I want to draw to very specific area of the window (starting from (250, 20) to right lower corner of the window, window also can be resized). I know I have to use viewport on a window sized view, but how to calculate its FloatRect? Viewport will be set to the black rectangle area and view will be moved by mouse so I can see whole loaded texture when it is bigger than window. I aiming for something like TileSet Editor from Godot engine.