Added animation

src/animation/float_track.h

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "animation_track.h"
+
+BEGIN_NAMESPACE
+
+class float_track : public animation_track {
+public:
+    animated_value get_value(const animated_value &first, const animated_value &second, float alpha) override;
+    void control_object(void *controlled_object, const animated_value &value) override;
+};
+
+END_NAMESPACE