Idea: The goal is to implement a live on-canvas iWarp like tool. Behavior: The basic usecase of this tool would be: 1. The user select the iwarp tool. Nothing is displayed on top of the image. 2. If needed, the user select a particular behavior for the tool (drag,shrink, grow, whirl, pinch ..) 3. The user do a stroke on the canvas. The image is updated accordingly.