Light Effect Help

[Ohk4y]

Hello, I'm trying to simulate being in a cave on my server and I was thinking I could show a polygon that covered the whole screen except for a little circle around your player.

Here's my current script to show a black screen:

PHP Code:

    showpoly(210, {
        0, 0, screenwidth, 0, screenwidth, screenheight, 0, screenheight
    });
    changeimgcolors(210, 0, 0, 0, 1); 


How could I modify this to show only the area around your player? Like maybe 1 - 2 tiles around your player.