// // ******************************************************************** // * License and Disclaimer * // * * // * The Geant4 software is copyright of the Copyright Holders of * // * the Geant4 Collaboration. It is provided under the terms and * // * conditions of the Geant4 Software License, included in the file * // * LICENSE and available at http://cern.ch/geant4/license . These * // * include a list of copyright holders. * // * * // * Neither the authors of this software system, nor their employing * // * institutes,nor the agencies providing financial support for this * // * work make any representation or warranty, express or implied, * // * regarding this software system or assume any liability for its * // * use. Please see the license in the file LICENSE and URL above * // * for the full disclaimer and the limitation of liability. * // * * // * This code implementation is the result of the scientific and * // * technical work of the GEANT4 collaboration. * // * By using, copying, modifying or distributing the software (or * // * any work based on the software) you agree to acknowledge its * // * use in resulting scientific publications, and indicate your * // * acceptance of all terms of the Geant4 Software license. * // ******************************************************************** // // // $Id: G4PolyconeSide.cc,v 1.19 2008/05/15 11:41:59 gcosmo Exp $ // GEANT4 tag $Name: geant4-09-02-ref-02 $ // // // -------------------------------------------------------------------- // GEANT 4 class source file // // // G4PolyconeSide.cc // // Implementation of the face representing one conical side of a polycone // // -------------------------------------------------------------------- #include "G4PolyconeSide.hh" #include "G4IntersectingCone.hh" #include "G4ClippablePolygon.hh" #include "G4AffineTransform.hh" #include "meshdefs.hh" #include "G4SolidExtentList.hh" #include "G4GeometryTolerance.hh" #include "Randomize.hh" // // Constructor // // Values for r1,z1 and r2,z2 should be specified in clockwise // order in (r,z). // G4PolyconeSide::G4PolyconeSide( const G4PolyconeSideRZ *prevRZ, const G4PolyconeSideRZ *tail, const G4PolyconeSideRZ *head, const G4PolyconeSideRZ *nextRZ, G4double thePhiStart, G4double theDeltaPhi, G4bool thePhiIsOpen, G4bool isAllBehind ) : ncorners(0), corners(0) { kCarTolerance = G4GeometryTolerance::GetInstance()->GetSurfaceTolerance(); fSurfaceArea = 0.0; // // Record values // r[0] = tail->r; z[0] = tail->z; r[1] = head->r; z[1] = head->z; phiIsOpen = thePhiIsOpen; if (phiIsOpen) { deltaPhi = theDeltaPhi; startPhi = thePhiStart; // // Set phi values to our conventions // while (deltaPhi < 0.0) deltaPhi += twopi; while (startPhi < 0.0) startPhi += twopi; // // Calculate corner coordinates // ncorners = 4; corners = new G4ThreeVector[ncorners]; corners[0] = G4ThreeVector( tail->r*std::cos(startPhi), tail->r*std::sin(startPhi), tail->z ); corners[1] = G4ThreeVector( head->r*std::cos(startPhi), head->r*std::sin(startPhi), head->z ); corners[2] = G4ThreeVector( tail->r*std::cos(startPhi+deltaPhi), tail->r*std::sin(startPhi+deltaPhi), tail->z ); corners[3] = G4ThreeVector( head->r*std::cos(startPhi+deltaPhi), head->r*std::sin(startPhi+deltaPhi), head->z ); } else { deltaPhi = twopi; startPhi = 0.0; } allBehind = isAllBehind; // // Make our intersecting cone // cone = new G4IntersectingCone( r, z ); // // Calculate vectors in r,z space // rS = r[1]-r[0]; zS = z[1]-z[0]; length = std::sqrt( rS*rS + zS*zS); rS /= length; zS /= length; rNorm = +zS; zNorm = -rS; G4double lAdj; prevRS = r[0]-prevRZ->r; prevZS = z[0]-prevRZ->z; lAdj = std::sqrt( prevRS*prevRS + prevZS*prevZS ); prevRS /= lAdj; prevZS /= lAdj; rNormEdge[0] = rNorm + prevZS; zNormEdge[0] = zNorm - prevRS; lAdj = std::sqrt( rNormEdge[0]*rNormEdge[0] + zNormEdge[0]*zNormEdge[0] ); rNormEdge[0] /= lAdj; zNormEdge[0] /= lAdj; nextRS = nextRZ->r-r[1]; nextZS = nextRZ->z-z[1]; lAdj = std::sqrt( nextRS*nextRS + nextZS*nextZS ); nextRS /= lAdj; nextZS /= lAdj; rNormEdge[1] = rNorm + nextZS; zNormEdge[1] = zNorm - nextRS; lAdj = std::sqrt( rNormEdge[1]*rNormEdge[1] + zNormEdge[1]*zNormEdge[1] ); rNormEdge[1] /= lAdj; zNormEdge[1] /= lAdj; } // // Fake default constructor - sets only member data and allocates memory // for usage restricted to object persistency. // G4PolyconeSide::G4PolyconeSide( __void__& ) : phiIsOpen(false), cone(0), ncorners(0), corners(0) { } // // Destructor // G4PolyconeSide::~G4PolyconeSide() { delete cone; if (phiIsOpen) delete [] corners; } // // Copy constructor // G4PolyconeSide::G4PolyconeSide( const G4PolyconeSide &source ) : G4VCSGface() { CopyStuff( source ); } // // Assignment operator // G4PolyconeSide& G4PolyconeSide::operator=( const G4PolyconeSide &source ) { if (this == &source) return *this; delete cone; if (phiIsOpen) delete [] corners; CopyStuff( source ); return *this; } // // CopyStuff // void G4PolyconeSide::CopyStuff( const G4PolyconeSide &source ) { r[0] = source.r[0]; r[1] = source.r[1]; z[0] = source.z[0]; z[1] = source.z[1]; startPhi = source.startPhi; deltaPhi = source.deltaPhi; phiIsOpen = source.phiIsOpen; allBehind = source.allBehind; kCarTolerance = source.kCarTolerance; fSurfaceArea = source.fSurfaceArea; cone = new G4IntersectingCone( *source.cone ); rNorm = source.rNorm; zNorm = source.zNorm; rS = source.rS; zS = source.zS; length = source.length; prevRS = source.prevRS; prevZS = source.prevZS; nextRS = source.nextRS; nextZS = source.nextZS; rNormEdge[0] = source.rNormEdge[0]; rNormEdge[1] = source.rNormEdge[1]; zNormEdge[0] = source.zNormEdge[0]; zNormEdge[1] = source.zNormEdge[1]; if (phiIsOpen) { ncorners = 4; corners = new G4ThreeVector[ncorners]; corners[0] = source.corners[0]; corners[1] = source.corners[1]; corners[2] = source.corners[2]; corners[3] = source.corners[3]; } } // // Intersect // G4bool G4PolyconeSide::Intersect( const G4ThreeVector &p, const G4ThreeVector &v, G4bool outgoing, G4double surfTolerance, G4double &distance, G4double &distFromSurface, G4ThreeVector &normal, G4bool &isAllBehind ) { G4double s1, s2; G4double normSign = outgoing ? +1 : -1; isAllBehind = allBehind; // // Check for two possible intersections // G4int nside = cone->LineHitsCone( p, v, &s1, &s2 ); if (nside == 0) return false; // // Check the first side first, since it is (supposed to be) closest // G4ThreeVector hit = p + s1*v; if (PointOnCone( hit, normSign, p, v, normal )) { // // Good intersection! What about the normal? // if (normSign*v.dot(normal) > 0) { // // We have a valid intersection, but it could very easily // be behind the point. To decide if we tolerate this, // we have to see if the point p is on the surface near // the intersecting point. // // What does it mean exactly for the point p to be "near" // the intersection? It means that if we draw a line from // p to the hit, the line remains entirely within the // tolerance bounds of the cone. To test this, we can // ask if the normal is correct near p. // G4double pr = p.perp(); if (pr < DBL_MIN) pr = DBL_MIN; G4ThreeVector pNormal( rNorm*p.x()/pr, rNorm*p.y()/pr, zNorm ); if (normSign*v.dot(pNormal) > 0) { // // p and intersection in same hemisphere // G4double distOutside2; distFromSurface = -normSign*DistanceAway( p, false, distOutside2 ); if (distOutside2 < surfTolerance*surfTolerance) { if (distFromSurface > -surfTolerance) { // // We are just inside or away from the // surface. Accept *any* value of distance. // distance = s1; return true; } } } else distFromSurface = s1; // // Accept positive distances // if (s1 > 0) { distance = s1; return true; } } } if (nside==1) return false; // // Well, try the second hit // hit = p + s2*v; if (PointOnCone( hit, normSign, p, v, normal )) { // // Good intersection! What about the normal? // if (normSign*v.dot(normal) > 0) { G4double pr = p.perp(); if (pr < DBL_MIN) pr = DBL_MIN; G4ThreeVector pNormal( rNorm*p.x()/pr, rNorm*p.y()/pr, zNorm ); if (normSign*v.dot(pNormal) > 0) { G4double distOutside2; distFromSurface = -normSign*DistanceAway( p, false, distOutside2 ); if (distOutside2 < surfTolerance*surfTolerance) { if (distFromSurface > -surfTolerance) { distance = s2; return true; } } } else distFromSurface = s2; if (s2 > 0) { distance = s2; return true; } } } // // Better luck next time // return false; } G4double G4PolyconeSide::Distance( const G4ThreeVector &p, G4bool outgoing ) { G4double normSign = outgoing ? -1 : +1; G4double distFrom, distOut2; // // We have two tries for each hemisphere. Try the closest first. // distFrom = normSign*DistanceAway( p, false, distOut2 ); if (distFrom > -0.5*kCarTolerance ) { // // Good answer // if (distOut2 > 0) return std::sqrt( distFrom*distFrom + distOut2 ); else return std::fabs(distFrom); } // // Try second side. // distFrom = normSign*DistanceAway( p, true, distOut2 ); if (distFrom > -0.5*kCarTolerance) { if (distOut2 > 0) return std::sqrt( distFrom*distFrom + distOut2 ); else return std::fabs(distFrom); } return kInfinity; } // // Inside // EInside G4PolyconeSide::Inside( const G4ThreeVector &p, G4double tolerance, G4double *bestDistance ) { // // Check both sides // G4double distFrom[2], distOut2[2], dist2[2]; G4double edgeRZnorm[2]; distFrom[0] = DistanceAway( p, false, distOut2[0], edgeRZnorm ); distFrom[1] = DistanceAway( p, true, distOut2[1], edgeRZnorm+1 ); dist2[0] = distFrom[0]*distFrom[0] + distOut2[0]; dist2[1] = distFrom[1]*distFrom[1] + distOut2[1]; // // Who's closest? // G4int i = std::fabs(dist2[0]) < std::fabs(dist2[1]) ? 0 : 1; *bestDistance = std::sqrt( dist2[i] ); // // Okay then, inside or out? // if ( (std::fabs(edgeRZnorm[i]) < tolerance) && (distOut2[i] < tolerance*tolerance) ) return kSurface; else if (edgeRZnorm[i] < 0) return kInside; else return kOutside; } // // Normal // G4ThreeVector G4PolyconeSide::Normal( const G4ThreeVector &p, G4double *bestDistance ) { if (p == G4ThreeVector(0.,0.,0.)) { return p; } G4ThreeVector dFrom; G4double dOut2; dFrom = DistanceAway( p, false, dOut2 ); *bestDistance = std::sqrt( dFrom*dFrom + dOut2 ); G4double rad = p.perp(); return G4ThreeVector( rNorm*p.x()/rad, rNorm*p.y()/rad, zNorm ); } // // Extent // G4double G4PolyconeSide::Extent( const G4ThreeVector axis ) { if (axis.perp2() < DBL_MIN) { // // Special case // return axis.z() < 0 ? -cone->ZLo() : cone->ZHi(); } // // Is the axis pointing inside our phi gap? // if (phiIsOpen) { G4double phi = axis.phi(); while( phi < startPhi ) phi += twopi; if (phi > deltaPhi+startPhi) { // // Yeah, looks so. Make four three vectors defining the phi // opening // G4double cosP = std::cos(startPhi), sinP = std::sin(startPhi); G4ThreeVector a( r[0]*cosP, r[0]*sinP, z[0] ); G4ThreeVector b( r[1]*cosP, r[1]*sinP, z[1] ); cosP = std::cos(startPhi+deltaPhi); sinP = std::sin(startPhi+deltaPhi); G4ThreeVector c( r[0]*cosP, r[0]*sinP, z[0] ); G4ThreeVector d( r[1]*cosP, r[1]*sinP, z[1] ); G4double ad = axis.dot(a), bd = axis.dot(b), cd = axis.dot(c), dd = axis.dot(d); if (bd > ad) ad = bd; if (cd > ad) ad = cd; if (dd > ad) ad = dd; return ad; } } // // Check either end // G4double aPerp = axis.perp(); G4double a = aPerp*r[0] + axis.z()*z[0]; G4double b = aPerp*r[1] + axis.z()*z[1]; if (b > a) a = b; return a; } // // CalculateExtent // // See notes in G4VCSGface // void G4PolyconeSide::CalculateExtent( const EAxis axis, const G4VoxelLimits &voxelLimit, const G4AffineTransform &transform, G4SolidExtentList &extentList ) { G4ClippablePolygon polygon; // // Here we will approximate (ala G4Cons) and divide our conical section // into segments, like G4Polyhedra. When doing so, the radius // is extented far enough such that the segments always lie // just outside the surface of the conical section we are // approximating. // // // Choose phi size of our segment(s) based on constants as // defined in meshdefs.hh // G4int numPhi = (G4int)(deltaPhi/kMeshAngleDefault) + 1; if (numPhi < kMinMeshSections) numPhi = kMinMeshSections; else if (numPhi > kMaxMeshSections) numPhi = kMaxMeshSections; G4double sigPhi = deltaPhi/numPhi; // // Determine radius factor to keep segments outside // G4double rFudge = 1.0/std::cos(0.5*sigPhi); // // Decide which radius to use on each end of the side, // and whether a transition mesh is required // // {r0,z0} - Beginning of this side // {r1,z1} - Ending of this side // {r2,z0} - Beginning of transition piece connecting previous // side (and ends at beginning of this side) // // So, order is 2 --> 0 --> 1. // ------- // // r2 < 0 indicates that no transition piece is required // G4double r0, r1, r2, z0, z1; r2 = -1; // By default: no transition piece if (rNorm < -DBL_MIN) { // // This side faces *inward*, and so our mesh has // the same radius // r1 = r[1]; z1 = z[1]; z0 = z[0]; r0 = r[0]; r2 = -1; if (prevZS > DBL_MIN) { // // The previous side is facing outwards // if ( prevRS*zS - prevZS*rS > 0 ) { // // Transition was convex: build transition piece // if (r[0] > DBL_MIN) r2 = r[0]*rFudge; } else { // // Transition was concave: short this side // FindLineIntersect( z0, r0, zS, rS, z0, r0*rFudge, prevZS, prevRS*rFudge, z0, r0 ); } } if ( nextZS > DBL_MIN && (rS*nextZS - zS*nextRS < 0) ) { // // The next side is facing outwards, forming a // concave transition: short this side // FindLineIntersect( z1, r1, zS, rS, z1, r1*rFudge, nextZS, nextRS*rFudge, z1, r1 ); } } else if (rNorm > DBL_MIN) { // // This side faces *outward* and is given a boost to // it radius // r0 = r[0]*rFudge; z0 = z[0]; r1 = r[1]*rFudge; z1 = z[1]; if (prevZS < -DBL_MIN) { // // The previous side is facing inwards // if ( prevRS*zS - prevZS*rS > 0 ) { // // Transition was convex: build transition piece // if (r[0] > DBL_MIN) r2 = r[0]; } else { // // Transition was concave: short this side // FindLineIntersect( z0, r0, zS, rS*rFudge, z0, r[0], prevZS, prevRS, z0, r0 ); } } if ( nextZS < -DBL_MIN && (rS*nextZS - zS*nextRS < 0) ) { // // The next side is facing inwards, forming a // concave transition: short this side // FindLineIntersect( z1, r1, zS, rS*rFudge, z1, r[1], nextZS, nextRS, z1, r1 ); } } else { // // This side is perpendicular to the z axis (is a disk) // // Whether or not r0 needs a rFudge factor depends // on the normal of the previous edge. Similar with r1 // and the next edge. No transition piece is required. // r0 = r[0]; r1 = r[1]; z0 = z[0]; z1 = z[1]; if (prevZS > DBL_MIN) r0 *= rFudge; if (nextZS > DBL_MIN) r1 *= rFudge; } // // Loop // G4double phi = startPhi, cosPhi = std::cos(phi), sinPhi = std::sin(phi); G4ThreeVector v0( r0*cosPhi, r0*sinPhi, z0 ), v1( r1*cosPhi, r1*sinPhi, z1 ), v2, w0, w1, w2; transform.ApplyPointTransform( v0 ); transform.ApplyPointTransform( v1 ); if (r2 >= 0) { v2 = G4ThreeVector( r2*cosPhi, r2*sinPhi, z0 ); transform.ApplyPointTransform( v2 ); } do { phi += sigPhi; if (numPhi == 1) phi = startPhi+deltaPhi; // Try to avoid roundoff cosPhi = std::cos(phi), sinPhi = std::sin(phi); w0 = G4ThreeVector( r0*cosPhi, r0*sinPhi, z0 ); w1 = G4ThreeVector( r1*cosPhi, r1*sinPhi, z1 ); transform.ApplyPointTransform( w0 ); transform.ApplyPointTransform( w1 ); G4ThreeVector deltaV = r0 > r1 ? w0-v0 : w1-v1; // // Build polygon, taking special care to keep the vertices // in order // polygon.ClearAllVertices(); polygon.AddVertexInOrder( v0 ); polygon.AddVertexInOrder( v1 ); polygon.AddVertexInOrder( w1 ); polygon.AddVertexInOrder( w0 ); // // Get extent // if (polygon.PartialClip( voxelLimit, axis )) { // // Get dot product of normal with target axis // polygon.SetNormal( deltaV.cross(v1-v0).unit() ); extentList.AddSurface( polygon ); } if (r2 >= 0) { // // Repeat, for transition piece // w2 = G4ThreeVector( r2*cosPhi, r2*sinPhi, z0 ); transform.ApplyPointTransform( w2 ); polygon.ClearAllVertices(); polygon.AddVertexInOrder( v2 ); polygon.AddVertexInOrder( v0 ); polygon.AddVertexInOrder( w0 ); polygon.AddVertexInOrder( w2 ); if (polygon.PartialClip( voxelLimit, axis )) { polygon.SetNormal( deltaV.cross(v0-v2).unit() ); extentList.AddSurface( polygon ); } v2 = w2; } // // Next vertex // v0 = w0; v1 = w1; } while( --numPhi > 0 ); // // We are almost done. But, it is important that we leave no // gaps in the surface of our solid. By using rFudge, however, // we've done exactly that, if we have a phi segment. // Add two additional faces if necessary // if (phiIsOpen && rNorm > DBL_MIN) { G4double cosPhi = std::cos(startPhi), sinPhi = std::sin(startPhi); G4ThreeVector a0( r[0]*cosPhi, r[0]*sinPhi, z[0] ), a1( r[1]*cosPhi, r[1]*sinPhi, z[1] ), b0( r0*cosPhi, r0*sinPhi, z[0] ), b1( r1*cosPhi, r1*sinPhi, z[1] ); transform.ApplyPointTransform( a0 ); transform.ApplyPointTransform( a1 ); transform.ApplyPointTransform( b0 ); transform.ApplyPointTransform( b1 ); polygon.ClearAllVertices(); polygon.AddVertexInOrder( a0 ); polygon.AddVertexInOrder( a1 ); polygon.AddVertexInOrder( b0 ); polygon.AddVertexInOrder( b1 ); if (polygon.PartialClip( voxelLimit , axis)) { G4ThreeVector normal( sinPhi, -cosPhi, 0 ); polygon.SetNormal( transform.TransformAxis( normal ) ); extentList.AddSurface( polygon ); } cosPhi = std::cos(startPhi+deltaPhi); sinPhi = std::sin(startPhi+deltaPhi); a0 = G4ThreeVector( r[0]*cosPhi, r[0]*sinPhi, z[0] ), a1 = G4ThreeVector( r[1]*cosPhi, r[1]*sinPhi, z[1] ), b0 = G4ThreeVector( r0*cosPhi, r0*sinPhi, z[0] ), b1 = G4ThreeVector( r1*cosPhi, r1*sinPhi, z[1] ); transform.ApplyPointTransform( a0 ); transform.ApplyPointTransform( a1 ); transform.ApplyPointTransform( b0 ); transform.ApplyPointTransform( b1 ); polygon.ClearAllVertices(); polygon.AddVertexInOrder( a0 ); polygon.AddVertexInOrder( a1 ); polygon.AddVertexInOrder( b0 ); polygon.AddVertexInOrder( b1 ); if (polygon.PartialClip( voxelLimit, axis )) { G4ThreeVector normal( -sinPhi, cosPhi, 0 ); polygon.SetNormal( transform.TransformAxis( normal ) ); extentList.AddSurface( polygon ); } } return; } // // DistanceAway // // Calculate distance of a point from our conical surface, including the effect // of any phi segmentation // // Arguments: // p - (in) Point to check // opposite - (in) If true, check opposite hemisphere (see below) // distOutside - (out) Additional distance outside the edges of the surface // edgeRZnorm - (out) if negative, point is inside // // return value = distance from the conical plane, if extrapolated beyond edges, // signed by whether the point is in inside or outside the shape // // Notes: // * There are two answers, depending on which hemisphere is considered. // G4double G4PolyconeSide::DistanceAway( const G4ThreeVector &p, G4bool opposite, G4double &distOutside2, G4double *edgeRZnorm ) { // // Convert our point to r and z // G4double rx = p.perp(), zx = p.z(); // // Change sign of r if opposite says we should // if (opposite) rx = -rx; // // Calculate return value // G4double deltaR = rx - r[0], deltaZ = zx - z[0]; G4double answer = deltaR*rNorm + deltaZ*zNorm; // // Are we off the surface in r,z space? // G4double s = deltaR*rS + deltaZ*zS; if (s < 0) { distOutside2 = s*s; if (edgeRZnorm) *edgeRZnorm = deltaR*rNormEdge[0] + deltaZ*zNormEdge[0]; } else if (s > length) { distOutside2 = sqr( s-length ); if (edgeRZnorm) { G4double deltaR = rx - r[1], deltaZ = zx - z[1]; *edgeRZnorm = deltaR*rNormEdge[1] + deltaZ*zNormEdge[1]; } } else { distOutside2 = 0; if (edgeRZnorm) *edgeRZnorm = answer; } if (phiIsOpen) { // // Finally, check phi // G4double phi = p.phi(); while( phi < startPhi ) phi += twopi; if (phi > startPhi+deltaPhi) { // // Oops. Are we closer to the start phi or end phi? // G4double d1 = phi-startPhi-deltaPhi; while( phi > startPhi ) phi -= twopi; G4double d2 = startPhi-phi; if (d2 < d1) d1 = d2; // // Add result to our distance // G4double dist = d1*rx; distOutside2 += dist*dist; if (edgeRZnorm) { *edgeRZnorm = std::max(std::fabs(*edgeRZnorm),std::fabs(dist)); } } } return answer; } // // PointOnCone // // Decide if a point is on a cone and return normal if it is // G4bool G4PolyconeSide::PointOnCone( const G4ThreeVector &hit, G4double normSign, const G4ThreeVector &p, const G4ThreeVector &v, G4ThreeVector &normal ) { G4double rx = hit.perp(); // // Check radial/z extent, as appropriate // if (!cone->HitOn( rx, hit.z() )) return false; if (phiIsOpen) { G4double phiTolerant = 2.0*kCarTolerance/(rx+kCarTolerance); // // Check phi segment. Here we have to be careful // to use the standard method consistent with // PolyPhiFace. See PolyPhiFace::InsideEdgesExact // G4double phi = hit.phi(); while( phi < startPhi-phiTolerant ) phi += twopi; if (phi > startPhi+deltaPhi+phiTolerant) return false; if (phi > startPhi+deltaPhi-phiTolerant) { // // Exact treatment // G4ThreeVector qx = p + v; G4ThreeVector qa = qx - corners[2], qb = qx - corners[3]; G4ThreeVector qacb = qa.cross(qb); if (normSign*qacb.dot(v) < 0) return false; } else if (phi < phiTolerant) { G4ThreeVector qx = p + v; G4ThreeVector qa = qx - corners[1], qb = qx - corners[0]; G4ThreeVector qacb = qa.cross(qb); if (normSign*qacb.dot(v) < 0) return false; } } // // We have a good hit! Calculate normal // if (rx < DBL_MIN) normal = G4ThreeVector( 0, 0, zNorm < 0 ? -1 : 1 ); else normal = G4ThreeVector( rNorm*hit.x()/rx, rNorm*hit.y()/rx, zNorm ); return true; } // // FindLineIntersect // // Decide the point at which two 2-dimensional lines intersect // // Equation of line: x = x1 + s*tx1 // y = y1 + s*ty1 // // It is assumed that the lines are *not* parallel // void G4PolyconeSide::FindLineIntersect( G4double x1, G4double y1, G4double tx1, G4double ty1, G4double x2, G4double y2, G4double tx2, G4double ty2, G4double &x, G4double &y ) { // // The solution is a simple linear equation // G4double deter = tx1*ty2 - tx2*ty1; G4double s1 = ((x2-x1)*ty2 - tx2*(y2-y1))/deter; G4double s2 = ((x2-x1)*ty1 - tx1*(y2-y1))/deter; // // We want the answer to not depend on which order the // lines were specified. Take average. // x = 0.5*( x1+s1*tx1 + x2+s2*tx2 ); y = 0.5*( y1+s1*ty1 + y2+s2*ty2 ); } // // Calculate surface area for GetPointOnSurface() // G4double G4PolyconeSide::SurfaceArea() { if(fSurfaceArea==0) { fSurfaceArea = (r[0]+r[1])* std::sqrt(sqr(r[0]-r[1])+sqr(z[0]-z[1])); fSurfaceArea *= 0.5*(deltaPhi); } return fSurfaceArea; } // // GetPointOnFace // G4ThreeVector G4PolyconeSide::GetPointOnFace() { G4double x,y,zz; G4double rr,phi,dz,dr; dr=r[1]-r[0];dz=z[1]-z[0]; phi=startPhi+deltaPhi*G4UniformRand(); rr=r[0]+dr*G4UniformRand(); x=rr*std::cos(phi); y=rr*std::sin(phi); // PolyconeSide has a Ring Form // if (dz==0.) { zz=z[0]; } else { if(dr==0.) // PolyconeSide has a Tube Form { zz = z[0]+dz*G4UniformRand(); } else { zz = z[0]+(rr-r[0])*dz/dr; } } return G4ThreeVector(x,y,zz); }