ClosestPointTo

Introduction

The ClosestPointTo returns the closest point on the calling Segment to the argument position. The closest point may be anywhere on the segment including the endpoints.

Code Example

The following creates a Segment and a Line as a visible representation of the Segment. The update method finds the closest point on the Segment to the Mouse and positions a Sprite there.

Add the following using statements:

using FlatRedBall.Math.Geometry;
using FlatRedBall.Input;

Add the following at class scope:

Sprite sprite;
Segment segment;

Add the following to Initialize after initializing FlatRedBall:

sprite = SpriteManager.AddSprite("redball.bmp");

segment = new Segment(
    -20, // first point X
    -8,  // first point Y
    20,  // second point X
    8);  // second point Y

// Let's make a visible representation of the segment
Line line = ShapeManager.AddLine();
line.RelativePoint1 = new Point3D(
    segment.Point1.X,
    segment.Point1.Y);
line.RelativePoint2 = new Point3D(
    segment.Point2.X,
    segment.Point2.Y);

Add the following to Update:

FlatRedBall.Math.Geometry.Point cursorPoint =
    new FlatRedBall.Math.Geometry.Point(
        InputManager.Mouse.WorldXAt(0),
        InputManager.Mouse.WorldYAt(0));

FlatRedBall.Math.Geometry.Point closestPoint =
    segment.ClosestPointTo(cursorPoint);

sprite.Position.X = (float)closestPoint.X;
sprite.Position.Y = (float)closestPoint.Y;

ClosestPoint.png