; surface.pro - Defines the ancestor to all CSG surface objects. This
; object by itself is null - It has no points on its interior, and a
; ray never intersects it
;
; ----------------------------------------------------------------------
; CONSTRUCTOR
; ----------------------------------------------------------------------
;
function surface::init
  status = 1
  return, status
end

;function is_inside
;Inputs:
;  R - a vector to test. May be a grid
;Returns:
;  1 if given vector is inside the surface, 0 if not. In general, this should
;  return true if the point is exactly on the surface. This particular
;  object occupies no space, so it always returns 0
function surface::is_inside,r
  return, bytarr(shape_grid(r))
end

;function intersect
;  Calculates intersection parameter t for this surface and a ray
;  R=R0+V*t
;Inputs:
;  R0 - Origin of ray to test. Must be a single vector
;  V  - Direction of ray to test. May be a grid
;Returns:
;  t parameter of intersection, or negative value or NaN if no intersection.
;  This particular object is never intersected, so it always returns -1
function surface::intersect,r0,v
  return, dblarr(shape_grid(v))-1
end

;function to_pov
;  Returns a string containing a representation of this surface in POV-Ray code.
;  All vectors in the representation must be converted to left-handed. This
;  particular object has no representation, so it returns an empty string
function surface::to_pov
  return,''
end
function surface::to_pov_array
  return,''
end

;--------------------------------------------------------------------------
; CLEANUP
; --------------------------------------------------------------------------
; PURPOSE:
;   Lifecycle method to clean itself up.
;
pro surface::CLEANUP

end

; --------------------------------------------------------------------------
; Object Data Structure Definition
; --------------------------------------------------------------------------
; PURPOSE:
;   Define the data structure associated with this object.
pro surface__define
  self = {surface, version:0}
end