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** 0: Contents
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1: Introduction
2: Build\Signing
3: Installation
4: Features

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** 1: Introduction
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This project is a collection of tools for use with the spatial types
in SQL Server. This project does not provide an 
end-user application, but rather a set of reusable functions which 
applications can make use of.

Development of this package is hosted at GitHub:
http://www.github.com/Microsoft/SQLServerSpatialTools.  
Source is available at this site.

This package is licensed under the Microsoft public license. See
http://www.github.com/Microsoft/SQLServerSpatialTools/blob/master/License.txt 
or the included License.txt file for details.

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** 2: Build\Signing
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This package contains a core assembly SQLSpatialTools.dll which can be 
included and used directly from a .NET application, or can be registered 
and used from within SQL Server.

Signing
-------
This dll is signed with Spatial.pfx file for security. So you need set the 
password for the certificate before you can build from VS.

Password for pfx:spatial@123

To set password open project properties-> Signing tab->Sign the assembly(section) 
Click the Certificate dropdown; you will be prompted with password text box; 
where you need to enter the above password before build.

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** 3: Installation
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Scripts for registering and unregistering the functionality in
SQL Server are included in the SQL Scripts directory.

Detailed Steps:

To Register:
1) Note the path to the SQLSpatialTools.dll file.
2) Edit the Register.sql file in the SQL Scripts directory:
  a) Insert the name of the database you are registering the 
     functionality to where indicated at the beginning of the script.
  b) Insert the path to the SQLSpatialTools.dll file where indicated
     at the beginning of the script.
3) Execute the script on your SQL Server instance.

To Unregister:
1) Edit the Unregister.sql file in the SQL Scripts directory and insert
   the name of the database use are unregistering the functionality
   from where indicated at the beginning of the script.
2) Execute the script on your SQL Server instance.

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** 4: Features
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Scripts
-------
Several scripts are included in the SQL Scripts directory. These include
scripts for registering and unregistering all of the following
components, as well as several examples of their use.

Functions
---------
These static methods, implemented in the class Functions, can both be
registered in SQL Server and used through T-SQL, as well as be used
directly from the CLR:

bool IsValidGeographyFromGeometry(SqlGeometry geometry)
Check if an input geometry can represent a valid geography without throwing an exception.
This function requires that the geometry be in longitude/latitude coordinates and that
those coordinates are in correct order in the geometry instance (i.e. latitude/longitude
not longitude/latitude). This function will return false (0) if the input geometry is not
in the correct latitude/longitude format, including a valid geography SRID.

bool IsValidGeographyFromText(string inputWKT, int srid)
Check if an input WKT can represent a valid geography. This function requires that
the WTK coordinate values are longitude/latitude values, in that order and that a valid
geography SRID value is supplied.  This function will not throw an exception even in
edge conditions (i.e. longitude/latitude coordinates are reversed to latitude/longitude).

SqlGeography MakeValidGeographyFromGeometry(SqlGeometry geometry)
Convert an input geometry instance to a valid geography instance.
This function requires that the WKT coordinate values are longitude/latitude values,
in that order and that a valid geography SRID value is supplied.

SqlGeography MakeValidGeographyFromText(string inputWKT, int srid)
Convert an input WKT to a valid geography instance.
This function requires that the WKT coordinate values are longitude/latitude values,
in that order and that a valid geography SRID value is supplied.

SqlGeography ConvexHullGeography(SqlGeography geography)
Computes ConvexHull of input geography and returns a polygon (unless all input points are colinear).

SqlGeography ConvexHullGeographyFromText(string inputWKT, int srid)
Computes ConvexHull of input WKT and returns a polygon (unless all input points are colinear).
This function does not require its input to be a valid geography. This function does require
that the WKT coordinate values are longitude/latitude values, in that order and that a valid
geography SRID value is supplied.

SqlGeography DensifyGeography(SqlGeography g, double maxAngle)
Returns a geography instance equivalent to its input, but with no two
consecutive points spaced more than maxAngle apart.

SqlGeography InterpolateBetweenGeog(SqlGeography start, 
  SqlGeography end, double distance)
Takes start and end geography points and returns a new point that is a
given distance from the start toward the end.

SqlGeometry InterpolateBetweenGeom(SqlGeometry start, SqlGeometry end,
  double distance)
Takes start and end geometry points and returns a new point that is a
given distance from the start toward the end.

SqlGeography LocateAlongGeog(SqlGeography g, double distance)
Takes a geography linestring and finds the point a given distance along
it.

SqlGeometry LocateAlongGeom(SqlGeometry g, double distance)
Takes a geometry linestring and finds the point a given distance along
it.

SqlGeometry ShiftGeometry(SqlGeometry g, double xShift, double yShift)
Takes a geometry instance and shifts if by a given X and Y amount.

SqlGeometry VacuousGeographyToGeometry(SqlGeography toConvert,
  int targetSrid)
A special case of the equirectangular projection, taking each point
(lat,long) --> (y, x).

SqlGeography VacuousGeometryToGeography(SqlGeometry toConvert,
  int targetSrid)
The inverse of the VacuousGeographyToGeometry projection.

Types
-----
These types can be registered in SQL Server or used directly through the
CLR.

SqlProjection
This class provides an extensible access point to various projections and
inverse projections. See the file projection_example.sql for a sample of
its use. Currently supported projections are:

    * Albers Equal Area
    * Equirectangular
    * Lambert Conformal Conic
    * Mercator
    * Oblique Mercator
    * Tranverse Mercator
    * Gnomonic


AffineTransform
This provides general affine transformations. See the example
transform_example.sql for a sample of its use.

Aggregates
----------
While implemented as classes, aggregates are essentially functions that
take a collection of inputs to a single result.

GeographyUnionAggregate
This aggregate finds the union of a set of geographies with an optional
additional buffer.

GeometryEnvelopeAggregate
This aggregate finds the envelope that contains a set of input
geometries.

LRS Functions
-------------
Linear referencing (also called linear reference system or linear referencing system or LRS), 
is a method of spatial referencing in engineering and construction, in which the locations of 
physical features along a linear element are described in terms of measurements from a fixed point, 
such as a milestone along a road.

 1. LRS_ClipGeometrySegment
     - Returns clipped geometry segment after clip operation.

 2. LRS_ConvertToLrsGeom
     - Converts a standard Geometry line string to an LRS geometric segment by adding measure information.

 3. LRS_GetEndMeasure
     - Returns the End Measure of a geometric segment.

 4.  LRS_GetMergePosition
     - Checks if two input geometries are spatially connected. 
       If connected returns the connected\merge position; else returns false.

 5. LRS_GetStartMeasure
     - Returns the Start Measure of a geometric segment.

 6. LRS_InterpolateBetweenGeom
     - Compute and get a new POINT with the specified measure between two input POINT of the geometric segment.

 7. LRS_IsConnected
     - Checks if two input geometries are spatially connected.

 8. LRS_IsValidPoint
     - Checks if a geometry segment is a valid POINT type or not.

 9. LRS_LocatePointAlongGeom
     - Returns the POINT located at a specified measure from the start of a geometric segment.

 10. LRS_MergeGeometrySegment
      - Returns the geometry object resulting from the concatenation of two geometric segments.

 11. LRS_MergeAndResetGeometrySegments
      - Merges the input segments within tolerance and reset the measure of the resultant geometry segment.

 12. LRS_OffsetGeometrySegments
      - Returns the geometric segment at a specified offset from a geometric segment.

 13. LRS_PopulateGeometryMeasures
      - Populates the measures of all shape points based on the startMeasure and endMeasure of a geometric segment, 
        overriding any previously assigned measures between the start point and end point.

 14. LRS_ResetMeasure
      - Sets all measures of a geometric segment, including the start and end measures, to null values, 
        overriding any previously assigned measures.

 15. LRS_ReverseLinearGeometry
      - Returns a new geometric segment by reversing the measure values and the direction of the original geometric segment.

 16. LRS_ScaleGeometrySegment
      - Returns a new geometric segment by scaling the original geometric segment 
       (that is, redefining and shifting the measure values of all the points by the given shift measure).

 17. LRS_SplitGeometrySegment
      - Splits a geometric segment into two geometric segments

 18. LRS_TranslateMeasure
      - Returns a new geometric segment by translating the original geometric segment 
       (that is, adding the measure values of all the points by the given translate measure).

 19. LRS_ValidateLRSGeometry
      - Checks if the input LRS geometry is valid.
 
Utility Functions
-----------------
  1. Util_PolygonToLine
      - Converts all polygon-type elements in a geometry to line-type elements.

  2. Util_RemoveDuplicateVertices
      - Removes consecutive duplicate vertices and co linear points of the valid geometry bounds within the tolerance.

  3. Util_Extract
      - Returns the geometry specified by the element index and ring index.