Enum ArcDirection

Namespace

Thunder.UnitsNET.Vectors.Geometry

Assembly

Thunder.UnitsNET.Vectors.Geometry.dll

Specifies the direction in which an arc sweeps around its circle.

In standard 2D mathematical convention, counter-clockwise is the positive direction (increasing angle from the positive X-axis). Clockwise is the negative direction.

public enum ArcDirection

Fields

Clockwise = 0

The arc sweeps in the clockwise direction (decreasing angle; negative sweep).

CounterClockwise = 1

The arc sweeps in the counter-clockwise direction (increasing angle; positive sweep). This is the standard positive direction in mathematics.

Examples

var circle = new Circle2(LengthPoint2.Origin, Radius.FromMeters(1));
// A counter-clockwise arc sweeps from East (0°) toward North (90°)
var arc = new Arc2(circle, Direction2.East, Angle.FromDegrees(90)); // CCW because angle > 0

// A clockwise arc sweeps from East (0°) toward South (270°, or −90° signed)
var cw  = new Arc2(circle, Direction2.East, Angle.FromDegrees(-90)); // CW because angle < 0

Remarks

In MonoGame's Y-down screen space (where Y increases downward), the visual appearance of arc direction is inverted relative to the mathematical convention. A CounterClockwise arc in world space (Y-up, mathematical convention) appears to sweep clockwise on screen when rendered via camera transformation. This is expected and correct — the mathematical direction is preserved; the visual inversion is a natural consequence of the Y-axis flip during coordinate transformation.

Both arc direction and camera transform are self-consistent: rendering a CCW arc with PointAt in Y-down space produces the expected visual traversal. Verify the on-screen sweep direction in your target coordinate system during your placement spike before committing to a direction convention.