trash-slots/slotreel.js

function SlotReel() {
	this.id = 0;
	this.position = {x: 0, y: 0};
	this.width = 256;
	this.height = 512;

	this.isSpinning = false;
	this.scrollAmount = 2048;
	this.scrollSpeed = 15;
	this.reelRotationsOffset = 0;
	this.remainingRevolutions = 0;
	this.spinTarget = 0;

	this.resizeModifier = 1;

	this.init = function(newPos, offset) {
		this.position.x = newPos.x;
		this.position.y = newPos.y;
		this.reelRotationsOffset = offset;
		this.spinTarget = Math.floor(7 * Math.random());
		this.scrollAmount = 256 *  this.spinTarget - 128;
		this.scrollSpeed = Math.floor(10 * Math.random() - 5) + 25;
	}

	this.update = function(delta) {

		if(this.isSpinning) {
			this.scrollAmount -= this.scrollSpeed;
			if(this.remainingRevolutions <= 0) {
			 if(this.scrollAmount <= 256 * this.spinTarget - 128) {
				this.scrollAmount = 256 *  this.spinTarget - 128;
				this.isSpinning = false;
			 }
			}

			if(this.scrollAmount <= -128) {
				this.scrollAmount += 2048;
				this.remainingRevolutions--;
			}
		}
	}

	this.draw = function(context) {
		
		context.save();
		context.translate(this.position.x * this.resizeModifier, this.position.y * this.resizeModifier);

		context.drawImage(system.assets.getSprite("slotreel"), 0, this.scrollAmount + 2048, 256, 512, 0, 0, 256 * this.resizeModifier, 512 * this.resizeModifier);
		context.drawImage(system.assets.getSprite("slotreel"), 0, this.scrollAmount, 256, 512, 0, 0, 256 * this.resizeModifier, 512 * this.resizeModifier);
		context.drawImage(system.assets.getSprite("slotreel"), 0, this.scrollAmount - 2048, 256, 512, 0, 0, 256 * this.resizeModifier, 512 * this.resizeModifier);
		context.restore();
	}

	this.handleResize = function(canvas) {
		this.resizeModifier = 1;
		if(canvas.width < 768) {
			this.resizeModifier = 0.5;
		}
	}

	this.startSpin = function() {
		this.isSpinning = true;
		this.remainingRevolutions = 1 + this.reelRotationsOffset;
		this.spinTarget = Math.floor(7 * Math.random());
	}
};