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25 // 25 //
26 // G4EllipticalTube implementation <<
27 // 26 //
28 // Author: David C. Williams (davidw@scipp.ucs << 27 // $Id: G4EllipticalTube.cc,v 1.26 2006/06/29 18:48:31 gunter Exp $
29 // Revision: Evgueni Tcherniaev (evgueni.tcher << 28 // GEANT4 tag $Name: geant4-08-01 $
>> 29 //
>> 30 //
>> 31 // --------------------------------------------------------------------
>> 32 // GEANT 4 class source file
>> 33 //
>> 34 //
>> 35 // G4EllipticalTube.cc
>> 36 //
>> 37 // Implementation of a CSG volume representing a tube with elliptical cross
>> 38 // section (geant3 solid 'ELTU')
>> 39 //
30 // ------------------------------------------- 40 // --------------------------------------------------------------------
31 41
32 #include "G4EllipticalTube.hh" 42 #include "G4EllipticalTube.hh"
33 43
34 #if !(defined(G4GEOM_USE_UELLIPTICALTUBE) && d <<
35 <<
36 #include "G4GeomTools.hh" <<
37 #include "G4RandomTools.hh" <<
38 #include "G4ClippablePolygon.hh" 44 #include "G4ClippablePolygon.hh"
39 #include "G4AffineTransform.hh" 45 #include "G4AffineTransform.hh"
>> 46 #include "G4SolidExtentList.hh"
40 #include "G4VoxelLimits.hh" 47 #include "G4VoxelLimits.hh"
41 #include "G4BoundingEnvelope.hh" << 48 #include "meshdefs.hh"
42 49
43 #include "Randomize.hh" 50 #include "Randomize.hh"
44 51
45 #include "G4VGraphicsScene.hh" 52 #include "G4VGraphicsScene.hh"
>> 53 #include "G4Polyhedron.hh"
46 #include "G4VisExtent.hh" 54 #include "G4VisExtent.hh"
47 55
48 #include "G4AutoLock.hh" <<
49 <<
50 namespace <<
51 { <<
52 G4Mutex polyhedronMutex = G4MUTEX_INITIALIZE <<
53 } <<
54 <<
55 using namespace CLHEP; 56 using namespace CLHEP;
56 57
57 ////////////////////////////////////////////// <<
58 // 58 //
59 // Constructor 59 // Constructor
60 << 60 //
61 G4EllipticalTube::G4EllipticalTube( const G4St << 61 G4EllipticalTube::G4EllipticalTube( const G4String &name,
62 G4do << 62 G4double theDx,
63 G4do << 63 G4double theDy,
64 G4do << 64 G4double theDz )
65 : G4VSolid(name), fDx(Dx), fDy(Dy), fDz(Dz) << 65 : G4VSolid( name ), fCubicVolume(0.), fpPolyhedron(0)
66 { << 66 {
67 CheckParameters(); << 67 dx = theDx;
>> 68 dy = theDy;
>> 69 dz = theDz;
68 } 70 }
69 71
70 ////////////////////////////////////////////// << 72
71 // 73 //
72 // Fake default constructor - sets only member 74 // Fake default constructor - sets only member data and allocates memory
73 // for usage restri 75 // for usage restricted to object persistency.
74 << 76 //
75 G4EllipticalTube::G4EllipticalTube( __void__& 77 G4EllipticalTube::G4EllipticalTube( __void__& a )
76 : G4VSolid(a), halfTolerance(0.), fDx(0.), f << 78 : G4VSolid(a), fCubicVolume(0.), fpPolyhedron(0)
77 fRsph(0.), fDDx(0.), fDDy(0.), fSx(0.), fS <<
78 fQ1(0.), fQ2(0.), fScratch(0.) <<
79 { 79 {
80 } 80 }
81 81
82 ////////////////////////////////////////////// <<
83 // 82 //
84 // Destructor 83 // Destructor
85 <<
86 G4EllipticalTube::~G4EllipticalTube() <<
87 { <<
88 delete fpPolyhedron; fpPolyhedron = nullptr; <<
89 } <<
90 <<
91 ////////////////////////////////////////////// <<
92 // 84 //
93 // Copy constructor << 85 G4EllipticalTube::~G4EllipticalTube() {delete fpPolyhedron;}
94 86
95 G4EllipticalTube::G4EllipticalTube(const G4Ell <<
96 : G4VSolid(rhs), halfTolerance(rhs.halfToler <<
97 fDx(rhs.fDx), fDy(rhs.fDy), fDz(rhs.fDz), <<
98 fCubicVolume(rhs.fCubicVolume), fSurfaceAr <<
99 fRsph(rhs.fRsph), fDDx(rhs.fDDx), fDDy(rhs <<
100 fSx(rhs.fSx), fSy(rhs.fSy), fR(rhs.fR), <<
101 fQ1(rhs.fQ1), fQ2(rhs.fQ2), fScratch(rhs.f <<
102 { <<
103 } <<
104 87
105 ////////////////////////////////////////////// <<
106 // 88 //
107 // Assignment operator << 89 // CalculateExtent
108 <<
109 G4EllipticalTube& G4EllipticalTube::operator = <<
110 { <<
111 // Check assignment to self <<
112 // <<
113 if (this == &rhs) { return *this; } <<
114 <<
115 // Copy base class data <<
116 // <<
117 G4VSolid::operator=(rhs); <<
118 <<
119 // Copy data <<
120 // <<
121 halfTolerance = rhs.halfTolerance; <<
122 fDx = rhs.fDx; <<
123 fDy = rhs.fDy; <<
124 fDz = rhs.fDz; <<
125 fCubicVolume = rhs.fCubicVolume; <<
126 fSurfaceArea = rhs.fSurfaceArea; <<
127 <<
128 fRsph = rhs.fRsph; <<
129 fDDx = rhs.fDDx; <<
130 fDDy = rhs.fDDy; <<
131 fSx = rhs.fSx; <<
132 fSy = rhs.fSy; <<
133 fR = rhs.fR; <<
134 fQ1 = rhs.fQ1; <<
135 fQ2 = rhs.fQ2; <<
136 fScratch = rhs.fScratch; <<
137 <<
138 fRebuildPolyhedron = false; <<
139 delete fpPolyhedron; fpPolyhedron = nullptr <<
140 <<
141 return *this; <<
142 } <<
143 <<
144 ////////////////////////////////////////////// <<
145 // 90 //
146 // Check dimensions << 91 G4bool
>> 92 G4EllipticalTube::CalculateExtent( const EAxis axis,
>> 93 const G4VoxelLimits &voxelLimit,
>> 94 const G4AffineTransform &transform,
>> 95 G4double &min, G4double &max ) const
>> 96 {
>> 97 G4SolidExtentList extentList( axis, voxelLimit );
>> 98
>> 99 //
>> 100 // We are going to divide up our elliptical face into small
>> 101 // pieces
>> 102 //
>> 103
>> 104 //
>> 105 // Choose phi size of our segment(s) based on constants as
>> 106 // defined in meshdefs.hh
>> 107 //
>> 108 G4int numPhi = kMaxMeshSections;
>> 109 G4double sigPhi = twopi/numPhi;
>> 110
>> 111 //
>> 112 // We have to be careful to keep our segments completely outside
>> 113 // of the elliptical surface. To do so we imagine we have
>> 114 // a simple (unit radius) circular cross section (as in G4Tubs)
>> 115 // and then "stretch" the dimensions as necessary to fit the ellipse.
>> 116 //
>> 117 G4double rFudge = 1.0/std::cos(0.5*sigPhi);
>> 118 G4double dxFudge = dx*rFudge,
>> 119 dyFudge = dy*rFudge;
>> 120
>> 121 //
>> 122 // As we work around the elliptical surface, we build
>> 123 // a "phi" segment on the way, and keep track of two
>> 124 // additional polygons for the two ends.
>> 125 //
>> 126 G4ClippablePolygon endPoly1, endPoly2, phiPoly;
>> 127
>> 128 G4double phi = 0,
>> 129 cosPhi = std::cos(phi),
>> 130 sinPhi = std::sin(phi);
>> 131 G4ThreeVector v0( dxFudge*cosPhi, dyFudge*sinPhi, +dz ),
>> 132 v1( dxFudge*cosPhi, dyFudge*sinPhi, -dz ),
>> 133 w0, w1;
>> 134 transform.ApplyPointTransform( v0 );
>> 135 transform.ApplyPointTransform( v1 );
>> 136 do
>> 137 {
>> 138 phi += sigPhi;
>> 139 if (numPhi == 1) phi = 0; // Try to avoid roundoff
>> 140 cosPhi = std::cos(phi),
>> 141 sinPhi = std::sin(phi);
>> 142
>> 143 w0 = G4ThreeVector( dxFudge*cosPhi, dyFudge*sinPhi, +dz );
>> 144 w1 = G4ThreeVector( dxFudge*cosPhi, dyFudge*sinPhi, -dz );
>> 145 transform.ApplyPointTransform( w0 );
>> 146 transform.ApplyPointTransform( w1 );
>> 147
>> 148 //
>> 149 // Add a point to our z ends
>> 150 //
>> 151 endPoly1.AddVertexInOrder( v0 );
>> 152 endPoly2.AddVertexInOrder( v1 );
>> 153
>> 154 //
>> 155 // Build phi polygon
>> 156 //
>> 157 phiPoly.ClearAllVertices();
>> 158
>> 159 phiPoly.AddVertexInOrder( v0 );
>> 160 phiPoly.AddVertexInOrder( v1 );
>> 161 phiPoly.AddVertexInOrder( w1 );
>> 162 phiPoly.AddVertexInOrder( w0 );
>> 163
>> 164 if (phiPoly.PartialClip( voxelLimit, axis ))
>> 165 {
>> 166 //
>> 167 // Get unit normal
>> 168 //
>> 169 phiPoly.SetNormal( (v1-v0).cross(w0-v0).unit() );
>> 170
>> 171 extentList.AddSurface( phiPoly );
>> 172 }
>> 173
>> 174 //
>> 175 // Next vertex
>> 176 //
>> 177 v0 = w0;
>> 178 v1 = w1;
>> 179 } while( --numPhi > 0 );
147 180
148 void G4EllipticalTube::CheckParameters() <<
149 { <<
150 // Check dimensions <<
151 // 181 //
152 halfTolerance = 0.5*kCarTolerance; // half t << 182 // Process the end pieces
153 G4double dmin = 2*kCarTolerance; << 183 //
154 if (fDx < dmin || fDy < dmin || fDz < dmin) << 184 if (endPoly1.PartialClip( voxelLimit, axis ))
155 { 185 {
156 std::ostringstream message; << 186 static const G4ThreeVector normal(0,0,+1);
157 message << "Invalid (too small or negative << 187 endPoly1.SetNormal( transform.TransformAxis(normal) );
158 << GetName() << 188 extentList.AddSurface( endPoly1 );
159 << "\n Dx = " << fDx <<
160 << "\n Dy = " << fDy <<
161 << "\n Dz = " << fDz; <<
162 G4Exception("G4EllipticalTube::CheckParame <<
163 FatalException, message); <<
164 } 189 }
165 << 190
166 // Set pre-calculatated values << 191 if (endPoly2.PartialClip( voxelLimit, axis ))
>> 192 {
>> 193 static const G4ThreeVector normal(0,0,-1);
>> 194 endPoly2.SetNormal( transform.TransformAxis(normal) );
>> 195 extentList.AddSurface( endPoly2 );
>> 196 }
>> 197
167 // 198 //
168 halfTolerance = 0.5*kCarTolerance; // half t << 199 // Return min/max value
169 fRsph = std::sqrt(fDx * fDx + fDy * fDy + fD << 200 //
170 fDDx = fDx * fDx; // X semi-axis squared << 201 return extentList.GetExtent( min, max );
171 fDDy = fDy * fDy; // Y semi-axis squared <<
172 <<
173 fR = std::min(fDx, fDy); // resulting radius <<
174 fSx = fR / fDx; // X scale factor <<
175 fSy = fR / fDy; // Y scale factor <<
176 <<
177 fQ1 = 0.5 / fR; // distance approxiamtion di <<
178 fQ2 = 0.5 * (fR + halfTolerance * halfTolera <<
179 fScratch = 2. * fR * fR * DBL_EPSILON; // sc <<
180 // fScratch = (B * B / A) * (2. + halfTolera <<
181 } 202 }
182 203
183 ////////////////////////////////////////////// <<
184 // <<
185 // Get bounding box <<
186 204
187 void G4EllipticalTube::BoundingLimits( G4Three << 205 //
188 G4Three << 206 // Inside
>> 207 //
>> 208 // Note that for this solid, we've decided to define the tolerant
>> 209 // surface as that which is bounded by ellipses with axes
>> 210 // at +/- 0.5*kCarTolerance.
>> 211 //
>> 212 EInside G4EllipticalTube::Inside( const G4ThreeVector& p ) const
189 { 213 {
190 pMin.set(-fDx,-fDy,-fDz); << 214 static const G4double halfTol = 0.5*kCarTolerance;
191 pMax.set( fDx, fDy, fDz); << 215
>> 216 //
>> 217 // Check z extents: are we outside?
>> 218 //
>> 219 G4double absZ = std::fabs(p.z());
>> 220 if (absZ > dz+halfTol) return kOutside;
>> 221
>> 222 //
>> 223 // Check x,y: are we outside?
>> 224 //
>> 225 // G4double x = p.x(), y = p.y();
>> 226
>> 227 if (CheckXY(p.x(), p.y(), +halfTol) > 1.0) return kOutside;
>> 228
>> 229 //
>> 230 // We are either inside or on the surface: recheck z extents
>> 231 //
>> 232 if (absZ > dz-halfTol) return kSurface;
>> 233
>> 234 //
>> 235 // Recheck x,y
>> 236 //
>> 237 if (CheckXY(p.x(), p.y(), -halfTol) > 1.0) return kSurface;
>> 238
>> 239 return kInside;
192 } 240 }
193 241
194 ////////////////////////////////////////////// <<
195 // <<
196 // Calculate extent under transform and specif <<
197 242
198 G4bool << 243 //
199 G4EllipticalTube::CalculateExtent( const EAxis << 244 // SurfaceNormal
200 const G4Vox << 245 //
201 const G4Aff << 246 G4ThreeVector G4EllipticalTube::SurfaceNormal( const G4ThreeVector& p ) const
202 G4dou <<
203 { 247 {
204 G4ThreeVector bmin, bmax; <<
205 G4bool exist; <<
206 <<
207 // Check bounding box (bbox) <<
208 // 248 //
209 BoundingLimits(bmin,bmax); << 249 // Which of the three surfaces are we closest to (approximately)?
210 G4BoundingEnvelope bbox(bmin,bmax); <<
211 #ifdef G4BBOX_EXTENT <<
212 return bbox.CalculateExtent(pAxis,pVoxelLimi <<
213 #endif <<
214 if (bbox.BoundingBoxVsVoxelLimits(pAxis, pVo <<
215 { <<
216 return exist = pMin < pMax; <<
217 } <<
218 <<
219 G4double dx = fDx; <<
220 G4double dy = fDy; <<
221 G4double dz = fDz; <<
222 <<
223 // Set bounding envelope (benv) and calculat <<
224 // 250 //
225 const G4int NSTEPS = 24; // number of steps << 251 G4double distZ = std::fabs(p.z()) - dz;
226 G4double ang = twopi/NSTEPS; << 252
227 << 253 G4double rxy = CheckXY( p.x(), p.y() );
228 G4double sinHalf = std::sin(0.5*ang); << 254 G4double distR2 = (rxy < DBL_MIN) ? DBL_MAX : 1.0/rxy;
229 G4double cosHalf = std::cos(0.5*ang); <<
230 G4double sinStep = 2.*sinHalf*cosHalf; <<
231 G4double cosStep = 1. - 2.*sinHalf*sinHalf; <<
232 G4double sx = dx/cosHalf; <<
233 G4double sy = dy/cosHalf; <<
234 <<
235 G4double sinCur = sinHalf; <<
236 G4double cosCur = cosHalf; <<
237 G4ThreeVectorList baseA(NSTEPS),baseB(NSTEPS <<
238 for (G4int k=0; k<NSTEPS; ++k) <<
239 { <<
240 baseA[k].set(sx*cosCur,sy*sinCur,-dz); <<
241 baseB[k].set(sx*cosCur,sy*sinCur, dz); <<
242 255
243 G4double sinTmp = sinCur; << 256 //
244 sinCur = sinCur*cosStep + cosCur*sinStep; << 257 // Closer to z?
245 cosCur = cosCur*cosStep - sinTmp*sinStep; << 258 //
246 } << 259 if (distZ*distZ < distR2)
>> 260 return G4ThreeVector( 0.0, 0.0, p.z() < 0 ? -1.0 : 1.0 );
247 261
248 std::vector<const G4ThreeVectorList *> polyg << 262 //
249 polygons[0] = &baseA; << 263 // Closer to x/y
250 polygons[1] = &baseB; << 264 //
251 G4BoundingEnvelope benv(bmin, bmax, polygons << 265 return G4ThreeVector( p.x()*dy*dy, p.y()*dx*dx, 0.0 ).unit();
252 exist = benv.CalculateExtent(pAxis, pVoxelLi <<
253 return exist; <<
254 } 266 }
255 267
256 ////////////////////////////////////////////// << 268
257 // 269 //
258 // Determine where is point: inside, outside o << 270 // DistanceToIn(p,v)
259 // 271 //
260 << 272 // Unlike DistanceToOut(p,v), it is possible for the trajectory
261 EInside G4EllipticalTube::Inside( const G4Thre << 273 // to miss. The geometric calculations here are quite simple.
262 { << 274 // More difficult is the logic required to prevent particles
263 G4double x = p.x() * fSx; << 275 // from sneaking (or leaking) between the elliptical and end
264 G4double y = p.y() * fSy; << 276 // surfaces.
265 G4double distR = fQ1 * (x * x + y * y) - fQ2 <<
266 G4double distZ = std::abs(p.z()) - fDz; <<
267 G4double dist = std::max(distR, distZ); <<
268 <<
269 if (dist > halfTolerance) return kOutside; <<
270 return (dist > -halfTolerance) ? kSurface : <<
271 } <<
272 <<
273 ////////////////////////////////////////////// <<
274 // 277 //
275 // Return unit normal at surface closest to p << 278 // Keep in mind that the true distance is allowed to be
276 << 279 // negative if the point is currently on the surface. For oblique
277 G4ThreeVector G4EllipticalTube::SurfaceNormal( << 280 // angles, it can be very negative.
>> 281 //
>> 282 G4double G4EllipticalTube::DistanceToIn( const G4ThreeVector& p,
>> 283 const G4ThreeVector& v ) const
278 { 284 {
279 G4ThreeVector norm(0, 0, 0); << 285 static const G4double halfTol = 0.5*kCarTolerance;
280 G4int nsurf = 0; << 286
>> 287 //
>> 288 // Check z = -dz planer surface
>> 289 //
>> 290 G4double sigz = p.z()+dz;
281 291
282 // check lateral surface << 292 if (sigz < halfTol)
283 G4double x = p.x() * fSx; <<
284 G4double y = p.y() * fSy; <<
285 G4double distR = fQ1 * (x * x + y * y) - fQ2 <<
286 if (std::abs(distR) <= halfTolerance) <<
287 { 293 {
288 norm = G4ThreeVector(p.x() * fDDy, p.y() * << 294 //
289 ++nsurf; << 295 // We are "behind" the shape in z, and so can
>> 296 // potentially hit the rear face. Correct direction?
>> 297 //
>> 298 if (v.z() <= 0)
>> 299 {
>> 300 //
>> 301 // As long as we are far enough away, we know we
>> 302 // can't intersect
>> 303 //
>> 304 if (sigz < 0) return kInfinity;
>> 305
>> 306 //
>> 307 // Otherwise, we don't intersect unless we are
>> 308 // on the surface of the ellipse
>> 309 //
>> 310 if (CheckXY(p.x(),p.y(),-halfTol) <= 1.0) return kInfinity;
>> 311 }
>> 312 else
>> 313 {
>> 314 //
>> 315 // How far?
>> 316 //
>> 317 G4double s = -sigz/v.z();
>> 318
>> 319 //
>> 320 // Where does that place us?
>> 321 //
>> 322 G4double xi = p.x() + s*v.x(),
>> 323 yi = p.y() + s*v.y();
>> 324
>> 325 //
>> 326 // Is this on the surface (within ellipse)?
>> 327 //
>> 328 if (CheckXY(xi,yi) <= 1.0)
>> 329 {
>> 330 //
>> 331 // Yup. Return s, unless we are on the surface
>> 332 //
>> 333 return (sigz < -halfTol) ? s : 0;
>> 334 }
>> 335 else if (xi*dy*dy*v.x() + yi*dx*dx*v.y() >= 0)
>> 336 {
>> 337 //
>> 338 // Else, if we are traveling outwards, we know
>> 339 // we must miss
>> 340 //
>> 341 return kInfinity;
>> 342 }
>> 343 }
290 } 344 }
291 345
292 // check lateral bases << 346 //
293 G4double distZ = std::abs(p.z()) - fDz; << 347 // Check z = +dz planer surface
294 if (std::abs(distZ) <= halfTolerance) << 348 //
>> 349 sigz = p.z() - dz;
>> 350
>> 351 if (sigz > -halfTol)
295 { 352 {
296 norm.setZ(p.z() < 0 ? -1. : 1.); << 353 if (v.z() >= 0)
297 ++nsurf; << 354 {
>> 355 if (sigz > 0) return kInfinity;
>> 356 if (CheckXY(p.x(),p.y(),-halfTol) <= 1.0) return kInfinity;
>> 357 }
>> 358 else {
>> 359 G4double s = -sigz/v.z();
>> 360
>> 361 G4double xi = p.x() + s*v.x(),
>> 362 yi = p.y() + s*v.y();
>> 363
>> 364 if (CheckXY(xi,yi) <= 1.0)
>> 365 {
>> 366 return (sigz > -halfTol) ? s : 0;
>> 367 }
>> 368 else if (xi*dy*dy*v.x() + yi*dx*dx*v.y() >= 0)
>> 369 {
>> 370 return kInfinity;
>> 371 }
>> 372 }
298 } 373 }
>> 374
>> 375 //
>> 376 // Check intersection with the elliptical tube
>> 377 //
>> 378 G4double s[2];
>> 379 G4int n = IntersectXY( p, v, s );
>> 380
>> 381 if (n==0) return kInfinity;
>> 382
>> 383 //
>> 384 // Is the original point on the surface?
>> 385 //
>> 386 if (std::fabs(p.z()) < dz+halfTol) {
>> 387 if (CheckXY( p.x(), p.y(), halfTol ) < 1.0)
>> 388 {
>> 389 //
>> 390 // Well, yes, but are we traveling inwards at this point?
>> 391 //
>> 392 if (p.x()*dy*dy*v.x() + p.y()*dx*dx*v.y() < 0) return 0;
>> 393 }
>> 394 }
>> 395
>> 396 //
>> 397 // We are now certain that point p is not on the surface of
>> 398 // the solid (and thus std::fabs(s[0]) > halfTol).
>> 399 // Return kInfinity if the intersection is "behind" the point.
>> 400 //
>> 401 if (s[0] < 0) return kInfinity;
>> 402
>> 403 //
>> 404 // Check to see if we intersect the tube within
>> 405 // dz, but only when we know it might miss
>> 406 //
>> 407 G4double zi = p.z() + s[0]*v.z();
299 408
300 // return normal << 409 if (v.z() < 0)
301 if (nsurf == 1) return norm; <<
302 else if (nsurf > 1) return norm.unit(); // e <<
303 else <<
304 { 410 {
305 // Point is not on the surface << 411 if (zi < -dz) return kInfinity;
306 // << 412 }
307 #ifdef G4SPECDEBUG << 413 else if (v.z() > 0)
308 std::ostringstream message; << 414 {
309 G4long oldprc = message.precision(16); << 415 if (zi > +dz) return kInfinity;
310 message << "Point p is not on surface (!?) <<
311 << GetName() << G4endl; <<
312 message << "Position:\n"; <<
313 message << " p.x() = " << p.x()/mm << " <<
314 message << " p.y() = " << p.y()/mm << " <<
315 message << " p.z() = " << p.z()/mm << " <<
316 G4cout.precision(oldprc); <<
317 G4Exception("G4EllipticalTube::SurfaceNorm <<
318 JustWarning, message ); <<
319 DumpInfo(); <<
320 #endif <<
321 return ApproxSurfaceNormal(p); <<
322 } 416 }
323 } <<
324 417
325 ////////////////////////////////////////////// << 418 return s[0];
326 // <<
327 // Find surface nearest to point and return co <<
328 // The algorithm is similar to the algorithm u <<
329 // This method normally should not be called. <<
330 <<
331 G4ThreeVector <<
332 G4EllipticalTube::ApproxSurfaceNormal( const G <<
333 { <<
334 G4double x = p.x() * fSx; <<
335 G4double y = p.y() * fSy; <<
336 G4double distR = fQ1 * (x * x + y * y) - fQ2 <<
337 G4double distZ = std::abs(p.z()) - fDz; <<
338 if (distR > distZ && (x * x + y * y) > 0) <<
339 return G4ThreeVector(p.x() * fDDy, p.y() * <<
340 else <<
341 return {0, 0, (p.z() < 0 ? -1. : 1.)}; <<
342 } 419 }
343 420
344 ////////////////////////////////////////////// <<
345 // <<
346 // Calculate distance to shape from outside, a <<
347 // return kInfinity if no intersection, or dis <<
348 421
349 G4double G4EllipticalTube::DistanceToIn( const << 422 //
350 const << 423 // DistanceToIn(p)
>> 424 //
>> 425 // The distance from a point to an ellipse (in 2 dimensions) is a
>> 426 // surprisingly complicated quadric expression (this is easy to
>> 427 // appreciate once one understands that there may be up to
>> 428 // four lines normal to the ellipse intersecting any point). To
>> 429 // solve it exactly would be rather time consuming. This method,
>> 430 // however, is supposed to be a quick check, and is allowed to be an
>> 431 // underestimate.
>> 432 //
>> 433 // So, I will use the following underestimate of the distance
>> 434 // from an outside point to an ellipse. First: find the intersection "A"
>> 435 // of the line from the origin to the point with the ellipse.
>> 436 // Find the line passing through "A" and tangent to the ellipse
>> 437 // at A. The distance of the point p from the ellipse will be approximated
>> 438 // as the distance to this line.
>> 439 //
>> 440 G4double G4EllipticalTube::DistanceToIn( const G4ThreeVector& p ) const
351 { 441 {
352 G4double offset = 0.; << 442 static const G4double halfTol = 0.5*kCarTolerance;
353 G4ThreeVector pcur = p; << 443
354 << 444 if (CheckXY( p.x(), p.y(), +halfTol ) < 1.0)
355 // Check if point is flying away <<
356 // <<
357 G4double safex = std::abs(pcur.x()) - fDx; <<
358 G4double safey = std::abs(pcur.y()) - fDy; <<
359 G4double safez = std::abs(pcur.z()) - fDz; <<
360 <<
361 if (safez >= -halfTolerance && pcur.z() * v. <<
362 if (safey >= -halfTolerance && pcur.y() * v. <<
363 if (safex >= -halfTolerance && pcur.x() * v. <<
364 <<
365 // Relocate point, if required <<
366 // <<
367 G4double Dmax = 32. * fRsph; <<
368 if (std::max(std::max(safex, safey), safez) <<
369 { 445 {
370 offset = (1. - 1.e-08) * pcur.mag() - 2. * << 446 //
371 pcur += offset * v; << 447 // We are inside or on the surface of the
372 G4double dist = DistanceToIn(pcur, v); << 448 // elliptical cross section in x/y. Check z
373 return (dist == kInfinity) ? kInfinity : d << 449 //
>> 450 if (p.z() < -dz-halfTol)
>> 451 return -p.z()-dz;
>> 452 else if (p.z() > dz+halfTol)
>> 453 return p.z()-dz;
>> 454 else
>> 455 return 0; // On any surface here (or inside)
374 } 456 }
375 << 457
376 // Scale elliptical tube to cylinder <<
377 // 458 //
378 G4double px = pcur.x() * fSx; << 459 // Find point on ellipse
379 G4double py = pcur.y() * fSy; <<
380 G4double pz = pcur.z(); <<
381 G4double vx = v.x() * fSx; <<
382 G4double vy = v.y() * fSy; <<
383 G4double vz = v.z(); <<
384 <<
385 // Set coefficients of quadratic equation: A <<
386 // 460 //
387 G4double rr = px * px + py * py; << 461 G4double qnorm = CheckXY( p.x(), p.y() );
388 G4double A = vx * vx + vy * vy; << 462 if (qnorm < DBL_MIN) return 0; // This should never happen
389 G4double B = px * vx + py * vy; << 463
390 G4double C = rr - fR * fR; << 464 G4double q = 1.0/std::sqrt(qnorm);
391 G4double D = B * B - A * C; << 465
392 << 466 G4double xe = q*p.x(), ye = q*p.y();
393 // Check if point is flying away relative to << 467
394 // 468 //
395 G4double distR = fQ1 * rr - fQ2; << 469 // Get tangent to ellipse
396 G4bool parallelToZ = (A < DBL_EPSILON || std <<
397 if (distR >= -halfTolerance && (B >= 0. || p <<
398 <<
399 // Find intersection with Z planes <<
400 // 470 //
401 G4double invz = (vz == 0) ? DBL_MAX : -1./v << 471 G4double tx = -ye*dx*dx, ty = +xe*dy*dy;
402 G4double dz = std::copysign(fDz, invz); << 472 G4double tnorm = std::sqrt( tx*tx + ty*ty );
403 G4double tzmin = (pz - dz) * invz; << 473
404 G4double tzmax = (pz + dz) * invz; <<
405 <<
406 // Solve qudratic equation. There are two ca <<
407 // 1) trajectory parallel to Z axis (A = 0 <<
408 // 2) touch (D = 0) or no intersection (D <<
409 // 474 //
410 if (parallelToZ) return (tzmin<halfTolerance << 475 // Calculate distance
411 if (D <= A * A * fScratch) return kInfinity; << 476 //
412 << 477 G4double distR = ( (p.x()-xe)*ty - (p.y()-ye)*tx )/tnorm;
413 // Find roots of quadratic equation << 478
414 G4double tmp = -B - std::copysign(std::sqrt( << 479 //
415 G4double t1 = tmp / A; << 480 // Add the result in quadrature if we are, in addition,
416 G4double t2 = C / tmp; << 481 // outside the z bounds of the shape
417 G4double trmin = std::min(t1, t2); << 482 //
418 G4double trmax = std::max(t1, t2); << 483 // We could save some time by returning the maximum rather
419 << 484 // than the quadrature sum
420 // Return distance << 485 //
421 G4double tin = std::max(tzmin, trmin); << 486 if (p.z() < -dz)
422 G4double tout = std::min(tzmax, trmax); << 487 return std::sqrt( (p.z()+dz)*(p.z()+dz) + distR*distR );
>> 488 else if (p.z() > dz)
>> 489 return std::sqrt( (p.z()-dz)*(p.z()-dz) + distR*distR );
423 490
424 if (tout <= tin + halfTolerance) return kInf << 491 return distR;
425 return (tin<halfTolerance) ? offset : tin + <<
426 } 492 }
427 493
428 ////////////////////////////////////////////// <<
429 // <<
430 // Estimate distance to the surface from outsi <<
431 // returns 0 if point is inside <<
432 <<
433 G4double G4EllipticalTube::DistanceToIn( const <<
434 { <<
435 // safety distance to bounding box <<
436 G4double distX = std::abs(p.x()) - fDx; <<
437 G4double distY = std::abs(p.y()) - fDy; <<
438 G4double distZ = std::abs(p.z()) - fDz; <<
439 G4double distB = std::max(std::max(distX, di <<
440 // return (distB < 0) ? 0 : distB; <<
441 <<
442 // safety distance to lateral surface <<
443 G4double x = p.x() * fSx; <<
444 G4double y = p.y() * fSy; <<
445 G4double distR = std::sqrt(x * x + y * y) - <<
446 <<
447 // return SafetyToIn <<
448 G4double dist = std::max(distB, distR); <<
449 return (dist < 0) ? 0 : dist; <<
450 } <<
451 <<
452 ////////////////////////////////////////////// <<
453 // <<
454 // Calculate distance to shape from inside and <<
455 // at exit point, if required <<
456 // - when leaving the surface, return 0 <<
457 494
>> 495 //
>> 496 // DistanceToOut(p,v)
>> 497 //
>> 498 // This method can be somewhat complicated for a general shape.
>> 499 // For a convex one, like this, there are several simplifications,
>> 500 // the most important of which is that one can treat the surfaces
>> 501 // as infinite in extent when deciding if the p is on the surface.
>> 502 //
458 G4double G4EllipticalTube::DistanceToOut( cons 503 G4double G4EllipticalTube::DistanceToOut( const G4ThreeVector& p,
459 cons 504 const G4ThreeVector& v,
460 cons 505 const G4bool calcNorm,
461 << 506 G4bool *validNorm,
462 << 507 G4ThreeVector *norm ) const
463 { 508 {
464 // Check if point flying away relative to Z << 509 static const G4double halfTol = 0.5*kCarTolerance;
>> 510
465 // 511 //
466 G4double pz = p.z(); << 512 // Our normal is always valid
467 G4double vz = v.z(); <<
468 G4double distZ = std::abs(pz) - fDz; <<
469 if (distZ >= -halfTolerance && pz * vz > 0) <<
470 { <<
471 if (calcNorm) <<
472 { <<
473 *validNorm = true; <<
474 n->set(0, 0, (pz < 0) ? -1. : 1.); <<
475 } <<
476 return 0.; <<
477 } <<
478 G4double tzmax = (vz == 0) ? DBL_MAX : (std: <<
479 <<
480 // Scale elliptical tube to cylinder <<
481 // 513 //
482 G4double px = p.x() * fSx; << 514 if (calcNorm) *validNorm = true;
483 G4double py = p.y() * fSy; << 515
484 G4double vx = v.x() * fSx; << 516 G4double sBest = kInfinity;
485 G4double vy = v.y() * fSy; << 517 const G4ThreeVector *nBest=0;
486 << 518
487 // Check if point is flying away relative to <<
488 // 519 //
489 G4double rr = px * px + py * py; << 520 // Might we intersect the -dz surface?
490 G4double B = px * vx + py * vy; << 521 //
491 G4double distR = fQ1 * rr - fQ2; << 522 if (v.z() < 0)
492 if (distR >= -halfTolerance && B > 0.) <<
493 { 523 {
494 if (calcNorm) << 524 static const G4ThreeVector normHere(0.0,0.0,-1.0);
495 { << 525 //
496 *validNorm = true; << 526 // Yup. What distance?
497 *n = G4ThreeVector(px * fDDy, py * fDDx, << 527 //
>> 528 sBest = -(p.z()+dz)/v.z();
>> 529
>> 530 //
>> 531 // Are we on the surface? If so, return zero
>> 532 //
>> 533 if (p.z() < -dz+halfTol) {
>> 534 if (calcNorm) *norm = normHere;
>> 535 return 0;
498 } 536 }
499 return 0.; << 537 else
>> 538 nBest = &normHere;
500 } 539 }
501 << 540
502 // Just in case check if point is outside, n <<
503 // 541 //
504 if (std::max(distZ, distR) > halfTolerance) << 542 // How about the +dz surface?
>> 543 //
>> 544 if (v.z() > 0)
505 { 545 {
506 #ifdef G4SPECDEBUG << 546 static const G4ThreeVector normHere(0.0,0.0,+1.0);
507 std::ostringstream message; << 547 //
508 G4long oldprc = message.precision(16); << 548 // Yup. What distance?
509 message << "Point p is outside (!?) of sol << 549 //
510 << GetName() << G4endl; << 550 G4double s = (dz-p.z())/v.z();
511 message << "Position: " << p << G4endl;; << 551
512 message << "Direction: " << v; << 552 //
513 G4cout.precision(oldprc); << 553 // Are we on the surface? If so, return zero
514 G4Exception("G4EllipticalTube::DistanceToO << 554 //
515 JustWarning, message ); << 555 if (p.z() > +dz-halfTol) {
516 DumpInfo(); << 556 if (calcNorm) *norm = normHere;
517 #endif << 557 return 0;
518 if (calcNorm) <<
519 { <<
520 *validNorm = true; <<
521 *n = ApproxSurfaceNormal(p); <<
522 } 558 }
523 return 0.; << 559
>> 560 //
>> 561 // Best so far?
>> 562 //
>> 563 if (s < sBest) { sBest = s; nBest = &normHere; }
524 } 564 }
525 << 565
526 // Set coefficients of quadratic equation: A <<
527 // 566 //
528 G4double A = vx * vx + vy * vy; << 567 // Check furthest intersection with ellipse
529 G4double C = rr - fR * fR; <<
530 G4double D = B * B - A * C; <<
531 <<
532 // Solve qudratic equation. There are two sp <<
533 // 1) trajectory parallel to Z axis (A = 0 <<
534 // 2) touch (D = 0) or no intersection (D <<
535 // 568 //
536 G4bool parallelToZ = (A < DBL_EPSILON || std << 569 G4double s[2];
537 if (parallelToZ) // 1) << 570 G4int n = IntersectXY( p, v, s );
>> 571
>> 572 if (n == 0)
538 { 573 {
539 if (calcNorm) << 574 if (sBest == kInfinity)
540 { 575 {
541 *validNorm = true; << 576 G4cout.precision(16) ;
542 n->set(0, 0, (vz < 0) ? -1. : 1.); << 577 G4cout << G4endl ;
>> 578 DumpInfo();
>> 579 G4cout << "Position:" << G4endl << G4endl ;
>> 580 G4cout << "p.x() = " << p.x()/mm << " mm" << G4endl ;
>> 581 G4cout << "p.y() = " << p.y()/mm << " mm" << G4endl ;
>> 582 G4cout << "p.z() = " << p.z()/mm << " mm" << G4endl << G4endl ;
>> 583 G4cout << "Direction:" << G4endl << G4endl;
>> 584 G4cout << "v.x() = " << v.x() << G4endl;
>> 585 G4cout << "v.y() = " << v.y() << G4endl;
>> 586 G4cout << "v.z() = " << v.z() << G4endl << G4endl;
>> 587 G4cout << "Proposed distance :" << G4endl << G4endl;
>> 588 G4cout << "snxt = " << sBest/mm << " mm" << G4endl << G4endl;
>> 589 G4Exception( "G4EllipticalTube::DistanceToOut(p,v,...)",
>> 590 "Notification", JustWarning, "Point p is outside !?" );
543 } 591 }
544 return tzmax; << 592 if (calcNorm) *norm = *nBest;
>> 593 return sBest;
545 } 594 }
546 if (D <= A * A * fScratch) // 2) << 595 else if (s[n-1] > sBest)
547 { 596 {
548 if (calcNorm) << 597 if (calcNorm) *norm = *nBest;
549 { << 598 return sBest;
550 *validNorm = true; << 599 }
551 *n = G4ThreeVector(px * fDDy, py * fDDx, << 600 sBest = s[n-1];
552 } << 601
553 return 0.; << 602 //
554 } << 603 // Intersection with ellipse. Get normal at intersection point.
555 <<
556 // Find roots of quadratic equation <<
557 G4double tmp = -B - std::copysign(std::sqrt( <<
558 G4double t1 = tmp / A; <<
559 G4double t2 = C / tmp; <<
560 G4double trmax = std::max(t1, t2); <<
561 <<
562 // Return distance <<
563 G4double tmax = std::min(tzmax, trmax); <<
564 <<
565 // Set normal, if required, and return dista <<
566 // 604 //
567 if (calcNorm) 605 if (calcNorm)
568 { 606 {
569 *validNorm = true; << 607 G4ThreeVector ip = p + sBest*v;
570 G4ThreeVector pnew = p + tmax * v; << 608 *norm = G4ThreeVector( ip.x()*dy*dy, ip.y()*dx*dx, 0.0 ).unit();
571 if (tmax == tzmax) << 609 }
572 n->set(0, 0, (pnew.z() < 0) ? -1. : 1.); << 610
573 else << 611 //
574 *n = G4ThreeVector(pnew.x() * fDDy, pnew << 612 // Do we start on the surface?
>> 613 //
>> 614 if (CheckXY( p.x(), p.y(), -halfTol ) > 1.0)
>> 615 {
>> 616 //
>> 617 // Well, yes, but are we traveling outwards at this point?
>> 618 //
>> 619 if (p.x()*dy*dy*v.x() + p.y()*dx*dx*v.y() > 0) return 0;
575 } 620 }
576 return tmax; << 621
>> 622 return sBest;
577 } 623 }
578 624
579 ////////////////////////////////////////////// << 625
580 // 626 //
581 // Estimate distance to the surface from insid << 627 // DistanceToOut(p)
582 // returns 0 if point is outside << 628 //
>> 629 // See DistanceToIn(p) for notes on the distance from a point
>> 630 // to an ellipse in two dimensions.
>> 631 //
>> 632 // The approximation used here for a point inside the ellipse
>> 633 // is to find the intersection with the ellipse of the lines
>> 634 // through the point and parallel to the x and y axes. The
>> 635 // distance of the point from the line connecting the two
>> 636 // intersecting points is then used.
583 // 637 //
584 <<
585 G4double G4EllipticalTube::DistanceToOut( cons 638 G4double G4EllipticalTube::DistanceToOut( const G4ThreeVector& p ) const
586 { 639 {
587 #ifdef G4SPECDEBUG << 640 static const G4double halfTol = 0.5*kCarTolerance;
588 if( Inside(p) == kOutside ) << 641
>> 642 //
>> 643 // We need to calculate the distances to all surfaces,
>> 644 // and then return the smallest
>> 645 //
>> 646 // Check -dz and +dz surface
>> 647 //
>> 648 G4double sBest = dz - std::fabs(p.z());
>> 649 if (sBest < halfTol) return 0;
>> 650
>> 651 //
>> 652 // Check elliptical surface: find intersection of
>> 653 // line through p and parallel to x axis
>> 654 //
>> 655 G4double radical = 1.0 - p.y()*p.y()/dy/dy;
>> 656 if (radical < +DBL_MIN) return 0;
>> 657
>> 658 G4double xi = dx*std::sqrt( radical );
>> 659 if (p.x() < 0) xi = -xi;
>> 660
>> 661 //
>> 662 // Do the same with y axis
>> 663 //
>> 664 radical = 1.0 - p.x()*p.x()/dx/dx;
>> 665 if (radical < +DBL_MIN) return 0;
>> 666
>> 667 G4double yi = dy*std::sqrt( radical );
>> 668 if (p.y() < 0) yi = -yi;
>> 669
>> 670 //
>> 671 // Get distance from p to the line connecting
>> 672 // these two points
>> 673 //
>> 674 G4double xdi = p.x() - xi,
>> 675 ydi = yi - p.y();
>> 676
>> 677 G4double normi = std::sqrt( xdi*xdi + ydi*ydi );
>> 678 if (normi < halfTol) return 0;
>> 679 xdi /= normi;
>> 680 ydi /= normi;
>> 681
>> 682 G4double s = 0.5*(xdi*(p.y()-yi) - ydi*(p.x()-xi));
>> 683 if (xi*yi < 0) s = -s;
>> 684
>> 685 if (s < sBest) sBest = s;
>> 686
>> 687 //
>> 688 // Return best answer
>> 689 //
>> 690 return sBest < halfTol ? 0 : sBest;
>> 691 }
>> 692
>> 693
>> 694 //
>> 695 // IntersectXY
>> 696 //
>> 697 // Decide if and where the x/y trajectory hits the elliptical cross
>> 698 // section.
>> 699 //
>> 700 // Arguments:
>> 701 // p - (in) Point on trajectory
>> 702 // v - (in) Vector along trajectory
>> 703 // s - (out) Up to two points of intersection, where the
>> 704 // intersection point is p + s*v, and if there are
>> 705 // two intersections, s[0] < s[1]. May be negative.
>> 706 // Returns:
>> 707 // The number of intersections. If 0, the trajectory misses. If 1, the
>> 708 // trajectory just grazes the surface.
>> 709 //
>> 710 // Solution:
>> 711 // One needs to solve: ( (p.x + s*v.x)/dx )**2 + ( (p.y + s*v.y)/dy )**2 = 1
>> 712 //
>> 713 // The solution is quadratic: a*s**2 + b*s + c = 0
>> 714 //
>> 715 // a = (v.x/dx)**2 + (v.y/dy)**2
>> 716 // b = 2*p.x*v.x/dx**2 + 2*p.y*v.y/dy**2
>> 717 // c = (p.x/dx)**2 + (p.y/dy)**2 - 1
>> 718 //
>> 719 G4int G4EllipticalTube::IntersectXY( const G4ThreeVector &p,
>> 720 const G4ThreeVector &v,
>> 721 G4double s[2] ) const
>> 722 {
>> 723 G4double px = p.x(), py = p.y();
>> 724 G4double vx = v.x(), vy = v.y();
>> 725
>> 726 G4double a = (vx/dx)*(vx/dx) + (vy/dy)*(vy/dy);
>> 727 G4double b = 2.0*( px*vx/dx/dx + py*vy/dy/dy );
>> 728 G4double c = (px/dx)*(px/dx) + (py/dy)*(py/dy) - 1.0;
>> 729
>> 730 if (a < DBL_MIN) return 0; // Trajectory parallel to z axis
>> 731
>> 732 G4double radical = b*b - 4*a*c;
>> 733
>> 734 if (radical < -DBL_MIN) return 0; // No solution
>> 735
>> 736 if (radical < DBL_MIN)
589 { 737 {
590 std::ostringstream message; << 738 //
591 G4long oldprc = message.precision(16); << 739 // Grazes surface
592 message << "Point p is outside (!?) of sol << 740 //
593 << "Position:\n" << 741 s[0] = -b/a/2.0;
594 << " p.x() = " << p.x()/mm << " << 742 return 1;
595 << " p.y() = " << p.y()/mm << " << 743 }
596 << " p.z() = " << p.z()/mm << " << 744
597 message.precision(oldprc) ; << 745 radical = std::sqrt(radical);
598 G4Exception("G4ElliptocalTube::DistanceToO << 746
599 JustWarning, message); << 747 G4double q = -0.5*( b + (b < 0 ? -radical : +radical) );
600 DumpInfo(); << 748 G4double sa = q/a;
601 } << 749 G4double sb = c/q;
602 #endif << 750 if (sa < sb) { s[0] = sa; s[1] = sb; } else { s[0] = sb; s[1] = sa; }
603 // safety distance to Z-bases << 751 return 2;
604 G4double distZ = fDz - std::abs(p.z()); <<
605 <<
606 // safety distance lateral surface <<
607 G4double x = p.x() * fSx; <<
608 G4double y = p.y() * fSy; <<
609 G4double distR = fR - std::sqrt(x * x + y * <<
610 <<
611 // return SafetyToOut <<
612 G4double dist = std::min(distZ, distR); <<
613 return (dist < 0) ? 0 : dist; <<
614 } 752 }
615 753
616 ////////////////////////////////////////////// << 754
617 // 755 //
618 // GetEntityType 756 // GetEntityType
619 << 757 //
620 G4GeometryType G4EllipticalTube::GetEntityType 758 G4GeometryType G4EllipticalTube::GetEntityType() const
621 { 759 {
622 return {"G4EllipticalTube"}; << 760 return G4String("G4EllipticalTube");
623 } 761 }
624 762
625 ////////////////////////////////////////////// <<
626 // <<
627 // Make a clone of the object <<
628 763
629 G4VSolid* G4EllipticalTube::Clone() const <<
630 { <<
631 return new G4EllipticalTube(*this); <<
632 } <<
633 <<
634 ////////////////////////////////////////////// <<
635 // 764 //
636 // Return volume << 765 // GetCubicVolume
637 << 766 //
638 G4double G4EllipticalTube::GetCubicVolume() 767 G4double G4EllipticalTube::GetCubicVolume()
639 { 768 {
640 if (fCubicVolume == 0.) << 769 if(fCubicVolume != 0.) ;
641 { << 770 else fCubicVolume = G4VSolid::GetCubicVolume();
642 fCubicVolume = twopi * fDx * fDy * fDz; <<
643 } <<
644 return fCubicVolume; 771 return fCubicVolume;
645 } 772 }
646 773
647 ////////////////////////////////////////////// <<
648 // <<
649 // Return cached surface area <<
650 <<
651 G4double G4EllipticalTube::GetCachedSurfaceAre <<
652 { <<
653 G4ThreadLocalStatic G4double cached_Dx = 0; <<
654 G4ThreadLocalStatic G4double cached_Dy = 0; <<
655 G4ThreadLocalStatic G4double cached_Dz = 0; <<
656 G4ThreadLocalStatic G4double cached_area = 0 <<
657 if (cached_Dx != fDx || cached_Dy != fDy || <<
658 { <<
659 cached_Dx = fDx; <<
660 cached_Dy = fDy; <<
661 cached_Dz = fDz; <<
662 cached_area = 2.*(pi*fDx*fDy + G4GeomTools <<
663 } <<
664 return cached_area; <<
665 } <<
666 774
667 ////////////////////////////////////////////// <<
668 // 775 //
669 // Return surface area << 776 // Stream object contents to an output stream
670 <<
671 G4double G4EllipticalTube::GetSurfaceArea() <<
672 { <<
673 if(fSurfaceArea == 0.) <<
674 { <<
675 fSurfaceArea = GetCachedSurfaceArea(); <<
676 } <<
677 return fSurfaceArea; <<
678 } <<
679 <<
680 ////////////////////////////////////////////// <<
681 // 777 //
682 // Stream object contents to output stream <<
683 <<
684 std::ostream& G4EllipticalTube::StreamInfo(std 778 std::ostream& G4EllipticalTube::StreamInfo(std::ostream& os) const
685 { 779 {
686 G4long oldprc = os.precision(16); <<
687 os << "------------------------------------- 780 os << "-----------------------------------------------------------\n"
688 << " *** Dump for solid - " << GetName 781 << " *** Dump for solid - " << GetName() << " ***\n"
689 << " ================================= 782 << " ===================================================\n"
690 << " Solid type: G4EllipticalTube\n" 783 << " Solid type: G4EllipticalTube\n"
691 << " Parameters: \n" 784 << " Parameters: \n"
692 << " length Z: " << fDz/mm << " mm \n" << 785 << " length Z: " << dz/mm << " mm \n"
693 << " lateral surface equation: \n" << 786 << " surface equation in X and Y: \n"
694 << " (X / " << fDx << ")^2 + (Y / " << 787 << " (X / " << dx << ")^2 + (Y / " << dy << ")^2 = 1 \n"
695 << "------------------------------------- 788 << "-----------------------------------------------------------\n";
696 os.precision(oldprc); <<
697 789
698 return os; 790 return os;
699 } 791 }
700 792
701 793
702 ////////////////////////////////////////////// <<
703 // 794 //
704 // Pick up a random point on the surface << 795 // GetPointOnSurface
705 << 796 //
>> 797 // Randomly generates a point on the surface,
>> 798 // with ~ uniform distribution across surface.
>> 799 //
706 G4ThreeVector G4EllipticalTube::GetPointOnSurf 800 G4ThreeVector G4EllipticalTube::GetPointOnSurface() const
707 { 801 {
708 // Select surface (0 - base at -Z, 1 - base << 802 G4double xRand, yRand, zRand, phi, cosphi, sinphi, zArea, cArea,p, chose;
709 // <<
710 G4double sbase = pi * fDx * fDy; <<
711 G4double ssurf = GetCachedSurfaceArea(); <<
712 G4double select = ssurf * G4UniformRand(); <<
713 803
714 G4int k = 0; << 804 phi = RandFlat::shoot(0., 2.*pi);
715 if (select > sbase) k = 1; << 805 cosphi = std::cos(phi);
716 if (select > 2. * sbase) k = 2; << 806 sinphi = std::sin(phi);
717 << 807
718 // Pick random point on selected surface (re << 808 // the ellipse perimeter from: "http://mathworld.wolfram.com/Ellipse.html"
719 // << 809 // m = (dx - dy)/(dx + dy);
720 G4ThreeVector p; << 810 // k = 1.+1./4.*m*m+1./64.*sqr(m)*sqr(m)+1./256.*sqr(m)*sqr(m)*sqr(m);
721 switch (k) { << 811 // p = pi*(a+b)*k;
722 case 0: // base at -Z << 812
723 { << 813 // perimeter below from "http://www.efunda.com/math/areas/EllipseGen.cfm"
724 G4TwoVector rho = G4RandomPointInEllipse << 814
725 p.set(rho.x(), rho.y(), -fDz); << 815 p = 2.*pi*std::sqrt(0.5*(dx*dx+dy*dy));
726 break; << 816
727 } << 817 cArea = 2.*dz*p;
728 case 1: // base at +Z << 818 zArea = pi*dx*dy;
729 { << 819
730 G4TwoVector rho = G4RandomPointInEllipse << 820 xRand = dx*cosphi;
731 p.set(rho.x(), rho.y(), fDz); << 821 yRand = dy*sinphi;
732 break; << 822 zRand = RandFlat::shoot(dz, -1.*dz);
733 } << 823
734 case 2: // lateral surface << 824 chose = RandFlat::shoot(0.,2.*zArea+cArea);
735 { << 825
736 G4TwoVector rho = G4RandomPointOnEllipse << 826 if( (chose>=0) && (chose < cArea) )
737 p.set(rho.x(), rho.y(), (2. * G4UniformR << 827 {
738 break; << 828 return G4ThreeVector (xRand,yRand,zRand);
739 } << 829 }
>> 830 else if( (chose >= cArea) && (chose < cArea + zArea) )
>> 831 {
>> 832 xRand = RandFlat::shoot(-1.*dx,dx);
>> 833 yRand = std::sqrt(1.-sqr(xRand/dx));
>> 834 yRand = RandFlat::shoot(-1.*yRand, yRand);
>> 835 return G4ThreeVector (xRand,yRand,dz);
>> 836 }
>> 837 else
>> 838 {
>> 839 xRand = RandFlat::shoot(-1.*dx,dx);
>> 840 yRand = std::sqrt(1.-sqr(xRand/dx));
>> 841 yRand = RandFlat::shoot(-1.*yRand, yRand);
>> 842 return G4ThreeVector (xRand,yRand,-1.*dz);
740 } 843 }
741 return p; <<
742 } 844 }
743 845
744 846
745 ////////////////////////////////////////////// <<
746 // 847 //
747 // CreatePolyhedron 848 // CreatePolyhedron
748 << 849 //
749 G4Polyhedron* G4EllipticalTube::CreatePolyhedr 850 G4Polyhedron* G4EllipticalTube::CreatePolyhedron() const
750 { 851 {
751 // create cylinder with radius=1... 852 // create cylinder with radius=1...
752 // 853 //
753 G4Polyhedron* eTube = new G4PolyhedronTube(0 << 854 G4Polyhedron* eTube = new G4PolyhedronTube(0.,1.,dz);
754 855
755 // apply non-uniform scaling... 856 // apply non-uniform scaling...
756 // 857 //
757 eTube->Transform(G4Scale3D(fDx, fDy, 1.)); << 858 eTube->Transform(G4Scale3D(dx,dy,1.));
758 return eTube; << 859 return eTube;
759 } 860 }
760 861
761 ////////////////////////////////////////////// << 862
762 // 863 //
763 // GetPolyhedron 864 // GetPolyhedron
764 << 865 //
765 G4Polyhedron* G4EllipticalTube::GetPolyhedron 866 G4Polyhedron* G4EllipticalTube::GetPolyhedron () const
766 { 867 {
767 if (fpPolyhedron == nullptr || << 868 if (!fpPolyhedron ||
768 fRebuildPolyhedron || <<
769 fpPolyhedron->GetNumberOfRotationStepsAt 869 fpPolyhedron->GetNumberOfRotationStepsAtTimeOfCreation() !=
770 fpPolyhedron->GetNumberOfRotationSteps() 870 fpPolyhedron->GetNumberOfRotationSteps())
771 { << 871 {
772 G4AutoLock l(&polyhedronMutex); << 872 delete fpPolyhedron;
773 delete fpPolyhedron; << 873 fpPolyhedron = CreatePolyhedron();
774 fpPolyhedron = CreatePolyhedron(); << 874 }
775 fRebuildPolyhedron = false; <<
776 l.unlock(); <<
777 } <<
778 return fpPolyhedron; 875 return fpPolyhedron;
779 } 876 }
780 877
781 ////////////////////////////////////////////// << 878
782 // 879 //
783 // DescribeYourselfTo 880 // DescribeYourselfTo
784 << 881 //
785 void G4EllipticalTube::DescribeYourselfTo( G4V 882 void G4EllipticalTube::DescribeYourselfTo( G4VGraphicsScene& scene ) const
786 { 883 {
787 scene.AddSolid (*this); 884 scene.AddSolid (*this);
788 } 885 }
789 886
790 ////////////////////////////////////////////// << 887
791 // 888 //
792 // GetExtent 889 // GetExtent
793 << 890 //
794 G4VisExtent G4EllipticalTube::GetExtent() cons 891 G4VisExtent G4EllipticalTube::GetExtent() const
795 { 892 {
796 return { -fDx, fDx, -fDy, fDy, -fDz, fDz }; << 893 return G4VisExtent( -dx, dx, -dy, dy, -dz, dz );
797 } 894 }
798 <<
799 #endif // !defined(G4GEOM_USE_UELLIPTICALTUBE) <<
800 895