Copyright (c) 2003, DM Solutions Group Inc. * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER * DEALINGS IN THE SOFTWARE. */ /** * Number of KM in a MILE * there are 5280 feet in a mile : start with 5280 * there are 12 inches in a foot : multiple by 12 * there are 0.0254 meters in an inch : multiple by 0.0254 * there are 1000 meters in a kilometer : divide by 1000 */ define( "KM_PER_MILE", (5280 * 12 * 0.0254 / 1000) ); /** * Constant returns miles per degree of latitude which is 69. */ define( "MilesPerDegreeLat", 69 ); define( "DegreesLatPerMile", (1 / 69.0) ); /** * function LonToLatRatio * * Given a latitude in decimal degrees, it will return the ratio of * longitude degress to latitude degrees. */ function LonToLatRatio ($latitude) { return cos($latitude * M_PI / 180); } /** * MilesPerDegreeLon($latitude) * * Given a latitude in decimal degrees, it will return the * miles per degree of longitude. */ function MilesPerDegreeLon ($latitude) { return 69 * LonToLatRatio($latitude); } /** * DegreesLonPerMile($latitude) * * Given a latitude in decimal degrees, it will return the * degrees of longitude per mile. */ function DegreesLonPerMile ($latitude) { return 1 / MilesPerDegreeLon( $latitude ); } /** * decimal_degrees($degrees, $minutes, $seconds) * * Given whole degrees, minutes, and seconds, B will * return the equivalent number of decimal degrees. B

function * takes the same inputs as B but returns a result * limited to 5 decimal places. */ function decimal_degrees ($degrees, $minutes, $seconds) { // if degrees are negative, subtrack minutes and seconds. if ($degrees < 0) { return $degrees - ( $minutes / 60 ) - ( $seconds / 3600); } // if degrees are positve, add minutes and seconds. return $degrees + ( $minutes / 60 ) + ( $seconds / 3600); } function dd ($degrees, $minutes, $seconds) { return sprintf("%.5f", decimal_degrees($degrees, $minutes, $seconds)); } /** * Lon2DMS(I) * * Given a longitude in decimal degrees, returns a string in the form of: * * IBIB<'>IB<">I * * where I is C for negative longitudes and C for * positive longitudes. */ function Lon2DMS ($longitude) { $degrees = intval( $longitude ); $minutes = intval( ( $longitude - $degrees ) * 60 ); $seconds = intval( ( $longitude - $degrees ) * 3600 ) - ( $minutes * 60 ); // west if longitude is negative if ($longitude < 0) { return abs($degrees) . 'd' . abs($minutes) . "'" . sprintf('%.3f', abs($seconds)) . '"W'; } // east if longitude is positive return abs($degrees) . 'd' . abs($minutes) . "'" . sprintf('%.3f', abs($seconds)) . '"E'; } /** * Lat2DMS(I) * * Given a latitude in decimal degrees, returns a string in the form of: * * IBIB<'>IB<">I * * where I is C for negative longitudes and C for * positive longitudes. */ function Lat2DMS ($latitude) { $degrees = intval( $latitude ); $minutes = intval( ( $latitude - $degrees ) * 60 ); $seconds = intval( ( $latitude - $degrees ) * 3600 ) - ( $minutes * 60 ); // south if latitude is negative if ($latitude < 0) { return abs($degrees) . 'd' . abs($minutes) . "'" . sprintf('%.3f', abs($seconds)) . '"S'; } // north if latitude is positive return abs($degrees) . 'd' . abs($minutes) . "'" . sprintf('%.3f', abs($seconds)) . '"N'; } /* * deprecated - only used by mapimagesharedresource widget, changed to Pix2Geo (below) function Pix2Georef ( $nX, $nY, $dfGeoMiddleX, $dfGeoMiddleY, $dfGeoWidth, $dfGeoHeight, $nPixelWidth, $nPixelHeight ) { // -------------------------------------------------------------------- // Calculate first the extent in georef as does mapserver // (fcution msAdjustScale in maputil.c). // -------------------------------------------------------------------- $dfGeoMinX = $dfGeoMiddleX - ($dfGeoWidth/2); $dfGeoMaxX = $dfGeoMiddleX + ($dfGeoWidth/2); $dfGeoMinY = $dfGeoMiddleY - ($dfGeoHeight/2); $dfGeoMaxY = $dfGeoMiddleY + ($dfGeoHeight/2); $dfTmp1 = ($dfGeoMaxX - $dfGeoMinX)/$nPixelWidth; $dfTmp2 = ($dfGeoMaxY - $dfGeoMinY)/$nPixelHeight; $cellsize = max($dfTmp1, $dfTmp2); if ($cellsize > 0) { $dfTmp1 = max(($nPixelWidth - ($dfGeoMaxX - $dfGeoMinX)/$cellsize)/2 , 0); $dfTmp2 = max(($nPixelHeight - ($dfGeoMaxY - $dfGeoMinY)/$cellsize)/2 , 0); $ox = $oy = 0; if ($dfTmp1 >= 0.0) { $ox = intval($dfTmp1 + 0.5); } else { $ox = intval($dfTmp1 - 0.5); } if ($dfTmp2 >= 0.0) { $oy = intval($dfTmp2 + 0.5); } else { $oy = intval($dfTmp2 - 0.5); } $dfGeoMinX = $dfGeoMinX - $ox*$cellsize; $dfGeoMaxX = $dfGeoMaxX + $ox*$cellsize; $dfGeoMinY = $dfGeoMinY - $oy*$cellsize; $dfGeoMaxY = $dfGeoMaxY + $oy*$cellsize; $dfPix2GeoX = ($dfGeoMaxX - $dfGeoMinX) / $nPixelWidth; $dfPix2GeoY = ($dfGeoMaxY - $dfGeoMinY) / $nPixelHeight; $nDeltaPixX = $nX; $nDeltaPixY = $nPixelHeight - $nY;# - $nPixelHeight; $dfDeltaGeoX = $nDeltaPixX * $dfPix2GeoX; $dfDeltaGeoY = $nDeltaPixY * $dfPix2GeoY; $dfPosGeoX = $dfGeoMinX + $dfDeltaGeoX; $dfPosGeoY = $dfGeoMinY + $dfDeltaGeoY; $aLatLong = array(); $aLatLong[0] = $dfPosGeoX; $aLatLong[1] = $dfPosGeoY; return $aLatLong; } } */ /** * convert a pixel position to a georef position * * @param nPixPos integer the pixel position * @param dfPixMin float the minimum pixel position * @param dfPixMax float the maximum pixel position * @param dfGeoMin float the minimum georeferenced position * @param dfGeoMax float the maximum georeferenced position * @param nInversePix boolean, flag to invert Y coordinates if UL > LR * @return double geocoded position. */ function Pix2Geo($nPixPos, $dfPixMin, $dfPixMax, $dfGeoMin, $dfGeoMax, $nInversePix = false) { $dfWidthGeo = $dfGeoMax - $dfGeoMin; $dfWidthPix = $dfPixMax - $dfPixMin; $dfPixToGeo = $dfWidthGeo / $dfWidthPix; if (!$nInversePix) $dfDeltaPix = $nPixPos - $dfPixMin; else $dfDeltaPix = $dfPixMax - $nPixPos; $dfDeltaGeo = $dfDeltaPix * $dfPixToGeo; $dfPosGeo = $dfGeoMin + $dfDeltaGeo; return ($dfPosGeo); } /** * convert a geocoded position to pixel coord * * @param nGeoPos double Geocoded position * @param dfPixMin double minimum map pixel value * @param dfPixMax double maximum map pixel value * @param dfGeoMin double minimum map geocoded value * @param dfGeoMax double maximum map geocoded value * @param nInverseGeo integer optional flag to inverse , set to 1 for * Y pixel coordinates where UL > LR * @return double geocoded position */ function Geo2Pix ($nGeoPos, $dfPixMin, $dfPixMax, $dfGeoMin, $dfGeoMax, $nInverseGeo = "") { // calculate the geocoded & pixel width $dfWidthGeo = abs($dfGeoMax - $dfGeoMin); $dfWidthPix = abs($dfPixMax - $dfPixMin); // get ratio if ( $dfWidthGeo <= 0 ) { return 0; } $dfGeoToPix = $dfWidthPix / $dfWidthGeo; // get difference if (!$nInverseGeo) $dfDeltaGeo = $nGeoPos - $dfGeoMin; else $dfDeltaGeo = $dfGeoMax - $nGeoPos; // calculate $dfDeltaPix = $dfDeltaGeo * $dfGeoToPix; $dfPosPix = $dfPixMin + $dfDeltaPix; // return value return round ($dfPosPix); // end pixel_to_geo function } /** * reproject a point nX,nY * no reprojection happens if either projection is * empty or if they are the same. Will prepend * init= if either contains epsg (or EPSG) * * @param nX float reference the x coordinate to project * @param nY float reference to the y coordinate to project * @param szFrom string the projection of nX,nY * @param szTo string the projection to convert to * @return none. Variables nX, nY are modified directly */ function reprojectPoint( &$nX, &$nY, $szFrom, $szTo ) { //echo "reproject $nX,$nY from $szFrom to $szTo
\n"; //check to see if reprojection is necessary if ($szFrom == '' || $szTo == '') { return; } if (stristr($szFrom, "epsg") !== false && stristr( $szFrom, "init=") == false) { $szFrom = "init=".strtolower($szFrom); } if (stristr($szTo, "epsg") !== false && stristr( $szTo, "init=") == false) { $szTo = "init=".strtolower($szTo); } if ($szFrom == $szTo) { return; } $oPoint = ms_newPointObj(); $oPoint->setXY( $nX, $nY ); $oPoint->project( ms_newProjectionObj( $szFrom ), ms_newProjectionObj( $szTo ) ); $nX = $oPoint->x; $nY = $oPoint->y; //echo "reprojection result: $nX, $nY
\n"; } ?>