# -----------------------------------------------------------------------------
# 
# MultiCurve feature interface
# 
# -----------------------------------------------------------------------------
# Copyright 2010 Daniel Azuma
# 
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
# 
# * Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
# * Redistributions in binary form must reproduce the above copyright notice,
#   this list of conditions and the following disclaimer in the documentation
#   and/or other materials provided with the distribution.
# * Neither the name of the copyright holder, nor the names of any other
#   contributors to this software, may be used to endorse or promote products
#   derived from this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
# -----------------------------------------------------------------------------
;


module RGeo
  
  module Feature
    
    
    # == SFS 1.1 Description
    # 
    # A MultiCurve is a 1-dimensional GeometryCollection whose elements are
    # Curves.
    # 
    # MultiCurve is a non-instantiable class in this specification; it
    # defines a set of methods for its subclasses and is included for
    # reasons of extensibility.
    # 
    # A MultiCurve is simple if and only if all of its elements are simple
    # and the only intersections between any two elements occur at Points
    # that are on the boundaries of both elements.
    # 
    # The boundary of a MultiCurve is obtained by applying the "mod 2"
    # union rule: A Point is in the boundary of a MultiCurve if it is in
    # the boundaries of an odd number of elements of the MultiCurve.
    # 
    # A MultiCurve is closed if all of its elements are closed. The
    # boundary of a closed MultiCurve is always empty.
    # 
    # A MultiCurve is defined as topologically closed.
    # 
    # == Notes
    # 
    # MultiCurve is defined as a module and is provided primarily
    # for the sake of documentation. Implementations need not necessarily
    # include this module itself. Therefore, you should not depend on the
    # kind_of? method to check type. Instead, use the provided check_type
    # class method (or === operator) defined in the Type module.
    
    module MultiCurve
      
      extend Type
      
      include GeometryCollection
      
      
      # === SFS 1.1 Description
      # 
      # The Length of this MultiCurve which is equal to the sum of the
      # lengths of the element Curves.
      # 
      # === Notes
      # 
      # Returns a floating-point scalar value.
      
      def length
        raise Error::UnsupportedCapability, "Method MultiCurve#length not defined."
      end
      
      
      # === SFS 1.1 Description
      # 
      # Returns true if this MultiCurve is closed [StartPoint() = EndPoint()
      # for each Curve in this MultiCurve].
      # 
      # === Notes
      # 
      # Returns a boolean value. Note that this is different from the SFS
      # specification, which stipulates an integer return value.
      
      def is_closed?
        raise Error::UnsupportedCapability, "Method MultiCurve#is_closed? not defined."
      end
      
      
    end
  
    
  end
  
end