so I found this code in the forums, which is immensely helpful.

	scrollScreen: function() {
      if(this.player.pos.x > (ig.game.collisionMap.width*ig.game.collisionMap.tilesize-ig.system.width/2))
      {
        this.screen.x = ig.game.collisionMap.width*ig.game.collisionMap.tilesize-ig.system.width;
      }
      else if (this.player.pos.x < ig.system.width/2) 
      {
        this.screen.x = 0;
      }
      else 
      {
        this.screen.x = (this.player.pos.x - ig.system.width/2);
      }
    
      if(this.player.pos.y > (ig.game.collisionMap.height*ig.game.collisionMap.tilesize-ig.system.height/2))
      {
        this.screen.y = ig.game.collisionMap.height*ig.game.collisionMap.tilesize-ig.system.height;
      }
      else if (this.player.pos.y < ig.system.height/2) 
      {
        this.screen.y = 0;
      }
      else 
      {
        this.screen.y = (this.player.pos.y - ig.system.height/2);
      }
    }

issue is -- the player is shifted to the right. I know what it is, it's not taking into account the player's width/2 (which in this case would be 8)

just not quite sure hwo to implement it properly without seeing black overscroll on the edges.