| | 1 | = !MapGuide RFC 55 - Switch from PROJ4 to CS-Map coordinate system library = |
| | 2 | |
| | 3 | This page contains an change request (RFC) for the !MapGuide Open Source project. |
| | 4 | More !MapGuide RFCs can be found on the [wiki:MapGuideRfcs RFCs] page. |
| | 5 | |
| | 6 | |
| | 7 | == Status == |
| | 8 | |
| | 9 | ||RFC Template Version||(1.0)|| |
| | 10 | ||Submission Date||August 07, 2008|| |
| | 11 | ||Last Modified||Hugues Wisniewski [[Timestamp]]|| |
| | 12 | ||Author||Hugues Wisniewski|| |
| | 13 | ||RFC Status||draft|| |
| | 14 | ||Implementation Status||(pending, under development, completed)|| |
| | 15 | ||Proposed Milestone||2.1|| |
| | 16 | ||Assigned PSC guide(s)||Tom Fukushima|| |
| | 17 | ||'''Voting History'''|| || |
| | 18 | ||+1|| || |
| | 19 | ||+0|| || |
| | 20 | ||-0|| || |
| | 21 | ||-1|| || |
| | 22 | ||no vote|| || |
| | 23 | |
| | 24 | == Overview == |
| | 25 | |
| | 26 | For the coordinate system work, MapGuide uses the PROJ4 library which is wrapped into the MgGeometry.dll binary module. |
| | 27 | The coordinate system functionality is exposed through all the API interfaces prefixed with MgCoodinateSystem |
| | 28 | This proposal aims at replacing the PROJ4 implementation with the CS-Map implementation. CS-Map was recently open sourced and posted on at:[[BR]] |
| | 29 | http://svn.osgeo.org/metacrs/csmap/ |
| | 30 | |
| | 31 | == Motivation == |
| | 32 | |
| | 33 | The CS-Map code has a broader range of functionality than what PROJ4 can offer.[[BR]] |
| | 34 | [[BR]] |
| | 35 | CS-Map can address things that are not well addressed by PROJ4 like:[[BR]] |
| | 36 | [[BR]] |
| | 37 | - vertical datum shifting[[BR]] |
| | 38 | - WKT transformations in multiple flavors like Oracle[[BR]] |
| | 39 | - greater coverage in terms of coordinate system definitions, right now more than 4000 systems, roughly 700 datums and 100 ellipsoids[[BR]] |
| | 40 | - CS-Map can provide an implementation to all the MgCoordinateSystem API methods that currently throw MgNotImplementedException[[BR]] |
| | 41 | |
| | 42 | == Proposed Solution == |
| | 43 | |
| | 44 | The current MgCoordinateSystem API implementation code is a wrapper around PROJ4[[BR]] |
| | 45 | This implementation code is located here: [[BR]] |
| | 46 | http://svn.osgeo.org/mapguide/trunk/MgDev/Common/CoordinateSystem/ [[BR]] |
| | 47 | The new API implementation would wrap the CS-Map code hosted at:[[BR]] |
| | 48 | http://svn.osgeo.org/metacrs/csmap/trunk/CsMapDev/ [[BR]] |
| | 49 | [[BR]] |
| | 50 | This API is part of the module MgGeometry.dll generated from the project:[[BR]] |
| | 51 | http://svn.osgeo.org/mapguide/trunk/MgDev/Common/Geometry/Geometry.vcproj [[BR]] |
| | 52 | [[BR]] |
| | 53 | This project is used in the solutions:[[BR]] |
| | 54 | [[BR]] |
| | 55 | http://svn.osgeo.org/mapguide/trunk/MgDev/Server/Server.sln [[BR]] |
| | 56 | http://svn.osgeo.org/mapguide/trunk/MgDev/Web/src/WebTier.sln [[BR]] |
| | 57 | [[BR]] |
| | 58 | The current PROJ4 implementation would not be supported anymore. Only CS-Map would remain in the place where the PROJ4 currently resides:[[BR]] |
| | 59 | http://svn.osgeo.org/mapguide/trunk/MgDev/Common/CoordinateSystem/ [[BR]] |
| | 60 | |
| | 61 | == Implications == |
| | 62 | |
| | 63 | PROJ4 would not be supported anymore.[[BR]] |
| | 64 | The coordinate system definitions will come from the CS-Map coordinate system dictionaries.[[BR]] |
| | 65 | All the MgCoordinateSystem API methods that currently throw MgNotImplementedException would have a fully functional implementation.[[BR]] |
| | 66 | The build process documentation will have to be updated to explain how to get and build CS-Map and then build MapGuide using CS-Map instead of PROJ4.[[BR]] |
| | 67 | |
| | 68 | == Test Plan == |
| | 69 | |
| | 70 | CS-Map has its own standalone unit tests so it can be tested separately.[[BR]] |
| | 71 | The existing unit MapGuide unit tests would remain the same.[[BR]] |
| | 72 | More can be added, especially for the new functionality that CS-Map provides, like the WKT conversions.[[BR]] |
| | 73 | |
| | 74 | == Funding/Resources == |
| | 75 | |
| | 76 | Provided by Autodesk.[[BR]] |
| | 77 | |
| | 78 | == Additional Notes == |
| | 79 | |
| | 80 | The code is ready to be distributed.[[BR]] |
| | 81 | If this request is accepted, the implementation would be trivial as it has already been intensively tested and is fully functional.[[BR]] |
| | 82 | |
