Bricks/public/scripts/lib/BenjoLibrary.js

var TOP = 1;
var RIGHT = 2
var BOTTOM = 3;
var LEFT = 4;
var TOP_RIGHT = 5;
var BOTTOM_RIGHT = 6;
var BOTTOM_LEFT = 7;
var TOP_LEFT = 8;

var wWidth = window.innerWidth;
var wHeight = window.innerHeight;
var oldWHeight;
var oldWWidth;

function updateVars(){
	oldWWidth = wWidth;
	oldWHeight = wHeight;
	wWidth = window.innerWidth;
	wHeight = window.innerHeight;
}

function collisionDetection(obj0, obj1){
	
	var sp = strokePadding;
	
	if (obj0.isEllipse && obj1.isRectangle){
		
		//Ball
		var b = obj0;
		
		//Rectangle
		var r = obj1;

		for (var i = 0; i < TWO_PI; i += PI / 32){
			
			/* Check every borderpoint of the ball beginning
			at the top in clock direction up to top again */

			// Ball Center X
			var bcx = b.x;
			
			// Ball Center Y
			var bcy = b.y;
			
			// Ball Border X
			var bbx = b.x + sin(i) * b.radius;
			
			// Ball Border Y inverted because Y = 0 is the TOP of the screen
			var bby = b.y - cos(i) * b.radius;
			
			// Rectangle Width
			var rW = r.width + 2 * sp;
			
			// Rectangle Height
			var rH = r.height + 2 * sp;
			
			// Rectangle Border X
			var rX = r.x - sp;
			
			// Rectangle Border Y
			var rY = r.y - sp;
			
			// Objects touch
			if (bbx > rX && bbx < rX + rW
			   && bby > rY && bby < rY + rH){
				
				// STRAIGHT FACES //
				
				//Top/Bottom touch
				if (bcx > rX && bcx < rX + rW){ 
					
					//Top touch
					if (b.v.y > 0) return {isTouching: true, location: TOP};
					
					//Bottom touch
					if (b.v.y < 0) return {isTouching: true, location: BOTTOM};
				}
				
				//Left/Right touch
				if (bcy > rY && bcy < rY + rH){
					
					//Left touch
					if (b.v.x > 0) return {isTouching: true, location: LEFT};
					
					//Right touch
					if (b.v.x < 0) return {isTouching: true, location: RIGHT};

				}
				
				// CORNERS //
				
				// BOTTOM Left/Right
				if (i > 0 && i <= PI / 2) return {isTouching: true, location: BOTTOM_LEFT};

				//LEFT Bottom/Top
				if (i > PI / 2 && i <= PI) return {isTouching: true, location: TOP_LEFT};

				//TOP Left/Right
				if (i > PI && i <= PI + PI / 2) return {isTouching: true, location: TOP_RIGHT};
				
				//RIGHT Bottom/Top
				if (i > PI + PI / 2 && i <= TWO_PI) return {isTouching: true, location: BOTTOM_RIGHT};
			}
		}
		
	}
	
	if (obj0.isEllipse && obj1.isEllipse){
		
		//Ball 1
		var b1 = obj0;
		
		//Ball 2
		var b2 = obj1;
		
		//Balls are close to each other
		if (b1.x + b1.radius > b2.x - b2.radius
		   && b1.x - b1.radius < b2.x + b2.radius
		   && b1.y + b1.radius > b2.y - b2.radius
		   && b1.y - b1.radius < b2.y + b2.radius){
			
			var distance = sqrt(pow(b1.x - b2.x, 2) + pow(b1.y - b2.y, 2));
			
			if (distance < b1.radius + b2.radius) return {isTouching: true};
		}
	}
	return {isTouching: false, location: 0};
}

function performCollision(obj0, obj1, collision){
	if (obj0.isEllipse){
		
		var ball = obj0;
		
		//Ball collides with frameborder
		if (obj1.isFrameborder){
			switch (collision.location){
				case BOTTOM:
					ball.v.y *= -1;
					break;
				case LEFT:
				case RIGHT:
					ball.v.x *= -1;
					break;
			}
			if (testMode && collision.location == TOP) ball.v.y *= -1;
			ball.move();
		}
		
		//Ball collides with any brick
		if (obj1.isBrick){
			switch (collision.location){
				case TOP:
				case BOTTOM:
					ball.v.y *= -1;
					ball.move();
					return;
				case LEFT:
				case RIGHT:
					ball.v.x *= -1;
					ball.move();
					return;
				case TOP_LEFT:
					var cornerX = obj1.x;
					var cornerY = obj1.y;
					break;
				case TOP_RIGHT:
					var cornerX = obj1.x + obj1.width;
					var cornerY = obj1.y;
					break;
				case BOTTOM_LEFT:
					var cornerX = obj1.x;
					var cornerY = obj1.y + obj1.height;
					break;
				case BOTTOM_RIGHT:
					var cornerX = obj1.x + obj1.width;
					var cornerY = obj1.y + obj1.height;
					break;
			}
			
			var nx = ball.x - cornerX;
			var ny = ball.y - cornerY;
			var length = sqrt(nx * nx + ny * ny);
			nx /= length;
			ny /= length;

			var projection = ball.v.x * nx + ball.v.y * ny;
			ball.v.x = ball.v.x - 2 * projection * nx;
			ball.v.y = ball.v.y - 2 * projection * ny;
			
			ball.move();

		}
		
		//Ball collides with paddleboard
		if (obj1.isPaddle){
			switch (collision.location){
				case TOP:
				case TOP_LEFT:
				case TOP_RIGHT:
					ball.v.x = ball.calcVelocityX(obj1, ball.v.x);
					ball.v.y = -ball.calcVelocityY();
					ball.move();
					return;
				case LEFT:
				case RIGHT:
					ball.v.x *= -1;
					ball.move();
					return;
				case BOTTOM_LEFT:
					var cornerX = obj1.x;
					var cornerY = obj1.y + obj1.height;
					break;
				case BOTTOM_RIGHT:
					var cornerX = obj1.x + obj1.width;
					var cornerY = obj1.y + obj1.height;
					break;
			}
			var nx = ball.x - cornerX;
			var ny = ball.y - cornerY;
			var length = sqrt(nx * nx + ny * ny);
			nx /= length;
			ny /= length;

			var projection = ball.v.x * nx + ball.v.y * ny;
			ball.v.x = ball.v.x - 2 * projection * nx;
			ball.v.y = ball.v.y - 2 * projection * ny;
			
			ball.move();
		}
		
		//Ball collides with other ball
		if (obj1.isEllipse){
			
			//Ball 1
			var b1 = obj0;
			
			//Ball 2
			var b2 = obj1;
			
			//Set mass equal to radius of each ball
			b1.mass = b1.radius;
			b2.mass = b2.radius;
			
			//Colliding angle of ball 1 to ball 2 using arc tan of both x and y differences
			var collisionAngle = atan2((b2.y - b1.y), (b2.x - b1.x));
			
			//Converting directions of velocity vector of balls into angles
			var d1 = atan2(b1.v.y, b1.v.x);
			var d2 = atan2(b2.v.y, b2.v.x);
			
			//Ignoring mass effects new velocites are simply magnitude multiplied with value of angle differences
			var newXspeed1 = b1.v.mag * cos(d1 - collisionAngle);
			var newYspeed1 = b1.v.mag * sin(d1 - collisionAngle);
			var newXspeed2 = b2.v.mag * cos(d2 - collisionAngle);
			var newYspeed2 = b2.v.mag * sin(d2 - collisionAngle);
		
			//According to the principle of linear momentum, kinetic energy stays the same after collision, so velocities are now related to masses
			var finalXspeed1 = ((b1.mass - b2.mass) * newXspeed1 + b2.mass * 2 * newXspeed2) / (b1.mass + b2.mass);
			var finalYspeed1 = newYspeed1;
			var finalXspeed2 = (b1.mass * 2 * newXspeed1 + (b2.mass - b1.mass) * newXspeed2) / (b1.mass + b2.mass);
			var finalYspeed2 = newYspeed2;
			
			//Values of collisionAngle
			var cosAngle = cos(collisionAngle);
			var sinAngle = sin(collisionAngle);
			
			//To also keep velocites relative to pure collisionAngle, subtract sin*x from cos*x and add sin*y to cos*y because coordSystem has y = 0 on the top
			var u1x = cosAngle * finalXspeed1 - sinAngle * finalYspeed1;
			var u1y = sinAngle * finalXspeed1 + cosAngle * finalYspeed1;
			var u2x = cosAngle * finalXspeed2 - sinAngle * finalYspeed2;
			var u2y = sinAngle * finalXspeed2 + cosAngle * finalYspeed2;
			
			//Set new velocities to both balls
			b1.v.x = u1x;
			b1.v.y = u1y;
			b2.v.x = u2x;
			b2.v.y = u2y;
			
		    //Update magnitude
			b1.v.mag = sqrt(pow(b1.v.x, 2) + pow(b1.v.y, 2));
			b2.v.mag = sqrt(pow(b2.v.x, 2) + pow(b2.v.y, 2));
			
			
			//Move balls one vx/vy forward to avoid double inverting collision detection
			b1.x += b1.v.x;
			b1.y += b1.v.y;
			b2.x += b2.v.x;
			b2.y += b2.v.y;
		}
	}
}



function toTimeString(time, hoursWanted){
	
	var time = floor(time / 10);
	
	var hs = String(floor(time % 100));
	var fs = String(floor((time / 100) % 60));
	
	if (hoursWanted){
		var min = String(floor(((time / 100) / 60) % 60));
		var hr = String(floor(((time / 100) / 60) / 60));
		
		if (hs.length < 2) hs = "0" + hs;
		if (fs.length < 2) fs = "0" + fs;
		if (min.length < 2) min = "0" + min;
		if (hr.length < 2) hr = "0" + hr;
		
		var timeString = hr + ":" + min + ":" + fs + ":" + hs;
	} else {
		var min = String(floor(((time / 100) / 60) % 60));
		
		if (hs.length < 2) hs = "0" + hs;
		if (fs.length < 2) fs = "0" + fs;
		if (min.length < 2) min = "0" + min;
		
		var timeString = min + ":" + fs + ":" + hs;
	}
		
	

	return timeString;
}


function setCookie(name, value, years){
	var expires = "";
	if (years){
		var date = new Date();
		date.setTime(date.getTime() + (years * 365 * 24 * 60 * 60 * 1000));
		expires = "; expires=" + date.toUTCString();
	}
	document.cookie = name + "=" + value + expires + "; path=/";
}

function getCookie(name){
	var nameEQ = name + "=";
	var ca = document.cookie.split(';');
	for (var i = 0; i < ca.length; i++){
		var c = ca[i];
		while (c.charAt(0) == ' ') c = c.substring(1, c.length);
		if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length, c.length);
	}
	return null;
}

function deleteCookies(){
	for (var i = 0; i < arguments.length; i++){
		setCookie(arguments[i], "", -1);
	}
}