player.js

var LEFT = 0;
var RIGHT = 1;

var ANIM_IDLE_LEFT = 0;
var ANIM_JUMP_LEFT = 1;
var ANIM_WALK_LEFT = 2;
var ANIM_IDLE_RIGHT = 3;
var ANIM_JUMP_RIGHT = 4;
var ANIM_WALK_RIGHT = 5;
var ANIM_MAX = 6;

var Player = function() {	
	this.sprite = new Sprite("ChuckNorris.png");
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [0, 1, 2, 3, 4, 5, 6, 7]);
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [8, 9, 10, 11, 12]);
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26]);
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [52, 53, 54, 55, 56, 57, 58, 59]);
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [60, 61, 62, 63, 64]);
	this.sprite.buildAnimation(12, 8, 165, 126, 0.05, [65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78]);
	
	for(var i=0; i<ANIM_MAX; i++)
	{
		this.sprite.setAnimationOffset(i, -55, -87);
	}

	this.startPosition = new Vector2();
	this.startPosition.set(9*TILE, 0*TILE); // 'TILE' is the width of a tile
	
	this.position = new Vector2();
	this.position.set(this.startPosition.x, this.startPosition.y); 
	
	this.width = 159;
	this.height = 163;	
	
	this.velocity = new Vector2();
	
	this.falling = true;
	this.jumping = false;
	
	this.direction = LEFT;
	
	this.lives = 3;
	this.isAlive = true;
	
	this.cooldownTimer = 0;
};

Player.prototype.update = function(deltaTime)
{		
	this.sprite.update(deltaTime);

	var left = false;
	var right = false;
	var jump = false;
	// check keypress events
	if(keyboard.isKeyDown(keyboard.KEY_LEFT) == true) {
		left = true;
		this.direction = LEFT;
		if (this.sprite.currentAnimation != ANIM_WALK_LEFT && this.jumping == false)
		{
			this.sprite.setAnimation(ANIM_WALK_LEFT);
		}
	}
	else if(keyboard.isKeyDown(keyboard.KEY_RIGHT) == true) {
		right = true;
		this.direction = RIGHT;
		if (this.sprite.currentAnimation != ANIM_WALK_RIGHT && this.jumping == false)
		{
			this.sprite.setAnimation(ANIM_WALK_RIGHT);
		}
	}
	else
	{
		if (this.jumping == false && this.falling == false)
		{
			if (this.direction == LEFT)
			{
				if (this.sprite.currentAnimation != ANIM_IDLE_LEFT)
				{
					this.sprite.setAnimation(ANIM_IDLE_LEFT);
				}
			}
			else
			{
				if (this.sprite.currentAnimation != ANIM_IDLE_RIGHT)
				{
					this.sprite.setAnimation(ANIM_IDLE_RIGHT);
				}
			}
		}
	}
	if(keyboard.isKeyDown(keyboard.KEY_UP) == true) {
		jump = true;
	}
	
	if (this.cooldownTimer > 0)
	{
		this.cooldownTimer -= deltaTime;
	}
	
	if (keyboard.isKeyDown(keyboard.KEY_SPACE) == true && this.cooldownTimer <= 0)
	{
		sfxFire.play();
		this.cooldownTimer = 0.3;
	}

	var wasleft = this.velocity.x < 0;
	var wasright = this.velocity.x > 0;
	var falling = this.falling;
	var ddx = 0; // acceleration
	var ddy = GRAVITY;

	if (left)
		ddx = ddx - ACCEL; // player wants to go left
	else if (wasleft)
		ddx = ddx + FRICTION; // player was going left, but not any more
	if (right)
		ddx = ddx + ACCEL; // player wants to go right
	else if (wasright)
		ddx = ddx - FRICTION; // player was going right, but not any more
	if (jump && !this.jumping && !falling)
	{
		ddy = ddy - JUMP; // apply an instantaneous (large) vertical impulse
		this.jumping = true;
		
		if (this.direction == LEFT)
		{
			this.sprite.setAnimation(ANIM_JUMP_LEFT);
		}
		else
		{
			this.sprite.setAnimation(ANIM_JUMP_RIGHT);
		}
	}
	
	// calculate the new position and velocity:
	this.position.y = Math.floor(this.position.y + (deltaTime * this.velocity.y));
	this.position.x = Math.floor(this.position.x + (deltaTime * this.velocity.x));
	this.velocity.x = bound(this.velocity.x + (deltaTime * ddx), -MAXDX, MAXDX);
	this.velocity.y = bound(this.velocity.y + (deltaTime * ddy), -MAXDY, MAXDY);
	if ((wasleft && (this.velocity.x > 0)) ||
	(wasright && (this.velocity.x < 0)))
	{
		// clamp at zero to prevent friction from making us jiggle side to side
		this.velocity.x = 0;
	}


	// we’ll insert code here later
	// collision detection
	// Our collision detection logic is greatly simplified by the fact that the
	// player is a rectangle and is exactly the same size as a single tile.
	// So we know that the player can only ever occupy 1, 2 or 4 cells.

	// This means we can short-circuit and avoid building a general purpose
	// collision detection engine by simply looking at the 1 to 4 cells that
	// the player occupies:
	var tx = pixelToTile(this.position.x);
	var ty = pixelToTile(this.position.y);
	var nx = (this.position.x)%TILE; // true if player overlaps right
	var ny = (this.position.y)%TILE; // true if player overlaps below
	var cell = cellAtTileCoord(LAYER_PLATFORMS, tx, ty);
	var cellright = cellAtTileCoord(LAYER_PLATFORMS, tx + 1, ty);
	var celldown = cellAtTileCoord(LAYER_PLATFORMS, tx, ty + 1);
	var celldiag = cellAtTileCoord(LAYER_PLATFORMS, tx + 1, ty + 1);
	
	// If the player has vertical velocity, then check to see if they have hit a platform
	// below or above, in which case, stop their vertical velocity, and clamp their
	// y position:
	if (this.velocity.y > 0) {
		if ((celldown && !cell) || (celldiag && !cellright && nx)) {
			// clamp the y position to avoid falling into platform below
			this.position.y = tileToPixel(ty);
			this.velocity.y = 0; // stop downward velocity
			this.falling = false; // no longer falling
			this.jumping = false; // (or jumping)
			ny = 0; // no longer overlaps the cells below
		}
	}
	else if (this.velocity.y < 0) {
		if ((cell && !celldown) || (cellright && !celldiag && nx)) {
			// clamp the y position to avoid jumping into platform above
			this.position.y = tileToPixel(ty + 1);
			this.velocity.y = 0; // stop upward velocity
			// player is no longer really in that cell, we clamped them to the cell below
			cell = celldown;
			cellright = celldiag; // (ditto)
			ny = 0; // player no longer overlaps the cells below
		}
	}
	if (this.velocity.x > 0) {
		if ((cellright && !cell) || (celldiag && !celldown && ny)) {
			// clamp the x position to avoid moving into the platform we just hit
			this.position.x = tileToPixel(tx);
			this.velocity.x = 0; // stop horizontal velocity
		}
	}
	else if (this.velocity.x < 0) {
		if ((cell && !cellright) || (celldown && !celldiag && ny)) {
			// clamp the x position to avoid moving into the platform we just hit
			this.position.x = tileToPixel(tx + 1);
			this.velocity.x = 0; // stop horizontal velocity
		}
	}
	
	if (this.position.y > canvas.height)
	{
		this.onDeath();
	}
}

Player.prototype.draw = function()
{
	this.sprite.draw(context, this.position.x - worldOffsetX, this.position.y);
}

Player.prototype.onDeath = function()
{
	if (this.isAlive == true)
	{
		this.lives -= 1;
			
		if (this.lives >= 0)
		{
			this.respawn();
		}
		else
		{
			this.isAlive = false;
			this.lives = 0;
		}
	}
}

Player.prototype.respawn = function() 
{
	this.position.set(this.startPosition.x, this.startPosition.y);
	this.sprite.setAnimation(ANIM_IDLE_RIGHT);
}