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DCL:GRPH1:SZPACK: Basic Graphics Routines:List of Subroutines:Basic Graphics Routines

5.2.2.1 Polyline Routines

	Input Coordinates	Contents of Processing
szxxlu	U	Rotation/Normalization Transformation, Linear Interpolation
szxxlt	T	Map projection, Great circle interpolation, clipping at map boundaries
szxxlv	V	Clipping a viewport
szxxlc	V	Expanding to labeled line segments
szxxld	V	Expanding to dotted lines
szxxlp	V	Perspective transformation
szxxlr	R	Clipping in a WS viewport
szxxlz	R	WS transformation, line drawing

There are 4 types according to the operation of xx: op: OPEN; mv: MOVE; pl: PLOT; and cl: CLOSE.

These routines can be considered as expansions of the interface routine SZPLZc(N,PX,PY). The following is a program for drawing a polyline using basic routines.

  CALL SZPLOP(ITYPE,INDEX)

    CALL SZOPLc  

      CALL SZMVLc(UXX,UYY)   

      CALL SZPLLc(UXX,UYY)        

            .........        

    CALL SZCLLc      

  CALL SZPLCL

The szplop changes line type and line index, as well as inquire the necessary information by sgrget, so calling it frequently will affect speed.