/**
* Takes all point vectors ("vertexes") of the polygon describing the face and sorts them
* in clockwise order.
*/
public function sortVerticesClockwise()
{
$center = $this->calculateCenter();
for ($n = 0; $n <= count($this->vertexes) - 3; $n++) {
$a = new \Math_Vector3(\Math_VectorOp::substract($this->vertexes[$n], $center)->getTuple());
$a->normalize();
$p = Plane::getInstanceByThreePositionVectors($this->vertexes[$n], $center, new \Math_Vector3(\Math_VectorOp::add($center, $this->plane->getNormalVectorNormalized())->getTuple()));
$smallestAngle = -1;
$smallest = -1;
for ($m = $n + 1; $m <= count($this->vertexes) - 1; $m++) {
if ($p->calculateSideOfPointVector($this->vertexes[$m]) !== Plane::SIDE_BACK) {
$b = new \Math_Vector3(\Math_VectorOp::substract($this->vertexes[$m], $center)->getTuple());
$b->normalize();
$angle = \Math_VectorOp::dotProduct($a, $b);
if ($angle > $smallestAngle) {
$smallestAngle = $angle;
$smallest = $m;
}
}
}
if ($smallest == -1) {
throw new \RuntimeException('Error: Degenerate polygon!');
}
//swap vertices
$temp = $this->vertexes[$n + 1];
$this->vertexes[$n + 1] = $this->vertexes[$smallest];
$this->vertexes[$smallest] = $temp;
unset($temp);
}
// Check if vertex order needs to be reversed for back-facing polygon
$newPlane = Plane::getInstanceByThreePositionVectors($this->vertexes[0], $this->vertexes[1], $this->vertexes[2]);
if (\Math_VectorOp::dotProduct($newPlane->getNormalVectorNormalized(), $this->plane->getNormalVectorNormalized()) < 0) {
array_reverse($this->vertexes);
}
}
/**
* Verify that an exception is thrown when trying to get the intersection point with two other parallel planes
*/
public function testIntersectionAllParalel()
{
$this->setExpectedException('InvalidArgumentException');
$p1 = Plane::getInstanceByThreePositionVectors($this->x1, $this->y1, $this->z1);
$add1 = new Math_Vector3(new Math_Tuple(array(0, 0, 16)));
$x1p = new Math_Vector3(Math_VectorOp::add($this->x1, $add1)->getTuple());
$y1p = new Math_Vector3(Math_VectorOp::add($this->y1, $add1)->getTuple());
$z1p = new Math_Vector3(Math_VectorOp::add($this->z1, $add1)->getTuple());
$p2 = Plane::getInstanceByThreePositionVectors($x1p, $y1p, $z1p);
$add2 = new Math_Vector3(new Math_Tuple(array(0, 0, 32)));
$x1p2 = new Math_Vector3(Math_VectorOp::add($this->x1, $add2)->getTuple());
$y1p2 = new Math_Vector3(Math_VectorOp::add($this->y1, $add2)->getTuple());
$z1p2 = new Math_Vector3(Math_VectorOp::add($this->z1, $add2)->getTuple());
$p3 = Plane::getInstanceByThreePositionVectors($x1p2, $y1p2, $z1p2);
$p1->calculateIntersectionPointWithTwoPlanes($p2, $p3);
}