OBB_Disjoint.h
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00026   The authors may be contacted via:
00027 
00028   US Mail:             S. Gottschalk
00029                        Department of Computer Science
00030                        Sitterson Hall, CB #3175
00031                        University of N. Carolina
00032                        Chapel Hill, NC 27599-3175
00033 
00034   Phone:               (919)962-1749
00035 
00036   EMail:               geom@cs.unc.edu
00037 
00038 
00039 \**************************************************************************/
00040 
00041 #ifndef PQP_OBB_DISJOINT
00042 #define PQP_OBB_DISJOINT
00043 
00044 #include "MatVec.h"
00045 #include "PQP_Compile.h"
00046 
00047 // int
00048 // obb_disjoint(PQP_REAL B[3][3], PQP_REAL T[3], PQP_REAL a[3], PQP_REAL b[3]);
00049 //
00050 // This is a test between two boxes, box A and box B.  It is assumed that
00051 // the coordinate system is aligned and centered on box A.  The 3x3
00052 // matrix B specifies box B's orientation with respect to box A.
00053 // Specifically, the columns of B are the basis vectors (axis vectors) of
00054 // box B.  The center of box B is located at the vector T.  The
00055 // dimensions of box B are given in the array b.  The orientation and
00056 // placement of box A, in this coordinate system, are the identity matrix
00057 // and zero vector, respectively, so they need not be specified.  The
00058 // dimensions of box A are given in array a.
00059 
00060 inline
00061 int
00062 obb_disjoint(PQP_REAL B[3][3], PQP_REAL T[3], PQP_REAL a[3], PQP_REAL b[3])
00063 {
00064   register PQP_REAL t, s;
00065   register int r;
00066   PQP_REAL Bf[3][3];
00067   const PQP_REAL reps = (PQP_REAL)1e-6;
00068   
00069   // Bf = fabs(B)
00070   Bf[0][0] = myfabs(B[0][0]);  Bf[0][0] += reps;
00071   Bf[0][1] = myfabs(B[0][1]);  Bf[0][1] += reps;
00072   Bf[0][2] = myfabs(B[0][2]);  Bf[0][2] += reps;
00073   Bf[1][0] = myfabs(B[1][0]);  Bf[1][0] += reps;
00074   Bf[1][1] = myfabs(B[1][1]);  Bf[1][1] += reps;
00075   Bf[1][2] = myfabs(B[1][2]);  Bf[1][2] += reps;
00076   Bf[2][0] = myfabs(B[2][0]);  Bf[2][0] += reps;
00077   Bf[2][1] = myfabs(B[2][1]);  Bf[2][1] += reps;
00078   Bf[2][2] = myfabs(B[2][2]);  Bf[2][2] += reps;
00079 
00080   // if any of these tests are one-sided, then the polyhedra are disjoint
00081   r = 1;
00082 
00083   // A1 x A2 = A0
00084   t = myfabs(T[0]);
00085   
00086   r &= (t <= 
00087           (a[0] + b[0] * Bf[0][0] + b[1] * Bf[0][1] + b[2] * Bf[0][2]));
00088   if (!r) return 1;
00089   
00090   // B1 x B2 = B0
00091   s = T[0]*B[0][0] + T[1]*B[1][0] + T[2]*B[2][0];
00092   t = myfabs(s);
00093 
00094   r &= ( t <=
00095           (b[0] + a[0] * Bf[0][0] + a[1] * Bf[1][0] + a[2] * Bf[2][0]));
00096   if (!r) return 2;
00097     
00098   // A2 x A0 = A1
00099   t = myfabs(T[1]);
00100   
00101   r &= ( t <= 
00102           (a[1] + b[0] * Bf[1][0] + b[1] * Bf[1][1] + b[2] * Bf[1][2]));
00103   if (!r) return 3;
00104 
00105   // A0 x A1 = A2
00106   t = myfabs(T[2]);
00107 
00108   r &= ( t <= 
00109           (a[2] + b[0] * Bf[2][0] + b[1] * Bf[2][1] + b[2] * Bf[2][2]));
00110   if (!r) return 4;
00111 
00112   // B2 x B0 = B1
00113   s = T[0]*B[0][1] + T[1]*B[1][1] + T[2]*B[2][1];
00114   t = myfabs(s);
00115 
00116   r &= ( t <=
00117           (b[1] + a[0] * Bf[0][1] + a[1] * Bf[1][1] + a[2] * Bf[2][1]));
00118   if (!r) return 5;
00119 
00120   // B0 x B1 = B2
00121   s = T[0]*B[0][2] + T[1]*B[1][2] + T[2]*B[2][2];
00122   t = myfabs(s);
00123 
00124   r &= ( t <=
00125           (b[2] + a[0] * Bf[0][2] + a[1] * Bf[1][2] + a[2] * Bf[2][2]));
00126   if (!r) return 6;
00127 
00128   // A0 x B0
00129   s = T[2] * B[1][0] - T[1] * B[2][0];
00130   t = myfabs(s);
00131   
00132   r &= ( t <= 
00133         (a[1] * Bf[2][0] + a[2] * Bf[1][0] +
00134          b[1] * Bf[0][2] + b[2] * Bf[0][1]));
00135   if (!r) return 7;
00136   
00137   // A0 x B1
00138   s = T[2] * B[1][1] - T[1] * B[2][1];
00139   t = myfabs(s);
00140 
00141   r &= ( t <=
00142         (a[1] * Bf[2][1] + a[2] * Bf[1][1] +
00143          b[0] * Bf[0][2] + b[2] * Bf[0][0]));
00144   if (!r) return 8;
00145 
00146   // A0 x B2
00147   s = T[2] * B[1][2] - T[1] * B[2][2];
00148   t = myfabs(s);
00149 
00150   r &= ( t <=
00151           (a[1] * Bf[2][2] + a[2] * Bf[1][2] +
00152            b[0] * Bf[0][1] + b[1] * Bf[0][0]));
00153   if (!r) return 9;
00154 
00155   // A1 x B0
00156   s = T[0] * B[2][0] - T[2] * B[0][0];
00157   t = myfabs(s);
00158 
00159   r &= ( t <=
00160           (a[0] * Bf[2][0] + a[2] * Bf[0][0] +
00161            b[1] * Bf[1][2] + b[2] * Bf[1][1]));
00162   if (!r) return 10;
00163 
00164   // A1 x B1
00165   s = T[0] * B[2][1] - T[2] * B[0][1];
00166   t = myfabs(s);
00167 
00168   r &= ( t <=
00169           (a[0] * Bf[2][1] + a[2] * Bf[0][1] +
00170            b[0] * Bf[1][2] + b[2] * Bf[1][0]));
00171   if (!r) return 11;
00172 
00173   // A1 x B2
00174   s = T[0] * B[2][2] - T[2] * B[0][2];
00175   t = myfabs(s);
00176 
00177   r &= (t <=
00178           (a[0] * Bf[2][2] + a[2] * Bf[0][2] +
00179            b[0] * Bf[1][1] + b[1] * Bf[1][0]));
00180   if (!r) return 12;
00181 
00182   // A2 x B0
00183   s = T[1] * B[0][0] - T[0] * B[1][0];
00184   t = myfabs(s);
00185 
00186   r &= (t <=
00187           (a[0] * Bf[1][0] + a[1] * Bf[0][0] +
00188            b[1] * Bf[2][2] + b[2] * Bf[2][1]));
00189   if (!r) return 13;
00190 
00191   // A2 x B1
00192   s = T[1] * B[0][1] - T[0] * B[1][1];
00193   t = myfabs(s);
00194 
00195   r &= ( t <=
00196           (a[0] * Bf[1][1] + a[1] * Bf[0][1] +
00197            b[0] * Bf[2][2] + b[2] * Bf[2][0]));
00198   if (!r) return 14;
00199 
00200   // A2 x B2
00201   s = T[1] * B[0][2] - T[0] * B[1][2];
00202   t = myfabs(s);
00203 
00204   r &= ( t <=
00205           (a[0] * Bf[1][2] + a[1] * Bf[0][2] +
00206            b[0] * Bf[2][1] + b[1] * Bf[2][0]));
00207   if (!r) return 15;
00208 
00209   return 0;  // should equal 0
00210 }
00211 
00212 #endif
00213 
00214 
00215 
00216 


jskeus
Author(s): JSK Alumnis
autogenerated on Thu Jun 6 2019 21:31:35