lw_segment_side()

int lw_segment_side	(	const POINT2D *	p1,
		const POINT2D *	p2,
		const POINT2D *	q
	)

lw_segment_side()

Return -1 if point Q is left of segment P Return 1 if point Q is right of segment P Return 0 if point Q in on segment P

Definition at line 64 of file lwalgorithm.c.

References SIGNUM, POINT2D::x, and POINT2D::y.

Referenced by edge_calculate_gbox(), lw_arc_calculate_gbox_cartesian_2d(), lw_arc_length(), lw_arc_side(), lw_dist2d_arc_arc_concentric(), lw_pt_in_arc(), lw_segment_intersects(), lwarc_linearize(), pt_continues_arc(), pta_unstroke(), ptarray_contains_point_partial(), rect_tree_contains_point(), and test_lw_segment_side().

{
        double side = ( (q->x - p1->x) * (p2->y - p1->y) - (p2->x - p1->x) * (q->y - p1->y) );
        return SIGNUM(side);
}

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