Source: main.js

/*jslint plusplus: true, white: true, indent: 2, maxlen: 90 */
/**
 *  @module $wk$
 *  @author    Wolfgang Kowarschick
 *  @copyright 2013, Wolfgang Kowarschick
 *  <br/>
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted under the terms of the 
 *  Creative Commons License Attribution-NonCommercial-ShareAlike 3.0 Unported    
 *  (CC BY-NC-SA 3.0: http://creativecommons.org/licenses/by-nc-sa/3.0/). 
 */

(function($wk$, window, document)
{ "use strict";

////////////////////////////////////////////////////////////////////////////////
// Class "Main"
////////////////////////////////////////////////////////////////////////////////

//------------------------------------------------------------------------------
// Constructor 
//------------------------------------------------------------------------------

// The class "Main". 
function Main()
{ var Paddle        = $wk$.Paddle,      // Import
      Collision     = $wk$.Collision, // Import
      i, n,
      self          = this,
      l_init        = INIT,
      l_init_canvas = l_init.canvas,
      l_init_paddle = l_init.paddle,
      l_init_game   = l_init.game,
      l_paddles     = [],
      l_context;
      
  // Save the init object so that methods can access them.
  this.initCanvas = l_init_canvas;
  this.initGame   = l_init_game;

  // Initialize the canvas.
  this.v_canvas        = document.getElementById("d_canvas");
  this.v_canvas.width  = l_init_canvas.width;
  this.v_canvas.height = l_init_canvas.height;
  this.v_context       = l_context = this.v_canvas.getContext("2d");

  // Initialize the paddle objects.
  this.v_paddles = l_paddles;     
  for (i = 0, n = l_init_game.paddlesNr; i < n ; i++)
  { l_paddles[i] = new Paddle(l_context, l_init_paddle, i); }

  // Initialize the collision object.
  this.v_collision = new Collision({left:   0, 
                                    right:  l_init_canvas.width, 
                                    top:    0,
                                    bottom: l_init_canvas.height
                                   },
                                   l_paddles
                                  );

  // React to key down and key up events.
  document.onkeydown = this.o_start_paddle_moving.bind(this);
  document.onkeyup   = this.o_stop_paddle_moving.bind(this);

  // Start the timer for redrawing the canvas every 1000/FPS milliseconds.
  this.v_timer 
    = window.setInterval(function(){ self.o_redraw(); }, 1000/l_init_game.fps);
}

//------------------------------------------------------------------------------
// End of Constructor
//------------------------------------------------------------------------------

Main.prototype =
{ //----------------------------------------------------------------------------
  // Methods (View)
  //----------------------------------------------------------------------------

  // Clears the canvas and draws all sprites.
  m_draw:
    function()
    { var i             = null,
          l_init_canvas = this.initCanvas,
          l_paddles     = this.v_paddles;
      this.v_context.clearRect(0, 0, l_init_canvas.width, l_init_canvas.height);
      for (i in l_paddles)
      { l_paddles[i].draw(); }
    },

  // An event observer: 
  // It is called every 1000/FPS milliseconds, but only when the game has been started.
  o_redraw:
    function() 
    { var i         = null,
          l_fps     = this.initGame.fps,
          l_paddles = this.v_paddles;
    
      // collision handling
      this.v_collision.handleCollision();

      // Move the paddles.
      for (i in l_paddles)
      { l_paddles[i].move(1000/l_fps); }
      
      // Redraw the canvas.
      this.m_draw();
    },
    
  // An event observer: 
  // It is called whenever a "start paddle moving event" is signaled.
  o_start_paddle_moving:
    function (p_event)
    { var l_keys = this.initGame.keys[p_event.keyCode];

      if (l_keys)
      { this.v_paddles[l_keys[0]].start(l_keys[1]); }
    },

   // An event observer: 
   // It is called whenever a "stop paddle moving event" is signaled.
   o_stop_paddle_moving:
     function (p_event)
     { var l_keys = this.initGame.keys[p_event.keyCode];
     
       if (l_keys)
       { this.v_paddles[l_keys[0]].stop(); }
     }
   
  //----------------------------------------------------------------------------
  // End of Methods
  //----------------------------------------------------------------------------
};

//Create the main object, after the HTML page has been loaded.
window.onload = function(){ new Main(); };

////////////////////////////////////////////////////////////////////////////////
// End of Class "Main"
////////////////////////////////////////////////////////////////////////////////

}(this.$wk$, this.window, this.document));