通过canvas每20ms绘制出一个对象?
//定义一个对象
function Flycar(x, y){
this.x = x;
this.y = y;
}
//绘制这个对象
function drawflycar(flycar){
flyCar.beginPath();
flyCar.fillRect(flycar.x, flycar.y, 50,50);
flyCar.fillStyle='blue';;
}
setInerval(function(){
var flycar = new Flycar(flyX,flyY); //每20ms实例化一个对象,flyX,flyY是随机产生的一个坐标
flyArr.push(flycar); //添加到数组中
for(x in flyArr){
drawflycar(flyArr[x]); //遍历这个数组,绘制出数组中的对象
}
},20)
想实现每20ms绘制出一个矩形
我这么写没有实现,错在哪里,或者要实现这个需求应该怎么写?
jquery canvas html5 JavaScript
我纯洁我骄傲
9 years, 9 months ago
Answers
<canvas height="480" width="480" ></canvas>
<script>
var canvas = document.querySelector("canvas");
var context = canvas.getContext("2d");
var flyArr = [];
function Flycar(x, y){
this.x = x;
this.y = y;
}
function drawflycar(flycar){
context.fillStyle = "blue";
context.fillRect(flycar.x,flycar.y,50,50);
}
setInterval(function(){
var x = Math.floor(Math.random()*canvas.offsetWidth);
var y = Math.floor(Math.random()*canvas.offsetHeight);
flyArr.push(new Flycar(x,y));
// console.log(flyArr);
flyArr.forEach(function(){
drawflycar(arguments[0]);
});
},20);
</script>
蛋疼D別扭控
answered 9 years, 9 months ago
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