refactoring of texture code into a 2D version first

src/system/include/pw/system/input.hpp

@@ -17,6 +17,7 @@ public:
     int mouse_button() const { return _mouse_button; }
 
 
+    bool has_input() const { return !_input_string.empty();}
     std::string input_string() const { return _input_string; }
 
 	~input() = default;