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--- wiki:documentation:devguide:geometry_module [2016/01/19 07:54]
gribeiro [LineString]
+++ wiki:documentation:devguide:geometry_module [2016/02/12 09:36] (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.
-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 =====
@@ Line 14: / Line 14: @@
     * 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.
-  * 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 //m// coordinate value represents arbitrary measurement.
   * The term //ring// is applied to a closed curve (the first and last points are coincident).
 ===== Geometry Class Hierarchy =====
@@ Line 43: / Line 42: @@
 <code cpp>
-std::unique_ptr<te::gm::Point> p = std::make_unique<te::gm::Point>(-54.0, -12.0, 4326);
+te::gm::Point p(-54.0, -12.0, 4326);
 </code>
@@ Line 69: / Line 68: @@
 <code cpp>
-std::unique_ptr<te::gm::LineString> l = 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>
@@ Line 94: / Line 93: @@
 <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, 1, 2);
-double yc = -12.0;
+r.setPoint(1, 1, 7);
-duble halfSize = size * 0.5;
+r.setPoint(2, 7, 7);
+r.setPoint(3, 7, 2);
-s->setPoint(0, xc - halfSize, yc - halfSize); // lower left
+r.setPoint(4, 1, 2);
-s->setPoint(1, xc - halfSize, yc + halfSize); // upper left
-s->setPoint(2, xc + halfSize, yc + halfSize); // upper right
-s->setPoint(3, xc + halfSize, yc - halfSize); // lower right
-s->setPoint(4, xc - halfSize, yc - halfSize); // closing
 </code>
@@ Line 155: / Line 150: @@
 **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>
 std::unique_ptr<te::gm::Polygon> p = std::make_unique<te::gm::Polygon>(0, te::gm::PolygonType);
@@ Line 252: / Line 263: @@
 ===== Spatial Relationships =====
+**1.** Does the red polygon contains the blue one?
 <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::Geometry> red( 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::Geometry> blue( te::gm::WKTReader::read("POLYGON ( (1 2, 1 7, 7 7, 7 2, 1 2) )") );
-std::cout << return g1->disjoint(g2);
+bool result =  red->within( blue() );
-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::Geometry> red( 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::Geometry> blue( te::gm::WKTReader::read("POLYGON ( (9 2, 9 7, 15 7, 15 2, 9 2) )") );
-std::cout << g1->touches(g2);
+bool result =  red->within( blue() );
-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->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 (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>
 ===== 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 =====
+<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 =====

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