[postgis-devel] [PostGIS] #1291: Create curve lines and polygons from points, similar to ST_MakeLine

[PostGIS]

#1291: Create curve lines and polygons from points, similar to ST_MakeLine
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 Reporter:  realityexists  |       Owner:  pramsey      
     Type:  enhancement    |      Status:  new          
 Priority:  medium         |   Milestone:  PostGIS 2.0.0
Component:  postgis        |     Version:  1.5.X        
 Keywords:                 |  
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 Currently there appears to be no way to create a CIRCULARSTRING,
 COMPOUNDCURVE or CURVEPOLYGON, except using ST_GeomFromText(). This does
 not allow the points to be calculated as part of the same SQL statement
 (eg. transformed from another SRID). Please add:

 1) a function similar to ST_MakeLine for CIRCULARSTRING

 2) a similar function for COMPOUNDCURVE

 3) support for CIRCULARSTRING and COMPOUNDSTRING to ST_MakePolygon (so it
 returns CURVEPOLYGON)

 Eg.

 ST_MakeCurveLine(ST_MakePoint(1,2), ST_MakePoint(3,4), ST_MakePoint(5,6))
     => CIRCULARSTRING(1 2, 3 4, 5 6)

 ST_MakeCurveLine(ARRAY[ST_MakePoint(1,2), ST_MakePoint(3,4),
 ST_MakePoint(5,6), ST_MakePoint(7,8), ST_MakePoint(9,10)])
     => CIRCULARSTRING(1 2, 3 4, 5 6,7 8,9 10)

 ST_MakeCompoundCurve(ARRAY[ST_GeomFromText('CIRCULARSTRING(0 0,2 0, 2 1, 2
 3, 4 3)'), ST_GeomFromText('LINESTRING(4 3, 4 5, 1 4, 0 0)'))
     => COMPOUNDCURVE(CIRCULARSTRING(0 0,2 0, 2 1, 2 3, 4 3),(4 3, 4 5, 1
 4, 0 0))

 ST_MakePolygon(ST_GeomFromText('COMPOUNDCURVE(CIRCULARSTRING(0 0,2 0, 2 1,
 2 3, 4 3),(4 3, 4 5, 1 4, 0 0))'), ST_GeomFromText('CIRCULARSTRING(1.7 1,
 1.4 0.4, 1.6 0.4, 1.6 0.5, 1.7 1)'))
     => CURVEPOLYGON(COMPOUNDCURVE(CIRCULARSTRING(0 0,2 0, 2 1, 2 3, 4
 3),(4 3, 4 5, 1 4, 0 0)), CIRCULARSTRING(1.7 1, 1.4 0.4, 1.6 0.4, 1.6 0.5,
 1.7 1))

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Ticket URL: <http://trac.osgeo.org/postgis/ticket/1291>
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