public function union(Polygon $subject, Polygon $clip)
{
$hState = new HorizontalEdgeStates();
$result = new Polygon();
if ($subject->isEmpty() && $clip->isEmpty()) {
return $result;
}
$lmtTable = new LocalMinimumTable();
$sbte = new ScanBeamTreeEntries();
$s_heap = null;
$c_heap = null;
if (!$subject->isEmpty()) {
$sHeap = $this->buildLmt($lmtTable, $sbte, $subject, self::SUBJ);
}
if (!$clip->isEmpty()) {
$cHeap = $this->buildLmt($lmtTable, $sbte, $clip, self::CLIP);
}
if ($lmtTable->getTopNode() === null) {
return $result;
}
/* Build scanbeam table from scanbeam tree */
$sbt = $sbte->buildSbt();
$parity = [];
$parity[0] = self::LEFT;
$parity[1] = self::LEFT;
$localMin = $lmtTable->getTopNode();
$outPoly = new TopPolygonNode();
//used to create resulting polygon
$aet = new AetTree();
$scanbeam = 0;
/* Process each scanbeam */
while ($scanbeam < count($sbt)) {
echo '$scanbeam : ' . $scanbeam . ', count($sbt): ' . count($sbt) . PHP_EOL;
/* Set yb and yt to the bottom and top of the scanbeam */
$yb = $sbt[$scanbeam++];
$yt = 0.0;
$dy = 0.0;
if ($scanbeam < count($sbt)) {
$yt = $sbt[$scanbeam];
$dy = $yt - $yb;
}
/* === SCANBEAM BOUNDARY PROCESSING ================================ */
/* If LMT node corresponding to yb exists */
if ($localMin != null) {
if ($localMin->getY() === $yb) {
/* Add edges starting at this local minimum to the AET */
for ($edge = $localMin->getFirstBound(); $edge != null; $edge = $edge->getNextBound()) {
$aet = $this->addEdgeToAet($aet, $edge);
}
$localMin = $localMin->getNext();
}
}
// $aet->printTree();
/* Set dummy previous x value */
$px = -INF;
/* Create bundles within AET */
$e0 = $aet->getTopNode();
$e1 = $aet->getTopNode();
/* Set up bundle fields of first edge */
$aet->getTopNode()->bundle[self::ABOVE][$aet->getTopNode()->getType()] = $aet->getTopNode()->getTop()->getY() !== $yb ? 1 : 0;
$aet->getTopNode()->bundle[self::ABOVE][$aet->getTopNode()->getType() === 0 ? 1 : 0] = 0;
$aet->getTopNode()->bstate[self::ABOVE] = BundleState::unbundled();
for ($nextEdge = $aet->getTopNode()->getNext(); $nextEdge != null; $nextEdge = $nextEdge->getNext()) {
$neType = $nextEdge->getType();
$neTypeOpp = $nextEdge->getType() === 0 ? 1 : 0;
//next edge type opposite
/* Set up bundle fields of next edge */
$nextEdge->bundle[self::ABOVE][$neType] = $nextEdge->getTop()->getY() !== $yb ? 1 : 0;
$nextEdge->bundle[self::ABOVE][$neTypeOpp] = 0;
$nextEdge->bstate[self::ABOVE] = BundleState::unbundled();
/* Bundle edges above the scanbeam boundary if they coincide */
if ($nextEdge->bundle[self::ABOVE][$neType] === 1) {
if (self::eq($e0->getXb(), $nextEdge->getXb()) && self::eq($e0->getDx(), $nextEdge->getDx()) && $e0->getTop()->getY() != $yb) {
$nextEdge->bundle[self::ABOVE][$neType] ^= $e0->bundle[self::ABOVE][$neType];
$nextEdge->bundle[self::ABOVE][$neTypeOpp] = $e0->bundle[self::ABOVE][$neTypeOpp];
$nextEdge->bstate[self::ABOVE] = BundleState::bundleHead();
$e0->bundle[self::ABOVE][self::CLIP] = 0;
$e0->bundle[self::ABOVE][self::SUBJ] = 0;
$e0->bstate[self::ABOVE] = BundleState::bundleTail();
}
$e0 = $nextEdge;
}
}
$horiz = [];
$horiz[self::CLIP] = HorizontalEdgeStates::NH;
$horiz[self::SUBJ] = HorizontalEdgeStates::NH;
$exists = [];
$exists[self::CLIP] = 0;
$exists[self::SUBJ] = 0;
/** @var PolygonNode|null $cf */
$cf = null;
/* Process each edge at this scanbeam boundary */
for ($edge = $aet->getTopNode(); $edge != null; $edge = $edge->getNext()) {
echo $edge->getVertex() . PHP_EOL;
$exists[self::CLIP] = $edge->bundle[self::ABOVE][self::CLIP] + ($edge->bundle[self::BELOW][self::CLIP] << 1);
$exists[self::SUBJ] = $edge->bundle[self::ABOVE][self::SUBJ] + ($edge->bundle[self::BELOW][self::SUBJ] << 1);
if ($exists[self::CLIP] !== 0 || $exists[self::SUBJ] !== 0) {
/* Set bundle side */
$edge->bside[self::CLIP] = $parity[self::CLIP];
$edge->bside[self::SUBJ] = $parity[self::SUBJ];
$contributing = false;
$br = 0;
$bl = 0;
$tr = 0;
$tl = 0;
$contributing = $exists[self::CLIP] !== 0 && (!($parity[self::SUBJ] !== 0) || $horiz[self::SUBJ] !== 0) || $exists[self::SUBJ] !== 0 && (!($parity[self::CLIP] !== 0) || $horiz[self::CLIP] !== 0) || $exists[self::CLIP] !== 0 && $exists[self::SUBJ] !== 0 && $parity[self::CLIP] === $parity[self::SUBJ];
$br = $parity[self::CLIP] !== 0 || $parity[self::SUBJ] !== 0 ? 1 : 0;
$bl = ($parity[self::CLIP] ^ $edge->bundle[self::ABOVE][self::CLIP]) !== 0 || ($parity[self::SUBJ] ^ $edge->bundle[self::ABOVE][self::SUBJ]) !== 0 ? 1 : 0;
$tr = ($parity[self::CLIP] ^ ($horiz[self::CLIP] !== HorizontalEdgeStates::NH ? 1 : 0)) !== 0 || ($parity[self::SUBJ] ^ ($horiz[self::SUBJ] !== HorizontalEdgeStates::NH ? 1 : 0)) !== 0 ? 1 : 0;
$tl = ($parity[self::CLIP] ^ ($horiz[self::CLIP] !== HorizontalEdgeStates::NH ? 1 : 0) ^ $edge->bundle[self::BELOW][self::CLIP]) !== 0 || ($parity[self::SUBJ] ^ ($horiz[self::SUBJ] !== HorizontalEdgeStates::NH ? 1 : 0) ^ $edge->bundle[self::BELOW][self::SUBJ]) !== 0 ? 1 : 0;
/* Update parity */
$parity[self::CLIP] ^= $edge->bundle[self::ABOVE][self::CLIP];
$parity[self::SUBJ] ^= $edge->bundle[self::ABOVE][self::SUBJ];
/* Update horizontal state */
if ($exists[self::CLIP] !== 0) {
$horiz[self::CLIP] = $hState->nextState[$horiz[self::CLIP]][($exists[self::CLIP] - 1 << 1) + $parity[self::CLIP]];
}
if ($exists[self::SUBJ] !== 0) {
$horiz[self::SUBJ] = $hState->nextState[$horiz[self::SUBJ]][($exists[self::SUBJ] - 1 << 1) + $parity[self::SUBJ]];
}
if ($contributing) {
$xb = $edge->getXb();
$vClass = VertexType::getType($tr, $tl, $br, $bl);
switch ($vClass) {
case VertexType::EMN:
case VertexType::IMN:
$edge->outp[self::ABOVE] = $outPoly->addLocalMin($xb, $yb);
$px = $xb;
$cf = $edge->outp[self::ABOVE];
break;
case VertexType::ERI:
if ($xb !== $px) {
$cf->addRight($xb, $yb);
$px = $xb;
}
$edge->outp[self::ABOVE] = $cf;
$cf = null;
break;
case VertexType::ELI:
$edge->outp[self::BELOW]->addLeft($xb, $yb);
$px = $xb;
$cf = $edge->outp[self::BELOW];
break;
case VertexType::EMX:
if ($xb !== $px) {
$cf->addLeft($xb, $yb);
$px = $xb;
}
$outPoly->mergeRight($cf, $edge->outp[self::BELOW]);
$cf = null;
break;
case VertexType::ILI:
if ($xb !== $px) {
$cf->addLeft($xb, $yb);
$px = $xb;
}
$edge->outp[self::ABOVE] = $cf;
$cf = null;
break;
case VertexType::IRI:
$edge->outp[self::BELOW]->addRight($xb, $yb);
$px = $xb;
$cf = $edge->outp[self::BELOW];
$edge->outp[self::BELOW] = null;
break;
case VertexType::IMX:
if ($xb !== $px) {
$cf->addRight($xb, $yb);
$px = $xb;
}
$outPoly->mergeLeft($cf, $edge->outp[self::BELOW]);
$cf = null;
$edge->outp[self::BELOW] = null;
break;
case VertexType::IMM:
if ($xb !== $px) {
$cf->addRight($xb, $yb);
$px = $xb;
}
$outPoly->mergeLeft($cf, $edge->outp[self::BELOW]);
$edge->outp[self::BELOW] = null;
$edge->outp[self::ABOVE] = $outPoly->addLocalMin($xb, $yb);
$cf = $edge->outp[self::ABOVE];
break;
case VertexType::EMM:
if ($xb !== $px) {
$cf->addLeft($xb, $yb);
$px = $xb;
}
$outPoly->mergeRight($cf, $edge->outp[self::BELOW]);
$edge->outp[self::BELOW] = null;
$edge->outp[self::ABOVE] = $outPoly->addLocalMin($xb, $yb);
$cf = $edge->outp[self::ABOVE];
break;
case VertexType::LED:
if ($edge->getBot()->getY() === $yb) {
$edge->outp[self::BELOW]->addLeft($xb, $yb);
}
$edge->outp[self::ABOVE] = $edge->outp[self::BELOW];
$px = $xb;
break;
case VertexType::RED:
if ($edge->getBot()->getY() === $yb) {
$edge->outp[self::BELOW]->addRight($xb, $yb);
}
$edge->outp[self::ABOVE] = $edge->outp[self::BELOW];
$px = $xb;
break;
default:
break;
}
/* End of switch */
}
/* End of contributing conditional */
}
/* End of edge exists conditional */
}
/* End of AET loop */
/* Delete terminating edges from the AET, otherwise compute xt */
for ($edge = $aet->getTopNode(); $edge != null; $edge = $edge->getNext()) {
if ($edge->getTop()->getY() === $yb) {
$prevEdge = $edge->getPrev();
$nextEdge = $edge->getNext();
if ($prevEdge !== null) {
$prevEdge->setNext($nextEdge);
} else {
$aet->setTopNode($nextEdge);
}
if ($nextEdge !== null) {
$nextEdge->setPrev($prevEdge);
}
/* Copy bundle head state to the adjacent tail edge if required */
if ($edge->getBstate()[self::BELOW] === BundleState::bundleHead() && $prevEdge != null) {
if ($prevEdge->getBstate()[self::BELOW] == BundleState::bundleTail()) {
$prevEdge->outp[self::BELOW] = $edge->outp[self::BELOW];
$prevEdge->addBstate(self::BELOW, BundleState::unbundled());
if ($prevEdge->getPrev() != null) {
if ($prevEdge->getPrev()->getBstate()[self::BELOW] == BundleState::bundleTail()) {
$prevEdge->addBstate(self::BELOW, BundleState::bundleHead());
}
}
}
}
} else {
if ($edge->getTop()->getY() === $yt) {
$edge->setXt($edge->getTop()->getX());
} else {
$edge->setXt($edge->getBot()->getX() + $edge->getDx() * ($yt - $edge->getBot()->getY()));
}
}
}
if ($scanbeam < $sbte->getSbtEntries()) {
/*
* === SCANBEAM INTERIOR PROCESSING
* ==============================
*/
/* Build intersection table for the current scanbeam */
$itTable = new ItNodeTable();
$this->buildIntersectionTable($aet, $dy, $itTable);
/* Process each node in the intersection table */
for ($insct = $itTable->getTopNode(); $insct != null; $insct = $insct->getNext()) {
$e0 = $insct->getIe()[0];
$e1 = $insct->getIe()[1];
/* Only generate output for contributing intersections */
if (($e0->bundle[self::ABOVE][self::CLIP] != 0 || $e0->bundle[self::ABOVE][self::SUBJ] != 0) && ($e1->bundle[self::ABOVE][self::CLIP] != 0 || $e1->bundle[self::ABOVE][self::SUBJ] != 0)) {
$p = $e0->outp[self::ABOVE];
$q = $e1->outp[self::ABOVE];
$ix = $insct->getPoint()->getX();
$iy = $insct->getPoint()->getY();
$inClip = $e0->bundle[self::ABOVE][self::CLIP] != 0 && !($e0->getBside()[self::CLIP] != 0) || $e1->bundle[self::ABOVE][self::CLIP] != 0 && $e1->getBside()[self::CLIP] != 0 || !($e0->bundle[self::ABOVE][self::CLIP] != 0) && !($e1->bundle[self::ABOVE][self::CLIP] != 0) && $e0->getBside()[self::CLIP] != 0 && $e1->getBside()[self::CLIP] != 0 ? 1 : 0;
$inSubj = $e0->bundle[self::ABOVE][self::SUBJ] != 0 && !($e0->getBside()[self::SUBJ] != 0) || $e1->bundle[self::ABOVE][self::SUBJ] != 0 && $e1->getBside()[self::SUBJ] != 0 || !($e0->bundle[self::ABOVE][self::SUBJ] != 0) && !($e1->bundle[self::ABOVE][self::SUBJ] != 0) && $e0->getBside()[self::SUBJ] != 0 && $e1->getBside()[self::SUBJ] != 0 ? 1 : 0;
$br = 0;
$bl = 0;
$tr = 0;
$tl = 0;
$tr = $inClip != 0 || $inSubj != 0 ? 1 : 0;
$tl = ($inClip ^ $e1->bundle[self::ABOVE][self::CLIP]) != 0 || ($inSubj ^ $e1->bundle[self::ABOVE][self::SUBJ]) != 0 ? 1 : 0;
$br = ($inClip ^ $e0->bundle[self::ABOVE][self::CLIP]) != 0 || ($inSubj ^ $e0->bundle[self::ABOVE][self::SUBJ]) != 0 ? 1 : 0;
$bl = ($inClip ^ $e1->bundle[self::ABOVE][self::CLIP] ^ $e0->bundle[self::ABOVE][self::CLIP]) != 0 || ($inSubj ^ $e1->bundle[self::ABOVE][self::SUBJ] ^ $e0->bundle[self::ABOVE][self::SUBJ]) != 0 ? 1 : 0;
$vClass = VertexType::getType($tr, $tl, $br, $bl);
switch ($vClass) {
case VertexType::EMN:
$e0->outp[self::ABOVE] = $outPoly->addLocalMin($ix, $iy);
$e1->outp[self::ABOVE] = $e0->outp[self::ABOVE];
break;
case VertexType::ERI:
if ($p != null) {
$p->addRight($ix, $iy);
$e1->outp[self::ABOVE] = $p;
$e0->outp[self::ABOVE] = null;
}
break;
case VertexType::ELI:
if ($q != null) {
$q->addLeft($ix, $iy);
$e0->outp[self::ABOVE] = $q;
$e1->outp[self::ABOVE] = null;
}
break;
case VertexType::EMX:
if ($p != null && $q != null) {
$p->addLeft($ix, $iy);
$outPoly->mergeRight($p, $q);
$e0->outp[self::ABOVE] = null;
$e1->outp[self::ABOVE] = null;
}
break;
case VertexType::IMN:
$e0->outp[self::ABOVE] = $outPoly->addLocalMin($ix, $iy);
$e1->outp[self::ABOVE] = $e0->outp[self::ABOVE];
break;
case VertexType::ILI:
if ($p != null) {
$p->addLeft($ix, $iy);
$e1->outp[self::ABOVE] = $p;
$e0->outp[self::ABOVE] = null;
}
break;
case VertexType::IRI:
if ($q != null) {
$q->addRight($ix, $iy);
$e0->outp[self::ABOVE] = $q;
$e1->outp[self::ABOVE] = null;
}
break;
case VertexType::IMX:
if ($p !== null && $q != null) {
$p->addRight($ix, $iy);
$outPoly->mergeLeft($p, $q);
$e0->outp[self::ABOVE] = null;
$e1->outp[self::ABOVE] = null;
}
break;
case VertexType::IMM:
if ($p !== null && $q != null) {
$p->addRight($ix, $iy);
$outPoly->mergeLeft($p, $q);
$e0->outp[self::ABOVE] = $outPoly->addLocalMin($ix, $iy);
$e1->outp[self::ABOVE] = $e0->outp[self::ABOVE];
}
break;
case VertexType::EMM:
if ($p !== null && $q != null) {
$p->addLeft($ix, $iy);
$outPoly->mergeRight($p, $q);
$e0->outp[self::ABOVE] = $outPoly->addLocalMin($ix, $iy);
$e1->outp[self::ABOVE] = $e0->outp[self::ABOVE];
}
break;
default:
break;
}
/* End of switch */
}
/* End of contributing intersection conditional */
/* Swap bundle sides in response to edge crossing */
if ($e0->bundle[self::ABOVE][self::CLIP] != 0) {
$e1->bside[self::CLIP] = $e1->bside[self::CLIP] === 0 ? 1 : 0;
}
if ($e1->bundle[self::ABOVE][self::CLIP] != 0) {
$e0->bside[self::CLIP] = $e0->bside[self::CLIP] === 0 ? 1 : 0;
}
if ($e0->bundle[self::ABOVE][self::SUBJ] != 0) {
$e1->bside[self::SUBJ] = $e1->bside[self::SUBJ] === 0 ? 1 : 0;
}
if ($e1->bundle[self::ABOVE][self::SUBJ] != 0) {
$e0->bside[self::SUBJ] = $e0->bside[self::SUBJ] === 0 ? 1 : 0;
}
/* Swap e0 and e1 bundles in the AET */
$prevEdge = $e0->getPrev();
$nextEdge = $e1->getNext();
if ($nextEdge != null) {
$nextEdge->setPrev($e0);
}
if ($e0->getBstate()[self::ABOVE] == BundleState::bundleHead()) {
$search = true;
while ($search) {
$prevEdge = $prevEdge->getPrev();
if ($prevEdge != null) {
if ($prevEdge->getBstate()[self::ABOVE] != BundleState::bundleTail()) {
$search = false;
}
} else {
$search = false;
}
}
}
if ($prevEdge === null) {
$aet->getTopNode()->setPrev($e1);
$e1->setNext($aet->getTopNode());
$aet->setTopNode($e0->getNext());
} else {
$prevEdge->getNext()->setPrev($e1);
$e1->setNext($prevEdge->getNext());
$prevEdge->setNext($e0->getNext());
}
$e0->getNext()->setPrev($prevEdge);
$e1->getNext()->setPrev($e1);
$e0->setNext($nextEdge);
}
/* End of IT loop */
/* Prepare for next scanbeam */
for ($edge = $aet->getTopNode(); $edge != null; $edge = $edge->getNext()) {
$nextEdge = $edge->getNext();
$succEdge = $edge->getSucc();
if ($edge->getTop()->getY() === $yt && $succEdge !== null) {
/* Replace AET edge by its successor */
$succEdge->outp[self::BELOW] = $edge->outp[self::ABOVE];
$succEdge->bstate[self::BELOW] = $edge->bstate[self::ABOVE];
$succEdge->bundle[self::BELOW][self::CLIP] = $edge->bundle[self::ABOVE][self::CLIP];
$succEdge->bundle[self::BELOW][self::SUBJ] = $edge->bundle[self::ABOVE][self::SUBJ];
$prevEdge = $edge->getPrev();
if ($prevEdge !== null) {
$prevEdge->setNext($succEdge);
} else {
$aet->setTopNode($succEdge);
}
if ($nextEdge !== null) {
$nextEdge->setPrev($succEdge);
}
$succEdge->setPrev($prevEdge);
$succEdge->setNext($nextEdge);
} else {
/* Update this edge */
$edge->outp[self::BELOW] = $edge->outp[self::ABOVE];
$edge->bstate[self::BELOW] = $edge->bstate[self::ABOVE];
$edge->bundle[self::BELOW][self::CLIP] = $edge->bundle[self::ABOVE][self::CLIP];
$edge->bundle[self::BELOW][self::SUBJ] = $edge->bundle[self::ABOVE][self::SUBJ];
$edge->setXb($edge->getXt());
}
$edge->outp[self::ABOVE] = null;
}
}
}
/* === END OF SCANBEAM PROCESSING ================================== */
/* Generate result polygon from out_poly */
$result = $outPoly->getResult();
return $result;
}
