Class: Geos::LineString

Inherits:
Geometry show all
Includes:
Enumerable
Defined in:
lib/ffi-geos/line_string.rb

Direct Known Subclasses

LinearRing

Constant Summary

Constants included from GeomTypes

GeomTypes::GEOS_GEOMETRYCOLLECTION, GeomTypes::GEOS_LINEARRING, GeomTypes::GEOS_LINESTRING, GeomTypes::GEOS_MULTILINESTRING, GeomTypes::GEOS_MULTIPOINT, GeomTypes::GEOS_MULTIPOLYGON, GeomTypes::GEOS_POINT, GeomTypes::GEOS_POLYGON

Instance Attribute Summary

Attributes inherited from Geometry

#ptr

Instance Method Summary collapse

Methods inherited from Geometry

#==, #area, #boundary, #buffer, #centroid, #clip_by_rect, #contains?, #convex_hull, #coord_seq, #covered_by?, #covers?, #crosses?, #delaunay_triangulation, #difference, #dimensions, #disjoint?, #distance, #empty?, #end_point, #envelope, #eql?, #eql_almost?, #eql_exact?, #extract_unique_points, #frechet_distance, #geom_type, #has_z?, #hausdorff_distance, #initialize, #initialize_copy, #interpolate, #interpolate_normalized, #intersection, #intersects?, #length, #line_merge, #minimum_clearance, #minimum_clearance_line, #minimum_rotated_rectangle, #minimum_width, #nearest_points, #node, #normalize!, #num_coordinates, #num_geometries, #overlaps?, #point_on_surface, #polygonize, #polygonize_cut_edges, #polygonize_full, #precision, #project, #project_normalized, #relate, #relate_boundary_node_rule, #relate_pattern, release, #reverse, #ring?, #shared_paths, #simple?, #simplify, #snap, #srid, #srid=, #start_point, #sym_difference, #to_prepared, #to_s, #topology_preserve_simplify, #touches?, #type_id, #unary_union, #union, #union_cascaded, #valid?, #valid_detail, #valid_reason, #voronoi_diagram, #with_precision, #within?

Methods included from Tools

#bool_result, #bool_to_int, #cast_geometry_ptr, #check_enum_value, #check_geometry, #extract_options!, #pick_srid_according_to_policy, #pick_srid_from_geoms, #symbol_for_enum

Constructor Details

This class inherits a constructor from Geos::Geometry

Instance Method Details

#[](*args) ⇒ Object Also known as: slice



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# File 'lib/ffi-geos/line_string.rb', line 36

def [](*args)
  if args.length == 1 && args.first.is_a?(Numeric) && args.first >= 0
    point_n(args.first)
  else
    to_a[*args]
  end
end

#closed?Boolean

Returns:

  • (Boolean)


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# File 'lib/ffi-geos/line_string.rb', line 59

def closed?
  bool_result(FFIGeos.GEOSisClosed_r(Geos.current_handle_pointer, ptr))
end

#dump_points(cur_path = []) ⇒ Object



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# File 'lib/ffi-geos/line_string.rb', line 77

def dump_points(cur_path = [])
  cur_path.concat(to_a)
end

#eachObject



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# File 'lib/ffi-geos/line_string.rb', line 7

def each
  if block_given?
    num_points.times do |n|
      yield point_n(n)
    end
    self
  else
    num_points.times.collect { |n|
      point_n(n)
    }.to_enum
  end
end

#line_interpolate_point(fraction) ⇒ Object Also known as: interpolate_point



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# File 'lib/ffi-geos/line_string.rb', line 103

def line_interpolate_point(fraction)
  if !fraction.between?(0, 1)
    raise ArgumentError.new("fraction must be between 0 and 1")
  end

  case fraction
    when 0
      self.start_point
    when 1
      self.end_point
    else
      length = self.length
      total_length = 0
      segs = self.num_points - 1

      segs.times do |i|
        p1 = self[i]
        p2 = self[i + 1]

        seg_length = p1.distance(p2) / length

        if fraction < total_length + seg_length
          dseg = (fraction - total_length) / seg_length;

          args = []
          args << p1.x + ((p2.x - p1.x) * dseg)
          args << p1.y + ((p2.y - p1.y) * dseg)
          args << p1.z + ((p2.z - p1.z) * dseg) if self.has_z?

          args << { :srid => pick_srid_according_to_policy(self.srid) } unless self.srid == 0

          return Geos.create_point(*args)
        end

        total_length += seg_length
      end

      # if all else fails...
      self.end_point
  end
end

#num_pointsObject



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# File 'lib/ffi-geos/line_string.rb', line 21

def num_points
  FFIGeos.GEOSGeomGetNumPoints_r(Geos.current_handle_pointer, ptr)
end

#offset_curve(width, options = {}) ⇒ Object



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# File 'lib/ffi-geos/line_string.rb', line 45

def offset_curve(width, options = {})
  options = Constants::BUFFER_PARAM_DEFAULTS.merge(options)

  cast_geometry_ptr(FFIGeos.GEOSOffsetCurve_r(
    Geos.current_handle_pointer,
    ptr,
    width,
    options[:quad_segs],
    options[:join],
    options[:mitre_limit]
  ), srid_copy: srid)
end

#point_n(n) ⇒ Object



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# File 'lib/ffi-geos/line_string.rb', line 30

def point_n(n)
  raise Geos::IndexBoundsError if n < 0 || n >= num_points

  cast_geometry_ptr(FFIGeos.GEOSGeomGetPointN_r(Geos.current_handle_pointer, ptr, n), srid_copy: srid)
end

#snap_to_grid(*args) ⇒ Object



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# File 'lib/ffi-geos/line_string.rb', line 97

def snap_to_grid(*args)
  ret = self.dup.snap_to_grid!(*args)
  ret.srid = pick_srid_according_to_policy(self.srid)
  ret
end

#snap_to_grid!(*args) ⇒ Object



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# File 'lib/ffi-geos/line_string.rb', line 81

def snap_to_grid!(*args)
  if !self.empty?
    cs = self.coord_seq.snap_to_grid!(*args)

    if cs.length == 0
      @ptr = Geos.create_empty_line_string(:srid => self.srid).ptr
    elsif cs.length <= 1
      raise Geos::InvalidGeometryError.new("snap_to_grid! produced an invalid number of points in for a LineString - found #{cs.length} - must be 0 or > 1")
    else
      @ptr = Geos.create_line_string(cs).ptr
    end
  end

  self
end

#to_linear_ringObject



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# File 'lib/ffi-geos/line_string.rb', line 64

def to_linear_ring
  return Geos.create_linear_ring(coord_seq, srid: pick_srid_according_to_policy(srid)) if closed?

  self_cs = coord_seq.to_a
  self_cs.push(self_cs[0])

  Geos.create_linear_ring(self_cs, srid: pick_srid_according_to_policy(srid))
end

#to_polygonObject



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# File 'lib/ffi-geos/line_string.rb', line 73

def to_polygon
  to_linear_ring.to_polygon
end