ARC Object

Software Customisation Reference Manual

Summary of Objects, Members and Methods : Object Type Details : ARC Object


Name	Type	Purpose
Orientation	ORIENTATION Get/Set	Orientation of the arc.
Position	POSITION Get/Set	Origin/Centre of the arc.
Radius	REAL Get/Set	Radius of the arc
StartAngle	REAL Get/Set	Angle from X axes to start of the arc.
EndAngle	REAL Get/Set	Angle from X axes to end of the arc.
Sense	BOOLEAN Get/Set	Arc sense: ·0 for clockwise ·1 for anti-clockwise

Table 2: 6.

Basic ARC Definition Members

Basic ARC Definition: Methods

These methods do not modify the original object.


Name	Result	Purpose
Arc( POSITION, ORIENTATION, REAL, REAL, REAL,BOOLEAN)	ARC	Creates an arc with the given Position, Orientation, Start Angle, End Angle, Radius. If the last argument is TRUE, the arc is clockwise.
String()	STRING	Returns the arc as a string

Table 2: 7.

Basic ARC Definition Methods

ARC Methods that Return ARCs

None of these methods modifies the original object.


Name	Result	Purpose
StartPosition(POSITION)	ARC	Returns a new arc, based on the original, where the start angle, if defined as the angle from the centre of the arc through the passed position mapped onto the arc plane, forms the X axis.
EndPosition(POSITION)	ARC	As StartPosition, but for the EndAngle.
Through(POSITION)	ARC	Returns a new arc, where the radius (of the full circle) passes through the passed position when mapped onto the arc plane.
ChordHeight(REAL)	ARC	Returns a new arc, based on the original, where the EndAngle is in such a position to produce the passed chord height. Chord height > Radius or Chord height < 0 return unset objects. New arc should not produce subtended angle > 180.
Chord(REAL)	ARC	Returns a new arc, maintaining the original StartAngle, so the EndAngle is at the specified distance from the Start Chord length > Radius * 2 or < 0 return an unset object.
Circle()	ARC	Returns a full circle definition of the arc.
Circle(BOOLEAN)	ARC	Returns a full circle definition of the arc. If True, the arc is anti-clock-wise
Complement()	ARC	Returns the complementary arc of the arc definition (the remainder of the circle)

Table 2: 8.

ARC Methods that Return ARCs

Figure 2:8.

ARCs Returned by ARC Methods

ARC Method that Returns POSITIONs

This method does not modify the original object.


Name	Result	Purpose
AnglePosition(REAL)	POSITION	Returns the position at the specified angle on the arc.

Table 2: 9.

ARC Methods that Return POSITIONs

Figure 2:9.

POSITIONs Returned by ARC Methods

ARC Methods that Return DIRECTIONs

None of these methods modifies the original object.


Name	Result	Purpose
AngleDirection(REAL)	DIRECTION	Returns the direction from the centre of the arc through a point at the given angle from the X axis
StartTangent()	DIRECTION	Returns the direction out of the arc, tangential to the start angle line. The “sense” of the arc is used.
EndTangent()	DIRECTION	Returns the direction out of the arc, tangential to the end angle line. The “sense” of the arc is used.
AngleTangent(REAL)	DIRECTION	Returns the direction, tangential to the angle passed.

Table 2: 10.

ARC Methods that Return DIRECTIONs

Figure 2:10.

DIRECTIONs Returned by ARC Methods

ARC Methods that Return XYOffsets

This method does not modify the original object.


Name	Result	Purpose
XYOffset(POSITION)	XYPOSITION	Returns the position, mapped onto the arc plane, in term of an XY offset from the arc plane origin

Figure 2:11.

ARC Methods that Return XYOffsets

Figure 2:12.

XYOffsets Returned from ARC Methods

ARC Methods that Return REALs

None of these methods modifies the original object.


Name	Result	Purpose
Proportion(REAL)	REAL	Returns the position, in terms of an angle from the X axis, at the proportion from the start angle of the arc: Angle = (EndAngle - StartAngle) * <real> + StartAngle
Angle()	REAL	Returns the subtended angle of the arc
Near(POSITION)	REAL	Returns the position, in terms of an angle from the X axis, to the position on the arc plane of the passed position

Table 2: 11.

ARC Methods that Return REALs (a)

Figure 2:13.

REALs Returned by ARC Methods (a)


Name	Result	Purpose
Chord()	REAL	Returns the chord length between the start and end of the arc definition
Length()	REAL	Returns the true length of the arc line
ChordHeight()	REAL	Returns the chord height of the arc line

Table 2: 12.

ARC Methods that Return REALs (b)

Figure 2:14.

REALs Returned by ARC Methods (b)

ARC Intersection Methods that Return REAL ARRAYs

None of these methods modifies the original object.


Name	Result	Purpose
Intersections(LINE)	REAL ARRAY	Returns the intersection points, in terms of angles from the X axis, of the passed line (mapped onto arc plane) with the circle defined by the arc
Intersections(PLANE)	REAL ARRAY	Returns the intersection points, in terms of angles from the X axis, of the passed plane with the circle defined by the arc
Intersections(ARC)	REAL ARRAY	Returns the intersection points, in terms of angles from the X axis, of the circle implied by the passed arc with the circle defined by the arc The Arcs must be in the same plane, i.e. the angle between Z components of the direction must be 0 or 180

Table 2: 13.

ARC Intersection Methods that Return REAL ARRAYs

Figure 2:15.

REAL ARRAYs Returned by ARC Intersection Methods

ARC Tangent Methods Returning Real Arrays

None of these methods modifies the original object.


Name	Result	Purpose
Tangents(POSITION)	REAL ARRAY	Returns the points of tangency on the arc circle from the passed position, in terms of angles from the X axis,
Tangents(ARC)	REAL ARRAY	Returns the points of tangency on the arc circle for the passed arc circle, in terms of angles from the X axis
Split()	REAL ARRAY	Splits the arc into a non-zero number of segments
Pole()	POSITION	Returns the pole position of the arc

Table 2: 14.

ARC Tangent Methods that Return REAL ARRAYs

Figure 2:16.

REAL ARRAYs Returned from ARC Tangent Methods

ARC Methods that Return BOOLEANs

None of these methods modify the original object.


Name	Result	Purpose
On(POSITION)	BOOLEAN	Returns true if the passed position lies on the arc line
OnProjected(POSITION)	BOOLEAN	Returns true if the passed position, when projected onto the arc line, lies within it
OnExtended(POSITION)	BOOLEAN	Returns true if the passed position, when mapped onto the arc line, lies outside it

Table 2: 15.

ARC Methods that Return BOOLEANs

Figure 2:17.

ARRAY Object PML Built-in Type