/**
* @param float $x
*
* @return float|null
*/
public function evaluate($x)
{
$nowPoint = new Point($x, 0);
$containingLine = null;
foreach ($this->path->getLineIterator() as $line) {
if ($nowPoint->betweenX($line->getStartPoint(), $line->getEndPoint())) {
$containingLine = $line;
break;
}
}
if (null === $containingLine) {
if (false === $this->extrapolate) {
return null;
}
if ($this->path->firstPoint()->getX() > $x) {
$containingLine = $this->path->firstLine();
} else {
$containingLine = $this->path->lastLine();
}
}
return $containingLine->getLinearFunction()->evaluate($x);
}
/**
* @param Path $path
*/
public function __construct(Path $path)
{
$this->points = $path->getPoints();
$this->index = 0;
}
