VARKON Version 1.15 1997-12-29

arc_2pos - Geometric procedure

Creates an arc


Description

Creates a circular arc defined by two positions and radius. The arc starts in the first position and turns anticlockwise to the second position where it ends. A positive value for radius creates the shorter of the two possible arcs (end-start < 180 degrees) and a negative value creates the longer (end-start > 180 degrees).

Syntax

arc_2pos(id, p1, p2, r:attributes);

REF	id;
VECTOR	p1;
VECTOR	p2;
FLOAT	r;

Principal parameters

id	- Local identity
p1	- Start position
p2	- End position
r	- Radius

Optional parameters

None.

Attributes

PEN	- Pen or colour number
LEVEL	- Level number
BLANK	- Visible(0) or invisible(1)
AFONT	- Solid(0), dashed(1) or centerline(2)
ADASHL	- Dashlength
WIDTH	- Linewidth

Examples

arc_2pos(#1, vec(1,0),vec(0,1),1);

Creates the first quarter of a circle with radius = 1.

Comments

In a 3D module the resulting arc is restricted to the XY-plane of the active coordinate system. If p1 or p2 are not in this plane they will be projected along the Z-axis onto the XY-plane before being used to create the arc. The absolute value of r must be larger than half the distance between p1 and p2.