public function getAngle(Image_3D_Vector $vector)
{
$length = $vector->length() * $this->length();
if ($length < 0.0001) {
return 1;
}
return abs(acos($this->scalar($vector) / $length) / M_PI - 0.5) * 2;
}
public function getColor(Image_3D_Interface_Enlightenable $polygon)
{
$color = clone $polygon->getColor();
$light = new Image_3D_Vector($this->_x, $this->_y, $this->_z);
$light->sub($polygon->getPosition());
$distance = $light->length();
if ($distance > $this->_distance) {
return $color;
}
$factor = 1 - pow($distance / $this->_distance, $this->_falloff);
$light->unify();
$light->add(new Image_3D_Vector(0, 0, -1));
$normale = $polygon->getNormale();
$angle = abs(1 - $normale->getAngle($light));
$color->addLight($this->_color, $angle * $factor);
return $color;
}