GPNLER - Nullify Element Range

Purpose

Use GPNLER to replace all elements between the specified structure elements in the open structure with Null Data structure elements. This subroutine requires that the structure state is Structure Open (STOP)

Two element search parameters, re1 and re2, specify the range of structure elements to be processed. Each of these parameters is an array of three fullword integers. The first integer specifies the method to use in the element search and the second specifies the target value of the element search. The third integer specifies an option value.

If both of the specified elements point beyond the last element in the structure, then no elements are replaced and the element pointer remains unchanged.

If one of the specified elements points beyond the last element in the structure, then the graPHIGS API uses the last last element in the open structure instead.

If both of the element numbers are less than one, then the graPHIGS API does not replace any elements and the element pointer remains unchanged.

If one of the element numbers is less than one, then the element number value defaults to a value of one.

Elements between the lower element number and the higher element number are replaced with Null Data (GPNULL) structure elements. If the element range consists of only one element and the options on parameters re1 and re2 are conflicting, then the graPHIGS API applies th the 2=EXCLUDE option value.

After replacement of elements, the element pointer moves to the last element replaced.

Parameters

    -----------------
  0 | search method | fullword integer
    |---------------|
  4 | target value  | fullword integer
    |---------------|
  8 | option value  | fullword integer
    -----------------
 
     Search method supported:
         Method 1 = ELEMNUM
     Target value:
         For method 1, the target value is a structure element
         number.
     Option values supported:
         1 = INCLUDE
             Nullifies the resulting structure element derived
             from the range element search parameter.
         2 = EXCLUDE
             Does not nullify the resulting structure element
             derived from the range element search parameter.