public function forward($p)
{
// Forward equations
$lam = $p->x;
$phi = $p->y;
$lam = Common::adjust_lon($lam - $this->long0);
if ($this->sphere) {
$x = asin(cos($phi) * sin($lam));
$y = atan2(tan($phi), cos($lam)) - $this->phi0;
} else {
// ellipsoid
$this->n = sin($phi);
$this->c = cos($phi);
$y = Common::pj_mlfn($phi, $this->n, $this->c, $this->en);
$this->n = 1.0 / sqrt(1.0 - $this->es * $this->n * $this->n);
$this->tn = tan($phi);
$this->t = $this->tn * $this->tn;
$this->a1 = $lam * $this->c;
$this->c *= $this->es * $this->c / (1 - $this->es);
$this->a2 = $this->a1 * $this->a1;
$x = $this->n * $this->a1 * (1.0 - $this->a2 * $this->t * ($this->C1 - (8.0 - $this->t + 8.0 * $this->c) * $this->a2 * $this->C2));
$y -= $this->m0 - $this->n * $this->tn * $this->a2 * (0.5 + (5.0 - $this->t + 6.0 * $this->c) * $this->a2 * $this->C3);
}
$p->x = $this->a * $x + $this->x0;
$p->y = $this->a * $y + $this->y0;
return $p;
}
public function forward($p)
{
#$x,y,delta_lon;
$lon = $p->x;
$lat = $p->y;
/* Forward equations
----------------- */
$lon = Common::adjust_lon($lon - $this->long0);
if (isset($this->sphere)) {
if (!$this->m) {
$lat = $this->n != 1.0 ? asin($this->n * sin($lat)) : $lat;
} else {
$k = $this->n * sin($lat);
for ($i = Common::MAX_ITER; $i; --$i) {
$V = ($this->m * $lat + sin($lat) - $k) / ($this->m + cos($lat));
$lat -= $V;
if (abs($V) < Common::EPSLN) {
break;
}
}
}
$x = $this->a * $this->C_x * $lon * ($this->m + cos($lat));
$y = $this->a * $this->C_y * $lat;
} else {
$s = sin($lat);
$c = cos($lat);
$y = $this->a * Common::pj_mlfn($lat, $s, $c, $this->en);
$x = $this->a * $lon * $c / sqrt(1.0 - $this->es * $s * $s);
}
$p->x = $x;
$p->y = $y;
return $p;
}
