Template:F

<!DOCTYPE html>  canvas { border:1px solid #d3d3d3; background-color: #f1f1f1; } 

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

function startGame { myGamePiece = new component(30, 30, "red", 10, 120); 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 = 270; 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; 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 == "text") { ctx.font = this.width + " " + this.height; ctx.fillStyle = color; ctx.fillText(this.text, this.x, this.y); } 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; 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 = 50; maxGap = 200; gap = Math.floor(Math.random*(maxGap-minGap+1)+minGap); myObstacles.push(new component(10, height, "green", x, 0)); myObstacles.push(new component(10, 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; } ACCELERATE Use the ACCELERATE button to stay in the air How long can you stay alive?