Phaser line of sight polygon and the "negative" invisible polygon

Phaser 3
1

I’m looking at this Line of sight code and managed to get it to work with Phaser3. It works similar to the demo, so when you move a sprite with the mouse it will draw a yellow polygon for the visible area, see screenshot below.

phaser line of sight
phaser line of sight640×640 5.76 KB

However, I would like to get the negative or the opposite polygon, so the blue area in the example screenshot. Then I could make the polygon a black fill color, so that it will block any sprites that are outside of the visible area.

What is the best way to change this polygon?
Or is there a better way to do line-of-sight in Phaser?
Like is there a line-of-sight plug-in maybe?

1 Like
2

I know I’m two years too late, but in case anyone else has the same question and runs across this thread like I did: polygon-tools has a subtract function that does exactly what you want.

Make a polygon for the outer boundaries and subtract the yellow polygon. The result is an array of polygons representing the blue area.