root/Chameleon/trunk/Chameleon/TrueNorth/TrueNorth.widget.php

<?php
/**
 * TrueNorth Widget class
 *
 * @project     CWC2
 * @revision    $Id: TrueNorth.widget.php,v 1.11 2005/01/11 16:20:24 pspencer Exp $
 * @purpose     Zoom In Widget class
 * @author      DM Solutions Group (sfournier@dmsolutions.ca)
 * @copyright
 * <b>Copyright (c) 2002, DM Solutions Group Inc.</b>
 * 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.
 */


include_once(dirname(__FILE__)."/../Widget.php");

/**
 * TrueNorth
 *
 * @desc Display a bitmap indicating true north
 */
class TrueNorth extends CWCWidget
{
    var $mszTrueNorthImage = "";
    var $mszImage = "";
    var $mnWidth = "";
    var $mnHeight = "";

    /**
     * TrueNorth
     *
     * Constructor. Set the default values.
     */
    function TrueNorth()
    {
        // invoke constructor of parent
        parent::CWCWidget();

        // User defined true north image to use
        $this->maAttributes["TRUENORTHIMAGE"] = new StringAttribute("TRUENORTHIMAGE", true);

        // This should be executed after navtool
        $this->mnPriority = PRIORITY_LAST;

        // set the description for this widget
        $this->szWidgetDescription = <<<EOT
The TrueNorth widget just display a bitmap rotated indicating the real north.
EOT;
        $this->mnMaturityLevel = MATURITY_BETA;
    }

    /**
     * Initialize some cnfiguration parameter
     */
    function InitDefaults()
    {
        parent::InitDefaults();
        $oApp = GetChameleonApplication();
        
        if (isset( $this->maParams["TRUENORTHIMAGE"]) && $this->maParams['TRUENORTHIMAGE'] != '')
            $this->mszTrueNorthImage = $oApp->findFile( $this->maParams["TRUENORTHIMAGE"] );
        if (!$this->mszTrueNorthImage)
        {
            $_SESSION['gErrorManager']->setError( ERR_CRITICAL, "TrueNorth: ".$this->maParams["TRUENORTHIMAGE"]." cannot be found." );
            $this->mszTrueNorthImage = '';
        }
    }

    /**
     * Steps:
     *        - Create a rectangle with extent of the map.
     *        - Reproject the rectangle in degrees.
     *        - create 2 points (vertical line) using the same x
     *          (middle of the image) but use 2 different Y distanced
     *          by 20 pixels.
     *        - Reproject those 2 points in original projection.
     *        - Calculate the angle of point1 relatively to point2.
     *        - Load and rotate the True North image.
     */
    function  ParseURL()
    {
        parent::ParseURL();

        if ($this->mszTrueNorthImage == '')
        {
            $_SESSION['gErrorManager']->setError( ERR_CRITICAL, "TrueNorth: invalid or no image specified." );
            return false;
        }
            
        if ( PHP_OS == "WINNT" || PHP_OS == "WIN32" )
            $szGDModule = "php_gd2.dll";
        else
            $szGDModule = "php_gd2.so";

        if (!extension_loaded("gd"))
            dl($szGDModule);

        $oMap = $this->moMapObject->oMap;
        
        // Get current projection
        $szTmpMapProj = $oMap->getProjection();

        // If the map does not have any projection, it's 
        // impossible to draw true north.
        if ($szTmpMapProj === false)
            return false;

        $projInObj = ms_newprojectionobj( $szTmpMapProj );
        $projOutObj = ms_newprojectionobj("init=epsg:4326");

        // Get map extent and reproject in degrees
        $oRect = ms_newrectobj();
        $oRect->setExtent($oMap->extent->minx, $oMap->extent->miny,
                          $oMap->extent->maxx, $oMap->extent->maxy);

        if (strcasecmp("init=epsg:4326", $szTmpMapProj) != 0)
            $oRect->project($projInObj, $projOutObj);

        // Create 2 points that represent a straight line (vertical)
        $nMinY = $this->pixel_to_geo($oMap->height/2-10, 0, $oMap->height, 
                                     $oRect->miny, $oRect->maxy);

        $nMaxY = $this->pixel_to_geo($oMap->height/2+10, 0, $oMap->height, 
                                     $oRect->miny, $oRect->maxy);

        $poPoint1 = ms_newpointobj();
        $poPoint2 = ms_newpointobj();
        $poPoint1->setXY(($oRect->maxx - $oRect->minx)/2+$oRect->minx, $nMaxY);
        $poPoint2->setXY($poPoint1->x, $nMinY);

        if (strcasecmp("init=epsg:4326", $szTmpMapProj) != 0)
        {
            // Reproject points back to original projection
            $poPoint1->project($projOutObj, $projInObj);
            $poPoint2->project($projOutObj, $projInObj);
        }

        // Calculate angle
        $nTop = ($poPoint1->y-$poPoint2->y);
        $nDeltaX = ($poPoint1->x-$poPoint2->x);
        $nDeltaY = ($poPoint1->y-$poPoint2->y);
        $nBottom = sqrt( $nDeltaX*$nDeltaX + $nDeltaY*$nDeltaY);
        if ($nBottom == 0)
        {
            $nDeg = 90;
        }
        else
        {
            $nDeg =  rad2deg(asin($nTop/$nBottom));
        }

        if ($poPoint1->x-$poPoint2->x<0)
            $szFileName = $this->drawSymbolRotated(90-$nDeg);
        else
            $szFileName = $this->drawSymbolRotated(-1*(90-$nDeg));

        $this->mszImage = "<IMG src=\"".$_SESSION['gszTmpWebPath']."/".
                           basename($szFileName)."\" width=\"".$this->mnWidth.
                           "\" height=\"".$this->mnHeight."\">\n";

        // return success
        return true;
    }

    function drawSymbolRotated($nDeg)
    {
        $szSufix = strtoupper(substr($this->mszTrueNorthImage, -3));
        if ($szSufix=="PNG")
        {
            $oImg = imagecreatefrompng($this->mszTrueNorthImage);
        }
        else
        {
            if ($szSufix=="GIF")
            {
                $oImg = imagecreatefromgif($this->mszTrueNorthImage);
            }
            else
            {
                if ($szSufix=="JPG")
                {
                    $oImg = imagecreatefromjpeg($this->mszTrueNorthImage);
                }
                else
                {
                    $oImg = imagecreatefrompng($this->mszTrueNorthImage);
                }
            }
        }

        $this->mnWidth = imagesx($oImg);
        $this->mnHeight = imagesy($oImg);
        
        $oMap = ms_newMapObj("");
        $oMap->selectOutputFormat("PNG24");
        $oMap->set("width", $this->mnWidth);
        $oMap->set("height", $this->mnHeight);
        $oMap->setExtent(0, 0, $this->mnWidth, $this->mnHeight);

        $oLayer = ms_newLayerObj($oMap);
        $oLayer->set("transform", MS_FALSE);
        $oLayer->set("type", MS_LAYER_POINT);

        $oImage = $oMap->prepareimage();

        $oClass = ms_newClassObj($oLayer);

        $nSymbol = ms_newSymbolObj($oMap, $this->mszTrueNorthImage);
        $oStyle = ms_newStyleObj($oClass);
        $oStyle->set("symbol", $nSymbol);

        $oi = $oClass->createLegendIcon($this->mnWidth, $this->mnHeight);

        $oImage->pasteImage($oi,0, $this->mnWidth/2, $this->mnHeight/2, $nDeg);

        $szTmpDir = $_SESSION['gszTmpImgPath'];
        if (substr($szTmpDir, -1) == "/")
            $szTmpDir = substr($szTmpDir, 0, -1 );

        $szFileName = str_replace("\\", "/", tempnam($szTmpDir, "TN").".png");

        $oImage->saveImage($szFileName);

        return $szFileName;
    }

    function drawPublish()
    {
        return $this->mszImage;
    }

    /**
     * convert a pixel position to geocoded position
     *
     * @param nPixPos double pixel 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 nInversePix integer optional flag to inverse , set to 1 for
     *                            Y pixel coordinates where UL > LR
     * @return double geocoded position
     */
    function pixel_to_geo($nPixPos, $dfPixMin, $dfPixMax, $dfGeoMin, $dfGeoMax,
                          $nInversePix = "")
    {
        // calculate the geocoded & pixel width
        $dfWidthGeo = $dfGeoMax - $dfGeoMin;
        $dfWidthPix = $dfPixMax - $dfPixMin;

        // get ratio
        $dfPixToGeo = $dfWidthGeo / $dfWidthPix;

    // get difference
        if (!$nInversePix)
            $dfDeltaPix = $nPixPos - $dfPixMin;
        else
            $dfDeltaPix = $dfPixMax - $nPixPos;

        // calculate
        $dfDeltaGeo = $dfDeltaPix * $dfPixToGeo;
        $dfPosGeo = $dfGeoMin + $dfDeltaGeo;

        // return value
        return ($dfPosGeo);

        // end pixel_to_geo function
    }

    /**
     * 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 geo_to_pixel ($nGeoPos, $dfPixMin, $dfPixMax, $dfGeoMin,
                    $dfGeoMax, $nInverseGeo = "")
     {
         // calculate the geocoded & pixel width
     $dfWidthGeo = abs($dfGeoMax - $dfGeoMin);
     $dfWidthPix = abs($dfPixMax - $dfPixMin);
                                                                                                           
     // get ratio
     $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
    }

}
?>