ちょっと事情があってマウス座標が欲しかったのです。 import { render } from 'preact' import { useCallback, useState } from 'preact/hooks' function App() { let a = 0 const [mousePoint, setMousePoint] = useState<[number, number]>([0, 0]) const track = useCallback((e: MouseEvent) => { if (mousePoint[0] == e.clientX && mousePoint…