2.6 Explanation of the Subroutines: Polyline Primitives

This is a subroutine group for the polyline output primitives.



When the internal variable 'LMISS' handled by GLpGET/GLpSET is set to .TRUE., missing-value handling will be performed. In other words, the polyline will not be connected before and after a missing value.



When the internal variable 'LCHAR' is set to .TRUE., a labeled polyline will be drawn. The labeled polyline here refers to a polyline with an empty space created in a part of the line, which is filled with the specified text, when the lwhole ength of the polyline to be drawn is a single cycle. The text for the label is specified with SGSPLC. (See Section 2.6.5.) The height of the text is specified with SGSPLS. (See Section 2.6.6.) For a definition of a cycle, see the explanation on the internal variable handled by SGpGET/SGpSET. (See Section 2.4.4.)



Setting the internal variable 'LCHAR' to .TRUE. affects  all of the routines for drawing lines. Therefore, after drawing the line segment with 'LCHAR' as .TRUE., remember to return the value to .FALSE..