iphone and gis development notes » tilecache

iPhone Note #20:Integrating Mapserver/TileCache to RouteMe

rupert — Thu, 14 Jan 2010 01:37:57 +0000

Below is a summary of how I was able to implement Mapserver, TileCache and Route-Me iPhone Mapping Framework.

1. Assuming you have a working Mapserver/TileCache setup. Take note of the ff parameters: resolution and bbox. Below is my tilecache.cfg:

 61 [mapserver_australia_3857]
 62 type=MapServerLayer
 63 mapfile=/Users/rupert/projects/pelicancorp/DMOB/trunk/map/australia_3857.map
 64 layers=all
 65 extension=jpg
 66 bbox=-20037508.34, -20037508.34, 20037508.34, 20037508.34
 68 maxResolution=156543.033928041
 70 levels=20
 71 srs=EPSG:3857
 72 tms_type=google
 73 extent_type=loose
 74 spherical_mercator=true

2. Grab the RMGenericMercatorWMSSource from http://groups.google.com/group/route-me-map/browse_thread/thread/b58fa1d20cf15823/e30c42d9c90a8170?lnk=gst&q=Generic#e30c42d9c90a8170

3. By default without any changes, the RMGenericMercatorWMSSource could display Mapserver WMS Tiles. This is possible by passing an NSDictionary *parameters, which contains arrayValues and arrayKeys for creating an http 256×256 image request to the http://127.0.0.1/cgi-bin/mapserv binary.

//This would request to http://127.0.0.1/cgi-bin/mapserv
NSArray *arrayValues = [[NSArray alloc] initWithObjects:@"/path-to/australia_3857.map", @"all", @"png", @"EPSG:3857",nil];
NSArray *arrayKeys = [[NSArray alloc] initWithObjects:@"MAP", @"LAYERS", @"FORMAT", @"SRS", nil];
NSDictionary *wmsParameters = [[NSDictionary alloc] initWithObjects: arrayValues forKeys:arrayKeys ];

Resulting http requests to the mapserv binary:

http://192.168.1.193:81/tilecache/tilecache.py?LAYERS=australia_3857&SRS=EPSG:3857&REQUEST=GetMap&SERVICE=WMS&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&FORMAT=png&VERSION=1.1.1&WIDTH=256&HEIGHT=256&BBOX=16828376.000000,-4006523.000000,16833268.000000,-4001631.000000

Note that the bbox values does not contain decimal places. Nevertheless, it still works on Mapserver.

4. Now, assuming we have a valid tilecache running. And it is tested from browser, i.e http://127.0.0.1/map/tilecache_3857.html, open up firebug to see the requests. Below is a sample…

http://192.168.1.193:81/tilecache/tilecache.py?LAYERS=australia_3857&FORMAT=jpg&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A3857&BBOX=16123932.497377,-4539747.9811239,16143500.376618,-4520180.1018829&WIDTH=256&HEIGHT=256

But it seems, route-me is not supplying the bbox values accurately, as the decimal values is truncated (BBOX=16828376.000000,-4006523.000000,16833268.000000,-4001631.000000) from our previous request(3).

After changing the wmsParameter values to create a tilecache request, I noticed that route-me is not displaying the tiles correctly.

//Testing for Windows:TileCache - ?
NSArray *arrayValues = [[NSArray alloc] initWithObjects:@"australia_3857", @"png", @"EPSG:3857",nil]; //for WIndows
 
//TileCache URL Parameters:
NSArray *arrayKeys = [[NSArray alloc] initWithObjects:@"LAYERS", @"FORMAT", @"SRS", nil];

5. The workaround is to use “double” instead of “floats” in the RMGenericMercatorWMSSource. You can download the zip from RMGenericMercatorWMSSource.zip. I have modified “initialResolution” and “originShift” to both use “double”.

typedef struct {
	double x;
	double y;
} CGDoublePoint;
 
typedef struct { 
	CGDoublePoint ul; 
	CGDoublePoint lr; 
} CGXYRect;

Afterwards, I copied the maxResolution and bbox (tilecache) and specified it for the initialResoultion and originShift respectively.

#import "RMGenericMercatorWMSSource.h"
 
CGFloat DegreesToRadians(CGFloat degrees) {return degrees * M_PI / 180;}; 
CGFloat RadiansToDegrees(CGFloat radians) {return radians * 180/ M_PI;}; 
 
@implementation RMGenericMercatorWMSSource
 
-(id) initWithBaseUrl:(NSString *)baseUrl parameters:(NSDictionary *)params
{ 
	if (![super init]) 
		return nil; 
 
	// 156543.03392804062 for sideLength 256 pixels 
	// initialResolution = 2 * M_PI * 6378137 / [self tileSideLength];
	// specify here whatever the resolution is from tilecache.
	initialResolution = 156543.033928041;
 
	// 20037508.342789244 
	//originShift = 2 * M_PI * 6378137 / 2;
	//originShift = 20037508.342789244f;
	// specify here whatever the bbox is from tilecache.
	originShift = 20037508.32;
 
	NSLog(@"test initialResolution:%f originShift:%f", initialResolution, originShift);
 
	// setup default parameters
	// use official EPSG:3857 by default, user can override to 900913 if needed.
	wmsParameters = [[NSMutableDictionary alloc] initWithObjects:[[[NSArray alloc] initWithObjects:@"EPSG:3857",@"image/png",@"GetMap",@"1.1.1",@"WMS",nil] autorelease] 
											  forKeys:[[[NSArray alloc] initWithObjects:@"SRS",@"FORMAT",@"REQUEST",@"VERSION",@"SERVICE",nil] autorelease]];
	[wmsParameters addEntriesFromDictionary:params];
 
	// build WMS request URL template
	urlTemplate = [NSString stringWithString:baseUrl];
	NSEnumerator *e = [wmsParameters keyEnumerator];
	NSString *key;
	NSString *delimiter = @"";
	while (key = [e nextObject]) {
		urlTemplate = [urlTemplate stringByAppendingFormat:@"%@%@=%@",
					   delimiter,
					   [[key uppercaseString] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding], 
					   [[wmsParameters objectForKey:key] stringByAddingPercentEscapesUsingEncoding:NSASCIIStringEncoding]];
		delimiter = @"&";
	}
	int sideLength =  [self tileSideLength];
	urlTemplate = [[urlTemplate stringByAppendingFormat:@"&WIDTH=%d&HEIGHT=%d",sideLength,sideLength] retain];
	return self;
}
 
// implement in subclass?
-(NSString*) uniqueTilecacheKey
{
	return @"AbstractMercatorWMSSource";
}
 
-(NSString *)shortName
{
	return @"Generic WMS Source";
}
-(NSString *)longDescription
{
	return @"Generic WMS Source";
}
-(NSString *)shortAttribution
{
	return @"Generic WMS Source";
}
-(NSString *)longAttribution
{
	return @"Generic WMS Source";
}
 
-(float) minZoom
{
	return 1.0f;
}
-(float) maxZoom
{
	return 19.0f;
}
 
// Converts given lat/lon in WGS84 Datum to XY in Spherical Mercator EPSG:3857 
-(CGPoint) LatLonToMeters: (CLLocationCoordinate2D) latlon 
{ 
	CGPoint meters; 
	meters.x = latlon.longitude * originShift / 180; 
	meters.y = (log( tan((90.0 + latlon.latitude) * M_PI / 360.0 )) / (M_PI / 180.0)) * originShift / 180; 
	return meters; 
}
 
//Converts XY point from Spherical Mercator EPSG:3857 to lat/lon in WGS84 Datum 
-(CLLocationCoordinate2D) MetersToLatLon: (CGPoint) meters 
{ 
	CLLocationCoordinate2D latlon; 
	latlon.longitude = (meters.x / originShift) * 180.0; 
	latlon.latitude = (meters.y / originShift) * 180.0; 
	//latlon.latitude = - 180 / M_PI * (2 * atan( exp( latlon.latitude * M_PI / 180.0)) - M_PI / 2.0); 
	latlon.latitude = 180 / M_PI * (2 * atan( exp( latlon.latitude * M_PI / 180.0)) - M_PI / 2.0); 
	return latlon; 
} 
 
// Converts pixel coordinates in given zoom level of pyramid to EPSG:3857 
-(CGDoublePoint) PixelsToMeters: (int) px PixelY:(int)py atZoom:(int)zoom 
{ 
	double resolution = [self ResolutionAtZoom: zoom]; 
	CGDoublePoint meters; 
	double x = (px * resolution - originShift); 
	double y = (py * resolution - originShift); 
 
	meters.x = x;
	meters.y = y;
 
	NSLog(@"px: %d py: %d resolution: %f originShift: %f x: %f y: %f", px, py, resolution, originShift, x, y);
 
	return meters; 
} 
 
-(NSString*) tileURL: (RMTile) tile 
{ 
	//RMLatLongBounds tileBounds = [self TileLatLonBounds:tile];
	// Get BBOX coordinates in meters
	CGXYRect tileBounds = [self TileBounds:tile];
 
	NSString *url = [urlTemplate stringByAppendingFormat:@"&BBOX=%f,%f,%f,%f",
					 tileBounds.ul.x,
					 tileBounds.lr.y,
					 tileBounds.lr.x,
					 tileBounds.ul.y];
 
	NSLog(@"Tile %d,%d,%d yields %@",tile.zoom, tile.x, tile.y, url); 
 
	return url; 
} 
 
 
//Returns bounds of the given tile in EPSG:3857 coordinates 
-(CGXYRect)  TileBounds: (RMTile) tile 
{
	int sideLength =  [self tileSideLength];
 
	int zoom = tile.zoom;
	long twoToZoom = pow(2,zoom);
	CGXYRect tileBounds; 
	tileBounds.ul = [self PixelsToMeters: (tile.x * sideLength) 
								  PixelY: ((twoToZoom-tile.y) * sideLength) 
								  atZoom: zoom ]; 
	tileBounds.lr = [self PixelsToMeters: ((tile.x+1) * sideLength) 
								  PixelY: ((twoToZoom-tile.y-1) * sideLength) 
								  atZoom: zoom];
	return tileBounds; 
} 
 
//Resolution (meters/pixel) for given zoom level (measured at Equator) 
-(double) ResolutionAtZoom : (int) zoom 
{ 
	return initialResolution / pow(2,zoom); 
} 
 
@end

6. Download TileCache_RouteMe.zip Note: You need a valid mapserver and tilecache running.

TileCache: Getting Cutoff on the edges

rupert — Fri, 24 Oct 2008 06:37:43 +0000

In Tilecache, metaTiling creates larger tiles and chops them up.
Note the difference between using metatile=yes and metatile=no.

Figure 1: metatile=no

Figure 2: metatile=yes

Recaching single tiles in Tilecache

rupert — Mon, 22 Sep 2008 06:16:12 +0000

Got this one from IRC this morning.. In order to recache single tiles in TC, as long as it is not metatile (metatile=false), then we can simply append “FORCE=1″ in the URL..

http://192.168.2.14/tilecache/tilecache.py?FORCE=1&LAYERS=beijing_900913_wide_en&MAP=%2Fmyhome%2Fmap%2Fbeijing%2Fnew%2Fbeijing_900913_wide_en%2Fbeijing.map&FORMAT=jpg&TRANSPARENT=true&SERVICE=WMS&VERSION=1.1.1&REQUEST=GetMap&STYLES=&EXCEPTIONS=application%2Fvnd.ogc.se_inimage&SRS=EPSG%3A900913&BBOX=12951949.03168994,4852222.893873828,12952101.905746482,4852375.767930372&WIDTH=256&HEIGHT=256

Well for completeness, I gave my ofcmate a DELETE tool which wipes out everything in the /tilecache/map_dir directory..

Using GDALWARP to reproject raster that will fit with Google Satellite

rupert — Tue, 29 Jul 2008 12:48:21 +0000

Just a couple of notes to onself using gdal: Use gdalwarp to reproject your GeoTIFF files! I wanted to use my own satellite images acquired from GeoEye, however, on some areas I wanted to use google sat images as well since I don’t have the coverage. In order to do so, I need to reproject the sat images to 900913. Note you need to specify this in your epsg file in my previous post.

rupert:beijing_900913_satellite rupert$ gdalinfo Mosaic_RGB.tif
Driver: GTiff/GeoTIFF
Files: Mosaic_RGB.tif
Size is 4248, 4553
Coordinate System is:
GEOGCS["WGS 84",
    DATUM["WGS_1984",
        SPHEROID["WGS 84",6378137,298.2572235630016,
            AUTHORITY["EPSG","7030"]],
        AUTHORITY["EPSG","6326"]],
    PRIMEM["Greenwich",0],
    UNIT["degree",0.0174532925199433],
    AUTHORITY["EPSG","4326"]]
Origin = (116.291476140000000,40.025198500000002)
Pixel Size = (0.000046860000000,-0.000035970000000)
Metadata:
  AREA_OR_POINT=Area
  TIFFTAG_XRESOLUTION=100
  TIFFTAG_YRESOLUTION=100
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  ( 116.2914761,  40.0251985) (116d17'29.31"E, 40d 1'30.71"N)
Lower Left  ( 116.2914761,  39.8614271) (116d17'29.31"E, 39d51'41.14"N)
Upper Right ( 116.4905374,  40.0251985) (116d29'25.93"E, 40d 1'30.71"N)
Lower Right ( 116.4905374,  39.8614271) (116d29'25.93"E, 39d51'41.14"N)
Center      ( 116.3910068,  39.9433128) (116d23'27.62"E, 39d56'35.93"N)
Band 1 Block=4248x1 Type=Byte, ColorInterp=Red
Band 2 Block=4248x1 Type=Byte, ColorInterp=Green
Band 3 Block=4248x1 Type=Byte, ColorInterp=Blue

rupert:beijing_900913_satellite rupert$ gdalwarp -s_srs epsg:4326 -t_srs epsg:900913 Mosaic_RGB.tif sat_4m_rgb.tif
Creating output file that is 4245P x 4556L.
Processing input file Mosaic_RGB.tif.
0...10...20...30...40...50...60...70...80...90...100 - done.

rupert:beijing_900913_satellite rupert$ gdalinfo sat_4m_rgb.tif
Driver: GTiff/GeoTIFF
Files: sat_4m_rgb.tif
Size is 4245, 4556
Coordinate System is:
PROJCS["Google Maps Global Mercator",
    GEOGCS["WGS 84",
        DATUM["WGS_1984",
            SPHEROID["WGS 84",6378137,298.2572235630016,
                AUTHORITY["EPSG","7030"]],
            AUTHORITY["EPSG","6326"]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433],
        AUTHORITY["EPSG","4326"]],
    PROJECTION["Mercator_1SP"],
    PARAMETER["central_meridian",0],
    PARAMETER["scale_factor",1],
    PARAMETER["false_easting",0],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Origin = (12945507.907502911984921,4869604.732793668285012)
Pixel Size = (5.219801430503303,-5.219801430503303)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=PIXEL
Corner Coordinates:
Upper Left  (12945507.908, 4869604.733) (116d17'29.31"E, 40d12'53.10"N)
Lower Left  (12945507.908, 4845823.317) (116d17'29.31"E, 40d 3'2.78"N)
Upper Right (12967665.965, 4869604.733) (116d29'25.89"E, 40d12'53.10"N)
Lower Right (12967665.965, 4845823.317) (116d29'25.89"E, 40d 3'2.78"N)
Center      (12956586.936, 4857714.025) (116d23'27.60"E, 40d 7'58.12"N)
Band 1 Block=4245x1 Type=Byte, ColorInterp=Red
Band 2 Block=4245x1 Type=Byte, ColorInterp=Green
Band 3 Block=4245x1 Type=Byte, ColorInterp=Blue

Jpeg decoder problem on TileCache on MacOSX Leopard

rupert — Mon, 12 May 2008 09:26:07 +0000

There is a problem with a “jpeg decoder” because Python Imaging Library (PIL) cannot find the jpeg libraries. Remember that we installed kyngchaos UnixIO libraries, therefore the PIL setup.py script should point to use those libraries.

Actually, I even installed the jpegsrc manually. I believe there is no need to do this, since UnixIO Image libraries is sufficient enough for PIL to install. What is important is to ensure that python tests succeeded. Once you get passed that, then installing PIL should work.

1. Extract Imaging-1.1.6.tar.gz
2. Edit setup.py to reflect:
JPEG_ROOT="/Library/Frameworks/UnixImageIO.framework/unix"
3. python setup.py build_ext -i
4. If no test fails, then go ahead and install
5. python setup.py install

Using TileCache, OpenLayers, Mapserver for Projection 900913

rupert — Tue, 08 Apr 2008 01:50:12 +0000

I had a few problems with TileCache the other week which I am eager to blog about, since I knew for sure that later on, I might encounter the same. I don’t have the exact errors with me right now, so I’m jotting this down from my head…

Classic Resolutions problem. Use extent_type=loose
Can not set image type

UPDATED (JAN 11, 2010): Classic Resolutions problem:

How are resolutions calculated? Assuming we have:

Original:
Lower Left (LL) or minx, miny: 12453557, -5434940
Upper Right (UR) or max, maxy: 16980842, -1180729

maxResolution = (max – minx)/tilesize = (16980842 – 12453557)/512 = 8842.353
where tilesize = 512.

Therefore, we can set/guess for max so that we have maxResolution as a whole number.

Adjusted:
minx, miny: 12453557, -5434940
maxx, maxy: 16980661, -1180729

gives a maxResolution (whole number) of 8842.

Now, you can use 8842 in both the TileCache.cfg and OpenLayers Javascript.
A. Google BaseLayer + Road WMS Overlay = Validation approach before we proceed to TC.

1. OpenLayers (OL) Code: http://www.gisnotes.com/platform/docs/examples/GoogleWMSRoads.cfm

2. Map File Configuration: /home/map/beijing/new/beijing_google_roads

Well the above files are not exactly for TC, but it is a good demonstration that we could overlay our custom layers (WMS) on top of Google as the base layer. For a more detailed explanation regarding Google + OL, please read my previous gisnote. Also, this is a good test to see if our Mapserver mapfile configuration is correct. I do suggest not to proceed with OL + TC not unless you have validated the mapfile through OL (Google + WMS).

B. Google900913 Tilecache as baselayer

Ok.. so here it is..

1. OpenLayers Code: http://www.gisnotes.com/platform/docs/examples/TilecacheGoogle900913Base.cfm

        window.onload = function() {
            var options = {
                        projection: new OpenLayers.Projection("EPSG:900913"),
                        units: "m",
 
                        //maxResolution: 156543.0339,
                        resolutions : [156543.03390000001, 78271.516950000005, 39135.758475000002, 19567.879237500001, 9783.9396187500006, 4891.9698093750003, 2445.9849046875001, 1222.9924523437501, 611.49622617187504, 305.74811308593752, 152.87405654296876, 76.43702827148438, 38.21851413574219, 19.109257067871095, 9.5546285339355475, 4.7773142669677737, 2.3886571334838869, 1.1943285667419434, 0.59716428337097172, 0.29858214168548586],
                        //zoom: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19] @ numZoomLevels: 20
                        numZoomLevels: 20,
                        //maxExtent: new OpenLayers.Bounds(12823075.86334, 4800551.12375, 13101918.14248, 5021301.26141)
                        //maxExtent: new OpenLayers.Bounds(12823075, 4800551, 13101918, 5021301)
                        //maxExtent: new OpenLayers.Bounds(12848138, 4785083, 13080212, 5021118.5)
                        maxExtent: new OpenLayers.Bounds(-20037508, -20037508,20037508, 20037508.34)
                    };
 
            OpenLayers.IMAGE_RELOAD_ATTEMPTS = 3;
            OpenLayers.Util.onImageLoadErrorColor = "transparent";
 
            map = new OpenLayers.Map('mapdiv',options);
 
            var serverURL = "/tilecache/tilecache.py";
            // start custom layer here
            var layer_obj = new OpenLayers.Layer.WMS(
                "Beijing",
                serverURL,
                {
                    layers: 'beijing_900913',
                    map: '/home/map/beijing/new/beijing_900913/beijing.map',
                    format: 'image/jpg',
                    'transparent': 'off'
                }
            );
            layer_obj.setIsBaseLayer(true);
            layer_obj.setVisibility(true);
            map.addLayer(layer_obj);

2. TileCache Configuration: /wwwroot/tilecache/tilecache.cfg

[beijing_900913]
type=WMSLayer
url=http://127.0.0.1/cgi-bin/mapserv?map=/home/map/beijing/new/beijing_900913/beijing.map
layers=beijing_900913
metatile=true
extension=jpg
levels=20
resolutions=156543.03390000001, 78271.516950000005, 39135.758475000002, 19567.879237500001, 9783.9396187500006, 4891.9698093750003, 2445.9849046875001, 1222.9924523437501, 611.49622617187504, 305.74811308593752, 152.87405654296876, 76.43702827148438, 38.21851413574219, 19.109257067871095, 9.5546285339355475, 4.7773142669677737, 2.3886571334838869, 1.1943285667419434, 0.59716428337097172, 0.29858214168548586
srs=EPSG:900913
bbox=-20037508, -20037508, 20037508, 20037508.34
#maxResolution=156543.0339
extent_type=loose
debug=on

You can either set resolutions or maxResolutions. I always wanted to be explicit, so setting the resolutions is my preference.

3. MapFile Configuration: /home/map/beijing/new/beijing_900913/beijing.map
I have a long mapfile, and using includes helped a lot, see my previous gisnote. For debugging your mapfile, read this post.

Always Remember…I believe when they made TC, I presume they always tested on WGS84(lonlat), this means if you don’t set anything explicit, it would implicitly set settings in WGS84(lon/lat)…

Ensure that you have the vector data in the necessary projection, in my case it’s 900913.

Ensure that the resolutions from OL (B.1) is reflected in TC configuration (B.2).

Ensure that the maxextents from OL (B.1) is reflected in TC configuration (B.2) as bbox.

C. Still can’t get it running?

1. Narrow down the error.

2. tail -f /var/log/apache2/error.log and access.log is your bestfriend. It’s a good starting point to trace down what went wrong. If you can’t see it from Apache’s error.log then ensure that python debugging is turned on.

3. Sometimes TC [a] gives you an obvious error or [b] its just a link to the mapserv request.

Examples of [a]:

Classic Resolution problem stated above. - If you followed my final notes above, then this should not happen. If you’ve set up things correctly but it’s still broken and you want to pull your hair out, then do a clean test stated below in D.
Cannot set image type – Check the extensions from the mapfile and TC config. Are they both in jpg’s?

The latter [b] is harder to debug. Most likely its a mapserver mapfile mishap and the easiest way to hunt this down is only thru your error.log (note: you need mapserver to have a debug=true when you compiled it, that’s another story.)

D. Doing a clean test as always
1. Always disable any caching when testing. Disable cache from your browser, for FF I use the webdeveloper toolbar. It’s as easy as Disable -> Disable Cache.

2. Stop/Start Apache. Hoping Python get’s a clean start as well. If you found any pyc (python compiled) under TC source directory… then stop Apache; remove the pycs; start Apache.

3. Seeing the same images? Always remove the image caches! rm -Rf /data/tilecache/beijing_900913

Installing TileCache on RedHat/CentOS

rupert — Wed, 25 Jul 2007 12:36:45 +0000

1. Install Apache
./configure –prefix=/usr/local/apache2 –enable-so –enable-rewrite –with-mpm=prefork
make
make install
rm -Rf /usr/local/apache2/htdocs/*

2. Install mod_python-3.3.1
./configure --with-apxs=/usr/local/apache2/bin/apxs make make install

3. Install Python Imaging Library (PIL) – Imaging-1.1.6
python setup.py install

Note: To check if PIL was successfully installed:
#python selftest.py
***Test Failed*** 1 failures.
*** 1 tests of 57 failed.

47 ln -s /usr/lib/libjpeg.so.62 /usr/lib/libjpeg.so
48 ldconfig
49 python setup.py install
51 python selftest.py
54 rm -rf Imaging-1.1.6
55 tar -zxvf Imaging-1.1.6.tar.gz
56 cd Imaging-1.1.6
58 python selftest.py -> still fails
59 python setup.py install
60 python selftest.py -> ok

4. Check if mod_python was sucessfully installed.
http://www.dscpl.com.au/wiki/ModPython/Articles/GettingModPythonWorking

[root@rupert-centos pytest]# python
Python 2.4.3 (#1, Mar 14 2007, 18:51:08)
[GCC 4.1.1 20070105 (Red Hat 4.1.1-52)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
&gt;&gt;&gt; import mod_python
&gt;&gt;&gt; mod_python.version
'3.3.1'
&gt;&gt;&gt;

4. Edit httpd.conf


 AddHandler python-program .py
 PythonHandler TileCache.Service
 PythonOption TileCacheConfig /usr/local/apache2/htdocs/tilecache/tilecache.cfg
 PythonDebug On
 PythonPath "sys.path + ['/usr/local/apache2/htdocs/tilecache/']"

 

 AddHandler mod_python .py
 PythonHandler test
 PythonDebug On

Note: This syntax will work for all versions of mod_python. In version 3.0 and later, the name of the mod_python handler reference has actually been changed and thus it is now preferred to use “mod_python” instead of “python-program”. The old name though is still supported and will be used here to avoid confusion for those using version 2.7.

5. Test your python

from mod_python import apache
 
def handler(req):
      req.log_error('handler')
      req.content_type = 'text/plain'
      req.send_http_header()
      req.write('mptest.py\n')
      return apache.OK

TileCache Experiment

rupert — Fri, 16 Feb 2007 00:55:48 +0000

I am now able to do tilecache using TileCache1.3 from metacarta. Base from archives (archive-user.txt)

From crschmidt at metacarta.com  Wed Nov 22 17:54:29 2006
From: crschmidt at metacarta.com (Christopher Schmidt)
Date: Wed, 22 Nov 2006 17:54:29 -0500
Subject: [OpenLayers-Users] TileCache - Tiling issues
In-Reply-To: <4564D326.6020607@refractions.net>
References: <4564D326.6020607@refractions.net>
Message-ID: <20061122225429.GA18180@metacarta.com>

On Wed, Nov 22, 2006 at 02:45:58PM -0800, Ben Brehmer wrote:
> Hello everyone,
>
> I have setup a basic OpenLayers application with TileCache doing the
> server-side caching. I was wondering if there is a way to pre-cache all
> the tiles (besides panning/zooming everywhere on the map)? I know in
> kamap there is a script that can be run to pre-cache all the tiles. Is
> there something similair for TileCache?

In the TileCache directory, there is a 'Client.py' script. To pre-cache
your data, use it in the following manner:

python Client.py "http://example.com/tilecachelocation/tilecache.cgi?"
"layername" startzoomlevel endzoomlevel [BBOX]

Something like:

python Client.py "http://labs.metacarta.com/wms-c/Basic.py?" "basic" 0 16

Is what we used to precache all of the Vmap0 data in the MetaCarta VMap0
layer.

> Also, I have attached two jpegs. Each has part of a symbol or label
> chopped off. I believe that the "chopping" occurs at the edge of a tile.
> Has anyone ever experience something like this in OpenLayers?

This is based on your Mapserver setup, rather than something specific in
OpenLayers. Using WMS would result in the same visual result. Labels can
have this prevented using the "PARTIALS OFF" on your label layer, if
you're using Mapserver. I'm not aware of a way to prevent this in symbol
generation. 

We are currently working on ka-map style rendering to add to TileCache,
to help people not run into this issue. No timeframe available yet on
when that'll be released. 

Regards,
--
Christopher Schmidt
MetaCarta

1. TileCache Configuration: tilecache.cfg

[cache]
type=DiskCache
base=E:\\usr\\local\\apache2\\htdocs\\tmp\\
 
[basemap]
type=WMSLayer
url=http://127.0.0.1/cgi-bin/mapserv.exe?map=/home/basemap/wmstest_longlat.map
layers=district,greens,major_river,minor_river
extension=png
 
[roads]
type=WMSLayer
url=http://127.0.0.1/cgi-bin/mapserv.exe?map=/home/basemap/wmstest_longlat.map
layers=road4,road4label,road3,road3label,road2,road2label,road1,road1label,road11,road11label
extension=png

2. Calling CFM Script: Test.cfm

    <cfset request.mapserv="http://127.0.0.1/tilecache/tilecache.py"> 
 
    <script src="/OpenLayers-2.2/lib/OpenLayers.js">script>
    <script type="text/javascript">script>
                //var lon = 116.3842;
        //var lat = 39.9150;
        var lon = 116.3846;
        var lat = 39.9202;
        var zoom = 16;
        var map, markers;
 
        function init(){
      	    map = new OpenLayers.Map( $('map'), { maxResolution: 'auto'});
 
	    var layer_base = new OpenLayers.Layer.WMS(
					"Base Layer",
					"#request.mapserv#",
					{
						layers: 'basemap',
						format: 'png', 'transparent': 'off'
					}
					);
 
                map.addLayer(layer_base);
	   layer_base.setIsBaseLayer(true);	
 
               ...more code here...
 
       }
cfset>

I want to fine tune this script since I am getting odd tiles like duplicate tiles or tiles shown of different scale on the same scale.

3. Precaching:
/d/Python24/python.exe Client.py “http://127.0.0.1/tilecache/tilecache.py” “roads” 14 16 116.35397,39.88984,116.42988,39.91918

I need to understand the “cache hit” or “cache miss” during execution.

TileCache for Windows Revisited

rupert — Wed, 17 Jan 2007 03:50:27 +0000

1. Downloaded TileCache1.8 from http://www.tilecache.org/

2. Get the current releases of python and mod_python.
http://www.python.org/download/releases/2.5/

http://httpd.apache.org/modules/python-download.cgi -> click on win32 binaries. Get the mod_python-3.3.1.win32-py2.5-Apache2.2.exe if your Apache is running on 2.2.

http://www.pythonware.com/products/pil/

http://effbot.org/downloads/PIL-1.1.6.win32-py2.5.exe

3. Install python2.5

4. Install mod_python and python_imaging.

5. Edit httpd.conf

LoadModule python_module modules/mod_python.so
 
<directory>
AddHandler python-program .py
PythonHandler test
PythonDebug On
directory>
 
<directory>
	AddHandler python-program .py .cgi
	PythonHandler TileCache.Service
	PythonOption TileCacheConfig /wwwroot/tilecache/tilecache.cfg
	PythonDebug On
directory>
 
ScriptInterpreterSource Registry
SetEnv PYTHONUNBUFFERED 1
PassEnv PYTHONPATH

6. run regedit. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Python\PythonCore\2.4\PythonPath. Append “E:\wwwroot\tilecache” to PYTHONPATH

D:\Python24\Lib;D:\Python24\DLLs;D:\Python24\Lib\lib-tk;E:\wwwroot\tilecache;

7. Put D:\Python24 in your WINDOWS PATH

8. Test if apache could read python by http://127.0.0.1/pytest/test.py

9. http://127.0.0.1/tilecache/test1.cfm

10. tilecache_seed.py “http://127.0.0.1/tilecache/tilecache.py” roads 12 17 “116.28229,39.85291,116.48657,39.98783″