| New file |
|---|
| 0,0 → 1,63 |
|---|
| <?php |
| /** |
| * Author : Julien Moquet |
| * |
| * Inspired by Proj4php from Mike Adair madairATdmsolutions.ca |
| * and Richard Greenwood rich@greenwoodma$p->com |
| * License: LGPL as per: http://www.gnu.org/copyleft/lesser.html |
| */ |
| class Proj4phpProjGstmerc { |
| |
| public function init() { |
| |
| // array of: a, b, lon0, lat0, k0, x0, y0 |
| $temp = $this->b / $this->a; |
| $this->e = sqrt( 1.0 - $temp * $temp ); |
| $this->lc = $this->long0; |
| $this->rs = sqrt( 1.0 + $this->e * $this->e * pow( cos( $this->lat0 ), 4.0 ) / (1.0 - $this->e * $this->e) ); |
| $sinz = sin( $this->lat0 ); |
| $pc = asin( $sinz / $this->rs ); |
| $sinzpc = sin( $pc ); |
| $this->cp = Proj4php::$common->latiso( 0.0, $pc, $sinzpc ) - $this->rs * Proj4php::$common->latiso( $this->e, $this->lat0, $sinz ); |
| $this->n2 = $this->k0 * $this->a * sqrt( 1.0 - $this->e * $this->e ) / (1.0 - $this->e * $this->e * $sinz * $sinz); |
| $this->xs = $this->x0; |
| $this->ys = $this->y0 - $this->n2 * $pc; |
| |
| if( !$this->title ) |
| $this->title = "Gauss Schreiber transverse mercator"; |
| } |
| |
| // forward equations--mapping lat,long to x,y |
| // ----------------------------------------------------------------- |
| public function forward( $p ) { |
| |
| $lon = $p->x; |
| $lat = $p->y; |
| |
| $L = $this->rs * ($lon - $this->lc); |
| $Ls = $this->cp + ($this->rs * Proj4php::$common->latiso( $this->e, $lat, sin( $lat ) )); |
| $lat1 = asin( sin( $L ) / Proj4php::$common . cosh( $Ls ) ); |
| $Ls1 = Proj4php::$common . latiso( 0.0, $lat1, sin( $lat1 ) ); |
| $p->x = $this->xs + ($this->n2 * $Ls1); |
| $p->y = $this->ys + ($this->n2 * atan( Proj4php::$common->sinh( $Ls ) / cos( $L ) )); |
| return $p; |
| } |
| |
| // inverse equations--mapping x,y to lat/long |
| // ----------------------------------------------------------------- |
| public function inverse( $p ) { |
| |
| $x = $p->x; |
| $y = $p->y; |
| |
| $L = atan( Proj4php::$common . sinh( ($x - $this->xs) / $this->n2 ) / cos( ($y - $this->ys) / $this->n2 ) ); |
| $lat1 = asin( sin( ($y - $this->ys) / $this->n2 ) / Proj4php::$common . cosh( ($x - $this->xs) / $this->n2 ) ); |
| $LC = Proj4php::$common . latiso( 0.0, $lat1, sin( $lat1 ) ); |
| $p->x = $this->lc + $L / $this->rs; |
| $p->y = Proj4php::$common . invlatiso( $this->e, ($LC - $this->cp) / $this->rs ); |
| return $p; |
| } |
| |
| } |
| |
| Proj4php::$proj['gstmerc'] = new Proj4phpProjGestmerc(); |