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wiki:documentation:devguide:geometry_module [2016/01/17 17:55]
gribeiro [CircularString]
wiki:documentation:devguide:geometry_module [2016/02/12 10:36] (current)
gribeiro [General Concepts]
Line 5: Line 5:
 It is important to notice that this module refers to //**a geometry model to be used in main memory**// and //**it doesn'​t assume any kind of persistence or data storage management**//​. This section explains the basic concepts, design behind this module ad how to use it. It is important to notice that this module refers to //**a geometry model to be used in main memory**// and //**it doesn'​t assume any kind of persistence or data storage management**//​. This section explains the basic concepts, design behind this module ad how to use it.
  
-All the types offered by Geometry module are in the namespace ''​te::​gm''​. Check the [[http://​www.dpi.inpe.br/​terralib5/​codedocs_5.1.0/​d9/​dba/​group__geometry.html|DOxygen ​documentation of this module]], where these and other classes are documented in details.+All the types offered by Geometry module are in the namespace ''​te::​gm''​. Check the [[http://​www.dpi.inpe.br/​terralib5/​codedocs_5.1.0/​d9/​dba/​group__geometry.html|Doxygen ​documentation of this module]], where these and other classes are documented in details.
 ===== General Concepts ===== ===== General Concepts =====
  
Line 14: Line 14:
     * A 1-dimensional geometry is one with a geometric dimension of 1 (one). Curves (lines) are 1-dimensional objects.     * A 1-dimensional geometry is one with a geometric dimension of 1 (one). Curves (lines) are 1-dimensional objects.
     * A 2-dimensional geometry is one with a geometric dimension of 2 (two). Surfaces (polygons) are 2-dimensional objects.     * A 2-dimensional geometry is one with a geometric dimension of 2 (two). Surfaces (polygons) are 2-dimensional objects.
-  * We can have geometries in ℜ2, ℜ3 or ℜ4 coordinate spaces.+  * We can have geometries in ℜ<sup>2</​sup>​, ℜ<sup>3</​sup> ​or ℜ<sup>4</​sup> ​coordinate spaces.
     * The //z// coordinate value not necessarely represents altitude.     * The //z// coordinate value not necessarely represents altitude.
     * The //m// coordinate value represents arbitrary measurement.     * The //m// coordinate value represents arbitrary measurement.
   * The term //ring// is applied to a closed curve (the first and last points are coincident).   * The term //ring// is applied to a closed curve (the first and last points are coincident).
- 
 ===== Geometry Class Hierarchy ===== ===== Geometry Class Hierarchy =====
  
Line 43: Line 42:
  
 <code cpp> <code cpp>
-std::​unique_ptr<​te::​gm::​Point= std::​make_unique<​te::​gm::​Point>​(-54.0, -12.0, 4326);+te::​gm::​Point p(-54.0, -12.0, 4326);
 </​code>​ </​code>​
  
Line 69: Line 68:
  
 <code cpp> <code cpp>
-std::​unique_ptr<​te::​gm::​LineString= std::​make_unique<​te::​gm::​ LineString>​(2, te::​gm::​LineStringType);​ +te::​gm::​LineString l(2, te::​gm::​LineStringType);​ 
- +  
-l->setPoint(0, -54.0, -12.0); +l.setPoint(0, -54.0, -12.0); 
-l->setPoint(1, -55.0, -13.0);+l.setPoint(1, -55.0, -13.0);
 </​code>​ </​code>​
  
Line 94: Line 93:
  
 <code cpp> <code cpp>
-std::​unique_ptr<​te::​gm::​LinearRing> s = std::​make_unique<​te::​gm::​LinearRing>​(5, te::​gm::​LineStringType);​+te::​gm::​LinearRing ​r(5, te::​gm::​LineStringType, 0);
  
-double xc = -54.0; +r.setPoint(0, ​12); 
-double yc = -12.0; +r.setPoint(1, ​17); 
-duble halfSize = size * 0.5; +r.setPoint(2, ​77); 
- +r.setPoint(3, ​72); 
-s->setPoint(0, ​xc - halfSizeyc - halfSize); // lower left  +r.setPoint(4, ​12);
-s->setPoint(1, ​xc - halfSizeyc + halfSize); // upper left +
-s->setPoint(2, ​xc + halfSizeyc + halfSize); // upper right +
-s->setPoint(3, ​xc + halfSizeyc - halfSize); // lower right +
-s->setPoint(4, ​xc - halfSizeyc - halfSize); // closing+
 </​code>​ </​code>​
  
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 **Polygon** is a subclass of CurvePolygon whose rings are defined by linear rings. **Polygon** is a subclass of CurvePolygon whose rings are defined by linear rings.
  
 +The code snippet below shows how to create a polygon with just one outer boundary (a LinearRing):​
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​LinearRing>​ r = std::​make_unique<​te::​gm::​LinearRing>​(5,​ te::​gm::​LineStringType,​ 4326);
 +
 +r->​setPoint(0,​ 1, 2);
 +r->​setPoint(1,​ 1, 7);
 +r->​setPoint(2,​ 7, 7);
 +r->​setPoint(3,​ 7, 2);
 +r->​setPoint(4,​ 1, 2);
 +    ​
 +te::​gm::​Polygon p(1, te::​gm::​PolygonType,​ 4326);
 +    ​
 +p.setRingN(0,​ r.release());​
 +</​code>​
 +
 +You have also methods that allows to add rings incrementally:​
 <code cpp> <code cpp>
 std::​unique_ptr<​te::​gm::​Polygon>​ p = std::​make_unique<​te::​gm::​Polygon>​(0,​ te::​gm::​PolygonType);​ std::​unique_ptr<​te::​gm::​Polygon>​ p = std::​make_unique<​te::​gm::​Polygon>​(0,​ te::​gm::​PolygonType);​
Line 252: Line 263:
  
 ===== Spatial Relationships ===== ===== Spatial Relationships =====
 +
 +**1.** Does the red polygon contains the blue one?
 <code cpp> <code cpp>
-std::​unique_ptr<​te::​gm::​Geometry> ​g1(0); +std::​unique_ptr<​te::​gm::​Geometry> ​red( te::gm::WKTReader::​read("​POLYGON ( (9 2, 9 7, 15 7, 15 2, 9 2) )"​) ​);
-std::​unique_ptr<​te::gm::Geometry>​ g2(0);+
  
-std::cout << g1->​contains(g2);+std::unique_ptr<te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (10 4, 10 7, 14 7, 14 4, 10 4) )") ); 
 +     
 +bool result = red->​contains( ​blue() ​);
  
-std::cout << ​g1->​coveredBy(g2);+std::cout << ​std::​boolalpha << result << std::end; 
 +</​code>​
  
-std::cout << g1->covers(g2);+**2.** Does the red polygon contains the blue one? 
 +<code cpp> 
 +std::unique_ptr<te::​gm::​Geometryred( te::​gm::​WKTReader::​read("​POLYGON ( (2 3, 2 6, 6 6, 6 3, 2 3) )"​) ​);
  
-std::cout << return g1->crosses(g2);+std::unique_ptr<te::​gm::​Geometryblue( te::​gm::​WKTReader::​read("​POLYGON ( (1 2, 1 7, 7 7, 7 2, 1 2) )"​) ​);
  
-std::cout << return g1->disjoint(g2);+bool result =  red->withinblue() ​);
  
-std::cout << ​return g1->​equals(g2);+std::cout << ​std::​boolalpha << result << std::endl; 
 +</​code>​
  
-std::cout << g1->intersects(g2);+<code cpp> 
 +std::unique_ptr<te::​gm::​Geometryred( te::​gm::​WKTReader::​read("​POLYGON ( (10 4, 10 7, 14 7, 14 4, 10 4) )"​) ​);
  
-std::cout << g1->overlaps(g2);+std::unique_ptr<te::​gm::​Geometryblue( te::​gm::​WKTReader::​read("​POLYGON ( (9 2, 9 7, 15 7, 15 2, 9 2) )"​) ​);
  
-std::cout << g1->touches(g2);+bool result =  red->withinblue() ​);
  
-std::cout << ​g1->within(g2);+std::cout << ​std::​boolalpha << result << std::​endl;​ 
 +</​code>​ 
 + 
 +**3.** Does the red line touches the blue one? 
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​LINESTRING (1 5, 1 7, 3 7)") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​LINESTRING (3 5, 1 7)") ); 
 +     
 +bool result = red->touchesblue.get() ); 
 + 
 +std::cout << std::​boolalpha << result << std::endl ; 
 +</​code>​ 
 + 
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​LINESTRING (4 5, 4 7, 6 7)") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​LINESTRING (5 5, 5 8)") ); 
 + 
 +bool result = red->​touches( blue.get() ); 
 + 
 +std::cout << std::​boolalpha << result << std::endl ; 
 +</​code>​ 
 + 
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​LINESTRING (1 3, 3 4)") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​LINESTRING (3 4, 5 3)") ); 
 +     
 +bool result = red->​touches( blue.get() ); 
 + 
 +std::cout << std::​boolalpha << result << std::endl ; 
 +</​code>​ 
 + 
 +**3.** Does the red polygon touches the blue one? 
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (1 0, 1 2, 4 2, 4 0, 1 0) )") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (4 0, 4 2, 7 2, 7 0, 4 0) )") ); 
 +     
 +bool result = red->​touches( blue.get() ); 
 + 
 +std::cout << std::​boolalpha << result << std::endl ; 
 +</​code>​ 
 +   
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (8 5, 8 7, 11 7, 11 5, 8 5) )") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (11 6, 13 8, 15 6, 13 4, 11 6) )") ); 
 + 
 +bool result = red->​touches( blue.get() ); 
 + 
 +std::cout << std::​boolalpha << result << std::endl ; 
 + 
 +</​code>​  
 +   
 +<code cpp> 
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (9 1, 9 3, 12 3, 12 1, 9 1) )") ); 
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (11 2, 13 3, 15 2, 13 1, 11 2) )") ); 
 +     
 +bool result = red->​touches( blue.get() ​)
 + 
 +std::cout << std::​boolalpha << result << std::​endl ​;
 </​code>​ </​code>​
  
 ===== Set Operations ===== ===== Set Operations =====
  
 +**1.** Polygon intersection:​
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (2 2, 2 4, 5 4, 5 2, 2 2) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (4 1, 4 3, 7 3, 7 1, 4 1) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​intersection( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::end;
 +</​code>​
 +
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (2 5, 2 7, 5 7, 5 5, 2 5) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (5 5, 5 7, 8 7, 8 5, 5 5) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​intersection( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 +
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (9 2, 9 4, 11 4, 11 2, 9 2) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (12 1, 12 3, 15 3, 15 1, 12 1) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​intersection( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 +
 +**2.** Polygon union:
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (2 2, 2 4, 5 4, 5 2, 2 2) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (4 1, 4 3, 7 3, 7 1, 4 1) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​Union( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 +
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (2 5, 2 7, 5 7, 5 5, 2 5) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (5 5, 5 7, 8 7, 8 5, 5 5) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​Union( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 +
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ red( te::​gm::​WKTReader::​read("​POLYGON ( (9 2, 9 4, 11 4, 11 2, 9 2) )") );
 +std::​unique_ptr<​te::​gm::​Geometry>​ blue( te::​gm::​WKTReader::​read("​POLYGON ( (12 1, 12 3, 15 3, 15 1, 12 1) )") );
 +    ​
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( red->​Union( blue.get() ) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 ===== Buffer ===== ===== Buffer =====
  
 +<code cpp>
 +std::​unique_ptr<​te::​gm::​Geometry>​ poly( te::​gm::​WKTReader::​read("​POLYGON ( (6 3, 6 5, 9 5, 9 3, 6 3) )") );
 +
 +std::​unique_ptr<​te::​gm::​Geometry>​ result( poly->​buffer(2.0) );
 +    ​
 +std::cout << result->​toString() ​ << std::endl;
 +</​code>​
 ===== Metric Operators ===== ===== Metric Operators =====