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How would I make a gif jump, while implementing gravity and a ground y-variable?

CatBus Code Link
I'm trying to make my gif "jump", while also coming back to rest at a y value of 730. No more, no less. It would work to the same extent as the Dinosaur game, when the wifi is out. I'd like to include a gravity function as well. I'm not sure how to do that. (I'm VERY new to coding.) Any tips?
[Code is below]
let img; //background
var bgImg; //also the background
var x1 = 0;
var x2;
var scrollSpeed = 4; //how fast background is
let bing; //for music
let cat = { //coordinates for catbus
x:70,
y:730
}
var mode; //determines whether the game has started
function preload() {
bgImg = loadImage("backgwound.png"); //importing background
bing=loadSound('catbus theme song.mp3'); //importing music
}
function setup() {
createCanvas(1000, 1000); //canvas size
img = loadImage("backgwound.png"); //background in
x2 = width;
bing.loop() //loops the music
catGif=createImg("catgif.gif") //creates catbus
catGif. position(cat.x, cat.y) //creates position
catGif. size(270,100) //creates how big
mode = 0; //game start
textSize(50); //text size
}
function draw() {
let time = frameCount; //start background loop
image(img, 0 - time, 0);
image(bgImg, x1, 2, width, height);
image(bgImg, x2, 2, width, height);
x1 -= scrollSpeed;
x2 -= scrollSpeed;
if (x1 <= -width) {
x1 = width;
}
if (x2 <= -width) {
x2 = width;
} //end background loop
fill("white") //text colour
if(mode==0){
text('Press SPACE to start the game.',150,500); //what text to type
}
if(mode==0){
text('CATBUS BIZZARE ADVENTURE',135,450) //what text to type
}
}
function pickRandom() {
x = random(20, width - 20);
}

I've updated your p5.js sketch to point you in the right direction.
I've introduced a few variables that are defined at the top of your code before setup:
let gravity = 0.1;
let velocity = 0;
let upForce = 3;
let startY = 730;
let startX = 70;
...
You can tweak these numbers to fit your game. But the basic premise here is that each frame we add the velocity to the cat.y and the velocity is incremented each frame by the gravity:
cat.y = cat.y + velocity;
velocity = velocity + gravity;
However, there's a caveat, we don't want to add the velocity to the cat.y if the cat is at its startY, as startY is the grass:
if (cat.y > startY) {
velocity = 0;
cat.y = startY;
}
catGif.position(cat.x, cat.y); // reposition the gif
And lastly, when you hit spacebar, jump!
(And get rid of the starting screen)
function keyPressed() {
if (keyCode === 32) {
//spacebar
mode = 1;
velocity -= upForce;
}
}

How do i make my character not go to space in p5js

When I run my code I when I jump for some reason when I press a on the keyboard my character(the purple rectangle) goes into space
Here is the code:
//Global
//Game control
var stage = 0; // keeps track of which function to run
//Player
var p1X = 400; // p1 for player one
var p1Y = 375;
var pWidth = 30;
var pHeight = 70;
//Boxes (Platforms)
var b1X = 200; // b1 for box one
var b1Y = 300;
var bWidth = 200;
var bHeight = 40;
//Gravity
var jump = false; //are we jumping?
var direction = 1;
var velocity = 2;
var jumpPower = 10;
var fallingSpeed = 2;
var minHeight = 375;
//Setup
function setup() {
createCanvas(800, 500);
rectMode(CENTER);
textAlign(CENTER);
}
//Close setup
//Draw
function draw() {
//Call functions
if (stage == 0) {
game();
} //Close = 0
keyPressed();
gravity();
}
//Close draw
//////////Game
function game() {
//apperence of game
background(150, 230, 240); //Sky blue
//grass
noStroke();
fill(100, 200, 75); //green
rect(width / 2, 450, width, 100);
//window frame
noFill();
stroke(0);
strokeWeight(15);
rect(width / 2, height / 2, width, height);
//Draw box
stroke(0);
strokeWeight(5);
fill(255, 120, 0); //Orange
rect(b1X, b1Y, bWidth, bHeight);
//Draw Character
stroke(0);
fill(150, 0, 170); //Purple
rect(p1X, p1Y, pWidth, pHeight);
} //Close game
function gravity() {
if (p1Y >= minHeight && jump == false) {
p1Y = p1Y;
} else {
p1Y = p1Y + (direction * velocity);
}
if (jump == true) {
velocity = -jumpPower;
} else {
velocity = fallingSpeed;
}
}
function keyPressed() {
if (keyIsDown(LEFT_ARROW)) {
p1X = p1X - 5; //Move Left
} //Close Left
if (keyIsDown(RIGHT_ARROW)) {
p1X = p1X + 5; //Move Right
if (keyIsDown(UP_ARROW)) {
jump = true;
}
} //close keypressed
}
function keyTyped() {
if (keyIsDown(65)) {
jump = true;
} else {
jump = false;
}
}
canvas {
/* make the canvas fit in the tiny StackOverflow snippet iframe */
transform-origin: top left;
transform: scale(0.35);
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.3.1/p5.js"></script>
I want my player to jump and move left that's all but for some reason p5js says no and doesn't explain way it goes to space. I tried to add some more code but it still went to space but when I press another key after pressing a the character comes down

There are a few things in your code that I would change, but for jumping, here's my suggestion:
Change the velocity during the jump. When you jump in real life, gravity will constantly reduce your (vertical) velocity until you hit the ground. In this situation, you want to do the same thing: when you first jump, set the vertical velocity to a certain value. Until you hit a surface, continue to reduce the value of velocity (even to negative numbers).

Basically just translating what #jstl suggested into code, apply vertical velocity to the player position for each frame like so:
function gravity() {
let newTime = millis();
let timeDeltaSeconds = (newTime - time) / 1000;
time = newTime;
p1Y += velocity * timeDeltaSeconds * pixelsPerMeter;
// ...
}
And update velocity based on acceleration due to gravity like so:
function gravity() {
// ...
if (p1Y >= minHeight) {
// Impact with the ground, zero out velocity.
velocity = 0;
p1Y = minHeight;
}
if (p1Y < minHeight) {
velocity -= gravityAccel * timeDeltaSeconds;
}
}
With this in place "jumping" is just applying a sudden impulsive increase to velocity:
function keyTyped() {
if (keyIsDown(65) && p1Y == minHeight) {
// only "jump" when we're actually touching the ground.
velocity = jumpPower;
}
}
Here's a runnable example:
//Global
//Game control
let stage = 0; // keeps track of which function to run
//Player
let p1X = 400; // p1 for player one
let p1Y = 375;
let pWidth = 30;
let pHeight = 70;
//Boxes (Platforms)
const b1X = 200; // b1 for box one
const b1Y = 300;
const bWidth = 200;
const bHeight = 40;
//Gravity
// vertical velocity
let velocity = 0;
const jumpPower = 17;
// I'm not sure why but the real value for acceleration due to gravity (9.8)
// just doesn't look right.
const gravityAccel = 28;
// Player will be impacting the ground
const minHeight = 375;
// Number of pixels to move for every meter. Note that this is negative
// since the Y axis goes from 0 at the top to height at the bottom, so
// when we have a positive vertical velocity we want to decrease the y
// value.
const pixelsPerMeter = -30;
let time;
//Setup
function setup() {
createCanvas(800, 500);
rectMode(CENTER);
textAlign(CENTER);
time = millis();
}
//Close setup
//Draw
function draw() {
//Call functions
if (stage == 0) {
game();
} //Close = 0
movement();
gravity();
}
//Close draw
//////////Game
function game() {
//apperence of game
background(150, 230, 240); //Sky blue
//grass
noStroke();
fill(100, 200, 75); //green
rect(width / 2, 450, width, 100);
//window frame
noFill();
stroke(0);
strokeWeight(15);
rect(width / 2, height / 2, width, height);
//Draw box
stroke(0);
strokeWeight(5);
fill(255, 120, 0); //Orange
rect(b1X, b1Y, bWidth, bHeight);
//Draw Character
stroke(0);
fill(150, 0, 170); //Purple
rect(p1X, p1Y, pWidth, pHeight);
} //Close game
function gravity() {
let newTime = millis();
let timeDeltaSeconds = (newTime - time) / 1000;
time = newTime;
p1Y += velocity * timeDeltaSeconds * pixelsPerMeter;
if (p1Y >= minHeight) {
// Impact with the ground.
velocity = 0;
p1Y = minHeight;
}
if (p1Y < minHeight) {
velocity -= gravityAccel * timeDeltaSeconds;
}
}
function movement() {
if (keyIsDown(LEFT_ARROW)) {
p1X = p1X - 5; //Move Left
} //Close Left
if (keyIsDown(RIGHT_ARROW)) {
p1X = p1X + 5; //Move Right
} //close keypressed
}
function keyTyped() {
if (keyIsDown(65) && p1Y == minHeight) {
// only "jump" when we're actually touching the ground.
velocity = jumpPower;
}
}
canvas {
/* make the canvas fit in the tiny StackOverflow snippet iframe */
transform-origin: top left;
transform: scale(0.35);
}
body {
overflow: hidden;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/p5.js/1.3.1/p5.js"></script>

How to rotate/transform image using arrow keys

I'm relatively new to canvas and I'm trying to make a space ship type game. I have everything else I'd like down, except for the ship turning itself. I want to make the image of the ship rotate when the arrow keys are clicked.
So if the left arrow key is clicked, it will turn to face the left, and the right arrow key is clicked it will turn to face the right, and so on. I really can't figure this out, if anyone can show me how to do this I would really appreciate it.
var canvas = document.getElementById('canvas');
var context = canvas.getContext('2d');
/*Variable to store score*/
var score = 0;
/*Variable that stores the players object properties*/
var x = 50;
var y = 100;
var speed = 6;
var sideLength = 50;
/*Flags to track when keypress is active*/
var down = false;
var up = false;
var left = false;
var right = false;
/*Variables that store target position and size*/
var targetX = 0;
var targetY = 0;
var targetLength = 25;
/*If a number is within range b to c*/
function isWithin(a, b, c) {
return (a > b && a < c)
}
var countDown = 30;
/*Id to track set time*/
var id = null;
/*Listening for if one of the keys is pressed*/
canvas.addEventListener('keydown', function (event) {
event.preventDefault();
console.log(event.key, event.keyCode);
if (event.keyCode === 40) {
down = true;
}
if (event.keyCode === 38) {
up = true;
}
if (event.keyCode === 37) {
left = true;
}
if (event.keyCode === 39) {
right = true;
}
});
/*Listening for if one of the keys is released*/
canvas.addEventListener('keyup', function (event) {
event.preventDefault();
console.log(event.key, event.keyCode);
if (event.keyCode === 40) {
down = false;
}
if (event.keyCode === 38) {
up = false;
}
if (event.keyCode === 37) {
left = false;
}
if (event.keyCode === 39) {
right = false;
}
});
/*Function to show menu*/
function menu() {
erase();
context.fillStyle = '#000000';
context.font = '36px Arial';
context.textAlign = 'center';
context.fillText('Collect The Thing', canvas.width / 2, canvas.height / 4);
context.font = '30px Arial';
context.fillText('Press to Start', canvas.width / 2, canvas.height / 2);
/*Listen for click to start game*/
canvas.addEventListener('click', startGame);
}
/*Function to start the game*/
function startGame() {
/*reduce the countdown timer every 1 second*/
id = setInterval(function () {
countDown--;
}, 1000)
/*remove click events*/
canvas.removeEventListener('click', startGame);
moveTarget();
draw();
}
/*Show game over screen*/
function endGame() {
/*stop the countdown*/
clearInterval(id);
/*clear game board*/
erase();
context.fillStyle = '#000000';
context.font = '36px Arial';
context.textAlign = 'center';
context.fillText('Finale Score: ' + score, canvas.width / 2, canvas.height / 4);
}
/*Move target to random location in canvas*/
function moveTarget() {
targetX = Math.round(Math.random() * canvas.width - targetLength);
targetY = Math.round(Math.random() * canvas.height - targetLength);
}
/*Clear the Canvas*/
function erase() {
context.fillStyle = '#FFFFFF';
context.fillRect(0, 0, 600, 500);
}
/*Main animation drawing loop with game logic*/
function draw() {
erase();
/*Move the player sqaure*/
if (down) {
y += speed;
}
if (up) {
y -= speed;
}
if (right) {
x += speed;
}
if (left) {
x -= speed;
}
if (y + sideLength > canvas.height) {
y = canvas.height - sideLength;
}
if (y < 0) {
y = 0;
}
if (x < 0) {
x = 0;
}
if (x + sideLength > canvas.width) {
x = canvas.width - sideLength;
}
/*Collide with target*/
if (isWithin(targetX, x, x + sideLength) || isWithin(targetX + targetLength, x, x + sideLength)) {
if (isWithin(targetY, y, y + sideLength) || isWithin(targetY + targetLength, y, y + sideLength)) {
/*respawn target in a random location*/
moveTarget();
/*Increase score by 1*/
score++;
}
}
//Draw player object
context.fillRect(x, y, sideLength, sideLength);
context.drawImage(baseImage, x, y, sideLength, sideLength);
/*Draw target sqaure*/
context.fillStyle = '#00FF00';
context.fillRect(targetX, targetY, targetLength, targetLength);
//Timer and Score
context.fillStyle = '#000000';
context.font = '24px Arial';
context.textAlign = 'left';
context.fillText('Score: ' + score, 10, 24);
context.fillText('Time Remaining: ' + countDown, 10, 50);
if (countDown <= 0) {
endGame();
} else {
window.requestAnimationFrame(draw);
}
}
baseImage= new Image();
baseImage.src='xwing3.png';
baseImage.onload= function() {
menu();
}
canvas.focus();

I think in this regard you have two options.
You could have a sprite for every direction that you want the ship to face, then when you draw the image, you could choose the sprite that matches.
if(left == true) {baseImage.src='xwing3left.png';}
You could use the canvas rotate() method. This would make things more complicated, but it actually rotates the canvas and could give more opportunity to experiment.
It actually applies a transformation matrix to the canvas before it draws so you could do things like:
context.rotate(45);
context.fillRect(x,y,width,height);
Just be careful, because rotate always occurs around the origin, so you might need to use translate() as well to make it work the way you expect.
Hope this helps! :)

Variable does not go into local storage and does not appear on other page. (JavaScript/HTML)

I am trying to create a scoreboard for my game by using local storage to carry over the score variable after a game is finished by a user. However, this is not working for some reason. I am relatively new to coding so I did some research on local storage but couldn't get the code to work to no avail. Could someone help me with this code thanks.
Page 1:
<html>
<title>Level Selector</title>
<canvas id="myCanvas" width="750" height="400"></canvas>
<style type="text/css">
canvas { background: #eee; }
</style>
<script>
document.addEventListener('load', draw);
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
var x = canvas.width/2;
var y = canvas.height-30;
var dx = 2;//Ball is moving in x direction at a constant rate
var dy = -2;//Ball is moving in y direction at a constant rate
var ballRadius = 10;//To see if ball is colliding with brick/canvas
var paddleHeight = 10;
var paddleWidth = 75;
var paddleX = (canvas.width-paddleWidth)/2;
var rightPressed = false;//This variable is false because the 'right arrow' key is not pressed.
var leftPressed = false;//This variable is false because the 'left arrow' key is not pressed.
var brickRowCount = 5;
var brickColumnCount = 8;
var brickWidth = 75;
var brickHeight = 20;
var brickPadding = 10;
var brickOffsetTop = 30;
var brickOffsetLeft = 30;
var score = 0;
var lives = 3;
var paused = false;
var bricks = [];//this is an array holding all the bricks
for(var c=0; c<brickColumnCount; c++) {
bricks[c] = [];
for(var r=0; r<brickRowCount; r++) {
bricks[c][r] = { x: 0, y: 0, status: 1 };//If status is '1' then draw it. However, is status is '0', fill in with background
}
}
document.addEventListener("keydown", keyDownHandler, false);//Functions only when key is pressed
document.addEventListener("keyup", keyUpHandler, false);//Functions only when key is not pressed
document.addEventListener("mousemove", mouseMoveHandler, false);//Functions only when mouse curcor moves
//keyCode(39) is the code for the 'right arrow' key and keyCode(37) is the code for the 'left arrow' key
function keyDownHandler(e) {
if(e.keyCode == 39) {
rightPressed = true;
}
else if(e.keyCode == 37) {
leftPressed = true;
}
}
function keyUpHandler(e) {
if(e.keyCode == 39) {
rightPressed = false;
}
else if(e.keyCode == 37) {
leftPressed = false;
}
}
function mouseMoveHandler(e) {
var relativeX = e.clientX - canvas.offsetLeft;//This represents the hoizontal mouse movement.
if(relativeX > 0 && relativeX < canvas.width) {
paddleX = relativeX - paddleWidth/2;
}
}
window.addEventListener('keydown', pauseGameKeyHandler, false);
function pauseGameKeyHandler(e) {
var keyCode = e.keyCode;
switch(keyCode){
case 80: //p
togglePause();
break;
}
}
function togglePause() {
paused = !paused;
draw();
}
/*************************************************************/
// NEW
const ballPowerupHalfWidth = 30;
const paddlePowerupHalfWidth = 30;
let ballPowerups = [];
let paddlePowerups = [];
// This function adds powerup to random position
function addPowerups() {
// I check only if none exist, you could
// add more than 1 powerup if you want
if (ballPowerups.length < 1) {
// otherwise half the triangle could be outside canvas
const padding = 50;
const xMin = 0 + padding;
const xMax = canvas.width - padding;
const yMin = 0 + padding;
const yMax = canvas.height - padding;
ballPowerups.push({
x: Math.floor(Math.random()*(xMax-xMin+1)+xMin),
y: Math.floor(Math.random()*(yMax-yMin+1)+yMin),
});
}
// I check only if none exist, you could
// add more than 1 powerup if you want
if (paddlePowerups.length < 1) {
// otherwise half the triangle could be outside canvas
const padding = 50;
const xMin = 0 + padding;
const xMax = canvas.width - padding;
const yMin = 0 + padding;
const yMax = canvas.height - padding;
paddlePowerups.push({
x: Math.floor(Math.random()*(xMax-xMin+1)+xMin),
y: Math.floor(Math.random()*(yMax-yMin+1)+yMin),
});
}
}
// NEW: do all collision detections
function doCollisionDetection() {
// ball powerups
ballPowerups.forEach((powerup, i) => {
rectangleCollisionDetection(
{x: powerup.x, y: powerup.y},
{w: ballPowerupHalfWidth, h: ballPowerupHalfWidth},
() => {
console.log('BALL POWERUP COLLISION');
// remove powerup
ballPowerups.splice(i, 1);
dy = dy/2
setTimeout(() => { dy=2 }, 5000)
// to make effect last 10 seconds:
// 1. add effect
// 2. and setTimeout(() => { /* code that removes effect */ }, 10000);
});
});
// paddle powerups
paddlePowerups.forEach((powerup, i) => {
rectangleCollisionDetection(
{x: powerup.x, y: powerup.y},
{w: ballPowerupHalfWidth, h: ballPowerupHalfWidth},
() => {
console.log('PADDLE POWERUP COLLISION');
// remove powerup
paddlePowerups.splice(i, 1);
paddleHeight = paddleHeight*1.5
paddleWidth = paddleWidth*1.5
setTimeout(() => { paddleHeight=10; }, 10000)
});
});
// bricks
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
var b = bricks[c][r];
if(b.status == 1) {
rectangleCollisionDetection(b, {w: brickWidth, h: brickHeight}, () => {
console.log('BRICK COLLISION');
dy = -dy;
b.status = 0;
score++;
if(score == brickRowCount*brickColumnCount) {
alert("YOU WIN, CONGRATULATIONS!");
window.location = "Intro Screen.html";
}
});
}
}
}
// NEW: collision detection between ball and rectangle shaped
// collision boundary (only need center(x, y) and half width)
function rectangleCollisionDetection(center, size, callback) {
if(
x > center.x &&
x < center.x+size.w &&
y > center.y &&
y < center.y+size.h
) {
callback && callback();
}
}
function drawBallpowerup() {
ballPowerups.forEach(powerup => {
ctx.beginPath();
ctx.moveTo(powerup.x, powerup.y);
ctx.lineTo(powerup.x+ballPowerupHalfWidth, powerup.y+ballPowerupHalfWidth);
ctx.lineTo(powerup.x+ballPowerupHalfWidth*2, powerup.y);
ctx.fillStyle = "#42f445";
ctx.fill();
ctx.closePath();
});
}
function drawPaddlepowerup() {
paddlePowerups.forEach(powerup => {
ctx.beginPath();
ctx.moveTo(powerup.x, powerup.y);
ctx.lineTo(powerup.x+paddlePowerupHalfWidth, powerup.y+paddlePowerupHalfWidth);
ctx.lineTo(powerup.x+paddlePowerupHalfWidth*2, powerup.y);
ctx.fillStyle = "#ce6210";
ctx.fill();
ctx.closePath();
});
}
// my big changes end here
/*************************************************************/
//this is the score variable of the game
function drawScore() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Score: "+score, 8, 20);
}
//this is the lives variable of the game
function drawLives() {
ctx.font = "16px Arial";
ctx.fillStyle = "#0095DD";
ctx.fillText("Lives: "+lives, canvas.width-65, 20);
}
//this creates the ball
function drawBall() {
ctx.beginPath();
ctx.arc(x, y, ballRadius, 0, Math.PI*2);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the paddle
function drawPaddle() {
ctx.beginPath();
ctx.rect(paddleX, canvas.height-paddleHeight, paddleWidth, paddleHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
//this creates the bricks
function drawBricks() {
for(var c=0; c<brickColumnCount; c++) {
for(var r=0; r<brickRowCount; r++) {
if(bricks[c][r].status == 1) {
var brickX = (c*(brickWidth+brickPadding))+brickOffsetLeft;
var brickY = (r*(brickHeight+brickPadding))+brickOffsetTop;
bricks[c][r].x = brickX;
bricks[c][r].y = brickY;
ctx.beginPath();
ctx.rect(brickX, brickY, brickWidth, brickHeight);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
}
}
}
function draw() {
// clears canvas content from previous frame
ctx.clearRect(0, 0, canvas.width, canvas.height);
drawBall();//this code draws the ball onto the canvas
drawPaddle();//this code draws the paddle onto the canvas
drawBricks();//this code draws the bricks onto the canvas
addPowerups();
doCollisionDetection();
drawScore();//this code draws the score variable onto the canvas
drawLives();//this code draws the lives variable onto the canvas
drawBallpowerup();
drawPaddlepowerup();
//Reverse Ball movement when the ball collides with wall in 'x' direction (Left/Right wall)
if(x + dx > canvas.width-ballRadius || x + dx < ballRadius) {
dx = -dx;
}
//Reverse Ball movement when the ball collides with wall in 'y' direction (Top/Bottom wall)
if(y + dy < ballRadius) {
dy = -dy;
} else if(y + dy > canvas.height-ballRadius) {
if(x > paddleX && x < paddleX + paddleWidth) {
dy = -dy;//If the ball collides with the paddle, the ball is rebounded in the opposite direction.
}
else {
lives--;
if(!lives) {
alert("GAME OVER");
localStorage.setItem("score", score);
}
window.location = "Intro Screen.html";
}
else {
x = canvas.width/2;
y = canvas.height-30;
dx = 2;
dy = -2;
paddleX = (canvas.width-paddleWidth)/2;
}
}
}
if(rightPressed && paddleX < canvas.width-paddleWidth) {//limits paddle movement in between the canvas width
paddleX += 7;//Paddle shifts 7 pixels in the positive x direction
}
else if(leftPressed && paddleX > 0) {//limits paddle movement in between the canvas width
paddleX -= 7;//Paddle shifts 7 pixels in the negative x direction
}
x += dx;//Ball is updated by painting it over each position it moves in
y += dy;//Ball is updated by painting it over each position it moves in
if(!paused) {
requestAnimationFrame(draw);
}
}
draw();
</script>
<body onload="draw();>
</body>
</html>
Page 2:
if (typeof(Storage) !== "undefined") {
// Retrieve
document.getElementById("result").innerHTML = localStorage.getItem("score"));
}
When I run it and after playing the game, the score should be added onto the scoreboard in decending order (highest to lowest). I have trouble bringing over the variable.

While there are no standard specifications about it, most browsers will consider different pages served from the file:// protocol as being different-origin.
This means your two pages will be considered as different-origin and will thus have their own Storage Area that they won't be able to share, just like you won't be able to access the Storage Area from www.xxxxx.com from www.yyyyy.com.
To overcome this limitation, the easiest is to run a local web-server on your machine. Many OSes comes with preinstalled such server, and all it requires is to activate it, and for the ones that don't do it, there are many free and easy solutions.
And if you are planning to play with web standards, it's a must have anyway.

Game Multiplayer converstion websockets

I've found a cool bit of code online that I'm looking to adapt into a game, but firstly I want to get multiplayer working on it using sockets like socket.io, express or eureca.io, but I'm not sure how to adapt the code I have to multiplayer, could anyone lend me a hand and show me how to do it?
Regards
A confused individual
<!DOCTYPE html>
<html>
<head>
<title></title>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.3/jquery.min.js"></script>
<script type="text/javascript" src="script.js"></script>
</head>
<body>
<center><canvas id="gameCanvas" width="600" height="600"></canvas></center>
$(document).ready(function() {
var socket = io.connect();
window.Game = {};
(function(){
function Rectangle(left, top, width, height){
this.left = left || 0;
this.top = top || 0;
this.width = width || 0;
this.height = height || 0;
this.right = this.left + this.width;
this.bottom = this.top + this.height;
}
Rectangle.prototype.set = function(left, top, /*optional*/width, /*optional*/height){
this.left = left;
this.top = top;
this.width = width || this.width;
this.height = height || this.height
this.right = (this.left + this.width);
this.bottom = (this.top + this.height);
}
Rectangle.prototype.within = function(r) {
return (r.left <= this.left &&
r.right >= this.right &&
r.top <= this.top &&
r.bottom >= this.bottom);
}
Rectangle.prototype.overlaps = function(r) {
return (this.left < r.right &&
r.left < this.right &&
this.top < r.bottom &&
r.top < this.bottom);
}
// add "class" Rectangle to our Game object
Game.Rectangle = Rectangle;
})();
// wrapper for "class" Camera (avoid global objects)
(function(){
// possibles axis to move the camera
var AXIS = {
NONE: "none",
HORIZONTAL: "horizontal",
VERTICAL: "vertical",
BOTH: "both"
};
// Camera constructor
function Camera(xView, yView, canvasWidth, canvasHeight, worldWidth, worldHeight)
{
// position of camera (left-top coordinate)
this.xView = xView || 0;
this.yView = yView || 0;
// distance from followed object to border before camera starts move
this.xDeadZone = 0; // min distance to horizontal borders
this.yDeadZone = 0; // min distance to vertical borders
// viewport dimensions
this.wView = canvasWidth;
this.hView = canvasHeight;
// allow camera to move in vertical and horizontal axis
this.axis = AXIS.BOTH;
// object that should be followed
this.followed = null;
// rectangle that represents the viewport
this.viewportRect = new Game.Rectangle(this.xView, this.yView, this.wView, this.hView);
// rectangle that represents the world's boundary (room's boundary)
this.worldRect = new Game.Rectangle(0, 0, worldWidth, worldHeight);
}
// gameObject needs to have "x" and "y" properties (as world(or room) position)
Camera.prototype.follow = function(gameObject, xDeadZone, yDeadZone)
{
this.followed = gameObject;
this.xDeadZone = xDeadZone;
this.yDeadZone = yDeadZone;
}
Camera.prototype.update = function()
{
// keep following the player (or other desired object)
if(this.followed != null)
{
if(this.axis == AXIS.HORIZONTAL || this.axis == AXIS.BOTH)
{
// moves camera on horizontal axis based on followed object position
if(this.followed.x - this.xView + this.xDeadZone > this.wView)
this.xView = this.followed.x - (this.wView - this.xDeadZone);
else if(this.followed.x - this.xDeadZone < this.xView)
this.xView = this.followed.x - this.xDeadZone;
}
if(this.axis == AXIS.VERTICAL || this.axis == AXIS.BOTH)
{
// moves camera on vertical axis based on followed object position
if(this.followed.y - this.yView + this.yDeadZone > this.hView)
this.yView = this.followed.y - (this.hView - this.yDeadZone);
else if(this.followed.y - this.yDeadZone < this.yView)
this.yView = this.followed.y - this.yDeadZone;
}
}
// update viewportRect
this.viewportRect.set(this.xView, this.yView);
// don't let camera leaves the world's boundary
if(!this.viewportRect.within(this.worldRect))
{
if(this.viewportRect.left < this.worldRect.left)
this.xView = this.worldRect.left;
if(this.viewportRect.top < this.worldRect.top)
this.yView = this.worldRect.top;
if(this.viewportRect.right > this.worldRect.right)
this.xView = this.worldRect.right - this.wView;
if(this.viewportRect.bottom > this.worldRect.bottom)
this.yView = this.worldRect.bottom - this.hView;
}
}
// add "class" Camera to our Game object
Game.Camera = Camera;
})();
// wrapper for "class" Player
(function(){
function Player(x, y){
// (x, y) = center of object
// ATTENTION:
// it represents the player position on the world(room), not the canvas position
this.x = x;
this.y = y;
// move speed in pixels per second
this.speed = 200;
// render properties
this.width = 50;
this.height = 50;
}
Player.prototype.update = function(step, worldWidth, worldHeight){
// parameter step is the time between frames ( in seconds )
// check controls and move the player accordingly
if(Game.controls.left)
this.x -= this.speed * step;
if(Game.controls.up)
this.y -= this.speed * step;
if(Game.controls.right)
this.x += this.speed * step;
if(Game.controls.down)
this.y += this.speed * step;
// don't let player leaves the world's boundary
if(this.x - this.width/2 < 0){
this.x = this.width/2;
}
if(this.y - this.height/2 < 0){
this.y = this.height/2;
}
if(this.x + this.width/2 > worldWidth){
this.x = worldWidth - this.width/2;
}
if(this.y + this.height/2 > worldHeight){
this.y = worldHeight - this.height/2;
}
}
Player.prototype.draw = function(context, xView, yView){
// draw a simple rectangle shape as our player model
context.save();
context.fillStyle = "black";
// before draw we need to convert player world's position to canvas position
context.fillRect((this.x-this.width/2) - xView, (this.y-this.height/2) - yView, this.width, this.height);
context.restore();
}
// add "class" Player to our Game object
Game.Player = Player;
})();
// wrapper for "class" Map
(function(){
function Map(width, height){
// map dimensions
this.width = width;
this.height = height;
// map texture
this.image = null;
}
// generate an example of a large map
Map.prototype.generate = function(){
var ctx = document.createElement("canvas").getContext("2d");
ctx.canvas.width = this.width;
ctx.canvas.height = this.height;
var rows = ~~(this.width/44) + 1;
var columns = ~~(this.height/44) + 1;
ctx.restore();
// store the generate map as this image texture
this.image = new Image();
this.image.src = ctx.canvas.toDataURL("image/png");
// clear context
ctx = null;
}
// draw the map adjusted to camera
Map.prototype.draw = function(context, xView, yView){
// easiest way: draw the entire map changing only the destination coordinate in canvas
// canvas will cull the image by itself (no performance gaps -> in hardware accelerated environments, at least)
//context.drawImage(this.image, 0, 0, this.image.width, this.image.height, -xView, -yView, this.image.width, this.image.height);
// didactic way:
var sx, sy, dx, dy;
var sWidth, sHeight, dWidth, dHeight;
// offset point to crop the image
sx = xView;
sy = yView;
// dimensions of cropped image
sWidth = context.canvas.width;
sHeight = context.canvas.height;
// if cropped image is smaller than canvas we need to change the source dimensions
if(this.image.width - sx < sWidth){
sWidth = this.image.width - sx;
}
if(this.image.height - sy < sHeight){
sHeight = this.image.height - sy;
}
// location on canvas to draw the croped image
dx = 0;
dy = 0;
// match destination with source to not scale the image
dWidth = sWidth;
dHeight = sHeight;
context.drawImage(this.image, sx, sy, sWidth, sHeight, dx, dy, dWidth, dHeight);
}
// add "class" Map to our Game object
Game.Map = Map;
})();
// Game Script
(function(){
// prepaire our game canvas
var canvas = document.getElementById("gameCanvas");
var context = canvas.getContext("2d");
// game settings:
var FPS = 30;
var INTERVAL = 1000/FPS; // milliseconds
var STEP = INTERVAL/1000 // seconds
// setup an object that represents the room
var room = {
width: 600,
height: 600,
map: new Game.Map(600, 600)
};
// generate a large image texture for the room
room.map.generate();
// setup player
var player = new Game.Player(50, 50);
// setup the magic camera !!!
var camera = new Game.Camera(0, 0, canvas.width, canvas.height, room.width, room.height);
camera.follow(player, canvas.width/2, canvas.height/2);
// Game update function
var update = function(){
player.update(STEP, room.width, room.height);
camera.update();
}
// Game draw function
var draw = function(){
// clear the entire canvas
context.clearRect(0, 0, canvas.width, canvas.height);
// redraw all objects
room.map.draw(context, camera.xView, camera.yView);
player.draw(context, camera.xView, camera.yView);
}
// Game Loop
var gameLoop = function(){
update();
draw();
}
// <-- configure play/pause capabilities:
// I'll use setInterval instead of requestAnimationFrame for compatibility reason,
// but it's easy to change that.
var runningId = -1;
Game.play = function(){
if(runningId == -1){
runningId = setInterval(function(){
gameLoop();
}, INTERVAL);
console.log("play");
}
}
Game.togglePause = function(){
if(runningId == -1){
Game.play();
}
else
{
clearInterval(runningId);
runningId = -1;
console.log("paused");
}
}
// -->
})();
// <-- configure Game controls:
Game.controls = {
left: false,
up: false,
right: false,
down: false,
};
window.addEventListener("keydown", function(e){
switch(e.keyCode)
{
case 37: // left arrow
Game.controls.left = true;
break;
case 38: // up arrow
Game.controls.up = true;
break;
case 39: // right arrow
Game.controls.right = true;
break;
case 40: // down arrow
Game.controls.down = true;
break;
}
}, false);
window.addEventListener("keyup", function(e){
switch(e.keyCode)
{
case 37: // left arrow
Game.controls.left = false;
break;
case 38: // up arrow
Game.controls.up = false;
break;
case 39: // right arrow
Game.controls.right = false;
break;
case 40: // down arrow
Game.controls.down = false;
break;
case 80: // key P pauses the game
Game.togglePause();
break;
}
}, false);
// -->
// start the game when page is loaded
window.onload = function(){
Game.play();
}
});

You create a canvas in Map.prototype.generate, and you select your existing canava in html at the end in Game Script (prepaire our game canvas)
It's normaly not worked ....