# -----------------------------------------------------------------------------
# 
# Surface 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"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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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 Features
    
    
    # == SFS 1.1 Description
    # 
    # A Surface is a 2-dimensional geometric object.
    # 
    # A simple Surface consists of a single "patch" that is associated with
    # one "exterior boundary" and 0 or more "interior" boundaries. Simple
    # Surfaces in 3-dimensional space are isomorphic to planar Surfaces.
    # Polyhedral Surfaces are formed by "stitching" together simple
    # Surfaces along their boundaries, polyhedral Surfaces in 3-dimensional
    # space may not be planar as a whole.
    # 
    # The boundary of a simple Surface is the set of closed Curves
    # corresponding to its "exterior" and "interior" boundaries.
    # 
    # The only instantiable subclass of Surface defined in this
    # specification, Polygon, is a simple Surface that is planar.
    # 
    # == Notes
    # 
    # Surface 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. A corresponding === operator is also provided to
    # to support case-when constructs.
    # 
    # Some implementations may support higher dimensional points.
    
    module Surface
      
      include Geometry
      
      
      # === SFS 1.1 Description
      # 
      # The area of this Surface, as measured in the spatial reference
      # system of this Surface.
      # 
      # === Notes
      # 
      # Returns a floating-point scalar value.
      
      def area
        raise Errors::MethodUnimplemented
      end
      
      
      # === SFS 1.1 Description
      # 
      # The mathematical centroid for this Surface as a Point. The result
      # is not guaranteed to be on this Surface.
      # 
      # === Notes
      # 
      # Returns an object that supports the Point interface.
      
      def centroid
        raise Errors::MethodUnimplemented
      end
      
      
      # === SFS 1.1 Description
      # 
      # A Point guaranteed to be on this Surface.
      # 
      # === Notes
      # 
      # Returns an object that supports the Point interface.
      
      def point_on_surface
        raise Errors::MethodUnimplemented
      end
      
      
    end
  
    
  end
  
end