Simplify

calculation of canvas position based on the cursor position and expected rotation

inc/App.hpp

@@ -16,7 +16,6 @@ private:
   int pos = 0;
   int screenWidth, screenHeight;
   std::vector<Canvas> canvases;
-  Vector2 center;
   float rotation = 0.0f;
   Rectangle destB;
   Rectangle destA;