The dot is chasing me! Your Task
Write a program that displays a dot that moves toward the position of your mouse at 4 pixels per second. The dot must be 100 pixels big and the window must fill the computer screen.
Input
None
Output
A window showing an animated dot moving towards the mouse at a fixed, non-changing speed.
Scoring
This is code-golf, so the shortest code in bytes wins.
HTML + JavaScript, 140 bytes

Infinite speed



t=c.getContext`2d`
c.onmousemove=e=&gt;(x=e.clientX,y=e.clientY)
setInterval(_=&gt;t.clearRect(0,0,1e5,1e5)||t.fillRect(x,y,10,10),9)
&lt;canvas id=c&gt;




Non-cheaty, 188 bytes



x=y=0,t=c.getContext`2d`
c.onmousemove=e=&gt;(z=e.pageX,w=e.pageY)
f=_=&gt;t.clearRect(0,0,1e5,1e5)||(m=((a=z-x)**2+(b=w-y)**2)**.5)|t.fillRect(x+=a/m,y+=b/m,10,10)
setInterval(f,9)
&lt;canvas id=c&gt;




Larger and faster:


x=y=0,s=3,t=c.getContext`2d`
c.onmousemove=e=&gt;(z=e.pageX,w=e.pageY)
f=_=&gt;t.clearRect(0,0,1e5,1e5)||(m=((a=z-x)**2+(b=w-y)**2)**.5)|t.fillRect(x+=s*a/m,y+=s*b/m,10,10)
setInterval(f,9)
&lt;canvas id=c height=999 width=999&gt;