title: HTML5 Canvas: Mouse and polygon collision detection
body: <p>So I'm making a tower defense game with HTML5 and Javascript. My sole problem is detecting when the mouse comes in contact with the attacker's pathway, which is necessary in order to stop the player from building towers on the path. The path of the attackers is determined in the MAP.js file (see the link at the bottom), by a two dimensional array (an array containing x and y pairs), so what I have to work with is a series of points that make up a path when connected. I merely want to prohibit the player from placing towers within, say, 50 pixels of the path. To be honest I am just awful with collision detection, so some help would be greatly appreciated.</p>
  
  <p>Here is the link to all the code:
  <a href="http://shapeshifting.comuv.com/Tower_Defense/td/" rel="noreferrer">http://shapeshifting.comuv.com/Tower_Defense/td/</a></p>
  
  <p>As you might imagine, only the .js files are applicable, but most of the relevant code is inside the objects.js file. (PLease excuse the messiness)</p>