Math, Physics, and Animation - HTML5 Canvas - page 326

}

var var numBalls = 100 ;

var

var maxSize = 8 ;
var var minSize = 5 ;

var var maxSpeed = maxSize + 5 ;

var

var balls = new new Array ();

var var tempBall ;

var

var tempX ;
var

var tempY ;
var

var tempSpeed ;
var

var tempAngle ;
var

var tempRadius ;
var var tempRadians ;

var var tempXunits ;

var

var tempYunits ;

theCanvas = document . getElementById ( "canvasOne" );
context = theCanvas . getContext ( "2d" );

for for ( var var i = 0 ; i < numBalls ; i ++ ) {

tempRadius = Math . floor ( Math . random () * maxSize ) + minSize ;
tempX = tempRadius * 2 + ( Math . floor ( Math . random () * theCanvas . width ) - tempRadius * 2 );
tempY = tempRadius * 2 + ( Math . floor ( Math . random () * theCanvas . height ) - tempRadius * 2 );
tempSpeed = maxSpeed - tempRadius ;
tempAngle = Math . floor ( Math . random () * 360 );
tempRadians = tempAngle * Math . PI / 180 ;
tempXunits = Math . cos ( tempRadians ) * tempSpeed ;
tempYunits = Math . sin ( tempRadians ) * tempSpeed ;

tempBall = { x : tempX , y : tempY , radius : tempRadius , speed : tempSpeed , angle : tempAngle ,
xunits : tempXunits , yunits : tempYunits }
balls . push ( tempBall );

}

function function gameLoop () {

window . setTimeout ( gameLoop , 20 );
drawScreen ()

}
gameLoop ();

}

< /script>