canvas实现鼠标可交互可拖动网的蜘蛛爬网动画效果代码-html代码-BFW代码库

代码语言：html
所属分类：动画
代码描述：canvas实现鼠标可交互可拖动网的蜘蛛爬网动画效果代码
下面为部分代码预览，完整代码请点击下载或在bfwstudio webide中打开
<!DOCTYPE html>
<html lang="en" >
<head>
  <meta charset="UTF-8">
<style>
    body{
        background: white;
    }
</style>

</head>
<body>

<canvas id="web"></canvas>

  <script>
      !function(e,t,n){function i(n,s){if(!t[n]){if(!e[n]){var o=typeof require=="function"&&require;if(!s&&o)return o(n,!0);if(r)return r(n,!0);throw new Error("Cannot find module '"+n+"'")}var u=t[n]={exports:{}};e[n][0].call(u.exports,function(t){var r=e[n][1][t];return i(r?r:t)},u,u.exports)}return t[n].exports}var r=typeof require=="function"&&require;for(var s=0;s<n.length;s++)i(n[s]);return i}({1:[function(require,module,exports){var VerletJS=require("./verlet");var constraint=require("./constraint");require("./objects");window.Vec2=require("./vec2");window.VerletJS=VerletJS;window.Particle=VerletJS.Particle;window.DistanceConstraint=constraint.DistanceConstraint;window.PinConstraint=constraint.PinConstraint;window.AngleConstraint=constraint.AngleConstraint},{"./verlet":2,"./constraint":3,"./objects":4,"./vec2":5}],3:[function(require,module,exports){exports.DistanceConstraint=DistanceConstraint;exports.PinConstraint=PinConstraint;exports.AngleConstraint=AngleConstraint;function DistanceConstraint(a,b,stiffness,distance){this.a=a;this.b=b;this.distance=typeof distance!="undefined"?distance:a.pos.sub(b.pos).length();this.stiffness=stiffness}DistanceConstraint.prototype.relax=function(stepCoef){var normal=this.a.pos.sub(this.b.pos);var m=normal.length2();normal.mutableScale((this.distance*this.distance-m)/m*this.stiffness*stepCoef);this.a.pos.mutableAdd(normal);this.b.pos.mutableSub(normal)};DistanceConstraint.prototype.draw=function(ctx){ctx.beginPath();ctx.moveTo(this.a.pos.x,this.a.pos.y);ctx.lineTo(this.b.pos.x,this.b.pos.y);ctx.strokeStyle="#d8dde2";ctx.stroke()};function PinConstraint(a,pos){this.a=a;this.pos=(new Vec2).mutableSet(pos)}PinConstraint.prototype.relax=function(stepCoef){this.a.pos.mutableSet(this.pos)};PinConstraint.prototype.draw=function(ctx){ctx.beginPath();ctx.arc(this.pos.x,this.pos.y,6,0,2*Math.PI);ctx.fillStyle="rgba(0,153,255,0.1)";ctx.fill()};function AngleConstraint(a,b,c,stiffness){this.a=a;this.b=b;this.c=c;this.angle=this.b.pos.angle2(this.a.pos,this.c.pos);this.stiffness=stiffness}AngleConstraint.prototype.relax=function(stepCoef){var angle=this.b.pos.angle2(this.a.pos,this.c.pos);var diff=angle-this.angle;if(diff<=-Math.PI)diff+=2*Math.PI;else if(diff>=Math.PI)diff-=2*Math.PI;diff*=stepCoef*this.stiffness;this.a.pos=this.a.pos.rotate(this.b.pos,diff);this.c.pos=this.c.pos.rotate(this.b.pos,-diff);this.b.pos=this.b.pos.rotate(this.a.pos,diff);this.b.pos=this.b.pos.rotate(this.c.pos,-diff)};AngleConstraint.prototype.draw=function(ctx){ctx.beginPath();ctx.moveTo(this.a.pos.x,this.a.pos.y);ctx.lineTo(this.b.pos.x,this.b.pos.y);ctx.lineTo(this.c.pos.x,this.c.pos.y);var tmp=ctx.lineWidth;ctx.lineWidth=5;ctx.strokeStyle="rgba(255,255,0,0.2)";ctx.stroke();ctx.lineWidth=tmp}},{}],5:[function(require,module,exports){module.exports=Vec2;function Vec2(x,y){this.x=x||0;this.y=y||0}Vec2.prototype.add=function(v){return new Vec2(this.x+v.x,this.y+v.y)};Vec2.prototype.sub=function(v){return new Vec2(this.x-v.x,this.y-v.y)};Vec2.prototype.mul=function(v){return new Vec2(this.x*v.x,this.y*v.y)};Vec2.prototype.div=function(v){return new Vec2(this.x/v.x,this.y/v.y)};Vec2.prototype.scale=function(coef){return new Vec2(this.x*coef,this.y*coef)};Vec2.prototype.mutableSet=function(v){this.x=v.x;this.y=v.y;return this};Vec2.prototype.mutableAdd=function(v){this.x+=v.x;this.y+=v.y;return this};Vec2.prototype.mutableSub=function(v){this.x-=v.x;this.y-=v.y;return this};Vec2.prototype.mutableMul=function(v){this.x*=v.x;this.y*=v.y;return this};Vec2.prototype.mutableDiv=function(v){this.x/=v.x;this.y/=v.y;return this};Vec2.prototype.mutableScale=function(coef){this.x*=coef;this.y*=coef;return this};Vec2.prototype.equals=function(v){return this.x==v.x&&this.y==v.y};Vec2.prototype.epsilonEquals=function(v,epsilon){return Math.abs(this.x-v.x)<=epsilon&&Math.abs(this.y-v.y)<=epsilon};Vec2.prototype.length=function(v){return Math.sqrt(this.x*this.x+this.y*this.y)};Vec2.prototype.length2=function(v){return this.x*this.x+this.y*this.y};Vec2.prototype.dist=function(v){return Math.sqrt(this.dist2(v))};Vec2.prototype.dist2=function(v){var x=v.x-this.x;var y=v.y-this.y;return x*x+y*y};Vec2.prototype.normal=function(){var m=Math.sqrt(this.x*this.x+this.y*this.y);return new Vec2(this.x/m,this.y/m)};Vec2.prototype.dot=function(v){return this.x*v.x+this.y*v.y};Vec2.prototype.angle=function(v){return Math.atan2(this.x*v.y-this.y*v.x,this.x*v.x+this.y*v.y)};Vec2.prototype.angle2=function(vLeft,vRight){return vLeft.sub(this).angle(vRight.sub(this))};Vec2.prototype.rotate=function(origin,theta){var x=this.x-origin.x;var y=this.y-origin.y;return new Vec2(x*Math.cos(theta)-y*Math.sin(theta)+origin.x,x*Math.sin(theta)+y*Math.cos(theta)+origin.y)};Vec2.prototype.toString=function(){return"("+this.x+", "+this.y+")"};function test_Vec2(){var assert=function(label,expression){console.log("Vec2("+label+"): "+(expression==true?"PASS":"FAIL"));if(expression!=true)throw"assertion failed"};assert("equality",new Vec2(5,3).equals(new Vec2(5,3)));assert("epsilon equality",new Vec2(1,2).epsilonEquals(new Vec2(1.01,2.02),.03));assert("epsilon non-equality",!new Vec2(1,2).epsilonEquals(new Vec2(1.01,2.02),.01));assert("addition",new Vec2(1,1).add(new Vec2(2,3)).equals(new Vec2(3,4)));assert("subtraction",new Vec2(4,3).sub(new Vec2(2,1)).equals(new Vec2(2,2)));assert("multiply",new Vec2(2,4).mul(new Vec2(2,1)).equals(new Vec2(4,4)));assert("divide",new Vec2(4,2).div(new Vec2(2,2)).equals(new Vec2(2,1)));assert("scale",new Vec2(4,3).scale(2).equals(new Vec2(8,6)));assert("mutable set",new Vec2(1,1).mutableSet(new Vec2(2,3)).equals(new Vec2(2,3)));assert("mutable addition",new Vec2(1,1).mutableAdd(new Vec2(2,3)).equals(new Vec2(3,4)));assert("mutable subtraction",new Vec2(4,3).mutableSub(new Vec2(2,1)).equals(new Vec2(2,2)));assert("mutable multiply",new Vec2(2,4).mutableMul(new Vec2(2,1)).equals(new Vec2(4,4)));assert("mutable divide",new Vec2(4,2).mutableDiv(new Vec2(2,2)).equals(new Vec2(2,1)));assert("mutable scale",new Vec2(4,3).mutableScale(2).equals(new Vec2(8,6)));assert("length",Math.abs(new Vec2(4,4).length()-5.65685)<=1e-5);assert("length2",new Vec2(2,4).length2()==20);assert("dist",Math.abs(new Vec2(2,4).dist(new Vec2(3,5))-1.4142135)<=1e-6);assert("dist2",new Vec2(2,4).dist2(new Vec2(3,5))==2);var normal=new Vec2(2,4).normal();assert("normal",Math.abs(normal.length()-1)<=1e-5&&normal.epsilonEquals(new Vec2(.4472,.89443),1e-4));assert("dot",new Vec2(2,3).dot(new Vec2(4,1))==11);assert("angle",new Vec2(0,-1).angle(new Vec2(1,0))*(180/Math.PI)==90);assert("angle2",new Vec2(1,1).angle2(new Vec2(1,0),new Vec2(2,1))*(180/Math.PI)==90);assert("rotate",new Vec2(2,0).rotate(new Vec2(1,0),Math.PI/2).equals(new Vec2(1,1)));assert("toString",new Vec2(2,4)=="(2, 4)")}},{}],4:[function(require,module,exports){var VerletJS=require("./verlet");var Particle=VerletJS.Particle;var constraints=require("./constraint");var DistanceConstraint=constraints.DistanceConstraint;VerletJS.prototype.point=function(pos){var composite=new this.Composite;composite.particles.push(new Particle(pos));this.composites.push(composite);return composite};VerletJS.prototype.lineSegments=function(vertices,stiffness){var i;var composite=new this.Composite;for(i in vertices){composite.particles.push(new Particle(vertices[i]));if(i>0)composite.constraints.push(new DistanceConstraint(composite.particles[i],composite.particles[i-1],stiffness))}this.composites.push(composite);return composite};VerletJS.prototype.cloth=function(origin,width,height,segments,pinMod,stiffness){var composite=new this.Composite;var xStride=width/segments;var yStride=height/segments;var x,y;for(y=0;y<segments;++y){for(x=0;x<segments;++x){var px=origin.x+x*xStride-width/2+xStride/2;var py=origin.y+y*yStride-height/2+yStride/2;composite.particles.push(new Particle(new Vec2(px,py)));if(x>0)composite.constraints.push(new DistanceConstraint(composite.particles[y*segments+x],composite.particles[y*segments+x-1],stiffness));if(y>0)composite.constraints.push(new DistanceConstraint(composite.particles[y*segments+x],composite.particles[(y-1)*segments+x],stiffness))}}for(x=0;x<segments;++x){if(x%pinMod==0)composite.pin(x)}this.composites.push(composite);return composite};VerletJS.prototype.tire=function(origin,radius,segments,spokeStiffness,treadStiffness){var stride=2*Math.PI/segments;var i;var composite=new this.Composite;for(i=0;i<segments;++i){var theta=i*stride;composite.particles.push(new Particle(new Vec2(origin.x+Math.cos(theta)*radius,origin.y+Math.sin(theta)*radius)))}var center=new Particle(origin);composite.particles.push(center);for(i=0;i<segments;++i){composite.constraints.push(new DistanceConstraint(composite.particles[i],composite.particles[(i+1)%segments],treadStiffness));composite.constraints.push(new DistanceConstrain.........完整代码请登录后点击上方下载按钮下载查看