ArcObjects Library Reference (Geometry)  

esriArcOrientation Constants

Describes how to rotate about the arc's center getting from the 'from' point to the 'to' point of an arc.

Constant Value Description
esriArcClockwise 0 The arc proceeds clockwise from its 'from' point to its 'to' point.
esriArcCounterClockwise 1 The arc proceeds counterclockwise from its 'from' point to its 'to' point.
esriArcMinor 2 The central angle of the arc is less than pi.
esriArcMajor 3 The central angle of the arc is greater than pi.

Product Availability

Available with ArcGIS Engine, ArcGIS Desktop, and ArcGIS Server.

Remarks

Describes the orientation of a CircularArc.  The orientation of a CircularArc is the direction of the arc between the From and To Points.  Orientation can be specified in terms of clockwise/counterclockwise orientation or in arc size (Minor/Major).  If the From and To Points are located at the same coordinates, clockwise and counterclockwise are ambiguous, and thus, it is necessary to specify the orientation of the arc based on the arc size.  The arc is a Minor arc if its Central Angle is less than half the full circle.  The arc is Major if its Central Angle is greater than half the circle.  If the Central Angle is exactly half a circle, Minor and Major are ambiguous, and thus, it is necessary to specify the orientation of the arc based on the clockwise/counterclockwise direction.

esriArcClockwise        = The arc goes clockwise between the From and To Points
esriArcCounterClockwise = The arc goes counterclockwise between the From and To Points
esriArcMinor            = The Central Angle is less than a half circle
esriArcMajor            = The Central Angle is greater than a half circle

esriArcOrientation Example