In this example I have used the map of the Itasca demo of the Mapserver. I have done only small changes to the map file. The Itasca demo has (into the html file) the parameters of the path where to store the images:
IMAGEPATH "set in index.html" IMAGEURL "set in index.html"
I have changed them as fixed path
IMAGEPATH "/tmp/ms_tmp/" IMAGEURL "/ms_tmp/"
Than I have set as STATUS ON several layers for a better map.
The Database
The positions and the images paths that have to be shown on the map are stored into a table of a database in MySql. I have created a new database named "mapexample" and a new table "weather":
CREATE TABLE weather (
id bigint(20) NOT NULL auto_increment,
imagepath varchar(255) default NULL,
x double(16,4) default NULL,
y double(16,4) default NULL,
PRIMARY KEY (id)
)
and than I have inserted into the table the positions of the weather images and the path of every icon:
INSERT INTO `weather` VALUES (1, '/data/weather/icons/sunny.gif', 478107.0000, 5250301.0000); INSERT INTO `weather` VALUES (2, ''/data/weather/icons/cloudy.gif', 408107.0000, 5220301.0000); INSERT INTO `weather` VALUES (3, ''/data/weather/icons/storm.gif', 468107.0000, 5270301.0000); INSERT INTO `weather` VALUES (4, ''/data/weather/icons/variable.gif', 408107.0000, 5310301.0000);
It is not necessary for the images to be stored into a directory visible from the web, because are taken directly by the script and then merged with the map.
The PHPMapscript code Here is the code I have used for generating the map:
define("img_WIDTH", 0); define("img_HEIGHT", 1); define("img_TYPE", 2);
// CONFIGURATION OF MYSQL ACCESS $MyHost = "localhost"; $MyLogin = "root"; $MyPassword = ""; $MyDatabase = "mapexample";
$mappath = "D:/data/web"; $scale_to_showicons = 1000000; // SCALE LIMIT TO START TO SHOW THE ICONS ON THE MAP
function AddImagesToMap($mapurl) {
global $MyHost, $MyLogin, $MyPassword, $MyDatabase, $scale_to_showicons, $map, $mappath;
// CONNECT TO DATABASE
@mysql_connect($MyHost, $MyLogin, $MyPassword);
@mysql_select_db($MyDatabase);
// IF the scale is small enougth to show the images on the map?
if ($scale_to_showicons > $map->scale) {
// PATH WHERE TO FIND THE MAP IMAGE GENERATED BY MAPSERVER
$mapimagepath = $mappath . $mapurl;
$mapdim = GetImageSize($mapimagepath);
$coords_map_width = $map->extent->maxx - $map->extent->minx;
$mapscale = $mapdim[img_WIDTH] / $coords_map_width;
switch ($mapdim[img_TYPE]) {
case 1:
$mapimg = ImageCreateFromGif($mapimagepath);
break;
case 2:
$mapimg = ImageCreateFromJpeg($mapimagepath);
break;
case 3:
$mapimg = ImageCreateFromPng($mapimagepath);
break;
} ;
$qry .= "select * from weather where x > '" . $map->extent->minx . "' AND x < '" . $map->extent->maxx . "'
AND y > '" . $map->extent->miny . "' AND y < '" . $map->extent->maxy . "'";
$res = mysql_query($qry);
while ($row = mysql_fetch_object($res)) {
$dimic = GetImageSize($row->imagepath);
switch ($dimic[img_TYPE]) {
case 1:
$tmpimg = ImageCreateFromGif($row->imagepath);
break;
case 2:
$tmpimg =?; ImageCreateFromJpeg($row->imagepath);
break;
case 3:
$tmpimg = ImageCreateFromPng($row->imagepath);
break;
}
$x = ($row->x - $map->extent->minx) * $mapscale;
$y = $mapdim[img_HEIGHT] - (($row->y - $map->extent->miny) * $mapscale);
@ImageCopy ($mapimg, $tmpimg, $x, $y, 0, 0, $dimic[img_WIDTH], $dimic[img_HEIGHT]);
} ;
// SAVE THE NEW IMAGE ON THE OLD ONE
switch ($mapdim[img_TYPE]) {
case 1:
ImageGif($mapimg, $mapimagepath);
break;
case 2:
ImageJpeg($mapimg, $mapimagepath);
break;
case 3:
ImagePng($mapimg, $mapimagepath);
break;
}
} ; } ;
$map = ms_newMapObj("itasca.map");
$img = $map->draw(); $url = $img->saveWebImage(); AddImagesToMap($url);
?>
Show Weather On Map
More info: http://www.parsec.it/tutorials/
Roberto Colonello owns and operates http://www.parsec.it and http://www.gmdir.com