reorganize properties

1 files changed, 45 insertions, 0 deletions

diff --git a/include/llmr/style/function_properties.hpp b/include/llmr/style/function_properties.hpp
new file mode 100644
index 0000000000..970d617d02
--- /dev/null
+++ b/include/llmr/style/function_properties.hpp
@@ -0,0 +1,45 @@
+#ifndef LLMR_STYLE_FUNCTION_PROPERTIES
+#define LLMR_STYLE_FUNCTION_PROPERTIES
+
+#include <vector>
+
+namespace llmr {
+
+namespace functions {
+
+float null(float z, const std::vector<float>&);
+float constant(float z, const std::vector<float>& values);
+float min(float z, const std::vector<float>& values);
+float max(float z, const std::vector<float>& values);
+float stops(float z, const std::vector<float>& values);
+float linear(float z, const std::vector<float>& values);
+float exponential(float z, const std::vector<float>& values);
+
+}
+
+struct FunctionProperty {
+    typedef float (*fn)(float z, const std::vector<float>& values);
+
+    fn function;
+    std::vector<float> values;
+
+    inline FunctionProperty() : function(&functions::null) {}
+
+    inline FunctionProperty(const FunctionProperty &property)
+        : function(property.function), values(property.values) {}
+    inline FunctionProperty(FunctionProperty &&property)
+        : function(property.function), values(std::move(property.values)) {}
+
+
+    inline void operator=(const FunctionProperty &rhs) {
+        function = rhs.function;
+        values = rhs.values;
+    }
+
+    inline FunctionProperty(float value) : function(&functions::constant), values(1, value) {}
+    template <typename T> inline T evaluate(float z) const { return function(z, values); }
+};
+
+}
+
+#endif