window.addEventListener("load", function() {
function clear(ctx, width, height) {
}
function drawRandomShape(width, height) {
//ctx.clearRect(0,0, canvas.width, canvas.height)
canvas.style.backgroundColor = 'white';
// var num = Math.floor(Math.random() * 10)
var number = 30;
var countdown = setInterval(function(){
timerSpan.innerHTML = number--;
//console.log(number)
if(number == 0 - 1){
clearInterval(countdown);
}
},1000);
function randomShape(){
var randomNum = Math.floor(Math.random() * 10);
//ctx.clearRect(0,0, canvas.width, canvas.height)
// if(number > 0){
if(randomNum >= 0 && randomNum <= 2){
// ctx.clearRect(0, 0, canvas.width, canvas.height);
var triangle = ctx.beginPath();
triangle += ctx.moveTo(0, 0);
triangle += ctx.lineTo(90, 90);
triangle += ctx.lineTo(0, 90);
triangle += ctx.closePath();
triangle += ctx.fillStyle = "red";
triangle += ctx.fill();
document.addEventListener('keyup', function shape(e){
if(e.keyCode == 37){
triangle += ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
document.removeEventListener('keyup', shape);
randomShape();
}
});
}else if(randomNum > 2 && randomNum <= 4){
// ctx.clearRect(0,0, canvas.width, canvas.height);
var blackTriangle = ctx.fillStyle = "black";
blackTriangle += ctx.beginPath();
blackTriangle += ctx.moveTo(0,0);
blackTriangle += ctx.lineTo(90, 90);
blackTriangle += ctx.lineTo(0, 90);
blackTriangle += ctx.fill();
document.addEventListener('keyup', function shape(e){
if(e.keyCode == 38){
blackTriangle += ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
document.removeEventListener('keyup', shape);
randomShape();
}
});
}else if(randomNum >= 4 && randomNum <= 6){
//ctx.clearRect(0, 0, canvas.width, canvas.height);
var redSquare = ctx.fillStyle = 'black';
redSquare += ctx.rect(200, 100, 90, 90)
redSquare += ctx.fill();
document.addEventListener('keyup', function shape(e){
if(e.keyCode == 39){
redSquare += ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
randomShape()
}
});
}else if(randomNum > 6 && randomNum < 10){
//ctx.clearRect(0,0, canvas.width, canvas.height);
var whiteSquare = ctx.rect(50,70,90,90);
whiteSquare += ctx.fillStyle = 'red';
whiteSquare += ctx.fill();
document.addEventListener('keyup', function shape(e) {
if(e.keyCode == 40){
whiteSquare += ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
document.removeEventListener('keyup', shape);
randomShape();
}
});
}
console.log(randomNum)
//};
}
randomShape();
}
//}, 1000);
function drawGameStartText(width, height ,score) {
width = 170;
height = 350;
ctx.fillStyle = 'White';
ctx.font = '30px Verdana'
ctx.fillText('Press space bar to start a new game' , width , height);
}
function restartGame(ctx, width, height){
}
var canvas = document.getElementById("shapes-game"),
height = canvas.scrollHeight,
width = canvas.scrollWidth,
gameOn = false,
expectedKey = undefined,
ctx = canvas.getContext('2d'),
// white triangle = up, red square = down,
// red triangle = left, white square = right
expectedKeysMap = {white0: 38, red1: 40, red0: 37, white1: 39};
timerSpan = document.getElementById("time-remaining");
scoreSpan = document.getElementById("score-val"),
seconds = 3;
// intervalId;
document.addEventListener("keyup", function(e) {
e.preventDefault();
if(e.keyCode == 32){
drawRandomShape();
}
});
drawGameStartText()
})body {
padding-bottom: 50px;
}
#shapes-game {
border: 4px solid grey;
background-color: black;
}
.canvas-container {
padding: 10px;
}
.canvas-container, #shapes-game {
height: 750px;
width: 800px;
}
.scores {
padding: 10px;
text-align: center;
}
.legend {
padding-top: 15px;
}
.legend-contents {
text-align: left;
padding-left: 30px;
}
.triangle-bottomleft-red {
width: 0;
height: 0;
border-bottom: 50px solid red;
border-right: 50px solid transparent;
}
.triangle-bottomleft-black {
width: 0;
height: 0;
border-bottom: 54px solid black;
border-right: 58px solid transparent;
}
.triangle-inner-white {
position: relative;
top: 2px;
left: 2px;
width: 0;
height: 0;
border-bottom: 50px solid white;
border-right: 50px solid transparent;
}
.triangle-left {
width: 0;
height: 0;
border-top: 23px solid transparent;
border-bottom: 23px solid transparent;
border-right: 23px solid red;
}
.inner-triangle {
position: relative;
top: -20px;
left: 2px;
width: 0;
height: 0;
border-top: 20px solid transparent;
border-bottom: 20px solid transparent;
border-right: 20px solid blue;
}
.red-square {
width: 50px;
height: 50px;
background-color: red;
}
.white-square {
width: 50px;
height: 50px;
background-color: white;
border-style: solid;
border-width: 1px;
}<!DOCTYPE html>
<html>
<head>
<title>Shapes!!</title>
<link rel="stylesheet" type="text/css" href="vendor/bootstrap.min.css">
<link rel="stylesheet" type="text/css" href="styles.css">
<script type="text/javascript" src="vendor/jquery-1.12.4.min.js"></script>
<script type="text/javascript" src="vendor/bootstrap.min.js"></script>
<script type="text/javascript" src="index.js"></script>
</head>
<body>
<div class="container">
<div class="col-xs-10 canvas-container">
<canvas id="shapes-game" height="750" width="800"></canvas>
</div>
<div class="col-xs-2 scores">
<h1>Score</h1>
<h3><span id="score-val">0</span></h3>
<h1>Timer</h1>
<h3><span id="time-remaining">30</span></h3>
<div class="legend">
<h1>Legend</h1>
<div class="legend-contents">
<div class="triangle-bottomleft-red">
</div>
<h4>Left</h4>
<div class="white-square">
</div>
<h4>Right</h4>
<div class="triangle-bottomleft-black">
<div class="triangle-inner-white"></div>
</div>
<h4>Up</h4>
<div class="red-square">
</div>
<h4>Down</h4>
</div>
</div>
</div>
</div>
</body>
</html>
答案 0 :(得分：0)
您的代码存在许多问题。
你为什么要做的第一个
var blackTriangle = ctx.fillStyle = "black"; blackTriangle += ctx.beginPath();
因为它绝对没有。
创建一个密钥处理程序并处理其中的所有内容而不是
document.addEventListener('keyup', function shape(e){ if(e.keyCode == 39){ redSquare += ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height); randomShape() } });
您只是在创建一堆关键处理程序。
如果要跟踪要绘制的形状，请为每个形状创建一个数组
const shapes = {
whiteSquares : [],
redSquares : [],
whiteTriangle : [],
redTriangle: [],
};
然后在添加形状时将其添加到相应的数组
if(randomNum <= 2){
ctx.beginPath();
ctx.lineTo(0, 0);
ctx.lineTo(90, 90);
ctx.lineTo(0, 90);
ctx.closePath();
ctx.fillStyle = "red";
ctx.fill();
shapes.redTriangle.push([0,0]); // store the top left of the triangle
}
然后你可以在密钥处理程序中清除它
var gameStarted = false;
const keyNames = {
space : 32,
left : 37;
up : 38,
right : 39,
down : 40,
}
// only one key handler needed.
document.addEventListener('keyup', e => {
if(gameStarted === false && e.keyCode === keyNames.space) {
gameStarted = true;
drawRandomShape();
}else if(e.keyCode === keyNames.left) {
if(shapes.redTriangle.length > 0){
var pos = shapes.redTriangle.shift(); // remove the bottom item in the array
ctx.clearRect(pos[0],pos[1],90,90); // clear that position
randomShape(); // create anothe shape.
}
}else if(e.keyCode === keyNames.right) {
if(shapes.whiteSquares.length > 0){
// same as above
}
}else if(e.keyCode === keyNames.up) {
if(shapes.whiteTriangle.length > 0){
// same as above
}
}else if(e.keyCode === keyNames.down) {
if(shapes.redSquares.length > 0){
// same as above
}
}
}
不要使条件语句复杂化。
你有
var randomNum = Math.floor(Math.random() * 10); if(randomNum >= 0 && randomNum <= 2){ // do stuff }else if(randomNum > 2 && randomNum <= 4){ // do stuff }else if(randomNum >= 4 && randomNum <= 6){ // do stuff }else if(randomNum > 6 && randomNum < 10){ // do stuff }
与
相同 var randomNum = Math.floor(Math.random() * 10);
if (randomNum <= 2) {
// do stuff
} else if(randomNum <= 4) {
// do stuff
} else if(randomNum <= 6) {
// do stuff
} else {
// do stuff
}