/* Assumption: p lies in the plane containing T.
* Returns a char:
* 'V': the query point p coincides with a Vertex of triangle T.
* 'E': the query point p is in the relative interior of an Edge of triangle T.
* 'F': the query point p is in the relative interior of a Face of triangle T.
* '0': the query point p does not intersect (misses) triangle T.
*/
public char InTri3D(tPointi T, int m, tPointi p)
{
int i; /* Index for X,Y,Z */
int j; /* Index for X,Y */
int k; /* Index for triangle vertex */
tPointi pp; /* projected p */
tPointi[] Tp; /* projected T: three new vertices */
pp = new tPointi();
Tp = new tPointi[3];
Tp[0] = new tPointi();
Tp[1] = new tPointi();
Tp[2] = new tPointi();
/* Project out coordinate m in both p and the triangular face */
j = 0;
for (i = 0; i < DIM; i++)
{
if (i != m)
{ /* skip largest coordinate */
pp.p[j] = p.p[i];
for (k = 0; k < 3; k++)
{
Tp[k].p[j] = Vertices[T.p[k]].p[i];
}
j++;
}
}
return(InTri2D(Tp, pp));
}
public int ComputeBox(int F, tPointi bmin, tPointi bmax)
{
int i, j;
double radius;
for (i = 0; i < F; i++)
{
for (j = 0; j < DIM; j++)
{
if (Vertices[i].p[j] < bmin.p[j])
{
bmin.p[j] = Vertices[i].p[j];
}
if (Vertices[i].p[j] > bmax.p[j])
{
bmax.p[j] = Vertices[i].p[j];
}
}
}
radius = Math.Sqrt(Math.Pow((double)(bmax.p[Xindex] - bmin.p[Xindex]), 2.0) +
Math.Pow((double)(bmax.p[Yindex] - bmin.p[Yindex]), 2.0) +
Math.Pow((double)(bmax.p[Zindex] - bmin.p[Zindex]), 2.0));
System.Diagnostics.Debug.WriteLine("radius = " + radius);
return((int)((radius + 1 + .5)) + 1);
}
public char SegTriInt(tPointi T, tPointi q, tPointi r, tPointd p)
{
char code = '?';
m = -1;
code = SegPlaneInt(T, q, r, p, m);
System.Diagnostics.Debug.WriteLine("****M is now after segplaneint: " + m);
System.Diagnostics.Debug.WriteLine("SegPlaneInt code= " + code + " , m= " + m + "; p=()" + p.p[Xindex] + " , " + p.p[Yindex] + " , " + p.p[Zindex]);
if (code == '0')
{
return('0');
}
else if (code == 'q')
{
return(InTri3D(T, m, q));
}
else if (code == 'r')
{
return(InTri3D(T, m, r));
}
else if (code == 'p')
{
return(InPlane(T, m, q, r, p));
}
else if (code == '1')
{
return(SegTriCross(T, q, r));
}
else /* Error */
{
return(code);
}
}
/*---------------------------------------------------------------------
* Computes N & D and returns index m of largest component.
* ---------------------------------------------------------------------*/
public int PlaneCoeff(tPointi T, tPointd N, double D0)
{
int i;
double t; /* Temp storage */
double biggest = 0.0; /* Largest component of normal vector. */
m = 0; /* Index of largest component. */
NormalVec(Vertices[T.p[0]], Vertices[T.p[1]], Vertices[T.p[2]], N);
System.Diagnostics.Debug.WriteLine("PlaneCoeff: N=()" + N.p[Xindex] + " , " + N.p[Yindex] + " , " + N.p[Zindex]);
D = Dot(Vertices[T.p[0]], N);
System.Diagnostics.Debug.WriteLine("D should be in planecoeff" + D);
/* Find the largest component of N. */
for (i = 0; i < DIM; i++)
{
t = (float)(Math.Abs(N.p[i]));
if (t > biggest)
{
biggest = t;
m = i;
}
}
return(m);
}
public char InTri2D(tPointi[] Tp, tPointi pp)
{
int area0, area1, area2;
/* compute three TriangleSign() values for pp w.r.t. each edge of the face in 2D */
System.Diagnostics.Debug.WriteLine("In tri 2d pp, tp 0,1,2" + pp.p[0] + ", " + pp.p[1] + " , " + pp.p[2]);
for (int b = 0; b < 3; b++)
{
for (int r = 0; r < 3; r++)
{
System.Diagnostics.Debug.WriteLine(Tp[b].p[r]);
}
}
area0 = TriangleSign(pp, Tp[0], Tp[1]);
area1 = TriangleSign(pp, Tp[1], Tp[2]);
area2 = TriangleSign(pp, Tp[2], Tp[0]);
System.Diagnostics.Debug.WriteLine("area0= " + area0 + " area1= " + area1 + " area2= " + area2);
if ((area0 == 0) && (area1 > 0) && (area2 > 0) ||
(area1 == 0) && (area0 > 0) && (area2 > 0) ||
(area2 == 0) && (area0 > 0) && (area1 > 0))
{
return('E');
}
if ((area0 == 0) && (area1 < 0) && (area2 < 0) ||
(area1 == 0) && (area0 < 0) && (area2 < 0) ||
(area2 == 0) && (area0 < 0) && (area1 < 0))
{
return('E');
}
if ((area0 > 0) && (area1 > 0) && (area2 > 0) ||
(area0 < 0) && (area1 < 0) && (area2 < 0))
{
return('F');
}
if ((area0 == 0) && (area1 == 0) && (area2 == 0))
{
System.Diagnostics.Debug.WriteLine("Error in InTriD");
return(' ');
}
if ((area0 == 0) && (area1 == 0) ||
(area0 == 0) && (area2 == 0) ||
(area1 == 0) && (area2 == 0))
{
return('V');
}
else
{
return('0');
}
}
/*---------------------------------------------------------------------
* Compute the cross product of (b-a)x(c-a) and place into N.
* ---------------------------------------------------------------------*/
public void NormalVec(tPointi a, tPointi b, tPointi c, tPointd N)
{
N.p[Xindex] = (c.p[Zindex] - a.p[Zindex]) * (b.p[Yindex] - a.p[Yindex]) -
(b.p[Zindex] - a.p[Zindex]) * (c.p[Yindex] - a.p[Yindex]);
N.p[Yindex] = (b.p[Zindex] - a.p[Zindex]) * (c.p[Xindex] - a.p[Xindex]) -
(b.p[Xindex] - a.p[Xindex]) * (c.p[Zindex] - a.p[Zindex]);
N.p[Zindex] = (b.p[Xindex] - a.p[Xindex]) * (c.p[Yindex] - a.p[Yindex]) -
(b.p[Yindex] - a.p[Yindex]) * (c.p[Xindex] - a.p[Xindex]);
}
/*---------------------------------------------------------------------
* a - b ==> c.
* ---------------------------------------------------------------------*/
public void SubVec(tPointi a, tPointi b, tPointi c)
{
int i;
for (i = 0; i < DIM; i++)
{
c.p[i] = a.p[i] - b.p[i];
}
}
public void AddVec(tPointi q, tPointi ray)
{
int i;
for (i = 0; i < DIM; i++)
{
ray.p[i] = q.p[i] + ray.p[i];
}
}
public bool InBox(tPointi q, tPointi bmin, tPointi bmax)
{
if ((bmin.p[Xindex] <= q.p[Xindex]) && (q.p[Xindex] <= bmax.p[Xindex]) &&
(bmin.p[Yindex] <= q.p[Yindex]) && (q.p[Yindex] <= bmax.p[Yindex]) &&
(bmin.p[Zindex] <= q.p[Zindex]) && (q.p[Zindex] <= bmax.p[Zindex]))
{
return(true);
}
return(false);
}
/*---------------------------------------------------------------------
* Returns the dot product of the two input vectors.
* ---------------------------------------------------------------------*/
public double Dot(tPointi a, tPointd b)
{
int i;
double sum = 0.0;
for (i = 0; i < DIM; i++)
{
sum += a.p[i] * b.p[i];
}
return(sum);
}
/*---------------------------------------------------------------------
* The signed volumes of three tetrahedra are computed, determined
* by the segment qr, and each edge of the triangle.
* Returns a char:
* 'v': the open segment includes a vertex of T.
* 'e': the open segment includes a point in the relative interior of an edge
* of T.
* 'f': the open segment includes a point in the relative interior of a face
* of T.
* '0': the open segment does not intersect triangle T.
* ---------------------------------------------------------------------*/
public char SegTriCross(tPointi T, tPointi q, tPointi r)
{
int vol0, vol1, vol2;
vol0 = VolumeSign(q, Vertices[T.p[0]], Vertices[T.p[1]], r);
vol1 = VolumeSign(q, Vertices[T.p[1]], Vertices[T.p[2]], r);
vol2 = VolumeSign(q, Vertices[T.p[2]], Vertices[T.p[0]], r);
System.Diagnostics.Debug.WriteLine("SegTriCross: vol0 = " + vol0 + " vol1 = " + vol1 + " vol2 = " + vol2);
/* Same sign: segment intersects interior of triangle. */
if (((vol0 > 0) && (vol1 > 0) && (vol2 > 0)) ||
((vol0 < 0) && (vol1 < 0) && (vol2 < 0)))
{
return('f');
}
/* Opposite sign: no intersection between segment and triangle */
if (((vol0 > 0) || (vol1 > 0) || (vol2 > 0)) &&
((vol0 < 0) || (vol1 < 0) || (vol2 < 0)))
{
return('0');
}
else if ((vol0 == 0) && (vol1 == 0) && (vol2 == 0))
{
System.Diagnostics.Debug.WriteLine("Error 1 in SegTriCross");
return('b');
}
/* Two zeros: segment intersects vertex. */
else if (((vol0 == 0) && (vol1 == 0)) ||
((vol0 == 0) && (vol2 == 0)) ||
((vol1 == 0) && (vol2 == 0)))
{
return('v');
}
/* One zero: segment intersects edge. */
else if ((vol0 == 0) || (vol1 == 0) || (vol2 == 0))
{
return('e');
}
else
{
System.Diagnostics.Debug.WriteLine("Error 2 in SegTriCross ");
return('b');
}
}
public int VolumeSign(tPointi a, tPointi b, tPointi c, tPointi d)
{
double vol;
double ax, ay, az, bx, by, bz, cx, cy, cz, dx, dy, dz;
double bxdx, bydy, bzdz, cxdx, cydy, czdz;
ax = a.p[Xindex];
ay = a.p[Yindex];
az = a.p[Zindex];
bx = b.p[Xindex];
by = b.p[Yindex];
bz = b.p[Zindex];
cx = c.p[Xindex];
cy = c.p[Yindex];
cz = c.p[Zindex];
dx = d.p[Xindex];
dy = d.p[Yindex];
dz = d.p[Zindex];
bxdx = bx - dx;
bydy = by - dy;
bzdz = bz - dz;
cxdx = cx - dx;
cydy = cy - dy;
czdz = cz - dz;
vol = (az - dz) * (bxdx * cydy - bydy * cxdx)
+ (ay - dy) * (bzdz * cxdx - bxdx * czdz)
+ (ax - dx) * (bydy * czdz - bzdz * cydy);
/* The volume should be an integer. */
if (vol > 0.5)
{
return(1);
}
else if (vol < -0.5)
{
return(-1);
}
else
{
return(0);
}
}
/*
* This function returns a char:
* '0': the segment [ab] does not intersect (completely misses) the
* bounding box surrounding the n-th triangle T. It lies
* strictly to one side of one of the six supporting planes.
* '?': status unknown: the segment may or may not intersect T.
*/
public char BoxTest(int n, tPointi a, tPointi b)
{
int i; /* Coordinate index */
int w;
for (i = 0; i < DIM; i++)
{
w = Box[n][0].p[i]; /* min: lower left */
if ((a.p[i] < w) && (b.p[i] < w))
{
return('0');
}
w = Box[n][1].p[i]; /* max: upper right */
if ((a.p[i] > w) && (b.p[i] > w))
{
return('0');
}
}
return('?');
}
public int TriangleSign(tPointi a, tPointi b, tPointi c)
{
double area2;
area2 = (b.p[0] - a.p[0]) * (double)(c.p[1] - a.p[1]) -
(c.p[0] - a.p[0]) * (double)(b.p[1] - a.p[1]);
/* The area should be an integer. */
if (area2 > 0.5)
{
return(1);
}
else if (area2 < -0.5)
{
return(-1);
}
else
{
return(0);
}
}
/* Return a random ray endpoint */
void RandomRay(tPointi ray, int radius)
{
double x, y, z, w, t;
/* Generate a random point on a sphere of radius 1. */
/* the sphere is sliced at z, and a random point at angle t
* generated on the circle of intersection. */
Random r = new Random();
z = 2.0 * (double)r.NextDouble() - 1.0;
t = 2.0 * Math.PI * r.NextDouble();
w = Math.Sqrt(1 - z * z);
x = w * Math.Cos(t);
y = w * Math.Sin(t);
ray.p[Xindex] = (int)(radius * x + .5);
ray.p[Yindex] = (int)(radius * y + .5);
ray.p[Zindex] = (int)(radius * z + .5);
System.Diagnostics.Debug.WriteLine("RandomRay returns" + ray.p[Xindex] + " , " + ray.p[Yindex] + " , " + ray.p[Zindex]);
}
//***********************
/*
* This function returns a char:
* 'V': the query point a coincides with a Vertex of polyhedron P.
* 'E': the query point a is in the relative interior of an Edge of polyhedron P.
* 'F': the query point a is in the relative interior of a Face of polyhedron P.
* 'i': the query point a is strictly interior to polyhedron P.
* 'o': the query point a is strictly exterior to( or outside of) polyhedron P.
*/
char InPolyhedron(int F, tPointi q, tPointi bmin, tPointi bmax, int radius)
{
tPointi r; /* Ray endpoint. */
tPointd p; /* Intersection point; not used. */
int f, k = 0, crossings = 0;
char code = '?';
r = new tPointi();
p = new tPointd();
/* If query point is outside bounding box, finished. */
if (!InBox(q, bmin, bmax))
{
return('o');
}
while (k++ < F)
{
crossings = 0;
RandomRay(r, radius);
AddVec(q, r);
System.Diagnostics.Debug.WriteLine("Ray endpoint: (" + r.p[0] + " , " + r.p[1] + " , " + r.p[2] + " )");
for (f = 0; f < F; f++)
{ /* Begin check each face */
if (BoxTest(f, q, r) == '0')
{
code = '0';
System.Diagnostics.Debug.WriteLine("BoxTest = 0!");
}
else
{
code = SegTriInt(Faces[f], q, r, p);
}
System.Diagnostics.Debug.WriteLine("Face = " + f + ": BoxTest/SegTriInt returns " + code);
/* If ray is degenerate, then goto outer while to generate another. */
if (code == 'p' || code == 'v' || code == 'e')
{
System.Diagnostics.Debug.WriteLine("Degenerate ray");
continue;
}
/* If ray hits face at interior point, increment crossings. */
else if (code == 'f')
{
crossings++;
System.Diagnostics.Debug.WriteLine("crossings = " + crossings);
}
/* If query endpoint q sits on a V/E/F, return that code. */
else if (code == 'V' || code == 'E' || code == 'F')
{
return(code);
}
/* If ray misses triangle, do nothing. */
else if (code == '0')
{
continue;
}
else
{
System.Diagnostics.Debug.WriteLine("Error");
return(' ');
}
} /* End check each face */
/* No degeneracies encountered: ray is generic, so finished. */
break;
} /* End while loop */
System.Diagnostics.Debug.WriteLine("Crossings at the end = " + crossings);
/* q strictly interior to polyhedron iff an odd number of crossings. */
if ((crossings % 2) == 1)
{
return('i');
}
else
{
return('o');
}
}
/*---------------------------------------------------------------------
* 'p': The segment lies wholly within the plane.
* 'q': The q endpoint is on the plane (but not 'p').
* 'r': The r endpoint is on the plane (but not 'p').
* '0': The segment lies strictly to one side or the other of the plane.
* '1': The segement intersects the plane, and 'p' does not hold.
* ---------------------------------------------------------------------*/
public char SegPlaneInt(tPointi T, tPointi q, tPointi r, tPointd p, int m)
{
tPointd N;
int D0 = 0;
tPointi rq;
double num, denom, t;
int i;
N = new tPointd();
rq = new tPointi();
m = PlaneCoeff(T, N, D0);
System.Diagnostics.Debug.WriteLine("m= " + m + "; plane=( " + N.p[Xindex] + " , " + N.p[Yindex] + " , " + N.p[Zindex] + " , " + D + " )");
num = D - Dot(q, N);
SubVec(r, q, rq);
denom = Dot(rq, N);
System.Diagnostics.Debug.WriteLine("SegPlaneInt: num=" + num + " , denom= " + denom);
if (denom == 0.0)
{ /* Segment is parallel to plane. */
if (num == 0.0) /* q is on plane. */
{
return('p');
}
else
{
return('0');
}
}
else
{
t = num / denom;
}
System.Diagnostics.Debug.WriteLine("SegPlaneInt: t= " + t);
System.Diagnostics.Debug.WriteLine("p in seg plane int is: p=()");
for (i = 0; i < DIM; i++)
{
p.p[i] = q.p[i] + t * (r.p[i] - q.p[i]);
System.Diagnostics.Debug.WriteLine(p.p[i]);
}
if ((0.0 < t) && (t < 1.0))
{
return('1');
}
else if (num == 0.0) /* t == 0 */
{
return('q');
}
else if (num == denom) /* t == 1 */
{
return('r');
}
else
{
return('0');
}
}
public char InPlane(tPointi T, int m, tPointi q, tPointi r, tPointd p)
{
/* NOT IMPLEMENTED */
return('p');
}
public InPolyh()
{
tPointi bmin, bmax;
double radius;
char[] line = new char[20];
int i = 0;
Vertices = new tPointi[PMAX];
Faces = new tPointi[PMAX];
Box = new tPointi[PMAX][];
//n = ReadVertices();
// F = ReadFaces();
VerifVertices();
/* Initialize the bounding box */
bmin = new tPointi();
bmax = new tPointi();
for (i = 0; i < DIM; i++)
{
bmin.p[i] = bmax.p[i] = Vertices[0].p[i];
}
radius = ComputeBox(n, bmin, bmax);
System.Diagnostics.Debug.WriteLine("radius=" + radius);
System.Diagnostics.Debug.WriteLine("Please input query point");
i = 0;
//try{
// System.Diagnostics.Debug.WriteLine("\n\nInput query point:\nCoord-s must be seperated by a *tab*\n"+
// "ENTER after each point"+"\nTo finish input type end + "+
// "ENTER at the end"+
// "\nExample:\n17 23 123\n34 5 1\nend\n"+
// "-----------------start entering data-------------------");
// //do {
// do {
//c = (char) System.in.read();
//line[i] = c;
//i++;
// } while (c !='\n' );
// s = new String(line);
// s = s.Substring(0,i-1);
// if (s.Equals("end"))
//break;
// flag = false;
// counter = 0;
// for (int j=0; j < s.Length(); j++) {
//if (s.charAt(j) == '\t')
// counter++;
//if (counter == 2) {
// flag = true; break;
//}
// }
// if (flag) {
//int t = s.IndexOf('\t');
//int t1 = s.LastIndexOf('\t');
//x = double.TryParse(s.Substring(0,t));
//y = double.TryParse(s.Substring(t+1,t1));
//z = double.TryParse(s.Substring(t1+1,s.Length()));
//q = new tPointi(x, y, z);
// q.x = x;
// q.y = y;
// q.z = z;
// i=0;
// }
// else
// break;
// char ans = InPolyhedron(F, q, bmin, bmax, radius);
// System.Diagnostics.Debug.WriteLine("InPolyhedron returned: "+ans);
// } while (!s.Equals("end"));
// }
//catch (NumberFormatException e) {System.Diagnostics.Debug.WriteLine ("Invalid input"); return;}
}
