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| <!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>HTML5 Canvas模拟飞机航班线路动画DEMO演示</title>
<style>
*{margin:0;padding:0;}
canvas {
background:#111;
background-size:cover;
display:block;
}
body{overflow: hidden;}
</style>
</head>
<body>
<div></div>
<script>
window.requestAnimFrame=function(){return window.requestAnimationFrame||window.webkitRequestAnimationFrame||window.mozRequestAnimationFrame||function(a){window.setTimeout(a,1E3/60)}}();
$ = {};
$.util = {
rand: function( min, max ) {
return Math.random() * ( max - min ) + min;
},
randInt: function( min, max ) {
return Math.floor( Math.random() * ( max - min + 1 ) ) + min;
},
norm: function( val, min, max ) {
return ( val - min ) / ( max - min );
},
lerp: function( norm, min, max ) {
return ( max - min ) * norm + min;
},
map: function( val, sMin, sMax, dMin, dMax ) {
return $.util.lerp( $.util.norm( val, sMin, sMax), dMin, dMax );
},
clamp: function( val, min, max ) {
return Math.min( Math.max( val, Math.min( min, max ) ), Math.max( min, max ) );
},
distance: function( p1, p2 ) {
var dx = p1.x - p2.x,
dy = p1.y - p2.y;
return Math.sqrt( dx * dx + dy * dy );
},
angle: function( p1, p2 ) {
return Math.atan2( p1.y - p2.y, p1.x - p2.x );
},
inRange: function( val, min, max ) {
return val >= Math.min( min, max ) && val <= Math.max( min, max );
},
pointInRect: function( x, y, rect ) {
return $.util.inRange( x, rect.x, rect.x + rect.width ) &&
$.util.inRange( y, rect.y, rect.y + rect.height );
},
pointInArc: function( p, a ) {
return distance( p, a ) <= a.radius;
},
setProps: function( obj, props ) {
for( var k in props ) {
obj[ k ] = props[ k ];
}
},
multicurve: function( points, ctx ) {
var p0, p1, midx, midy;
ctx.moveTo(points[0].x, points[0].y);
for(var i = 1; i < points.length - 2; i += 1) {
p0 = points[i];
p1 = points[i + 1];
midx = (p0.x + p1.x) / 2;
midy = (p0.y + p1.y) / 2;
ctx.quadraticCurveTo(p0.x, p0.y, midx, midy);
}
p0 = points[points.length - 2];
p1 = points[points.length - 1];
ctx.quadraticCurveTo(p0.x, p0.y, p1.x, p1.y);
}
};
$.init = function() {
$.c = document.createElement( 'canvas' );
$.ctx = $.c.getContext( '2d' );
document.body.appendChild( $.c );
$.ports = [];
$.planes = [];
window.addEventListener( 'resize', $.reset, false );
window.addEventListener( 'click', $.reset, false );
$.reset();
$.step();
};
$.reset = function() {
$.cw = $.c.width = window.innerWidth;
$.ch = $.c.height = window.innerHeight;
$.dimAvg = ( $.cw + $.ch ) / 2;
$.ctx.textAlign = 'center';
$.ctx.textBaseline = 'middle';
$.ctx.font = '16px monospace';
$.opt = {};
$.opt.portCount = 6;
$.opt.planeCount = 80;
$.opt.portSpacingDist = $.dimAvg / $.opt.portCount;
$.opt.holdingDist = 5;
$.opt.approachDist = 80;
$.opt.planeDist = 20;
$.opt.pathSpacing = 15;
$.opt.pathCount = 40;
$.opt.avoidRadius = 30;
$.opt.avoidMult = 0.025;
$.ports.length = 0;
$.planes.length = 0;
$.lt = Date.now();
$.dt = 1;
$.et = 0;
$.tick = 0;
for( var i = 0; i < $.opt.portCount; i++ ) {
$.ports.push( new $.Port() );
}
for( var i = 0; i < $.opt.planeCount; i++ ) {
$.planes.push( new $.Plane() );
}
};
$.Port = function() {
this.x = $.util.rand( $.cw * 0.1, $.cw * 0.9 );
this.y = $.util.rand( $.ch * 0.1, $.ch * 0.9 );
while( !this.validSpacing() ) {
this.x = $.util.rand( $.cw * 0.1, $.cw * 0.9 );
this.y = $.util.rand( $.ch * 0.1, $.ch * 0.9 );
}
};
$.Port.prototype.validSpacing = function() {
var spaced = true,
i = $.ports.length;
while( i-- ) {
var otherPort = $.ports[ i ];
if( $.util.distance( otherPort, this ) < $.opt.portSpacingDist ) {
spaced = false;
break;
}
}
return spaced;
};
$.Port.prototype.update = function( i ) {
var j = $.planes.length;
this.approachingCount = 0;
while( j-- ) {
var plane = $.planes[ j ];
if( plane.destIndex == i && plane.approaching ) {
this.approachingCount++;
}
}
};
$.Port.prototype.render = function( i ) {
$.ctx.beginPath();
$.ctx.arc( this.x, this.y, 3 + ( this.approachingCount + 5 ), 0, Math.PI * 2 );
$.ctx.fillStyle = 'hsla(120, 90%, 80%, ' + ( 0.35 + Math.sin( $.et / 20 ) * 0.2 ) + ')';
$.ctx.fill();
$.ctx.fillStyle = '#fff';
$.ctx.fillText( this.approachingCount, this.x, this.y - 30 );
};
$.Plane = function( opt ) {
this.originIndex = $.util.randInt( 0, $.ports.length - 1 );
this.origin = $.ports[ this.originIndex ];
this.path = [];
this.x = this.origin.x;
this.y = this.origin.y;
this.vx = $.util.rand( -0.35, 0.35 );
this.vy = $.util.rand( -0.35, 0.35 );
this.vmax = 1;
this.accel = 0.01;
this.decel = 0.96;
this.angle = 0;
this.approaching = false;
this.holding = false;
this.setDest();
};
$.Plane.prototype.setDest = function() {
if( this.destIndex != undefined ) {
this.originIndex = this.destIndex;
this.origin = $.ports[ this.originIndex ];
}
this.destIndex = $.util.randInt( 0, $.ports.length - 1 );
while( this.destIndex == this.originIndex ) {
this.destIndex = $.util.randInt( 0, $.ports.length - 1 );
}
this.dest = $.ports[ this.destIndex ];
this.approaching = false;
this.holding = false;
}
$.Plane.prototype.update = function( i ) {
this.ox = this.x;
this.oy = this.y;
if( $.tick % $.opt.pathSpacing == 0 ) {
this.path.push( { x: this.x, y: this.y } );
}
if( this.path.length > $.opt.pathCount ) {
this.path.shift();
}
this.angle = $.util.angle( this.dest, this );
this.speed = ( Math.abs( this.vx ) + Math.abs( this.vy ) ) / 2;
if( !$.util.pointInRect( this.x, this.y, { x: 0, y: 0, width: $.cw, height: $.ch } ) ) {
this.vx *= this.decel;
this.vy *= this.decel;
}
if( this.speed > 0.1 ) {
if( $.util.distance( this.dest, this ) < $.opt.approachDist ) {
this.vx *= this.decel;
this.vy *= this.decel;
this.approaching = true;
}
}
if( $.util.distance( this.dest, this ) < $.opt.holdingDist ) {
this.holding = true;
this.setDest();
}
this.vx += Math.cos( this.angle ) * this.accel;
this.vy += Math.sin( this.angle ) * this.accel;
if( this.speed > this.vmax ) {
this.vx *= this.decel;
this.vy *= this.decel;
}
this.x += this.vx * $.dt;
this.y += this.vy * $.dt;
};
$.Plane.prototype.render = function( i ) {
if( this.approaching ) {
$.ctx.strokeStyle = 'hsla(0, 80%, 50%, 1)';
} else {
$.ctx.strokeStyle = 'hsla(180, 80%, 50%, 1)';
}
$.ctx.beginPath();
$.ctx.moveTo( this.x, this.y );
var angle = $.util.angle( { x: this.ox, y: this.oy }, this );
$.ctx.lineWidth = 2;
$.ctx.lineTo(
this.x - Math.cos( angle ) * ( 3 + this.speed * 2 ),
this.y - Math.sin( angle ) * ( 3 + this.speed * 2 )
);
$.ctx.stroke();
var pathLength = this.path.length;
if( pathLength > 1) {
$.ctx.strokeStyle = 'hsla(0, 0%, 100%, 0.15)';
$.ctx.lineWidth = 1;
$.ctx.beginPath();
if( pathLength >= $.opt.pathCount ) {
var angle = $.util.angle( this.path[ 1 ], this.path[ 0 ] ),
dx = this.path[ 0 ].x - this.path[ 1 ].x,
dy = this.path[ 0 ].y - this.path[ 1 ].y,
dist = Math.sqrt( dx * dx + dy * dy ),
x = this.path[ 0 ].x + Math.cos( angle ) * ( dist * ( ( $.tick % $.opt.pathSpacing ) / $.opt.pathSpacing ) ),
y = this.path[ 0 ].y + Math.sin( angle ) * ( dist * ( ( $.tick % $.opt.pathSpacing ) / $.opt.pathSpacing ) );
} else {
var x = this.path[ 0 ].x,
y = this.path[ 0 ].y
}
$.ctx.moveTo( x, y );
for( var i = 1; i < pathLength; i++ ) {
var point = this.path[ i ];
$.ctx.lineTo( point.x, point.y );
}
$.ctx.lineTo( this.x, this.y );
$.ctx.stroke();
}
};
$.step = function() {
requestAnimFrame( $.step );
$.ctx.globalCompositeOperation = 'destination-out';
$.ctx.fillStyle = 'hsla(0, 0%, 0%, 1)';
$.ctx.fillRect( 0, 0, $.cw, $.ch );
$.ctx.globalCompositeOperation = 'lighter';
var i;
i = $.ports.length; while( i-- ) { $.ports[ i ].update( i ) }
i = $.planes.length; while( i-- ) { $.planes[ i ].update( i ) }
i = $.ports.length; while( i-- ) { $.ports[ i ].render( i ) }
i = $.planes.length; while( i-- ) { $.planes[ i ].render( i ) }
var now = Date.now();
$.dt = $.util.clamp( ( now - $.lt ) / ( 1000 / 60 ), 0.001, 10 );
$.lt = now;
$.et += $.dt;
$.tick++;
};
$.init();
</script>
</body>
</html>
|
