【发布时间】：2016-11-19 08:57:38
【问题描述】：
我正在尝试解决一个 JavaScript 难题。 绘制一个 3D 立方体线框并沿着穿过其中心的轴旋转。旋转物体在停止之前应该以‘X’度/秒^2的速度减速。 该对象应如下响应以下用户输入 滑动 /拖动 ：根据速度差对旋转物体进行加速或减速 之间 以摩擦系数 Y 旋转和滑动。 触碰 /点击 产生摩擦，应使旋转进一步减速 Y（摩擦系数） 这是我写的代码
<!DOCTYPE html>
<html>
<body>
<canvas id="myCanvas" width="1000" height="1000"></canvas>
<script>
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext("2d");
ctx.translate(200,200);
var x1,x2,y1,y2,tempx,tempy,up=false,down = false,inter, interval;
function line(context, p1,p2) {
context.beginPath();
context.moveTo(p1.x, p1.y);
context.lineTo(p2.x, p2.y);
context.closePath();
context.stroke();
}
function project() {
ctx.clearRect(-500, -500, canvas.width, canvas.height);
for(var i=0;i<edges.length;i++)
{
// var x1 = vertices[edges[i][0]][0];
// var y1 = vertices[edges[i][0]][1];
// var x2 = vertices[edges[i][1]][0];
// var y2 = vertices[edges[i][1]][1];
// var z1 = vertices[edges[i][0]][3];
// var z2 = vertices[edges[i][1]][3];
// vertices[edges[i][0]][0] = x1 + 20;
// vertices[edges[i][0]][1] = y1 + 20;
// vertices[edges[i][1]][0] = x2 + 20;
// vertices[edges[i][1]][1] = y2 + 20;
line(ctx,{x:vertices[edges[i][0]][0],y:vertices[edges[i][0]][1]}, {x:vertices[edges[i][1]][0],y:vertices[edges[i][1]][1]});
}
}
function rep()
{
rotateX(tempy/3000);
rotateY(tempx/3000);
project();
}
function stop()
{
console.log(inter);
inter += 0.5;
rotateX(tempy/3000);
rotateY(tempx/3000);
project();
clearInterval(interval);
interval = setInterval(stop, inter);
}
var vertices = [[-100,-100,-100],[-100,-100,100],[-100,100,-100], [-100,100,100],[100,-100,-100],[100,-100,100],[100,100,-100],[100,100,100]];
var edges =[[0,1],[1,3],[3,2],[2,0],[4,5],[5,7],[7,6],[6,4],[0,4],[1,5],[2,6],[3,7]];
var rotateX = function(theta) {
var sina = Math.sin(theta);
var cosa = Math.cos(theta);
for (var i=0; i<vertices.length; i++) {
var vertice = vertices[i];
var y = vertice[1];
var z = vertice[2];
vertice[1] = y * cosa - z * sina;
vertice[2] = z * cosa + y * sina;
}
};
var rotateY = function(theta) {
var sina = Math.sin(theta);
var cosa = Math.cos(theta);
for (var i=0; i<vertices.length; i++) {
var vertice = vertices[i];
var x = vertice[0];
var z = vertice[2];
vertice[0] = x * cosa - z * sina;
vertice[2] = z * cosa + x * sina;
}
};
var rotateZ = function(theta) {
var sina = Math.sin(theta);
var cosa = Math.cos(theta);
for (var i=0; i<vertices.length; i++) {
var vertice = vertices[i];
var x = vertice[0];
var y = vertice[1];
vertice[0] = x * cosa - y * sina;
vertice[1] = y * cosa + x * sina;
}
};
rotateZ(60);
rotateY(60);
rotateZ(60);
project();
canvas.addEventListener("mousedown",function(event)
{
old = Date.now();
x1 = event.clientX;
y1 = event.clientY;
down = true;
},false);
canvas.addEventListener("mouseup",function(event)
{
up = true;
newt = Date.now();
dt = newt - old;
x2 = event.clientX;
y2 = event.clientY;
dx = Math.sqrt(Math.pow((x2-x1),2)-Math.pow((y2-y1),2));
inter = (dx / dt) * 2;
//console.log(inter);
tempx = x2 - x1;
tempy = y2 - y1;
interval = setInterval(rep, inter);
// console.log("x1:" + x1 +" y1:" + y1 + "x2:" + x2 + "y2:" + y2);
},false);
canvas.addEventListener("mousemove",function(event)
{
if(down){
newt = Date.now();
dt = newt - old;
x2 = event.clientX;
y2 = event.clientY;
// console.log("x1:" + x1 +" y1:" + y1 + "x2:" + x2 + "y2:" + y2);
rotateX((y2-y1)/3000);
rotateY((x2-x1)/3000);
project();
}
},false);
canvas.addEventListener("click",function(event)
{
if(down)
{
down = false;
}
if(up)
{
clearInterval(interval);
interval = setInterval(stop, inter);
up = false;
}
},false);
// canvas.addEventListener("swipe",function)
</script>
<body>
</html>
我想通过线性减慢旋转速度来停止立方体并停止。如何为此改进我的代码
【问题讨论】：
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你有相同的纯脚本代码
标签： javascript rotation cube