/// <summary>
/// Computes an intersection of the line and the segment
/// </summary>
public static bool LineSegment(Line2 line, Segment2 segment, out IntersectionLineSegment2 intersection)
{
return(LineSegment(line.origin, line.direction, segment.a, segment.b, out intersection));
}
/// <summary>
/// Computes an intersection of the ray and the segment
/// </summary>
public static bool RaySegment(Ray2D ray, Segment2 segment, out IntersectionRaySegment2 intersection)
{
return(RaySegment(ray.origin, ray.direction, segment.a, segment.b, out intersection));
}
public static void DrawSegment(Segment2 segment, Color color, float duration, bool depthTest)
{
Debug.DrawLine((Vector3)segment.a, (Vector3)segment.b, color, duration, depthTest);
}
/// <summary>
/// Tests if the point lies on the segment
/// </summary>
/// <param name="side">
/// -1 if the point is to the left of the segment,
/// 0 if it is on the line,
/// 1 if it is to the right of the segment
/// </param>
public static bool PointSegment(Vector2 point, Segment2 segment, out int side)
{
return(PointSegment(point, segment.a, segment.b, out side));
}
public static bool SegmentToSegment(float start0x, float start0y, float end0x, float end0y, float start1x,
float start1y, float end1x, float end1y, out Segment2 intersection, bool testBoundingBox = false)
{
return(SegmentToSegmentE(start0x, start0y, end0x, end0y, start1x, start1y, end1x, end1y,
out intersection, testBoundingBox) != IntersectionType.None);
}
public static IntersectionType SegmentToSegmentE(Segment2 segment0, Segment2 segment1,
out Segment2 intersection, bool testBoundingBox = false)
{
return(SegmentToSegmentE(segment0.a, segment0.b, segment1.a, segment1.b, out intersection,
testBoundingBox));
}
/// <summary>
/// Draws a segment
/// </summary>
public static void DrawSegment2(Segment2 segment)
{
Draw.Segment2(drawLine, segment);
}
public static bool SegmentToPoint(Segment2 segment, Vertex2 point)
{
return(SegmentToPoint(segment.a, segment.b, point));
}
public Segment2(Segment2 segment)
{
a = segment.a;
b = segment.b;
}
public bool Intersects(Segment2 segment, out Segment2 intersection, bool testBoundingBox = false)
{
return(Intersection.SegmentToSegment(this, segment, out intersection, testBoundingBox));
}
public static void DrawSegment(Segment2 segment, Color color, float duration)
{
DrawSegment(segment, color, duration, true);
}
public static void DrawSegment(Segment2 segment, Color color)
{
DrawSegment(segment, color, 0f, true);
}
public static void DrawSegment(Segment2 segment)
{
DrawSegment(segment, Color.white, 0f, true);
}
/// <summary>
/// Computes an intersection of the segments
/// </summary>
public static bool SegmentSegment(Segment2 segment1, Segment2 segment2, out IntersectionSegmentSegment2 intersection)
{
return(SegmentSegment(segment1.a, segment1.b, segment2.a, segment2.b, out intersection));
}
public static float LineSegmentToLineSegment(Segment2 S1, Segment2 S2)
{
Vertex2 u = S1.b - S1.a;
Vertex2 v = S2.b - S2.a;
Vertex2 w = S1.a - S2.a;
float a = Vertex2.Dot(u, u); // always >= 0
float b = Vertex2.Dot(u, v);
float c = Vertex2.Dot(v, v); // always >= 0
float d = Vertex2.Dot(u, w);
float e = Vertex2.Dot(v, w);
float D = a * c - b * b; // always >= 0
float sN, sD = D; // sc = sN / sD, default sD = D >= 0
float tN, tD = D; // tc = tN / tD, default tD = D >= 0
// compute the line parameters of the two closest points
if (D < Mathf.Epsilon)
{
// the lines are almost parallel
sN = 0; // force using point P0 on segment S1
sD = 1; // to prevent possible division by 0.0 later
tN = e;
tD = c;
}
else
{
// get the closest points on the infinite lines
sN = (b * e - c * d);
tN = (a * e - b * d);
if (sN < 0)
{
// sc < 0 => the s=0 edge is visible
sN = 0;
tN = e;
tD = c;
}
else if (sN > sD)
{
// sc > 1 => the s=1 edge is visible
sN = sD;
tN = e + b;
tD = c;
}
}
if (tN < 0)
{
// tc < 0 => the t=0 edge is visible
tN = 0;
// recompute sc for this edge
if (-d < 0)
{
sN = 0;
}
else if (-d > a)
{
sN = sD;
}
else
{
sN = -d;
sD = a;
}
}
else if (tN > tD)
{
// tc > 1 => the t=1 edge is visible
tN = tD;
// recompute sc for this edge
if ((-d + b) < 0)
{
sN = 0;
}
else if ((-d + b) > a)
{
sN = sD;
}
else
{
sN = (-d + b);
sD = a;
}
}
// finally do the division to get sc and tc
float sc = (Mathf.Abs(sN) < Mathf.Epsilon ? 0 : sN / sD);
float tc = (Mathf.Abs(tN) < Mathf.Epsilon ? 0 : tN / tD);
// get the difference of the two closest points
Vertex2 dP = w + (sc * u) - (tc * v); // = S1(sc) - S2(tc)
return(dP.magnitude); // return the closest distance
}
/// <summary>
/// Returns a random point on a segment
/// </summary>
public static Vector2 PointOnSegment(Segment2 segment)
{
return(PointOnSegment(segment.a, segment.b));
}
public static float PointToLine(Vertex2 point, Segment2 segment)
{
return(PointToLine(point, segment.a, segment.b));
}
public static bool SegmentToRay(Segment2 segment, Ray2D ray)
{
Vertex2 intersection;
return(SegmentToRay(segment.a, segment.b, ray.origin, ray.origin + ray.direction, out intersection));
}
public bool Intersects(Segment2 segment)
{
return(Intersection.PolygonToSegment(this, segment));
}
public static bool SegmentToRay(Segment2 segment, Vertex2 rayStart, Vertex2 rayEnd)
{
Vertex2 intersection;
return(SegmentToRay(segment.a, segment.b, rayStart, rayEnd, out intersection));
}
/// <summary>
/// Tests if the point lies on the segment
/// </summary>
public static bool PointSegment(Vector2 point, Segment2 segment)
{
return(PointSegment(point, segment.a, segment.b));
}
public static IntersectionType SegmentToSegmentE(Vertex2 start0, Vertex2 end0, Vertex2 start1,
Vertex2 end1, out Segment2 intersection, bool testBoundingBox = false)
{
return(SegmentToSegmentE(start0.x, start0.y, end0.x, end0.y, start1.x, start1.y, end1.x, end1.y,
out intersection, testBoundingBox));
}
/// <summary>
/// Draws a segment
/// </summary>
public static void DrawSegment2(Segment2 segment)
{
DrawLine((Vector3)segment.a, (Vector3)segment.b);
}
