Impact Gamepad Plugin

gistfile1.js

ig.module(
	'plugins.gamepad' 
)
.requires(
	'impact.input',
	'impact.game'
)
.defines(function(){

// Assign some values to the Gamepad buttons. We use an offset of 256
// here so we don't collide with the keyboard buttons when binding.
ig.GAMEPAD_BUTTON_OFFSET = 256;
ig.GAMEPAD = {
	FACE_1: ig.GAMEPAD_BUTTON_OFFSET + 0, // A
	FACE_2: ig.GAMEPAD_BUTTON_OFFSET + 1, // Y
	FACE_3: ig.GAMEPAD_BUTTON_OFFSET + 2, // B
	FACE_4: ig.GAMEPAD_BUTTON_OFFSET + 3, // X
	LEFT_SHOULDER: ig.GAMEPAD_BUTTON_OFFSET + 4,
	RIGHT_SHOULDER: ig.GAMEPAD_BUTTON_OFFSET + 5,
	LEFT_SHOULDER_BOTTOM: ig.GAMEPAD_BUTTON_OFFSET + 6,
	RIGHT_SHOULDER_BOTTOM: ig.GAMEPAD_BUTTON_OFFSET + 7,
	SELECT: ig.GAMEPAD_BUTTON_OFFSET + 8,
	START: ig.GAMEPAD_BUTTON_OFFSET + 9,
	LEFT_ANALOGUE_STICK: ig.GAMEPAD_BUTTON_OFFSET + 10,
	RIGHT_ANALOGUE_STICK: ig.GAMEPAD_BUTTON_OFFSET + 11,
	PAD_TOP: ig.GAMEPAD_BUTTON_OFFSET + 12,
	PAD_BOTTOM: ig.GAMEPAD_BUTTON_OFFSET + 13,
	PAD_LEFT: ig.GAMEPAD_BUTTON_OFFSET + 14,
	PAD_RIGHT: ig.GAMEPAD_BUTTON_OFFSET + 15
};


ig.normalizeVendorAttribute(navigator, 'getGamepads');

if( !navigator.getGamepads ) {
	// No Gamepad support; nothing to do here
	return;
}

ig.Input.inject({
	gamepad: null,
	lastButtons: {},
	hasButtonObject: !!window.GamepadButton,

	getFirstGamepadSnapshot: function() {
		var gamepads = navigator.getGamepads();
		for( var i = 0; i < gamepads.length; i++ ) {
			if( gamepads[i] ) {
				return gamepads[i];
			}
		}
		return null;
	},

	pollGamepad: function() {
		this.gamepad = this.getFirstGamepadSnapshot();
		if( !this.gamepad ) {
			// No gamepad snapshot?
			return;
		}

		// Iterate over all buttons, see if they're bound and check
		// for their state
		for( var b = 0; b < this.gamepad.buttons.length; b++ ) {
			var action = this.bindings[b+ig.GAMEPAD_BUTTON_OFFSET];
			var currentState = false;

			// Is the button bound to an action?
			if( action ) {
				var button = this.gamepad.buttons[b];
				currentState = (typeof button.pressed !== 'undefined')
					? button.pressed // W3C Standard 
					: button; // Current Chrome version
				
				var prevState = this.lastButtons[b];
				
				// Was not pressed, but is now?
				if( !prevState && currentState ) {					
					this.actions[action] = true;
					this.presses[action] = true;
				}
				// Was pressed, but is no more?
				else if( prevState && !currentState ) {
					this.delayedKeyup[action] = true;
				}
			}

			this.lastButtons[b] = currentState;
		}
	}
});

// Always poll gamepad before each frame
ig.Game.inject({
	run: function() {
		ig.input.pollGamepad();
		this.parent();
	}
})

});