Changes between Version 4 and Version 5 of MapGuideRfc98


Ignore:
Timestamp:
Jun 21, 2010, 1:46:27 PM (14 years ago)
Author:
NormOlsen
Comment:

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  • MapGuideRfc98

    v4 v5  
    2424== Overview ==
    2525
    26 CS-MAP RFC 2 proposes to add three items to the coordinate system dictionary, and one item each to the Datums and Ellipsoid dictionaries.  (The format doesn't change, we'll be using currently unused holes in the structures.)  This RFC proposes to expose these new data values through the MgCoordinateSystem interface.  The items being added are EPSG code, Oracle SRID code, and the EPSG Quadrant code.
     26CS-MAP RFC 3 proposes to add three items to the coordinate system dictionary, and one item each to the Datums and Ellipsoid dictionaries.  (The format doesn't change, we'll be using currently unused holes in the structures.)  This RFC proposes to expose these new data values through the MgCoordinateSystem interface.  The items being added are EPSG code, Oracle SRID code, and the EPSG Quadrant code.
    2727
    2828== Motivation ==
    2929
    30 The EPSG code and the Oracle SRID code are becomming frequently desired/referenced data items.  Conversion between CS-MAP key name and EPSG code is currently possible, but requires the use of the NameMapper which can be painfully slow if one intends to map large segments of the EPSG code set.  While supported in the NameMapper, mapping between CS-MAP key names and Oracle SRID codes is not expsed through the MgCoordinateSystem interface.  Implementation of this RFC would, in conjunction with CS-MAP RFC 2, enable direct access to both codes using the MgCoordinateSystem interface.
     30The EPSG code and the Oracle SRID code are becomming frequently desired/referenced data items.  Conversion between CS-MAP key name and EPSG code is currently possible, but requires the use of the NameMapper which can be painfully slow if one intends to map large segments of the EPSG code set.  While supported in the NameMapper, mapping between CS-MAP key names and Oracle SRID codes is not expsed through the MgCoordinateSystem interface.  Implementation of this RFC would, in conjunction with CS-MAP RFC 3, enable direct access to both codes using the MgCoordinateSystem interface.
    3131
    32 There exists a problem encountered when using the latest version of WMS specification.  This new specification now requires strict adherence to the axis specifications in Coordinate Reference System (CRS) definitions.  CS-MAP RFC 2 calls for the addition to the coordinate system dictionary an quadrant value (using the same values as the standard CS-MAP quad parameter) which indicates what the EPSG definition indicates the axis specification to be.  Implementation of this RFC will expose this value through the MgCoordinateSystem interface.
     32There exists a problem encountered when using the latest version of WMS specification.  This new specification now requires strict adherence to the axis specifications in Coordinate Reference System (CRS) definitions.  CS-MAP RFC 3 calls for the addition to the coordinate system dictionary an quadrant value (using the same values as the standard CS-MAP quad parameter) which indicates what the EPSG definition indicates the axis specification to be.  Implementation of this RFC will expose this value through the MgCoordinateSystem interface.
    3333
    3434== Proposed Solution ==
    … …  
    5454||-1||X increases to the north, Y increases to the east||
    5555||-2||X increases to the north, Y increases to the west||
    56 ||-1||X increases to the south, Y increases to the west||
    57 ||-1||X increases to the south, Y increases to the east||
     56||-3||X increases to the south, Y increases to the west||
     57||-4||X increases to the south, Y increases to the east||
    5858
    5959== Implications ==
    6060
    61 Since we would be using currently unused holes in the CS-MAP dictionary structures, it would be nice to rename these elements.  Doing so will break the buiold of MapGuide if the changes are not synchronized.
     61Since we would be using currently unused holes in the CS-MAP dictionary structures, it would be nice to rename these elements.  Doing so will break the build of MapGuide if the changes are not synchronized.
    6262
    6363== Test Plan ==
    6464
    65 A test function wioll be written which will cycle through the three dictionaries affected and the results of these new methods compared to the current contents of the NameMapper.  This effort will be done at the CS-MAP level.  As these methods are simple on liners, no special test module is being planned at the MgCoordinateSystem level.
     65A test function will be written which will cycle through the three dictionaries affected and the results of these new methods compared to the current contents of the NameMapper.  This effort will be done at the CS-MAP level.  As these methods are simple one liners, no special test module is being planned at the MgCoordinateSystem level.
    6666
    6767== Funding/Resources ==