--- /dev/null
+#ifndef EFFECT_H
+#define EFFECT_H
+
+/// ***** Header Class *****
+class Effect
+{
+ public:
+ virtual Vector2 positionAfter(const Vector&, float) const = 0;
+ virtual Vector2 velocityAfter(const Vector&, float) const = 0;
+}
+
+#endif // EFFECT_H
--- /dev/null
+#include "Gravity.h"
+
+/// ***** Header Class *****
+Vector2 Gravity::positionAfter(const Vector2&, float)
+{
+
+}
+Vector2 Gravity::velocityAfter(const Vector2&, float)
+{
+
+}
+
+#endif // GRAVITY_H
--- /dev/null
+#ifndef GRAVITY_H
+#define GRAVITY_H
+
+#include "Effect.h"
+
+/// ***** Header Class *****
+class Gravity: public Effect
+{
+ Vector2 positionAfter(const Vector2&, float);
+ Vector2 velocityAfter(const Vector2&, float);
+}
+
+#endif // GRAVITY_H