Update August 2015: check “scaled”- based fast SVG rendering on top of Leaflet here
Testing SVG limits of plotting points on map using D3, Leaflet following this base sample:http://bost.ocks.org/mike/leaflet. However instead of scaling SVG in deep zooms, I am using Enter/Update/Exit pattern from D3 to dynamically update points on map. This has been prototyped also here http://bl.ocks.org/sumbera/9972460 with brushing of 100T points.
For zooming out (causing all points to be displayed), I am filtering out points that can’t be effectively visible, thus reducing number of points in SVG. (check console for log output).
This sample is using real data of 24T coordinates where points are clustered around cities, rather than artifically randomized. Real number of rendered points / removed points can be seen in console
What it takes to transfer from Microsoft .NET to Apple iOS developer ?
Update 2015: more longer and similar story/explanation found here
So this was me ‘before’ with all my friends: Windows, C#, .NET, Visual Studio, MSDN :
transcript:
– easy ‘managed’ life,
– can smile and make ceremony
– implicit friends and friends of friends you can’t get rid of them
– shallow water, no deep dive
– few freezes
– slightly detuned, but good enough for many
– moon shots
…and me ‘after’ passing through the fire of iOS, Objective-C, Cocoa Touch, XCode, Documentation, Mac, Certificates, AppStore
transcript:
– different game, different rules
– lot of explosive material (resources)
– focused, not distracted by ‘friends’
– intelligence and luck needed
– dangerous and too explicit
– very rewarding
I have crafted really simple and quick code at ESA App dev camp for viewing WMS sources. And as few people questioned me on how to do this, I am posting the full code of the MapView component that takes sample WMS service (Ozone) and overlays this above MapKit.
#1. that sample code uses experimentaly MKNetworkKit, which has some occasional troubles. You can replace the download method in WMSOverlayView class downloadTile
#2 it uses simple hash for storing tiles on cache.
Update: be aware as this is not working on iOS7, however in iOS7 MapKit officially supports to disable base layer !
This blog : https://blog.sumbera.com/2011/09/18/how-to-disable-base-google-maps-in-mapkit/ wrote about how to disable Google maps in MapKit. Now with new iOS6 and brand new Apple maps and OpenGL rendering , the question is how to disable rendering of the base maps without using undocumented functions. Removing whole base layer (VKMapView) is possible but cripples touch handling of the overlays. So here is very simple way how to do this without removing VKMapView – just set opacity of the layer to 0.0. This will erase base iOS6 maps .
This post [https://blog.sumbera.com/2010/02/25/overlay-wms-on- google-in-silverlight-bing/ ] talked about how to overlay over the Bing maps Silverlight control Google tiles and tiled WMS. It was quite easy to port this web sample into the Windows Phone 7 emulator. I took a smaple code from Training kit called “Ex1-TheBingMapControl” and extend it with the 2 classes : GoogleTile and WmsTile, with slight changes to the namespace using Microsoft.Phone.Controls.Maps (original for Silverlight was Microsoft.Maps.MapControl). Then extend MainPage.XAML with :
Update: I found the way calculating BoundingBox from the quadkey somehow limiting (the DeepEarth weay) since it worked only till the level 18. So here is updated class fro getting correct bounding box of the tiled WMS request in the Bing Silverlight control:
Sample application can be found here: http://www.sumbera.com/lab/GoogleV3/tiledWMSoverlayGoogleV3.htm You can try to run it on your mobile device as well – suprisingly it run very well on my iPhone (sometimes it just crash Safari :), however on the iPad there are some more serious issues that will be hopefuly resolved with new iOS update (JavaScript stops to run).
For the new Google Map v3 you have to do the following :
//Define custom WMS tiled layer
var SLPLayer =
new google.maps.ImageMapType (
{
getTileUrl:
function (coord, zoom) {
var proj = map.getProjection();
var zfactor = Math.pow(2, zoom);
// get Long Lat coordinates
var top = proj.fromPointToLatLng(
new google.maps.Point(coord.x * 256 / zfactor, coord.y * 256 / zfactor) );
var bot = proj.fromPointToLatLng(
new google.maps.Point((coord.x + 1) * 256 / zfactor, (coord.y + 1) * 256 / zfactor));
//corrections for the slight shift of the SLP (mapserver)
var deltaX = 0.0013;
var deltaY = 0.00058;
//create the Bounding box string
var bbox = (top.lng() + deltaX) + "," +(bot.lat() + deltaY) +","
+(bot.lng() + deltaX) +"," +(top.lat() + deltaY);
//base WMS URL
var url =
"http://mapserver-slp.mendelu.cz/cgi-bin/mapserv?map=/var/local/slp/krtinyWMS.map&" ;
url +="&REQUEST=GetMap"; //WMS operation
url +="&SERVICE=WMS"; //WMS service
url +="&VERSION=1.1.1"; //WMS version
url +="&LAYERS=" + "typologie,hm2003"; //WMS layers
url +="&FORMAT=image/png"; //WMS format
url +="&BGCOLOR=0xFFFFFF" ;
url +="&TRANSPARENT=TRUE" ;
url +="&SRS=EPSG:4326"; //set WGS84
url +="&BBOX="+ bbox; // set bounding box
url +="&WIDTH=256"; //tile size in google
url +="&HEIGHT=256" ;
return url; // return URL for the tile
}, //getTileURL
Is it possible to display WMS (EPSG:4326) over the Google (EPSG:900913) in Openlayers ? Yes ! thanks to the great img ‘feature’ that enables you to shrink/expand your return image based on defined image size. That means that if your map view is rectangular or you request WMS as tiles (rectangular too) you get proper overlay of EPSG:4326 on EPSG:900913) . Example of various image sizes follows (these are actually WMS GetMap requests):
256 x 160256 x 256
Here is the way how to implement it in OpenLayers – very simplified:
// recalculate bounds from Google to WGS
var proj = new OpenLayers.Projection(“EPSG:4326”);
bounds.transform(map.getProjectionObject(), proj);
// this is not necessary for most servers display overlay correctly,
//but in my case the WMS has been slightly shifted, so I had to correct this with this delta shift
Update May 2014: version for Windows Phone 8.1 is here: 
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