private function init(S2CellId $id)
{
$this->cellId = $id;
$ij = array(0, 0);
$mOrientation = 0;
// echo " $mOrientation\n";
$this->face = $id->toFaceIJOrientation($ij[0], $ij[1], $mOrientation);
// echo ">> $mOrientation\n";
$this->orientation = $mOrientation;
$this->level = $id->level();
$cellSize = 1 << S2CellId::MAX_LEVEL - $this->level;
for ($d = 0; $d < 2; ++$d) {
// Compute the cell bounds in scaled (i,j) coordinates.
$sijLo = ($ij[$d] & -$cellSize) * 2 - self::MAX_CELL_SIZE;
$sijHi = $sijLo + $cellSize * 2;
$this->uv[$d][0] = S2Projections::stToUV(1.0 / self::MAX_CELL_SIZE * $sijLo);
$this->uv[$d][1] = S2Projections::stToUV(1.0 / self::MAX_CELL_SIZE * $sijHi);
}
}
/**
* Public helper function that calls FromFaceIJ if sameFace is true, or
* FromFaceIJWrap if sameFace is false.
*/
public static function fromFaceIJSame($face, $i, $j, $sameFace)
{
if ($sameFace) {
return S2CellId::fromFaceIJ($face, $i, $j);
} else {
return S2CellId::fromFaceIJWrap($face, $i, $j);
}
}
/** Computes a set of initial candidates that cover the given region. */
private function getInitialCandidates()
{
// Optimization: if at least 4 cells are desired (the normal case),
// start with a 4-cell covering of the region's bounding cap. This
// lets us skip quite a few levels of refinement when the region to
// be covered is relatively small.
if ($this->maxCells >= 4) {
// Find the maximum level such that the bounding cap contains at most one
// cell vertex at that level.
$cap = $this->region->getCapBound();
$level = min(S2Projections::MIN_WIDTH()->getMaxLevel(2 * $cap->angle()->radians()), min($this->maxLevel(), S2CellId::MAX_LEVEL - 1));
if ($this->levelMod() > 1 && $level > $this->minLevel()) {
$level -= ($level - $this->minLevel()) % $this->levelMod();
}
// We don't bother trying to optimize the level == 0 case, since more than
// four face cells may be required.
if ($level > 0) {
// Find the leaf cell containing the cap axis, and determine which
// subcell of the parent cell contains it.
/** @var S2CellId[] $base */
$base = array();
$s2point_tmp = $cap->axis();
$id = S2CellId::fromPoint($s2point_tmp);
$id->getVertexNeighbors($level, $base);
for ($i = 0; $i < count($base); ++$i) {
// printf("(face=%s pos=%s level=%s)\n", $base[$i]->face(), dechex($base[$i]->pos()), $base[$i]->level());
// echo "new S2Cell(base[i])\n";
$cell = new S2Cell($base[$i]);
// echo "neighbour cell: " . $cell . "\n";
$c = $this->newCandidate($cell);
// if ($c !== null)
// echo "addCandidato getInitialCandidates: " . $c->cell->id() . "\n";
$this->addCandidate($c);
}
// echo "\n\n\n";
return;
}
}
// Default: start with all six cube faces.
$face_cells = self::FACE_CELLS();
for ($face = 0; $face < 6; ++$face) {
$c = $this->newCandidate($face_cells[$face]);
echo "addCandidato getInitialCandidates_default: " . $c->cell->id() . "\n";
$this->addCandidate($c);
}
}
