MapGuide RFC 13 - Configurable tile size

This page contains an change request (RFC) for the MapGuide Open Source project. More MapGuide RFCs can be found on the RFCs page.

Status

RFC Template Version	(1.0)
Submission Date	Jan 24 17:07:00 2007
Last Modified	Trevor Wekel Timestamp
Author	Trevor Wekel
RFC Status	Adopted
Implementation Status	pending
Proposed Milestone	1.2
Assigned PSC guide(s)	Tom Fukushima
Voting History	Feb 26, 2007
+1	Tom, Jason, Andy, Bruce, Bob, Paul, Haris
+0
-0
-1

Overview

Provide a mechanism to set the size of the tiles created and served from MapGuide.

Motivation

Currently, the MapGuide tile size is hard coded in the Server code and Ajax script as 300x300 pixels. For the purposes of performance tuning and to allow for alignment with 3rd party tile sets, it would be useful to set the tile size as a Server configuration parameter. However, this parameter would need to be exposed through the Web Extensions API so that the Ajax viewer is aware of the custom tile size.

Ideally, tile sizes should be associated with the map. However that will require changes to both the map definition and any authoring tools used to edit the map definition. Due to the impact of such a change, map definition based tile size is beyond the scope of this RFC. It would be appropriate to consider it in future work.

Proposed Solution

Add new parameters to the TileService section in serverconfig.ini
TileSizeX = 300
TileSizeY = 300
ImageFormat = PNG

If not specified, the Server will default to 300x300.

Add two additional APIs to MgTileService
INT32 GetDefaultTileSizeX();
INT32 GetDefaultTileSizeY();

Modify mapframe.php, mapframe.jsp, mapframe.aspx, and ajaxmappane.templ to pull the tile size from the MgTileService instead of simply hard coding the value.

Implications

Previous Ajax viewer scripts will only function correctly with an updated Server if the tile size is set to 300x300.

Test Plan

Modify the tile size on the server and view the Sheboygan tiled map to visually verify that the tiles are georeferenced correctly in the Ajax viewer. The regular (non-tiled) map can be used as a reference.

Funding/Resources

Autodesk