V9/jerq/include/line.h

/*
 * Definitions for globals involved with lines
 */
short Jdmajor;		/* Delta for major direction */
short Jdminor;		/* Delta for minor direction */
short Jxmajor;	/* flag: is x the major direction? */
short Jslopeneg;	/* flag: is slope of line negative? */
Point Jsetline();