export default {
data() {
return {
canvas: null,
ctx: null,
arcObj: {}
};
},
mounted() {
this.canvas = document.getElementById("canvas");
this.ctx = this.canvas.getContext("2d");
// this.move(); // 矩形的边缘碰撞函数
// this.moveArc(); // 绘制碰撞圆形,对象形式
this.moveRect()
},
methods: {
move() {
let x = 0;
let y = 0;
let width = 100;
let height = 100;
let speedX = 2;
let speedY = 2;
let ctx = this.ctx;
ctx.fillStyle = "red";
ctx.fillRect(x, y, width, height);
setInterval(() => {
ctx.clearRect(x, y, this.canvas.width, this.canvas.height);
x += speedX;
if (x > this.canvas.width - width) {
speedX *= -1;
} else if (x < 0) {
speedX *= -1;
}
y += speedY;
if (y > this.canvas.height - height) {
speedY *= -1;
} else if (y < 0) {
speedY *= -1;
}
ctx.fillRect(x, y, width, height);
}, 10);
// this.requestmove(x,y,width,height,ctx,speedX,speedY); // 请求帧的动画过程
},
requestmove(x, y, width, height, ctx, speedX, speedY) {
ctx.clearRect(x, y, this.canvas.width, this.canvas.height);
x += speedX;
if (x > this.canvas.width - width) {
speedX *= -1;
} else if (x < 0) {
speedX *= -1;
}
y += speedY;
if (y > this.canvas.height - height) {
speedY *= -1;
} else if (y < 0) {
speedY *= -1;
}
ctx.fillRect(x, y, width, height);
window.requestAnimationFrame(
this.requestmove(x, y, width, height, ctx, speedX, speedY)
);
},
moveArc(x, y, r, speedX, speedY) {
this.x = x;
this.y = y;
this.r = r;
this.speedX = speedX;
this.speedY = speedY;
this.moveUpdata = function() {
this.x += this.speedX;
if (this.x > this.canvas.width - this.r) {
this.speedX *= -1;
} else if (this.x < 0) {
this.speedX *= -1;
}
this.y += this.speedY;
if (this.y > this.canvas.height - this.r) {
this.speedY *= -1;
} else if (this.y < 0) {
this.speedY *= -1;
}
};
},
moveRect(){
// 面向对象编程
function Rect(x,y,width,height,color,speedX,speedY,ctx,canvas) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.color = color
this.speedX = speedX
this.speedY = speedY
this.ctxRect = ctx
this.canvas = canvas
}
Rect.prototype.draw = function() {
this.ctxRect.beginPath();
this.ctxRect.fillStyle = this.color
this.ctxRect.fillRect(this.x,this.y,this.width,this.height)
this.ctxRect.closePath();
}
Rect.prototype.move = function() {
this.x += this.speedX
if(this.x > this.canvas.width - this.width){
this.speedX *= -1
} else if(this.x < 0){
this.speedX *= -1
}
this.y += this.speedY
if(this.y > this.canvas.height - this.height){
this.speedY *= -1
} else if(this.y < 0){
this.speedY *= -1
}
}
let rect1 = new Rect(0,100,100,100,'red',2,2,this.ctx,this.canvas)
let rect2 = new Rect(300,100,100,100,'blue',-2,-2,this.ctx,this.canvas)
// rect1.draw();
// rect2.draw()
let animate = ()=>{
this.ctx.clearRect(0,0,this.canvas.width,this.canvas.height)
rect1.draw()
rect1.move()
rect2.draw()
rect2.move()
let rect1Min = rect1.x;
let rect1Max = rect1.x + rect1.width
let rect2Min = rect2.x
let rect2Max = rect2.x + rect2.width
let min = Math.max(rect1Min,rect2Min)
let max = Math.min(rect1Max,rect2Max)
if(min < max){
rect1.speedX *= -1;
rect1.speedY *= 1;
rect2.speedX *= -1
rect2.speedY *= 1
}
window.requestAnimationFrame(animate)
}
animate()
}
}
};