ b/include/mbgl/style/types.hpp
@@ -5,6 +5,7 @@
 #include <string>
 #include <array>
 #include <vector>
+#include <utility>
 
 namespace mbgl {
 
@@ -20,6 +21,26 @@ struct FontStackHash {
     std::size_t operator()(const FontStack&) const;
 };
 
+template <typename T>
+class Function {
+public:
+    using Stop = std::pair<float, T>;
+    using Stops = std::vector<Stop>;
+
+    Function(const T& constant)
+        : stops({{ 0, constant }}) {}
+
+    explicit Function(const Stops& stops_, float base_)
+        : base(base_), stops(stops_) {}
+
+    float getBase() const { return base; }
+    const std::vector<std::pair<float, T>>& getStops() const { return stops; }
+
+private:
+    float base = 1;
+    std::vector<std::pair<float, T>> stops;
+};
+
 // -------------------------------------------------------------------------------------------------
 
 enum class SourceType : uint8_t {