| New file |
|---|
| 0,0 → 1,129 |
|---|
| <?php |
| |
| /** |
| * Author : Julien Moquet |
| * |
| * Inspired by Proj4php from Mike Adair madairATdmsolutions.ca |
| * and Richard Greenwood rich@greenwoodma$p->com |
| * License: LGPL as per: http://www.gnu.org/copyleft/lesser.html |
| */ |
| /* * ***************************************************************************** |
| NAME MERCATOR |
| |
| PURPOSE: Transforms input longitude and latitude to Easting and |
| Northing for the Mercator projection. The |
| longitude and latitude must be in radians. The Easting |
| and Northing values will be returned in meters. |
| |
| PROGRAMMER DATE |
| ---------- ---- |
| D. Steinwand, EROS Nov, 1991 |
| T. Mittan Mar, 1993 |
| |
| ALGORITHM REFERENCES |
| |
| 1. Snyder, John P., "Map Projections--A Working Manual", U.S. Geological |
| Survey Professional Paper 1395 (Supersedes USGS Bulletin 1532), United |
| State Government Printing Office, Washington D.C., 1987. |
| |
| 2. Snyder, John P. and Voxland, Philip M., "An Album of Map Projections", |
| U.S. Geological Survey Professional Paper 1453 , United State Government |
| Printing Office, Washington D.C., 1989. |
| * ***************************************************************************** */ |
| |
| //static double r_major = a; /* major axis */ |
| //static double r_minor = b; /* minor axis */ |
| //static double lon_center = long0; /* Center longitude (projection center) */ |
| //static double lat_origin = lat0; /* center latitude */ |
| //static double e,es; /* eccentricity constants */ |
| //static double m1; /* small value m */ |
| //static double false_northing = y0; /* y offset in meters */ |
| //static double false_easting = x0; /* x offset in meters */ |
| //scale_fact = k0 |
| |
| class Proj4phpProjMerc { |
| |
| public function init() { |
| //?$this->temp = $this->r_minor / $this->r_major; |
| //$this->temp = $this->b / $this->a; |
| //$this->es = 1.0 - sqrt($this->temp); |
| //$this->e = sqrt( $this->es ); |
| //?$this->m1 = cos($this->lat_origin) / (sqrt( 1.0 - $this->es * sin($this->lat_origin) * sin($this->lat_origin))); |
| //$this->m1 = cos(0.0) / (sqrt( 1.0 - $this->es * sin(0.0) * sin(0.0))); |
| if( $this->lat_ts ) { |
| if( $this->sphere ) { |
| $this->k0 = cos( $this->lat_ts ); |
| } else { |
| $this->k0 = Proj4php::$common->msfnz( $this->es, sin( $this->lat_ts ), cos( $this->lat_ts ) ); |
| } |
| } |
| } |
| |
| /* Mercator forward equations--mapping lat,long to x,y |
| -------------------------------------------------- */ |
| |
| public function forward( $p ) { |
| |
| //alert("ll2m coords : ".coords); |
| $lon = $p->x; |
| $lat = $p->y; |
| // convert to radians |
| if( $lat * Proj4php::$common->R2D > 90.0 && |
| $lat * Proj4php::$common->R2D < -90.0 && |
| $lon * Proj4php::$common->R2D > 180.0 && |
| $lon * Proj4php::$common->R2D < -180.0 ) { |
| Proj4php::reportError( "merc:forward: llInputOutOfRange: " . $lon . " : " . $lat ); |
| return null; |
| } |
| |
| if( abs( abs( $lat ) - Proj4php::$common->HALF_PI ) <= Proj4php::$common->EPSLN ) { |
| Proj4php::reportError( "merc:forward: ll2mAtPoles" ); |
| return null; |
| } else { |
| if( $this->sphere ) { |
| $x = $this->x0 + $this->a * $this->k0 * Proj4php::$common->adjust_lon( $lon - $this->long0 ); |
| $y = $this->y0 + $this->a * $this->k0 * log( tan( Proj4php::$common->FORTPI + 0.5 * $lat ) ); |
| } else { |
| $sinphi = sin( lat ); |
| $ts = Proj4php::$common . tsfnz( $this->e, $lat, $sinphi ); |
| $x = $this->x0 + $this->a * $this->k0 * Proj4php::$common->adjust_lon( $lon - $this->long0 ); |
| $y = $this->y0 - $this->a * $this->k0 * log( $ts ); |
| } |
| |
| $p->x = $x; |
| $p->y = $y; |
| |
| return $p; |
| } |
| } |
| |
| /* Mercator inverse equations--mapping x,y to lat/long |
| -------------------------------------------------- */ |
| |
| public function inverse( $p ) { |
| |
| $x = $p->x - $this->x0; |
| $y = $p->y - $this->y0; |
| |
| if( $this->sphere ) { |
| $lat = Proj4php::$common->HALF_PI - 2.0 * atan( exp( -$y / $this->a * $this->k0 ) ); |
| } else { |
| $ts = exp( -$y / ($this->a * $this->k0) ); |
| $lat = Proj4php::$common->phi2z( $this->e, $ts ); |
| if( $lat == -9999 ) { |
| Proj4php::reportError( "merc:inverse: lat = -9999" ); |
| return null; |
| } |
| } |
| $lon = Proj4php::$common->adjust_lon( $this->long0 + $x / ($this->a * $this->k0) ); |
| |
| $p->x = $lon; |
| $p->y = $lat; |
| return $p; |
| } |
| |
| } |
| |
| Proj4php::$proj['merc'] = new Proj4phpProjMerc(); |
| |
| |