Slither.io Mod to Orient View to Player Perspective

slither_fps.js

if (typeof my_reset != "undefined") my_reset();
my_init = function() {
  old_redraw = redraw;
  var mag = 0.1;
  var c_ang = 0;
  var get_ang = function(snake_ang) {
    var diff = Math.abs(snake_ang - c_ang);
    if (diff < mag) return snake_ang;
    else if ((c_ang < snake_ang && snake_ang - c_ang < Math.PI)
         ||  (c_ang > snake_ang && c_ang - snake_ang > Math.PI))
      c_ang += mag;
    else if ((c_ang > snake_ang && c_ang - snake_ang < Math.PI)
         ||  (c_ang < snake_ang && snake_ang - c_ang > Math.PI))
      c_ang -= mag;

         if (c_ang < 0)          c_ang = Math.PI * 2 - c_ang;
    else if (c_ang > Math.PI *2) c_ang %= Math.PI * 2;
    return c_ang;
  }

  my_redraw = function() {
    var cx = mc.width/2, cy = mc.height/2;
    var b = mc.getContext('2d');
    b.save();
    if (snake) {
      b.translate(cx, cy);
      b.rotate(-get_ang(snake.ang) - (Math.PI / 2));
      b.translate(-cx, -cy);
    }
    old_redraw();
    b.restore();
  }
  redraw = my_redraw;
}

my_reset = function() {
  redraw = old_redraw;
}

my_init();