/// <summary>
/// Compute the projection of a point onto the line determined
/// by this line segment.
/// Note that the projected point may lie outside the line segment.
/// If this is the case, the projection factor will lie outside the range [0.0, 1.0].
/// </summary>
public static Point Project(Point p, Point lineSegFrom, Point lineSegTo)
{
if (p.Equals(lineSegFrom) || p.Equals(lineSegTo))
return new Point(p.X, p.Y);
var r = ProjectionFactor(p, lineSegFrom, lineSegTo);
var coord = new Point { X = lineSegFrom.X + r * (lineSegTo.X - lineSegFrom.X), Y = lineSegFrom.Y + r * (lineSegTo.Y - lineSegFrom.Y) };
return coord;
}
public static void Main(string[] args)
{
var x = new Point(1, 2);
var y = x;
Console.WriteLine(y); // x のメンバー毎コピー = (1, 2)
// メンバー毎比較(全メンバー一致なら一致)
Console.WriteLine(x.Equals(new Point(1, 2))); // true
Console.WriteLine(x.Equals(new Point(1, 3))); // false
}
/// <summary>
/// Computes the distance from a line segment AB to a line segment CD.
/// Note: NON-ROBUST!
/// </summary>
/// <param name="a">A point of one line.</param>
/// <param name="b">The second point of the line (must be different to A).</param>
/// <param name="c">One point of the line.</param>
/// <param name="d">Another point of the line (must be different to A).</param>
/// <returns>The distance from line segment AB to line segment CD.</returns>
public static double DistanceLineLine(Point a, Point b, Point c, Point d)
{
// check for zero-length segments
if (a.Equals(b))
return DistancePointLine(a, c, d);
if (c.Equals(d))
return DistancePointLine(d, a, b);
// AB and CD are line segments
/* from comp.graphics.algo
Solving the above for r and s yields
(Ay-Cy)(Dx-Cx)-(Ax-Cx)(Dy-Cy)
r = ----------------------------- (eqn 1)
(Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
(Ay-Cy)(Bx-Ax)-(Ax-Cx)(By-Ay)
s = ----------------------------- (eqn 2)
(Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
Let Point be the position vector of the intersection point, then
Point=A+r(B-A) or
Px=Ax+r(Bx-Ax)
Py=Ay+r(By-Ay)
By examining the values of r & s, you can also determine some other
limiting conditions:
If 0<=r<=1 & 0<=s<=1, intersection exists
r<0 or r>1 or s<0 or s>1 line segments do not intersect
If the denominator in eqn 1 is zero, AB & CD are parallel
If the numerator in eqn 1 is also zero, AB & CD are collinear.
*/
var rTop = (a.Y - c.Y)*(d.X - c.X) - (a.X - c.X)*(d.Y - c.Y);
var rBottom = (b.X - a.X)*(d.Y - c.Y) - (b.Y - a.Y)*(d.X - c.X);
var sTop = (a.Y - c.Y)*(b.X - a.X) - (a.X - c.X)*(b.Y - a.Y);
var sBottom = (b.X - a.X)*(d.Y - c.Y) - (b.Y - a.Y)*(d.X - c.X);
// ReSharper disable CompareOfFloatsByEqualityOperator
if ((rBottom == 0) || (sBottom == 0))
return Math.Min(DistancePointLine(a, c, d),
Math.Min(DistancePointLine(b, c, d),
Math.Min(DistancePointLine(c, a, b),
DistancePointLine(d, a, b))));
// ReSharper restore CompareOfFloatsByEqualityOperator
var s = sTop/sBottom;
var r = rTop/rBottom;
if ((r < 0) || (r > 1) || (s < 0) || (s > 1))
//no intersection
return Math.Min(DistancePointLine(a, c, d),
Math.Min(DistancePointLine(b, c, d),
Math.Min(DistancePointLine(c, a, b),
DistancePointLine(d, a, b))));
return 0.0; //intersection exists
}
/// <summary>
/// Computes the distance from a line segment AB to a line segment CD.
/// Note: NON-ROBUST!
/// </summary>
/// <param name="A">A point of one line.</param>
/// <param name="B">The second point of the line (must be different to A).</param>
/// <param name="C">One point of the line.</param>
/// <param name="D">Another point of the line (must be different to A).</param>
/// <returns>The distance from line segment AB to line segment CD.</returns>
public static double DistanceLineLine(Point A, Point B, Point C, Point D)
{
// check for zero-length segments
if (A.Equals(B))
return DistancePointLine(A, C, D);
if (C.Equals(D))
return DistancePointLine(D, A, B);
// AB and CD are line segments
/* from comp.graphics.algo
Solving the above for r and s yields
(Ay-Cy)(Dx-Cx)-(Ax-Cx)(Dy-Cy)
r = ----------------------------- (eqn 1)
(Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
(Ay-Cy)(Bx-Ax)-(Ax-Cx)(By-Ay)
s = ----------------------------- (eqn 2)
(Bx-Ax)(Dy-Cy)-(By-Ay)(Dx-Cx)
Let Point be the position vector of the intersection point, then
Point=A+r(B-A) or
Px=Ax+r(Bx-Ax)
Py=Ay+r(By-Ay)
By examining the values of r & s, you can also determine some other
limiting conditions:
If 0<=r<=1 & 0<=s<=1, intersection exists
r<0 or r>1 or s<0 or s>1 line segments do not intersect
If the denominator in eqn 1 is zero, AB & CD are parallel
If the numerator in eqn 1 is also zero, AB & CD are collinear.
*/
double r_top = (A.Y - C.Y) * (D.X - C.X) - (A.X - C.X) * (D.Y - C.Y);
double r_bot = (B.X - A.X) * (D.Y - C.Y) - (B.Y - A.Y) * (D.X - C.X);
double s_top = (A.Y - C.Y) * (B.X - A.X) - (A.X - C.X) * (B.Y - A.Y);
double s_bot = (B.X - A.X) * (D.Y - C.Y) - (B.Y - A.Y) * (D.X - C.X);
if ((r_bot == 0) || (s_bot == 0))
return Math.Min(DistancePointLine(A, C, D),
Math.Min(DistancePointLine(B, C, D),
Math.Min(DistancePointLine(C, A, B),
DistancePointLine(D, A, B))));
double s = s_top / s_bot;
double r = r_top / r_bot;
if ((r < 0) || (r > 1) || (s < 0) || (s > 1))
//no intersection
return Math.Min(DistancePointLine(A, C, D),
Math.Min(DistancePointLine(B, C, D),
Math.Min(DistancePointLine(C, A, B),
DistancePointLine(D, A, B))));
return 0.0; //intersection exists
}
public void TestEquality()
{
// Setup.
var p1 = new Point(1, 0);
var p2 = new Point(1, 0);
var p3 = new Point(0, 1);
// Dissimilar objects.
var s = "Test";
Assert.IsFalse(p1.Equals(s));
// Null object.
Assert.IsFalse(p1.Equals((object) null));
// Null point.
Assert.IsFalse(p1.Equals(null));
// Point as object equals.
Assert.IsTrue(p1.Equals((object) p2));
Assert.IsTrue(p2.Equals((object) p1));
Assert.IsFalse(p3.Equals((object) p1));
// Point as point equals.
Assert.IsTrue(p1.Equals(p2));
Assert.IsTrue(p2.Equals(p1));
Assert.IsFalse(p3.Equals(p1));
// Reference equals.
Assert.IsTrue(p1 == p1);
// Null checks.
Assert.IsFalse(null == p1);
Assert.IsFalse(p1 == null);
// Two different objects.
Assert.IsTrue(p1 == p2);
// Inequality operator.
Assert.IsTrue(p1 != p3);
}
/// <summary>
/// Compute the projection factor for the projection of the point p
/// onto this <c>LineSegment</c>. The projection factor is the constant k
/// by which the vector for this segment must be multiplied to
/// equal the vector for the projection of p.
/// </summary>
/// <returns></returns>
public static double ProjectionFactor(Point p, Point lineSegFrom, Point lineSegTo)
{
if (p.Equals(lineSegFrom)) return 0.0;
if (p.Equals(lineSegTo)) return 1.0;
// Otherwise, use comp.graphics.algorithms Frequently Asked Questions method
/* AC dot AB
r = ------------
||AB||^2
r has the following meaning:
r=0 Point = A
r=1 Point = B
r<0 Point is on the backward extension of AB
r>1 Point is on the forward extension of AB
0<r<1 Point is interior to AB
*/
var dx = lineSegTo.X - lineSegFrom.X;
var dy = lineSegTo.Y - lineSegFrom.Y;
var len2 = dx * dx + dy * dy;
var r = ((p.X - lineSegFrom.X) * dx + (p.Y - lineSegFrom.Y) * dy) / len2;
return r;
}
public override bool IsValidMove(Point target)
{
Point[] jiugong = this.Side.sideType == SideType.Bottom ?
Board.BottomJiuGong : Board.TopJiuGong;
if (!jiugong.Contains(target)) return false;
if (target.Equals(this.Position)) return false;
// * can horizontally or vertically move 1 position
// * the target position must NOT be under attack
if (((target.X == this.Position.X && Math.Abs(target.Y - this.Position.Y) == 1)
|| (target.Y == this.Position.Y && Math.Abs(target.X - this.Position.X) == 1))
&& !this.Side.Opponent.PointInAttackRange(target))
return true;
//otherwise...
return false;
}
public void CheckLinesTest()
{
Board b = new Board(7, 7, 3);
Point p, pc;
List<Point> result;
List<Point> knownh, knownv, knowndl, knowndr, known;
pc = new Point(2, 2);
knownh = new List<Point>();
ushort row;
ushort col;
ushort count;
/* o o o o o o o o
* o o o o o o o o
* + + + + o o o o
* o o o o o o o o
* o o o o o o o o
*/
for (row = pc.Row, col = 0, count = 0; count < 4; col++, count++)
{
p = new Point(row, col);
knownh.Add(p);
b.PlaceItem(p, 1);
}
result = b.CheckLines(knownh.ElementAt(0));
Assert.AreEqual(0, result.Count);
/* o o o o o o o o
* o o o o o o o o
* + + + + + o o o
* o o o o o o o o
* o o o o o o o o
*/
p = new Point(row, col++);
knownh.Add(p);
b.PlaceItem(p, 1);
// from right
result = b.CheckLines(knownh.ElementAt(4));
CollectionAssert.AreEquivalent(knownh, result);
// from middle
result = b.CheckLines(knownh.ElementAt(2));
CollectionAssert.AreEquivalent(knownh, result);
// from left
result = b.CheckLines(knownh.ElementAt(0));
CollectionAssert.AreEquivalent(knownh, result);
// switch out the color
b.ClearItem(pc);
b.PlaceItem(pc, 2);
// from left
result = b.CheckLines(knownh.ElementAt(0));
Assert.AreEqual(0, result.Count);
// from middle
result = b.CheckLines(knownh.ElementAt(2));
Assert.AreEqual(0, result.Count);
// from right
result = b.CheckLines(knownh.ElementAt(4));
Assert.AreEqual(0, result.Count);
b.ClearItem(pc);
b.PlaceItem(pc, 1);
// more than 5
/* o o o o o o o o
* o o o o o o o o
* + + + + + + o o
* o o o o o o o o
* o o o o o o o o
*/
p = new Point(row, col++);
knownh.Add(p);
b.PlaceItem(p, 1);
result = b.CheckLines(p);
CollectionAssert.AreEquivalent(knownh, result);
/* o o + o o o o o
* o o + o o o o o
* + + + + + + + o
* o o + o o o o o
* o o + o o o o o
*/
knownv = new List<Point>();
for (row = 0, col = pc.Col, count = 0; count < 5; row++, count++)
{
p = new Point(row, col);
knownv.Add(p);
if (!p.Equals(pc))
b.PlaceItem(p, 1);
}
// from bottom
result = b.CheckLines(p);
CollectionAssert.AreEquivalent(knownv, result);
// from top
result = b.CheckLines(knownv.ElementAt(0));
CollectionAssert.AreEquivalent(knownv, result);
// two directions
known = new List<Point>();
known.AddRange(knownh.AsEnumerable());
known.AddRange(knownv.AsEnumerable());
// there is an extra point at the intersection
known.Remove(pc);
result = b.CheckLines(pc);
CollectionAssert.AreEquivalent(known, result);
/* o o + o o o o o
* o o + o o o o o
* + + + + + + + o
* o o + + o o o o
* o o + o + o o o
* o o o o o + o o
* o o o o o o + o
*/
knowndl = new List<Point>();
for (row = pc.Row, col = pc.Col, count = 0; count < 5; row++, col++, count++)
{
p = new Point(row, col);
knowndl.Add(p);
if (!p.Equals(pc))
b.PlaceItem(p, 1);
}
// from top left (second)
result = b.CheckLines(knowndl.ElementAt(1));
CollectionAssert.AreEquivalent(knowndl, result);
// from bottom right
result = b.CheckLines(knowndl.ElementAt(4));
CollectionAssert.AreEquivalent(knowndl, result);
// three directions
known.AddRange(knowndl.AsEnumerable());
known.Remove(pc);
result = b.CheckLines(pc);
CollectionAssert.AreEquivalent(known, result);
/* o o + o + o o o
* o o + + o o o o
* + + + + + + + o
* o + + + o o o o
* + o + o + o o o
* o o + o o + o o
* o o + o o o + o
*/
knowndr = new List<Point>();
for (row = 4, col = 0, count = 0; count < 5; row--, col++, count++)
{
p = new Point(row, col);
knowndr.Add(p);
if (!p.Equals(pc))
b.PlaceItem(p, 1);
}
// from bottom left
result = b.CheckLines(knowndr.ElementAt(0));
CollectionAssert.AreEquivalent(knowndr, result);
// from top right
result = b.CheckLines(knowndr.ElementAt(4));
CollectionAssert.AreEquivalent(knowndr, result);
// four directions
known.AddRange(knowndr.AsEnumerable());
known.Remove(pc);
result = b.CheckLines(pc);
CollectionAssert.AreEquivalent(known, result);
}
/// <summary>
/// Computes the distance from a point p to a line segment AB.
/// Note: NON-ROBUST!
/// </summary>
/// <param name="p">The point to compute the distance for.</param>
/// <param name="a">One point of the line.</param>
/// <param name="b">Another point of the line (must be different to A).</param>
/// <returns> The distance from p to line segment AB.</returns>
public static double DistancePointLine(Point p, Point a, Point b)
{
// if start == end, then use pt distance
if (a.Equals(b))
return p.Distance(a);
// otherwise use comp.graphics.algorithms Frequently Asked Questions method
/*(1) AC dot AB
r = ---------
||AB||^2
r has the following meaning:
r=0 Point = A
r=1 Point = B
r<0 Point is on the backward extension of AB
r>1 Point is on the forward extension of AB
0<r<1 Point is interior to AB
*/
var r = ((p.X - a.X)*(b.X - a.X) + (p.Y - a.Y)*(b.Y - a.Y))
/
((b.X - a.X)*(b.X - a.X) + (b.Y - a.Y)*(b.Y - a.Y));
if (r <= 0.0) return p.Distance(a);
if (r >= 1.0) return p.Distance(b);
/*(2)
(Ay-Cy)(Bx-Ax)-(Ax-Cx)(By-Ay)
s = -----------------------------
Curve^2
Then the distance from C to Point = |s|*Curve.
*/
var s = ((a.Y - p.Y)*(b.X - a.X) - (a.X - p.X)*(b.Y - a.Y))
/
((b.X - a.X)*(b.X - a.X) + (b.Y - a.Y)*(b.Y - a.Y));
return Math.Abs(s)*Math.Sqrt((b.X - a.X)*(b.X - a.X) + (b.Y - a.Y)*(b.Y - a.Y));
}
private static IEnumerable<Rotation> GetPath(Dictionary<Point, int> d, Point from, Point to)
{
var res = new List<Rotation>();
while (!to.Equals(from))
{
var i = d[to] - 1;
var nf = to.NearFour();
int j;
for (j = 0; j < nf.Length; j++)
{
if (d.ContainsKey(nf[j]) && d[nf[j]] == i)
{
res.Add((Rotation)j);
to = nf[j];
break;
}
}
if (j == 4) throw new Exception();
}
var ress = res.ToArray();
ReversePath(ress);
return ress;
}
public Line(Point beg, Point end) {
double l = beg.Distance(end);
if (FP.eq(l, Math.PI)) {
Debug.Assert(FP.eq(beg.ra, end.ra));
phi = -Math.PI/2;
theta = Math.PI/2;
psi = beg.ra < 0.0 ? Math.PI*2 + beg.ra : beg.ra;
length = Math.PI;
return;
}
if (beg.Equals(end)) {
phi = Math.PI/2;
theta = beg.dec;
psi = beg.ra - Math.PI/2;
length = 0.0;
} else {
Point3D beg3d = new Point3D(beg);
Point3D end3d = new Point3D(end);
Point3D tp = new Point3D();
Point spt = beg3d.cross(end3d).toSpherePoint();
Euler euler = new Euler();
euler.phi = - spt.ra - Math.PI/2;
euler.theta = spt.dec - Math.PI/2;
euler.psi = 0.0 ;
euler.psi_a = Euler.AXIS_Z;
euler.theta_a = Euler.AXIS_X;
euler.phi_a = Euler.AXIS_Z;
euler.transform(tp, beg3d);
spt = tp.toSpherePoint();
// invert
phi = spt.ra;
theta = -euler.theta;
psi = -euler.phi;
length = l;
}
}
public void Equals(Point a, Point b, bool result)
{
(a == b).Should().Be(result);
(a.Equals(b)).Should().Be(result);
}
/// <summary>
/// Compute the projection of a point onto the line determined
/// by this line segment.
/// Note that the projected point may lie outside the line segment.
/// If this is the case, the projection factor will lie outside the range [0.0, 1.0].
/// </summary>
/// <param name="p"></param>
/// <returns></returns>
public static Point Project(Point p, Point LineSegFrom, Point LineSegTo)
{
if (p.Equals(LineSegFrom) || p.Equals(LineSegTo))
return new Point(p.X, p.Y);
var r = ProjectionFactor(p, LineSegFrom, LineSegTo);
Point coord = new Point { X = LineSegFrom.X + r * (LineSegTo.X - LineSegFrom.X), Y = LineSegFrom.Y + r * (LineSegTo.Y - LineSegFrom.Y) };
return coord;
}
public void TestPointEquals ()
{
var point = new Point (2, 4);
Assert.True (point.Equals (new Point (2, 4)));
Assert.False (point.Equals (new Point (3, 4)));
Assert.False (point.Equals ("Point"));
}
public List<Point> GetWarpingPath(int i, int j)
{
List<Point> bSeq = new List<Point>();
Point p = new Point(i, j);
while ((!p.Equals(Point.Empty)) && (!p.Equals(new Point(0,0))))
{
bSeq.Insert(0, p);
p = MinimalPath[(int)p.X, (int)p.Y];
//when reaching end, stop procedure
if (p.Equals(new Point(0,0)))
{
//insert point <0,0>
bSeq.Insert(0, p);
break;
}
}
return bSeq;
}
