/**
* Player System
*
* Provides player controls for jump and run style games.
*
* @class player
* @namespace zerk.game.engine.system
* @extends zerk.game.engine.system
* @module zerk
**/
zerk.define({
name: 'zerk.game.engine.system.player',
extend: 'zerk.game.engine.system'
},{
/**
* Name of the system
*
* @property _name
* @type String
* @protected
*/
_name: 'player',
/**
* Thread that runs this system
*
* @property _thread
* @type String
* @protected
**/
_thread: 'simulation',
/**
* Physics system instance
*
* @property _physics
* @type zerk.game.engine.system.physics
* @protected
**/
_physics: null,
/**
* Keyboard interface
*
* @property _keyboard
* @type zerk.game.engine.system.control.keyboard
* @protected
**/
_keyboard: null,
/**
* Indicates that the jump key is not pressed
*
* @property _keyReleased
* @type Boolean
* @protected
**/
_keyReleased: true,
/**
* Class constructor
*
* @method init
* @param {zerk.game.engine} engine Game engine
* @param {Object} config System configuration
*/
init: function(engine,config) {
zerk.parent('zerk.game.engine.system.player').init.apply(
this,
arguments
);
this._keyboard=this._getSystem('control').keyboard;
this._physics=this._getSystem('physics');
if (!this._physics) {
console.log('Player system need physics system to be active');
}
},
/**
* Returns true when the system is interested in given component
*
* @method useComponent
* @param {String} name Component name
* @return {Boolean} True when the system is intereseted in given component
**/
useComponent: function(name) {
return (name=='player');
},
/**
* Adds an entity to the system
*
* @method addEntity
* @param {config.entity} entity Entity state
**/
addEntity: function(entity) {
zerk.parent('zerk.game.engine.system.player').addEntity.apply(
this,
arguments
);
},
/**
* Starts the system
*
* @method start
**/
start: function() {
zerk.parent('zerk.game.engine.system.player').start.apply(
this,
arguments
);
this._physics.on(
'contactbegin',
this._onContactBegin,
this
);
this._physics.on(
'contactend',
this._onContactEnd,
this
);
this._keyboard.on(
'keydown',
this._onKeyDown,
this
);
this._keyboard.on(
'keyup',
this._onKeyUp,
this
);
},
/**
* Stops the system
*
* @method stop
**/
stop: function() {
zerk.parent('zerk.game.engine.system.player').stop.apply(
this,
arguments
);
this._physics.un(
'contactbegin',
this._onContactBegin
);
this._physics.un(
'contactend',
this._onContactEnd
);
this._keyboard.un(
'keydown',
this._onKeyDown
);
this._keyboard.un(
'keyup',
this._onKeyUp
);
},
/**
* Updates the system
*
* @method update
**/
update: function() {
zerk.parent('zerk.game.engine.system.player').update.apply();
for (var i=0;i<this._entities.length;i++) {
if (!this._entities[i].components.player.enableControl) return;
if (this._keyboard.pressedSpace) {
this.actionJump(this._entities[i]);
}
if (this._keyboard.pressedArrowLeft) {
this.actionWalkLeft(this._entities[i]);
}
if (this._keyboard.pressedArrowRight) {
this.actionWalkRight(this._entities[i]);
}
}
},
/**
* Makes given player win
*
* @method win
* @param {config.entity} entity Entity state
**/
win: function(entity) {
this.fireEvent('win',entity);
},
/**
* Makes given player die
*
* @method dead
* @param {config.entity} entity Entity state
**/
dead: function(entity) {
this._physics.setBodyMoveable(entity,'main',false);
this.fireEvent('dead',entity);
},
/**
* Fires when a key is pressed down
*
* @method _onKeyDown
* @param {DOMEvent} event Event information
* @protected
**/
_onKeyDown: function(event) {
for (var i=0;i<this._entities.length;i++) {
var componentState=this._entities[i].components.player;
if (!componentState.enableControl) continue;
if (event.keyCode==32) {
if (componentState.grounded && this._keyReleased) {
componentState.jumping=true;
}
this._keyReleased=false;
}
}
},
/**
* Fires when a key is released
*
* @method _onKeyUp
* @param {DOMEvent} event Event information
* @protected
**/
_onKeyUp: function(event) {
for (var i=0;i<this._entities.length;i++) {
var componentState=this._entities[i].components.player;
if (!componentState.enableControl) continue;
if (event.keyCode==32) {
this._keyReleased=true;
componentState.jumping=false;
}
}
},
/**
* Fires when two fixtures start colliding
*
* @method _onContactBegin
* @param {Object} sourceInfo Contact source information
* @param {Object} targetInfo Contact target information
* @protected
**/
_onContactBegin: function(sourceInfo,targetInfo) {
if (typeof sourceInfo.entity.components.player=='undefined'
&& typeof targetInfo.entity.components.player=='undefined') {
return true;
}
var info=((typeof sourceInfo.entity.components.player!='undefined')
? sourceInfo
: targetInfo);
var entity=info.entity;
var componentState=entity.components.player;
if (info.fixture=='foot') {
componentState.contactCount++;
if (componentState.contactCount>0) {
componentState.grounded=true;
componentState.jumping=false;
componentState.jumpCounter=0;
}
}
},
/**
* Fires when two fixtures stop colliding
*
* @method _onContactEnd
* @param {Object} sourceInfo Contact source information
* @param {Object} targetInfo Contact target information
* @protected
**/
_onContactEnd: function(sourceInfo,targetInfo) {
if (typeof sourceInfo.entity.components.player=='undefined'
&& typeof targetInfo.entity.components.player=='undefined') {
return true;
}
var info=((typeof sourceInfo.entity.components.player!='undefined')
? sourceInfo
: targetInfo);
var entity=info.entity;
var componentState=entity.components.player;
if (info.fixture=='foot') {
componentState.contactCount--;
if (componentState.contactCount==0) {
componentState.grounded=false;
}
}
},
/**
* Makes given player jump
*
* @method actionJump
* @param {config.entity} entity Entity state
**/
actionJump: function(entity) {
var componentState=entity.components.player;
if (!componentState.jumping) return;
var maxPower=15;
var steps=5;
if (componentState.jumpCounter==steps) return;
var power=(100-(componentState.jumpCounter*(100/steps)))
*(maxPower/100);
this._physics.bodyApplyImpulse(entity,'main',270,power);
componentState.jumpCounter++;
},
/**
* Makes given player walk left
*
* @method actionWalkLeft
* @param {config.entity} entity Entity state
**/
actionWalkLeft: function(entity) {
var componentState=entity.components.player;
var velocity=this._physics.getBodyLinearVelocity(entity,'main');
if (velocity.x<=-7) return;
var power=1;
if (componentState.jumping) {
power=0.75;
}
this._physics.bodyApplyImpulse(entity,'main',180,power);
},
/**
* Makes given player walk right
*
* @method actionWalkRight
* @param {config.entity} entity Entity state
**/
actionWalkRight: function(entity) {
var componentState=entity.components.player;
var velocity=this._physics.getBodyLinearVelocity(entity,'main');
if (velocity.x>=7) return;
var power=1;
if (componentState.jumping) {
power=0.75;
}
this._physics.bodyApplyImpulse(entity,'main',0,power);
}
});
