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25 //
26 // Class G4VoxelLimits implementation
27 //
28 // 13.07.95, P.Kent - Initial version
29 // --------------------------------------------------------------------
30
31 #include "G4VoxelLimits.hh"
32
33 #include "G4ios.hh"
34
35 ///////////////////////////////////////////////////////////////////////////
36 //
37 // Further restrict limits
38 // No checks for illegal restrictions
39 //
40 void G4VoxelLimits::AddLimit( const EAxis pAxis,
41 const G4double pMin,
42 const G4double pMax )
43 {
44 if ( pAxis == kXAxis )
45 {
46 if ( pMin > fxAxisMin ) fxAxisMin = pMin ;
47 if ( pMax < fxAxisMax ) fxAxisMax = pMax ;
48 }
49 else if ( pAxis == kYAxis )
50 {
51 if ( pMin > fyAxisMin ) fyAxisMin = pMin ;
52 if ( pMax < fyAxisMax ) fyAxisMax = pMax ;
53 }
54 else
55 {
56 assert( pAxis == kZAxis ) ;
57
58 if ( pMin > fzAxisMin ) fzAxisMin = pMin ;
59 if ( pMax < fzAxisMax ) fzAxisMax = pMax ;
60 }
61 }
62
63 ///////////////////////////////////////////////////////////////////////////
64 //
65 // ClipToLimits
66 //
67 // Clip the line segment pStart->pEnd to the volume described by the
68 // current limits. Return true if the line remains after clipping,
69 // else false, and leave the vectors in an undefined state.
70 //
71 // Process:
72 //
73 // Use Cohen-Sutherland clipping in 3D
74 // [Fundamentals of Interactive Computer Graphics,Foley & Van Dam]
75 //
76 G4bool G4VoxelLimits::ClipToLimits( G4ThreeVector& pStart,
77 G4ThreeVector& pEnd ) const
78 {
79 G4int sCode, eCode ;
80 G4bool remainsAfterClip ;
81
82 // Determine if line is trivially inside (both outcodes==0) or outside
83 // (logical AND of outcodes !=0)
84
85 sCode = OutCode(pStart) ;
86 eCode = OutCode(pEnd) ;
87
88 if ( (sCode & eCode) != 0 )
89 {
90 // Trivially outside, no intersection with region
91
92 remainsAfterClip = false;
93 }
94 else if ( sCode == 0 && eCode == 0 )
95 {
96 // Trivially inside, no intersections
97
98 remainsAfterClip = true ;
99 }
100 else
101 {
102 // Line segment *may* cut volume boundaries
103 // At most, one end point is inside
104
105 G4double x1, y1, z1, x2, y2, z2 ;
106
107 x1 = pStart.x() ;
108 y1 = pStart.y() ;
109 z1 = pStart.z() ;
110
111 x2 = pEnd.x() ;
112 y2 = pEnd.y() ;
113 z2 = pEnd.z() ;
114
115 while ( sCode != eCode ) // Loop checking, 06.08.2015, G.Cosmo
116 {
117 // Copy vectors to work variables x1-z1,x2-z2
118 // Ensure x1-z1 lies outside volume, swapping vectors and outcodes
119 // if necessary
120
121 if ( sCode != 0 )
122 {
123 if ( (sCode & 0x01) != 0 ) // Clip against fxAxisMin
124 {
125 z1 += (fxAxisMin-x1)*(z2-z1)/(x2-x1);
126 y1 += (fxAxisMin-x1)*(y2-y1)/(x2-x1);
127 x1 = fxAxisMin;
128 }
129 else if ( (sCode & 0x02) != 0 ) // Clip against fxAxisMax
130 {
131 z1 += (fxAxisMax-x1)*(z2-z1)/(x2-x1);
132 y1 += (fxAxisMax-x1)*(y2-y1)/(x2-x1);
133 x1 = fxAxisMax ;
134 }
135 else if ( (sCode & 0x04) != 0 ) // Clip against fyAxisMin
136 {
137 x1 += (fyAxisMin-y1)*(x2-x1)/(y2-y1);
138 z1 += (fyAxisMin-y1)*(z2-z1)/(y2-y1);
139 y1 = fyAxisMin;
140 }
141 else if ( (sCode & 0x08) != 0 ) // Clip against fyAxisMax
142 {
143 x1 += (fyAxisMax-y1)*(x2-x1)/(y2-y1);
144 z1 += (fyAxisMax-y1)*(z2-z1)/(y2-y1);
145 y1 = fyAxisMax;
146 }
147 else if ( (sCode & 0x10) != 0 ) // Clip against fzAxisMin
148 {
149 x1 += (fzAxisMin-z1)*(x2-x1)/(z2-z1);
150 y1 += (fzAxisMin-z1)*(y2-y1)/(z2-z1);
151 z1 = fzAxisMin;
152 }
153 else if ( (sCode & 0x20) != 0 ) // Clip against fzAxisMax
154 {
155 x1 += (fzAxisMax-z1)*(x2-x1)/(z2-z1);
156 y1 += (fzAxisMax-z1)*(y2-y1)/(z2-z1);
157 z1 = fzAxisMax;
158 }
159 }
160 if ( eCode != 0 ) // Clip 2nd end: repeat of 1st, but 1<>2
161 {
162 if ( (eCode & 0x01) != 0 ) // Clip against fxAxisMin
163 {
164 z2 += (fxAxisMin-x2)*(z1-z2)/(x1-x2);
165 y2 += (fxAxisMin-x2)*(y1-y2)/(x1-x2);
166 x2 = fxAxisMin;
167 }
168 else if ( (eCode & 0x02) != 0 ) // Clip against fxAxisMax
169 {
170 z2 += (fxAxisMax-x2)*(z1-z2)/(x1-x2);
171 y2 += (fxAxisMax-x2)*(y1-y2)/(x1-x2);
172 x2 = fxAxisMax;
173 }
174 else if ( (eCode & 0x04) != 0 ) // Clip against fyAxisMin
175 {
176 x2 += (fyAxisMin-y2)*(x1-x2)/(y1-y2);
177 z2 += (fyAxisMin-y2)*(z1-z2)/(y1-y2);
178 y2 = fyAxisMin;
179 }
180 else if ((eCode&0x08) != 0) // Clip against fyAxisMax
181 {
182 x2 += (fyAxisMax-y2)*(x1-x2)/(y1-y2);
183 z2 += (fyAxisMax-y2)*(z1-z2)/(y1-y2);
184 y2 = fyAxisMax;
185 }
186 else if ( (eCode & 0x10) != 0 ) // Clip against fzAxisMin
187 {
188 x2 += (fzAxisMin-z2)*(x1-x2)/(z1-z2);
189 y2 += (fzAxisMin-z2)*(y1-y2)/(z1-z2);
190 z2 = fzAxisMin;
191 }
192 else if ( (eCode & 0x20) != 0 ) // Clip against fzAxisMax
193 {
194 x2 += (fzAxisMax-z2)*(x1-x2)/(z1-z2);
195 y2 += (fzAxisMax-z2)*(y1-y2)/(z1-z2);
196 z2 = fzAxisMax;
197 }
198 }
199 pStart = G4ThreeVector(x1,y1,z1);
200 pEnd = G4ThreeVector(x2,y2,z2);
201 sCode = OutCode(pStart);
202 eCode = OutCode(pEnd);
203 }
204 remainsAfterClip = sCode == 0 && eCode == 0;
205 }
206 return remainsAfterClip;
207 }
208
209 ////////////////////////////////////////////////////////////////////////////
210 //
211 // Calculate the `outcode' for the specified vector:
212 // The following bits are set:
213 // 0 pVec.x()<fxAxisMin && IsXLimited()
214 // 1 pVec.x()>fxAxisMax && IsXLimited()
215 // 2 pVec.y()<fyAxisMin && IsYLimited()
216 // 3 pVec.y()>fyAxisMax && IsYLimited()
217 // 4 pVec.z()<fzAxisMin && IsZLimited()
218 // 5 pVec.z()>fzAxisMax && IsZLimited()
219 //
220 G4int G4VoxelLimits::OutCode( const G4ThreeVector& pVec ) const
221 {
222 G4int code = 0 ; // The outcode
223
224 if ( IsXLimited() )
225 {
226 if ( pVec.x() < fxAxisMin ) code |= 0x01 ;
227 if ( pVec.x() > fxAxisMax ) code |= 0x02 ;
228 }
229 if ( IsYLimited() )
230 {
231 if ( pVec.y() < fyAxisMin ) code |= 0x04 ;
232 if ( pVec.y() > fyAxisMax ) code |= 0x08 ;
233 }
234 if (IsZLimited())
235 {
236 if ( pVec.z() < fzAxisMin ) code |= 0x10 ;
237 if ( pVec.z() > fzAxisMax ) code |= 0x20 ;
238 }
239 return code;
240 }
241
242 ///////////////////////////////////////////////////////////////////////////////
243
244 std::ostream& operator << (std::ostream& os, const G4VoxelLimits& pLim)
245 {
246 os << "{";
247 if (pLim.IsXLimited())
248 {
249 os << "(" << pLim.GetMinXExtent()
250 << "," << pLim.GetMaxXExtent() << ") ";
251 }
252 else
253 {
254 os << "(-,-) ";
255 }
256 if (pLim.IsYLimited())
257 {
258 os << "(" << pLim.GetMinYExtent()
259 << "," << pLim.GetMaxYExtent() << ") ";
260 }
261 else
262 {
263 os << "(-,-) ";
264 }
265 if (pLim.IsZLimited())
266 {
267 os << "(" << pLim.GetMinZExtent()
268 << "," << pLim.GetMaxZExtent() << ")";
269 }
270 else
271 {
272 os << "(-,-)";
273 }
274 os << "}";
275 return os;
276 }
277