I have an interactive animation I want to show as a canvas in Monogatari. I have it fully functional as its own html/js file, but I can't get it to work within Monogatari's canvas mode. When I load it in as a prop, the base shapes are drawn correctly, but it doesn't react to mouse movement like I want it to. The documentation says states are for objects with changing properties and props are for static things, but it doesn't explain how to actually use states. How can I use states to update variables and create interactive animation?