Math, Physics, and Animation - HTML5 Canvas - page 346

var var tempBall ;

var

var tempX ;
var

var tempY ;
var

var tempSpeed ;
var var tempAngle ;

var var tempRadius ;

var

var tempRadians ;
var var tempvelocityx ;

var

var tempvelocityy ;

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

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

tempRadius = 5 ;
var

var placeOK = false false ;

while while ( ! placeOK ) {

tempX = tempRadius * 3 + ( Math . floor ( Math . random () * theCanvas . width )
- tempRadius * 3 );
tempY = tempRadius * 3 + ( Math . floor ( Math . random () * theCanvas . height )
- tempRadius * 3 );
tempSpeed = 4 ;
tempAngle = Math . floor ( Math . random () * 360 );
tempRadians = tempAngle * Math . PI / 180 ;
tempvelocityx = Math . cos ( tempRadians ) * tempSpeed ;
tempvelocityy = Math . sin ( tempRadians ) * tempSpeed ;

tempBall = { x : tempX , y : tempY , nextX : tempX , nextY : tempY , radius : tempRadius ,
speed : tempSpeed , angle : tempAngle , velocityx : tempvelocityx ,
velocityy : tempvelocityy , mass : tempRadius };
placeOK = canStartHere ( tempBall );

}
balls . push ( tempBall );

}

function function canStartHere ( ball ) {

var

var retval = true true ;

for for ( var var i = 0 ; i < balls . length ; i ++ ) {

iif ( hitTestCircle ( ball , balls [ i ])) {
retval = false

false ;

}

}
return

return retval ;

}
function function gameLoop () {

window . setTimeout ( gameLoop , 20 );