public function triangulate()
{
$triangles = [];
$points = $this->getPoints();
// Loop until it remains a triangle
while (count($points) > 3) {
for ($p = 0; $p < count($points); $p++) {
$a = $points[$p - 1 == -1 ? count($points) - 1 : $p - 1];
$b = $points[$p];
$c = $points[($p + 1) % count($points)];
$angle = Line::getAntiClockwiseAngleBetweenLines(new Line($a, $b), new Line($b, $c));
if ($angle == 180) {
array_splice($points, $p, 1);
} else {
if ($angle > 180) {
$triangle = (new Polygon([$a, $b, $c]))->getDetermined();
foreach ($points as $point) {
if (!in_array($point, [$a, $b, $c])) {
if ($triangle->isPointInside($point, true)) {
continue 2;
}
}
}
array_splice($points, $p, 1);
$triangles[] = $triangle;
continue 2;
}
}
}
}
$triangles[] = (new Polygon($points))->getDetermined();
return $triangles;
}
public function isConvex()
{
$lines = $this->getLines();
$lines[] = $lines[0];
// to loop on every angles
for ($i = 1, $imax = count($lines); $i < $imax; $i++) {
$angle = Line::getAntiClockWiseAngleBetweenLines($lines[$i], $lines[$i - 1]);
if (abs($angle) > 180) {
return false;
}
}
return true;
}
