VARKON Version 1.15 1997-12-29

arc_1pos - Geometric procedure

Creates an arc


Description

Creates a circular arc with specified origin and radius. An optional start and end angle may be specified.

Syntax

arc_1pos(id, p, r, start, end:attributes);

REF	id;
VECTOR	p;
FLOAT	r;
FLOAT	start;
FLOAT	end;

Principal parameters

id	- Local identity
p	- Arc centre
r	- Radius

Optional parameters

start	- Start angle, default = 0
end	- End angle, default = 360

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

Example

arc_1pos(#1,vec(10,10),20, ,90);

Creates the first quarter of a circle with centre in X=Y=10 and radius 20. A default value of 0 is taken for the start angle and 90 is used for the end angle.

Comments

The sense of direction for an arc is counterclockwise from start to end. The positive X-axis represents an angle of zero degrees. Angles may be given as negative or positive values but start should always be smaller then end.

In a 3D module the resulting arc is restricted to the XY-plane of the active coordinate system. If p is not in this plane ( p.z <> 0) p is projected along the Z-axis (p.z is set to zero) before the arc is created.