4 This is a PHP file to be used as a backend for a ka-Map layer. It requires
5 PHP with Mapscript and libgd modules installed. The top of the file
6 is a configuration section: please edit the variables in this configuration
7 section to meet your needs, then rename this file to tile.php or something
8 similar and put it in a web accessible directory. More information
9 on the OpenLayers ka-Map layer is available from:
11 http://trac.openlayers.org/wiki/OpenLayers.Layer.KaMap
14 /**********************************************************************
16 * $Id: tile.php,v 1.33 2006/02/07 03:19:55 pspencer Exp $
18 * purpose: a simple phpmapscript-based tile renderer that implements
19 * rudimentary caching for reasonable efficiency. Note the
20 * cache never shrinks in this version so your disk could
23 * author: Paul Spencer (pspencer@dmsolutions.ca)
25 * modifications by Daniel Morissette (dmorissette@dmsolutions.ca)
27 * Modified by Christopher Schmidt for OpenLayers redistribution.
29 **********************************************************************
31 * Copyright (c) 2005, DM Solutions Group Inc.
33 * Permission is hereby granted, free of charge, to any person obtaining a
34 * copy of this software and associated documentation files (the "Software"),
35 * to deal in the Software without restriction, including without limitation
36 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
37 * and/or sell copies of the Software, and to permit persons to whom the
38 * Software is furnished to do so, subject to the following conditions:
40 * The above copyright notice and this permission notice shall be included
41 * in all copies or substantial portions of the Software.
43 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
44 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
45 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
46 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
47 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
48 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
49 * DEALINGS IN THE SOFTWARE.
51 **********************************************************************/
54 /******************************************************************************
55 * basic system configuration
57 * kaMap! uses PHP/MapScript and the PHP GD extension to
58 * render tiles, and uses PHP/MapScript to generate initialization parameters
59 * a legend, and a keymap from the selected map file.
61 * Make sure to set the correct module names for your PHP extensions.
63 * WINDOWS USERS: you will likely need to use php_gd2.dll instead of php_gd.dll
65 $szPHPMapScriptModule = 'php_mapscript.'.PHP_SHLIB_SUFFIX;
66 $szPHPGDModule = 'php_gd.'.PHP_SHLIB_SUFFIX;
68 /******************************************************************************
69 * tile generation parameters
71 * kaMap! generates tiles to load in the client application by first rendering
72 * larger areas from the map file and then slicing them up into smaller tiles.
73 * This approach reduces the overhead of loading PHP/MapScript and PHP GD and
74 * drawing the map file. These larger areas are referred to as metaTiles in
75 * the code. You can set the size of both the small tiles and the metaTiles
76 * here. A reasonable size for the small tiles seems to be 200 pixels square.
77 * Smaller tiles seem to cause problems in client browsers by causing too many
78 * images to be created and thus slowing performance of live dragging. Larger
79 * tiles take longer to download to the client and are inefficient.
81 * The number of smaller tiles that form a metaTile can also be configured.
82 * This parameter allows tuning of the tile generator to ensure optimal
83 * performance and for label placement. MapServer will produce labels only
84 * within a rendered area. If the area is too small then features may be
85 * labelled multiple times. If the area is too large, it may exceed MapServer,s
86 * maximum map size (by default 2000x2000) or be too resource-intensive on the
87 * server, ultimately reducing performance.
93 /* $metaBuffer = Buffer size in pixels to add around metatiles to avoid
94 * rendering issues along the edge of the map image
98 /******************************************************************************
99 * in-image debugging information - tile location, outlines etc.
100 * to use this, you need to remove images from your cache first. This also
101 * affects the meta tiles - if debug is on, they are not deleted.
105 /******************************************************************************
106 * aszMapFiles - an array of map files available to the application. How this
107 * is used is determined by the application. Each map file is entered into
108 * this array as a key->value pair.
110 * The key is the name to be used by the tile caching system to store cached
111 * tiles within the base cache directory. This key should be a single word
112 * that uniquely identifies the map.
114 * The value associated with each key is an array of three values. The first
115 * value is a human-readable name to be presented to the user (should the
116 * application choose to do so) and the second value is the path to the map
117 * file. It is assumed that the map file is fully configured for use with
118 * MapServer/MapScript as no error checking or setting of values is done. The
119 * third value is an array of scale values for zooming.
122 $aszMapFiles = array(
123 "world" => array( "World", "/path/to/your/mapfile",
124 array( 10000 ), # in openlayers, the scale array doesn't matter.
127 /* Add more elements to this array to offer multiple mapfiles */
131 /******************************************************************************
132 * figure out which map file to use and set up the necessary variables for
133 * the rest of the code to use. This does need to be done on every page load
136 * szMap should be set to the default map file to use but can change if
137 * this script is called with map=<mapname>.
141 /******************************************************************************
144 * this is the directory within which kaMap! will create its tile cache. The
145 * directory does NOT have to be web-accessible, but it must be writable by the
146 * web-server-user and allow creation of both directories AND files.
148 * the tile caching system will create a separate subdirectory within the base
149 * cache directory for each map file. Within the cache directory for each map
150 * file, directories will be created for each group of layers. Within the group
151 * directories, directories will be created at each of the configured scales
152 * for the application (see mapfile configuration above.)
154 $szBaseCacheDir = "/var/cache/kamap/";
156 /***** END OF CONFIGURABLE STUFF - unless you know what you are doing *****/
160 /***** END OF CONFIGURABLE STUFF - unless you know what you are doing *****/
162 if (isset($_REQUEST['map']) && isset($aszMapFiles[$_REQUEST['map']]))
164 $szMap = $_REQUEST['map'];
167 $szMapCacheDir = $szBaseCacheDir.$szMap."/";
168 $szMapName = $aszMapFiles[$szMap][0];
169 $szMapFile = $aszMapFiles[$szMap][1];
170 $anScales = $aszMapFiles[$szMap][2];
171 setOutputFormat($aszMapFiles[$szMap][3]);
172 /******************************************************************************
173 * output format of the map and resulting tiles
175 * The output format used with MapServer can greatly affect appearance and
176 * performance. It is recommended to use an 8 bit format such as PNG
178 * NOTE: the tile caching code in tile.php is not configurable here. It
179 * currently assumes that it is outputting 8bit PNG files. If you change to
180 * PNG24 here then you will need to update tile.php to use the gd function
181 * imagecreatetruecolor. If you change the output format to jpeg then
182 * you would need to change imagepng() to imagejpeg(). A nice enhancement
183 * would be to make that fully configurable from here.
185 function setOutputFormat($szFormat)
189 $GLOBALS['szMapImageFormat'] = 'PNG24'; //mapscript format name
190 $GLOBALS['szMapImageCreateFunction'] = "imagecreatefrompng"; // appropriate GD function
191 $GLOBALS['szImageExtension'] = '.png'; //file extension
192 $GLOBALS['szImageCreateFunction'] = "imagecreatetruecolor"; //or imagecreatetruecolor if PNG24 ...
193 $GLOBALS['szImageOutputFunction'] = "imagepng"; //or imagegif, imagejpeg ...
194 $GLOBALS['szImageHeader'] = 'image/png'; //the content-type of the image
197 $GLOBALS['szMapImageFormat'] = 'GIF'; //mapscript format name
198 $GLOBALS['szMapImageCreateFunction'] = "imagecreatefromgif"; // appropriate GD function
199 $GLOBALS['szImageExtension'] = '.gif'; //file extension
200 $GLOBALS['szImageCreateFunction'] = "imagecreate"; //or imagecreatetruecolor if PNG24 ...
201 $GLOBALS['szImageOutputFunction'] = "imagegif"; //or imagegif, imagejpeg ...
202 $GLOBALS['szImageHeader'] = 'image/gif'; //the content-type of the image
205 $GLOBALS['szMapImageFormat'] = 'JPEG'; //mapscript format name
206 $GLOBALS['szMapImageCreateFunction'] = "imagecreatefromjpeg"; // appropriate GD function
207 $GLOBALS['szImageExtension'] = '.jpg'; //file extension
208 $GLOBALS['szImageCreateFunction'] = "imagecreatetruecolor"; //or imagecreatetruecolor if PNG24 ...
209 $GLOBALS['szImageOutputFunction'] = "imagejpeg"; //or imagegif, imagejpeg ...
210 $GLOBALS['szImageHeader'] = 'image/jpeg'; //the content-type of the image
213 $GLOBALS['szMapImageFormat'] = 'PNG'; //mapscript format name
214 $GLOBALS['szMapImageCreateFunction'] = "imagecreatefrompng"; // appropriate GD function
215 $GLOBALS['szImageExtension'] = '.png'; //file extension
216 $GLOBALS['szImageCreateFunction'] = "imagecreate"; //or imagecreatetruecolor if PNG24 ...
217 $GLOBALS['szImageOutputFunction'] = "imagepng"; //or imagegif, imagejpeg ...
218 $GLOBALS['szImageHeader'] = 'image/png'; //the content-type of the image
222 $GLOBALS['szMapImageFormat'] = 'dithered';
223 $GLOBALS['szMapImageCreateFunction'] = "imagecreatefrompng";
224 $GLOBALS['szImageExtension'] = '.png';
225 $GLOBALS['szImageCreateFunction'] = "imagecreate";
226 $GLOBALS['szImageOutputFunction'] = "imagepng";
227 $GLOBALS['szImageHeader'] = 'image/png';
233 * create all directories in a directory tree - found on the php web site
234 * under the mkdir function ...
236 function makeDirs($strPath, $mode = 0775)
238 return is_dir($strPath) or ( makeDirs(dirname($strPath), $mode) and mkdir($strPath, $mode) );
242 * This function replaces all special characters in the given string.
244 * @param szString string - The string to convert.
246 * @return string converted
248 function normalizeString($szString)
250 // Normalize string by replacing all special characters
251 // e.g. "http://my.host.com/cgi-bin/mywms?"
252 // becomes "http___my_host_com_cgi_bin_mywms_"
253 return preg_replace("/(\W)/", "_", $szString);
256 /* bug 1253 - root permissions required to delete cached files */
257 $orig_umask = umask(0);
259 /* create the main cache directory if necessary */
260 if (!@is_dir($szMapCacheDir))
261 makeDirs($szMapCacheDir);
263 /* get the various request parameters
264 * also need to make sure inputs are clean, especially those used to
265 * build paths and filenames
268 * the tile renderer accepts several parameters and returns a tile image from
269 * the cache, creating the tile only if necessary.
271 * all requests include the pixel location of the request at a certain scale
272 * and this script figures out the geographic location of the tile from the
273 * scale assuming that 0,0 in pixels is 0,0 in geographic units
275 * Request parameters are:
277 * map: the name of the map to use. This is handled by config.php.
279 * t: top pixel position
280 * l: left pixel position
282 * g: (optional) comma-delimited list of group names to draw
283 * layers: (optional) comma-delimited list of layers to draw
284 * force: optional. If set, force redraw of the meta tile. This was added to
285 * help with invalid images sometimes being generated.
286 * tileid: (optional) can be used instead of t+l to specify the tile coord.,
287 * useful in regenerating the cache
290 $top = isset( $_REQUEST['t'] ) ? intval($_REQUEST['t']) : 0;
291 $left = isset( $_REQUEST['l'] ) ? intval($_REQUEST['l']) : 0;
292 $scale = isset( $_REQUEST['s'] ) ? $_REQUEST['s'] : $anScales[0];
293 $bForce = isset($_REQUEST['force'])? true : false;
294 $groups = isset( $_REQUEST['g'] ) ? $_REQUEST['g'] : "";
295 $layers = isset( $_REQUEST['layers'] ) ? $_REQUEST['layers'] : "";
297 // dynamic imageformat ----------------------------------------------
298 //use the function in config.php to set the output format
299 if (isset($_REQUEST['i']))
300 setOutputFormat( $_REQUEST['i'] );
301 //----------------------------------------------------------------
303 /* tileid=t#####l#### can be used instead of t+l parameters. Useful in
304 * regenerating the cache for instance.
306 if (isset( $_REQUEST['tileid']) &&
307 preg_match("/t(-?\d+)l(-?\d+)/", $_REQUEST['tileid'], $aMatch) )
309 $top = intval($aMatch[1]);
310 $left = intval($aMatch[2]);
313 /* Calculate the metatile's top-left corner coordinates.
314 * Include the $metaBuffer around the metatile to account for various
315 * rendering issues happening around the edge of a map
317 $metaLeft = floor( ($left)/($tileWidth*$metaWidth) ) * $tileWidth * $metaWidth;
318 $metaTop = floor( ($top)/($tileHeight*$metaHeight) ) * $tileHeight *$metaHeight;
319 $szMetaTileId = "t".$metaTop."l".$metaLeft;
320 $metaLeft -= $metaBuffer;
321 $metaTop -= $metaBuffer;
323 /* caching is done by scale value, then groups and layers and finally metatile
324 * and tile id. Create a new directory if necessary
326 $szGroupDir = $groups != "" ? normalizeString($groups) : "def";
327 $szLayerDir = $layers != "" ? normalizeString($layers) : "def";
329 $szCacheDir = $szMapCacheDir."/".$scale."/".$szGroupDir."/".$szLayerDir."/".$szMetaTileId;
330 if (!@is_dir($szCacheDir))
331 makeDirs($szCacheDir);
333 /* resolve cache hit - clear the os stat cache if necessary */
334 $szTileId = "t".$top."l".$left;
335 $szCacheFile = $szCacheDir."/".$szTileId.$szImageExtension;
338 $szMetaDir = $szCacheDir."/meta";
339 if (!@is_Dir($szMetaDir))
340 makeDirs($szMetaDir);
342 /* simple locking in case there are several requests for the same meta
343 tile at the same time - only draw it once to help with performance */
344 $szLockFile = $szMetaDir."/lock_".$metaTop."_".$metaLeft;
345 $fpLockFile = fopen($szLockFile, "a+");
347 if (!file_exists($szCacheFile) || $bForce)
349 flock($fpLockFile, LOCK_EX);
350 fwrite($fpLockFile, ".");
352 //check once more to see if the cache file was created while waiting for
355 if (!file_exists($szCacheFile) || $bForce)
357 if (!extension_loaded('MapScript'))
359 dl( $szPHPMapScriptModule );
361 if (!extension_loaded('gd'))
366 if (!@is_Dir($szMetaDir))
367 makeDirs($szMetaDir);
369 $oMap = ms_newMapObj($szMapFile);
371 /* Metatile width/height include 2x the metaBuffer value */
372 $oMap->set('width', $tileWidth * $metaWidth + 2*$metaBuffer);
373 $oMap->set('height', $tileHeight * $metaHeight + 2*$metaBuffer);
375 /* Tell MapServer to not render labels inside the metaBuffer area
377 * TODO: Until MapServer bugs 1353/1355 are resolved, we need to
378 * pass a negative value for "labelcache_map_edge_buffer"
380 $oMap->setMetadata("labelcache_map_edge_buffer", -$metaBuffer);
382 $inchesPerUnit = array(1, 12, 63360.0, 39.3701, 39370.1, 4374754);
383 $geoWidth = $scale/($oMap->resolution*$inchesPerUnit[$oMap->units]);
384 $geoHeight = $scale/($oMap->resolution*$inchesPerUnit[$oMap->units]);
386 /* draw the metatile */
387 $minx = $metaLeft * $geoWidth;
388 $maxx = $minx + $geoWidth * $oMap->width;
389 $maxy = -1 * $metaTop * $geoHeight;
390 $miny = $maxy - $geoHeight * $oMap->height;
392 $nLayers = $oMap->numlayers;
393 $oMap->setExtent($minx,$miny,$maxx,$maxy);
394 $oMap->selectOutputFormat( $szMapImageFormat );
395 $aszLayers = array();
396 if ($groups || $layers)
398 /* Draw only specified layers instead of default from mapfile*/
401 $aszLayers = explode(",", $layers);
406 $aszGroups = explode(",", $groups);
409 for($i=0;$i<$nLayers;$i++)
411 $oLayer = $oMap->getLayer($i);
412 if (($aszGroups && in_array($oLayer->group,$aszGroups)) ||
413 ($aszLayers && in_array($oLayer->name,$aszLayers)) ||
414 ($aszGroups && $oLayer->group == '' &&
415 in_array( "__base__", $aszGroups)))
417 $oLayer->set("status", MS_ON );
421 $oLayer->set("status", MS_OFF );
424 //need transparency if groups or layers are used
425 $oMap->outputformat->set("transparent", MS_ON );
429 $oMap->outputformat->set("transparent", MS_OFF );
433 $szMetaImg = $szMetaDir."/t".$metaTop."l".$metaLeft.$szImageExtension;
434 $oImg = $oMap->draw();
435 $oImg->saveImage($szMetaImg);
437 eval("\$oGDImg = ".$szMapImageCreateFunction."('".$szMetaImg."');");
440 $blue = imagecolorallocate($oGDImg, 0, 0, 255);
441 imagerectangle($oGDImg, 0, 0, $tileWidth * $metaWidth - 1, $tileHeight * $metaHeight - 1, $blue );
443 for($i=0;$i<$metaWidth;$i++)
445 for ($j=0;$j<$metaHeight;$j++)
447 eval("\$oTile = ".$szImageCreateFunction."( ".$tileWidth.",".$tileHeight." );");
448 // Allocate BG color for the tile (in case the metatile has transparent BG)
449 $nTransparent = imagecolorallocate($oTile, $oMap->imagecolor->red, $oMap->imagecolor->green, $oMap->imagecolor->blue);
450 //if ($oMap->outputformat->transparent == MS_ON)
452 imagecolortransparent( $oTile,$nTransparent);
454 $tileTop = $j*$tileHeight + $metaBuffer;
455 $tileLeft = $i*$tileWidth + $metaBuffer;
456 imagecopy( $oTile, $oGDImg, 0, 0, $tileLeft, $tileTop, $tileWidth, $tileHeight );
457 /* debugging stuff */
460 $black = imagecolorallocate($oTile, 1, 1, 1);
461 $green = imagecolorallocate($oTile, 0, 128, 0 );
462 $red = imagecolorallocate($oTile, 255, 0, 0);
463 imagerectangle( $oTile, 1, 1, $tileWidth-2, $tileHeight-2, $green );
464 imageline( $oTile, 0, $tileHeight/2, $tileWidth-1, $tileHeight/2, $red);
465 imageline( $oTile, $tileWidth/2, 0, $tileWidth/2, $tileHeight-1, $red);
466 imagestring ( $oTile, 3, 10, 10, ($metaLeft+$tileLeft)." x ".($metaTop+$tileTop), $black );
467 imagestring ( $oTile, 3, 10, 30, ($minx+$i*$geoWidth)." x ".($maxy - $j*$geoHeight), $black );
469 $szTileImg = $szCacheDir."/t".($metaTop+$tileTop)."l".($metaLeft+$tileLeft).$szImageExtension;
470 eval("$szImageOutputFunction( \$oTile, '".$szTileImg."' );");
471 imagedestroy($oTile);
477 imagedestroy($oGDImg);
482 unlink( $szMetaImg );
485 //release the exclusive lock
486 flock($fpLockFile, LOCK_UN );
489 //acquire shared lock for reading to prevent a problem that could occur
490 //if a tile exists but is only partially generated.
491 flock($fpLockFile, LOCK_SH);
493 $h = fopen($szCacheFile, "r");
494 header("Content-Type: ".$szImageHeader);
495 header("Content-Length: " . filesize($szCacheFile));
496 header("Expires: " . date( "D, d M Y H:i:s GMT", time() + 31536000 ));
497 header("Cache-Control: max-age=31536000, must-revalidate" );
504 /* bug 1253 - root permissions required to delete cached files */