function Filter(rune)
{
  Module.call(this,rune);
  
  this.parameters = [Any];
  
  this.active = function(cmd)
  {
    if(cmd.content.length < 1){ return; }
    
    var p = cmd.content;
    var filter_name = p[0];
    p.shift();
    
    switch(filter_name) {
      case "saturation":
        this.filter_saturation(this.pixels(),p);
        break;
      case "chromatic":
        this.filter_chromatic(this.pixels(),p);
        break;
      case "offset":
        this.filter_offset(this.pixels(),p);
        break;
      case "eval":
        this.filter_eval(this.pixels(),p);
        break;
      case "balance":
        this.filter_balance(this.pixels(),p);
        break;
    }
  }
  
  this.passive = function(cmd)
  {
  }
	
	this.set_color = function(pixels, color, x, y){
		x = Math.max(0,Math.min(x,pixels.width-1));
		y = Math.max(0,Math.min(y,pixels.height-1));
		var index = (x+y*pixels.width)*4;
		pixels.data[index] = color.r;
		pixels.data[index+1] = color.g;
		pixels.data[index+2] = color.b;
		pixels.data[index+3] = color.a;
	}
	
	this.get_color = function(pixels,x,y){
		x = Math.max(0,Math.min(x,pixels.width-1));
		y = Math.max(0,Math.min(y,pixels.height-1));
		var index = (x+y*pixels.width)*4;
		return {r:pixels.data[index], g:pixels.data[index+1], b:pixels.data[index+2], a:pixels.data[index+3]};
	}
	
	this.get_color_bilinear = function(pixels, x, y){
		var c1 = this.get_color(pixels, Math.floor(x),Math.floor(y));
		var c2 = this.get_color(pixels, Math.ceil(x),Math.floor(y));
		var c3 = this.get_color(pixels, Math.floor(x),Math.ceil(y));
		var c4 = this.get_color(pixels, Math.ceil(x),Math.ceil(y));
		return this.lerp_color(this.lerp_color(c1,c2, x%1),this.lerp_color(c3,c4, x%1), y%1);
	}
	
	this.lerp_color = function(c1, c2, t){
		return {r:c1.r+t*(c2.r-c1.r), g:c1.g+t*(c2.g-c1.g), b:c1.b+t*(c2.b-c1.b), a:c1.a+t*(c2.a-c1.a)};
	}
  
  //
  
  this.pixels = function()
  {
    return ronin.canvas.context().getImageData(0,0,ronin.canvas.element.width,ronin.canvas.element.height);
  }
}
