Docs - Add warning (to use clear method) for Graphics component when updating draw

[bichotll]

Description

We should add a warning in the Graphics component to warn the user that he may want to clear the canvas if new properties have received.

I can work on that and create a PR.

Steps to reproduce

I created a simple example: https://codepen.io/bichotll/pen/KBYBpd?editors=0011

[inlet]

I believe this should be up to the developer. PIXI memoizes the elements to render, clears the canvas and redraw the elements back to improve performance.

If you're using the Graphics.draw prop, you can simply add g.clear() before you draw another rectangle. See this example: https://codepen.io/inlet/pen/RMLJKm?editors=0011

We could clear the graphics before the prop draw is called here, but I think this is not what you want as a developer.

[inlet]

Closing issue now, please let me know if you think we should reopen it.

[bichotll]

Yes. I'm using g.clear() :)

I just think it would be helpful for the user to let them know that.
My point is: If they are not familiar enough with Pixi, they may expect that passing a new prop to the Graphics component, it would just clear the Graphics component "canvas" and write on a blank canvas (You have to explicitly call the method .clear() in order to have that desired behaviour).

That actually confused me - when it happened to me - until I found out what it was going on.

Again, if that make sense to you, I can create a PR (an update of the docs with the note).
It's not a big deal and it's not part of the library, but it's a good thing to know - at least for newbies.

[inlet]

Good point, would be great if you add this to the README. Thanks!

[bichotll]

Sure thing. I'll work on that soon-ish 👍

[inlet]

Hi @bichotll,

I've added a note to the Graphics doc, see:
https://reactpixi.org/#/components/graphics