Difference between revisions of "Linden Lab Official:Map API"

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Extend the reach of your Web site into Second Life using the ''Second Life Map API'', which enables you to embed interactive Second Life maps directly into your web pages. These maps look and act much like Google Maps, except that, instead of the Earth, they display the topography of the Second Life virtual world. See http://maps.secondlife.com/ for an example.


== Getting Started ==
When you use the Map API to embed Second Life maps on your site, your visitors can:


The Second Life Map API is a set of Javascript objects and functions that enable you to embed Second Life maps onto your web pages.  It is a purely client-side Javascript API.  If needed, you can also [[#Accessing_map_images_directly|directly access]] the map images. 
* Click and drag the mouse pointer to pan the map view up, down, left, and right.
 
'''NOTE:'''
This API is still in beta.  URLs and API signatures may change.  See the [[#Release notes|Release Notes]] for information on new features and known issues.
 
=== Map UI features ===
 
The Map API enables you to create web pages that have Google Maps functionality, using maps of Second Life, rather than Earth.  In general, the default map interface looks as shown here.
 
[[Image:Map ui cropped.png|right]]
 
The main map display area shows the current map area.  By default, the map provides the following features:
 
* Click and drag the mouse pointer to pan the map view up, down, left, and right. If desired, you can [[Map_API_Advanced_Examples#Disabling_and_enabling_dragging|disable this behavior]]. 
* Double-click to zoom in by one level (power of two) and display the teleport window.
* Double-click to zoom in by one level (power of two) and display the teleport window.
* Click anywhere on the map to open a "teleport" window; see '''Teleport window''' below.
* Click anywhere on the map to open a "teleport" window.
* Use the mouse wheel to zoom in and out.  See [[#Zoom_levels|Zoom levels]] for more information about zoom levels.
* Use the mouse wheel or pan controls to zoom in and out.
* Use the zoom and pan controls at upper left to zoom the view in and out and to pan the view up, down, left, and right.  If desired, you can easily [[Map_API_Advanced_Examples#Customizing_zoom_and_pan_controls|create your own custom zoom and pan controls]].
* Use the overview control to move the view around by clicking and dragging, or double-clicking.  Close the overview control by clicking on the diagonal arrow at the very bottom right of the map.  You can specify whether the map provides an overview control when you [[Map_API_Reference#MarkerOptions|create the map object]].
 
<br clear="all" />
 
'''Teleport window'''
[[Image:Teleport window.png|left]]
Clicking anywhere on the map opens a window,  such as the one shown at left, indicating the point on which you clicked.  Clicking on the teleport button in the window then starts the Second Life Viewer, automatically teleporting you to the window's location.  This feature is implemented with the [[Map_API_Reference#Global_functions|gotoSLURL()]] global function.
 
<br clear="all" />
 
=== Working examples ===
 
See [[Map API Basic Examples]] for a detailed explanation of the working examples at http://slurl.com/examples/.
 
=== Using slurl.com and DirectSLurl ===
 
The website http://slurl.com uses the Map API to provide a mechanism to teleport directly to locations in Second Life from web pages.
 
For more information, see [[Using Second Life URLs (SLURLs)]].
 
=== Prerequisites ===
 
To use the Second Life Map API in a web page, you must first:
* [http://www.google.com/apis/maps/signup.html Sign up for a Google Maps API key].  This enables you to use the Google Maps API, which is required to use SLMAPI.  See the [http://code.google.com/apis/maps/documentation/ Google Maps API documentation] for more information.
* Add the [[#Common_HTML_header|common header code]] at the beginning of each HTML file.  This code loads the Google Maps and Webmap Javascript libraries, the Webmap cascading stylesheet (CSS), and some other basic code.
 
NOTE: In general, it is best to reference the Map API Javascript library and CSS files that are on http://slurl.com.  Although you can download these files locally and modify them for your own use, if Linden Lab updates or changes these files, your applications will not get the benefit and may even stop working properly. 
 
=== Common HTML header ===
 
To use the Map API, put the following lines at the beginning of each HTML page.  This includes:
* Statements to load the required Second Life Map API and Google Maps Javascript libraries.
* Link to the Webmap cascading style sheet.
* Style declaration for the map div element.  This defines the size and other layout attributes of the map display.
 
<pre>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<script src="http://maps.google.com/maps?file=api&v=2&key={GOOGLE MAPS KEY}"
  type="text/javascript"></script>
<script src="http://slurl.com/_scripts/slmapapi.js" type="text/javascript"></script>
 
<link rel="stylesheet" type="text/css" href="http://slurl.com/_styles/MAIN.css" />
<style>
div#map-container {
      width: 500px;
      height: 500px;
}
</style>
...
</pre>
 
Replace {GOOGLE MAPS KEY} with you Google Maps Key.
 
All the examples also require additional script statements in the HTML header.
 
'''Stylesheet'''
 
To use your own stylesheet, just include it AFTER the Webmap CSS, for example:
 
<link rel="stylesheet" type="text/css" href="http://slurl.com/_styles/MAIN.css" />
<link rel="stylesheet" type="text/css" href="myStyleSheet.css" />
 
'''Body element'''
 
Use the following body element in your HTML document:
 
<body load="loadmap()" onunload="GUnload();">
...
 
The '''GUnload()''' function is a Google Maps API  function that reduces memory leaks, particularly with Internet Explorer.  For more information, see the [http://code.google.com/apis/maps/documentation/#Memory_Leaks Google Maps API documentation].
 
=== Browser compatibility ===
The Map API has been tested to work with the following browsers:
* Internet Explorer 6.0
* Internet Explorer 7.0
* Firefox 2.0 or greater
* Safari 2.0
 
Other browsers may work but little issues may appear. Unless otherwise noted, all features work in all supported browsers.
 
=== Comments and feedback ===
 
If you encounter problems or bugs or have feature requests, please email '''webmap@secondlife.com'''.
 
Happy coding from the Second Life Web team!
 
== Basic concepts ==
 
The Map API's fundamental class is [[Webmap_API_Reference#SLMap|SLMap]].  It is a Javascript object representing the map with a large number of methods, enabling you to zoom, pan the view, and so on.
 
Additionally, the API includes the following key classes:
* [[Webmap_API_Reference#Marker|Marker]] - represents an image to display at a specify (x,y) point on the map.  You provide a set of images to display at each zoom level.  Contains several event handlers and other properties.  See [[#Map_with_a_marker|Map with a marker]] for a basic example.
* [[Webmap_API_Reference#MapWindow|Window]] - represents a captioned balloon pointing to a specified map location.  See [[Webmap_API#Map_with_an_initial_open_window|Map with an initial open window]] for a basic example.
* [[Webmap_API_Reference#Img|Img]] and [[Webmap_API_Reference#Icon|Icon]] - represent an image to use for markers, controls, or in windows.
 
===About coordinates===
 
Map coordinates are based on the Second Life grid system for positioning regions.
 
[[Image:Webmap coords.jpg]]
 
As illustrated in the diagram above, the Map API maps the Second Life world to the upper right quadrant of the Google world map.  A large scaling value
called slGridEdgeSizeInRegions (equal to 2<sup>20</sup> or 1,048,576) defines the largest region coordinate at the top and far right edge of the displayed area.  This value creates a map area with room for one trillion sims.
 
The little blue square illustrates where the populated sims are in Second Life.
 
=== Zoom levels ===
There are eight zoom levels: one through eight, one being the closest and eight being the farthest. Each level zooms by a power of two. In other words, at zoom level five, each region is twice the width as it was at zoom level six.
 
== Accessing map images directly ==
 
The Second Life map images are stored on [http://aws.amazon.com/s3/ Amazon Simple Storage Service (Amazon S3)].  You can access the map images directly on the Amazon S3 servers using the following URL format (new as of February 10, 2009):
 
<nowiki>http://map.secondlife.com/map-Z-X-Y-objects.jpg</nowiki>
 
Where:
* Z - Zoom level desired:
** One (1) is the most zoomed-in view, showing individual region tiles.
** Eight (8) is the maximum zoom level, showing the entire world.
* X,Y - X and Y coordinates on the Second Life Grid of the region, for example, region Ahern is (997,1002). 
 
Tiles with zoom greater than one are stored at the lower left corner coordinate of the tiles that are included in the image.
In other words, you can find the zoom tile containing region (X,Y) for zoom level Z with the filename map-Z-X'-Y'-objects.jpg where:
 
X' = X - (X % (2<sup>Z - 1</sup>) )
 
and  
 
Y' = Y - (Y % (2<sup>Z - 1</sup>) )
 
Note that 2<sup>Z - 1</sup> is the number of regions encompassed by the width of a tile at resolution Z.
 
=== Examples ===
 
For example: if Z = 1, the four region tiles are:
 
* http://map.secondlife.com/map-1-1000-1000-objects.jpg
* http://map.secondlife.com/map-1-1001-1000-objects.jpg
* http://map.secondlife.com/map-1-1000-1001-objects.jpg
* http://map.secondlife.com/map-1-1001-1001-objects.jpg
 
These four region tiles are compressed into the single tile:
 
http://map.secondlife.com/map-2-1000-1000-objects.jpg
 
The following shows the map zoomed all the way out, showing the entire Second Life world view:
http://map.secondlife.com/map-8-1024-896-objects.jpg
 
The following displays a single tile contained in the view above, zoomed all the way in:
http://map.secondlife.com/map-1-1027-1019-objects.jpg
 
===Implementation notes=== 
 
The map generation process is more scalable than the previous release, and is able to image the entire Second Life grid of about 30,000 regions in less than two days. 
 
There is a "decay period" for offline regions. If a region is disabled, the tile will stay up for several days (in case it comes back or something else has gone wrong) before the tile disappears. That several-day period will be longer than the time it takes to update existing regions or put new regions on the map.
 
=== Getting a map URL from LSL ===
 
The following LSL script illustrates how to display a map of the current region to an avatar:
 
<lsl>
ShowMap(key avatar) {
    string url = "http://map.secondlife.com/";
    vector sim_coord = llGetRegionCorner();
    string x = (string)((integer)(sim_coord.x / 256.0));
    string y = (string)((integer)(sim_coord.y / 256.0));
    url += "map-1-" + x + "-" + y + "-objects.jpg";
    llLoadURL(avatar, "View the sim map", url);
}
</lsl>
 
== Release notes ==
 
This section describes new features and known issues with the current release of the Map API.  See also [http://blog.secondlife.com/2009/01/22/improvements-to-mapping-and-upgrade-to-slurlcom/ Philip Linden's blog post announcement].
 
The current version of the Map API was released on Jan 15, 2009.
 
=== New features ===
 
This release of the Map API provides significant performance improvements over the previous release, including:
* Map loads faster and operates more smoothly.
* Map images are updated more accurately and rapidly.  Changes to the Second Life Grid or content will now be visible within about two days. 
* Map images look smoother and are more accurate when compared to the actual in-world content.
 
Changes in functionality:
* You can now single-click on any location on the map and teleport directly there. 
* Zoom levels go up to eight, so you can now zoom out and see how big SL has really become!
* More intuitive map tile image file naming convention.
 
The Map API now gets map tile images directly from [http://aws.amazon.com/s3/ Amazon S3], and the file naming convention will make it easier to develop other third party maps based on the tiles we are generating.
 
=== Known issues ===


* Map object click and doubleclick handlers do not work.  They always have the default behavior. 
For more information, see [[Map API Introduction]].
* Method '''SLMap.clickMarker(marker)''' doesn't work.
<br clear="all"/>
* Marker options do not work:
** '''centerOnClick: true''' - This works, but does NOT work if you open a window onclicking the marker.
** '''autopanOnClick: false''' - Always autopans
** '''autopanPadding: n''' - No effect
* Setting a different marker image/icon for each zoom level doesn't work - always uses first icon.
* Window width option doesn't work.

Latest revision as of 13:27, 4 May 2011

NOTE: This is an official Second Life API provided and documented by Linden Lab. Its use is subject to the API Terms of Use.

Extend the reach of your Web site into Second Life using the Second Life Map API, which enables you to embed interactive Second Life maps directly into your web pages. These maps look and act much like Google Maps, except that, instead of the Earth, they display the topography of the Second Life virtual world. See http://maps.secondlife.com/ for an example.

When you use the Map API to embed Second Life maps on your site, your visitors can:

  • Click and drag the mouse pointer to pan the map view up, down, left, and right.
  • Double-click to zoom in by one level (power of two) and display the teleport window.
  • Click anywhere on the map to open a "teleport" window.
  • Use the mouse wheel or pan controls to zoom in and out.

For more information, see Map API Introduction.

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