Chad Doubi Chad Doubi - 5 months ago 13
HTML Question

how to add a play again feature to javascript game

I am having a hard time adding a play again function for my code and I do not know what I am doing wrong. Any help???? It seems like I do not update my gameArea after the player is dead in the game.

Also, my score does not show anymore after I used an image instead of text in the display. How can I add score while displaying images in my code

<!DOCTYPE html>
<html>
<head>


<style>
canvas {
border:1px solid #d3d3d3;
background-image: url("http://i.stack.imgur.com/WHu9Z.png");
}
</style>
</head>
<body>
<script>

var myGamePiece;
var myObstacles = [];
var myScore;

function startGame() {
myGamePiece = new component(40, 40, "http://orig15.deviantart.net/a436/f/2012/101/1/c/mario_sprite_by_flamingdragon5000-d4vt57a.png", 10, 120, "image");
myGamePiece.gravity = 0.05;
myScore = new component("30px", "Consolas", "black", 280, 40, "text");
myGameArea.start();
}

var myGameArea = {
canvas : document.createElement("canvas"),
start : function() {
this.canvas.width = 480;
this.canvas.height = 350;
this.context = this.canvas.getContext("2d");
document.body.insertBefore(this.canvas, document.body.childNodes[0]);
this.frameNo = 0;
this.interval = setInterval(updateGameArea, 20);
},
clear : function() {
this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
}
}

function component(width, height, color, x, y, type) {
this.type = type;
if (type == "image") {
this.image = new Image();
this.image.src = color;
}
this.score = 0;
this.width = width;
this.height = height;
this.speedX = 0;
this.speedY = 0;
this.x = x;
this.y = y;
this.gravity = 0;
this.gravitySpeed = 0;
this.update = function() {
ctx = myGameArea.context;
if (this.type == "image") {
ctx.drawImage(this.image,
this.x,
this.y,
this.width, this.height);
} else {
ctx.fillStyle = color;
ctx.fillRect(this.x, this.y, this.width, this.height);
}
}
this.newPos = function() {
this.gravitySpeed += this.gravity;
this.x += this.speedX;
this.y += this.speedY + this.gravitySpeed;
this.hitBottom();
}
this.hitBottom = function() {
var rockbottom = myGameArea.canvas.height - this.height -23;
if (this.y > rockbottom) {
this.y = rockbottom;
this.gravitySpeed = 0;
}
}
this.crashWith = function(otherobj) {
var myleft = this.x;
var myright = this.x + (this.width);
var mytop = this.y;
var mybottom = this.y + (this.height);
var otherleft = otherobj.x;
var otherright = otherobj.x + (otherobj.width);
var othertop = otherobj.y;
var otherbottom = otherobj.y + (otherobj.height);
var crash = true;
if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
crash = false;
}
return crash;
}
}

function updateGameArea() {
var x, height, gap, minHeight, maxHeight, minGap, maxGap;
for (i = 0; i < myObstacles.length; i += 1) {
if (myGamePiece.crashWith(myObstacles[i])) {
return;
}
}
myGameArea.clear();
myGameArea.frameNo += 1;
if (myGameArea.frameNo == 1 || everyinterval(150)) {
x = myGameArea.canvas.width;
minHeight = 20;
maxHeight = 200;
height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
minGap = 90;
maxGap = 200;
gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
myObstacles.push(new component(50, height, "green", x, 0));
myObstacles.push(new component(50, x - height - gap, "green", x, height + gap));
}
for (i = 0; i < myObstacles.length; i += 1) {
myObstacles[i].x += -1;
myObstacles[i].update();
}
myScore.text="SCORE: " + myGameArea.frameNo;
myScore.update();
myGamePiece.newPos();
myGamePiece.update();
}

function everyinterval(n) {
if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
return false;
}

function accelerate(n) {
myGamePiece.gravity = n;
}

function clickPlayagain() {
myGameArea.stop();

// myGameArea2.stop();
startGame();


}
startGame();
</script>
<br>
<button onmousedown="accelerate(-0.15)" onmouseup="accelerate(0.08)">ACCELERATE</button>
<button id="playagain" onclick="clickPlayagain()">Play again</button>

<p>Use the ACCELERATE button to stay in the air</p>
</body>
</html>

Answer

Hope it helps:

<!DOCTYPE html>
<html>
<head>


<style>
canvas {
    border:1px solid #d3d3d3;
    background-image: url("http://i.stack.imgur.com/WHu9Z.png");
}
</style>
</head>
<body>
<script>

var myGamePiece;
var myObstacles = [];
var myScore;
var myGameArea;

function startGame() {
    myGamePiece = new component(40, 40, "http://orig15.deviantart.net/a436/f/2012/101/1/c/mario_sprite_by_flamingdragon5000-d4vt57a.png", 10, 120, "image");
    myGamePiece.gravity = 0.05;
    myScore = new component("30px", "Consolas", "black", 280, 40, "text");
    if(myGameArea){
        document.removeChild(myGameArea.canvas);
    }
    myGameArea = {
        canvas : document.createElement("canvas"),
        start : function() {
            this.canvas.width = 480;
            this.canvas.height = 350;
            this.context = this.canvas.getContext("2d");
            document.body.insertBefore(this.canvas, document.body.childNodes[0]);
            this.frameNo = 0;
            this.interval = setInterval(updateGameArea, 20);
            },
        clear : function() {
            this.context.clearRect(0, 0, this.canvas.width, this.canvas.height);
        }
    }
    myGameArea.start();
}

function reset(){
    myGamePiece = undefined;
    myObstacles = [];
    myScore = "";
}

function component(width, height, color, x, y, type) {
    this.type = type;
    if (type == "image") {
        this.image = new Image();
        this.image.src = color;
    }
    this.score = 0;
    this.width = width;
    this.height = height;
    this.speedX = 0;
    this.speedY = 0;
    this.x = x;
    this.y = y;
    this.gravity = 0;
    this.gravitySpeed = 0;
    this.update = function() {
        ctx = myGameArea.context;
        if (this.type == "image") {
            ctx.drawImage(this.image,
                this.x,
                this.y,
                this.width, this.height);
        } else {
            ctx.fillStyle = color;
            ctx.fillRect(this.x, this.y, this.width, this.height);
        } 
    }
    this.newPos = function() {
        this.gravitySpeed += this.gravity;
        this.x += this.speedX;
        this.y += this.speedY + this.gravitySpeed;
        this.hitBottom();
    }
    this.hitBottom = function() {
        var rockbottom = myGameArea.canvas.height - this.height -23;
        if (this.y > rockbottom) {
            this.y = rockbottom;
            this.gravitySpeed = 0;
        }
    }
    this.crashWith = function(otherobj) {
        var myleft = this.x;
        var myright = this.x + (this.width);
        var mytop = this.y;
        var mybottom = this.y + (this.height);
        var otherleft = otherobj.x;
        var otherright = otherobj.x + (otherobj.width);
        var othertop = otherobj.y;
        var otherbottom = otherobj.y + (otherobj.height);
        var crash = true;
        if ((mybottom < othertop) || (mytop > otherbottom) || (myright < otherleft) || (myleft > otherright)) {
            crash = false;
        }
        return crash;
    }
}

function updateGameArea() {
    var x, height, gap, minHeight, maxHeight, minGap, maxGap;
    for (i = 0; i < myObstacles.length; i += 1) {
        if (myGamePiece.crashWith(myObstacles[i])) {
            return;
        }
    }
    myGameArea.clear();
    myGameArea.frameNo += 1;
    if (myGameArea.frameNo == 1 || everyinterval(150)) {
        x = myGameArea.canvas.width;
        minHeight = 20;
        maxHeight = 200;
        height = Math.floor(Math.random()*(maxHeight-minHeight+1)+minHeight);
        minGap = 90;
        maxGap = 200;
        gap = Math.floor(Math.random()*(maxGap-minGap+1)+minGap);
        myObstacles.push(new component(50, height, "green", x, 0));
        myObstacles.push(new component(50, x - height - gap, "green", x, height + gap));
    }
    for (i = 0; i < myObstacles.length; i += 1) {
        myObstacles[i].x += -1;
        myObstacles[i].update();
    }
    myScore.text="SCORE: " + myGameArea.frameNo;
    myScore.update();
    myGamePiece.newPos();
    myGamePiece.update();
}

function everyinterval(n) {
    if ((myGameArea.frameNo / n) % 1 == 0) {return true;}
    return false;
}

function accelerate(n) {
    myGamePiece.gravity = n;
}

function clickPlayagain() {
     reset();
     startGame();

}
startGame();
</script>
<br>
<button onmousedown="accelerate(-0.15)" onmouseup="accelerate(0.08)">ACCELERATE</button>
<button id="playagain" onclick="clickPlayagain()">Play again</button>

<p>Use the ACCELERATE button to stay in the air</p>
</body>
</html>
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