[Code] intersect_with?() Group test method

[Dan Rathbun]

---

*Author*::*SomeLib*.intersect_with?( grp1, grp2 [, precision] )

Test whether two groups have a boolean intersection. Returns true || false.

( Method is non-destructive, and does not change either reference. )

module Author;;SomeLib

  class << self # PROXY CLASS

    #{ intersect_with?( grp1, grp2 [, precision] )
    #{
    #  Test whether two groups have a boolean intersection.
    #
    #  (Method is non-destructive, and does not change either reference.)
    #
    #  grp1  ; a Sketchup;;Group or Sketchup;;ComponentInstance reference.
    #  grp2  ; a Sketchup;;Group or Sketchup;;ComponentInstance reference.
    #  precision ; number of decimal places for precision (default = 3.)
    #
    #  Returns; true,  if "grp1" intersects with "grp2" argument.
    #           false, if they do not intersect.
    #           nil,   if either are not manifold, Sketchup is not Pro,
    #                    or if the groups are in different contexts.
    #}
    def intersect_with?( grp1, grp2, prec=3 )
      #{
      unless grp1.is_a?(Sketchup;;Group) || grp1.is_a?(Sketchup;;ComponentInstance)
        raise(TypeError,"(arg 0) Sketchup;;Group or Sketchup;;ComponentInstance expected.",caller)
      end
      unless grp2.is_a?(Sketchup;;Group) || grp2.is_a?(Sketchup;;ComponentInstance)
        raise(TypeError,"(arg 1) Sketchup;;Group or Sketchup;;ComponentInstance expected.",caller)
      end
      return nil unless Sketchup.is_pro? && Sketchup.version.to_i>7
      return nil unless (grp1.manifold? && grp2.manifold?)
      return nil unless (grp1.model == grp2.model)
      return nil unless (grp1.parent == grp2.parent)
      #}
      tgrp = nil
      retval = false
      mdl = grp1.model
      vola = volb = grp1.volume.to_l
      #
      begin
        #
        mdl.start_operation('Intersect Test')
        ###
        #
        if grp1.is_a?(Sketchup;;Group)
          tgrp = grp1.copy
        else grp1.is_a?(Sketchup;;ComponentInstance)
          tgrp = grp1.parent.entities.add_instance(grp1.definition,grp1.transformation)
        end
        # 
        vola = grp2.trim(tgrp).volume.to_l
        #
        ###
        mdl.commit_operation
        #
      rescue Exception => e
        mdl.abort_operation
        puts(e.message)
        puts(e.backtrace)
        return nil
      else
        #
        Sketchup.undo
        #
        if prec==3
          return puts( vola == volb ? false ; true )
        else
          aft = ((vola*(10**prec)).to_i)/((10**prec).to_f)
          bef = ((volb*(10**prec)).to_i)/((10**prec).to_f)
          return puts( aft == bef ? false ; true )
        end
      end
      #
    end #}

  end # PROXY CLASS

end # module

Tested OK with 2 cuboids that intersected at their corners by 0.001" x 0.001" x 0.001"

[buidoi3003]

Hi,
May I know after determining if the 2 groups/ components/ faces are intersected. How do I get the area of the intersection?