| |
| /* |
| * Box-Box collision detection re-distributed under the ZLib license with permission from Russell L. Smith |
| * Original version is from Open Dynamics Engine, Copyright (C) 2001,2002 Russell L. Smith. |
| * All rights reserved. Email: russ@q12.org Web: www.q12.org |
| Bullet Continuous Collision Detection and Physics Library |
| Bullet is Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/ |
| |
| This software is provided 'as-is', without any express or implied warranty. |
| In no event will the authors be held liable for any damages arising from the use of this software. |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it freely, |
| subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| ///ODE box-box collision detection is adapted to work with Bullet |
| |
| #include "BulletCollision/CollisionDispatch/btBoxBoxDetector.h" |
| #include "BulletCollision/CollisionShapes/btBoxShape.h" |
| |
| #include <float.h> |
| #include <string.h> |
| |
| btBoxBoxDetector::btBoxBoxDetector(btBoxShape* box1,btBoxShape* box2) |
| : m_box1(box1), |
| m_box2(box2) |
| { |
| |
| } |
| |
| |
| // given two boxes (p1,R1,side1) and (p2,R2,side2), collide them together and |
| // generate contact points. this returns 0 if there is no contact otherwise |
| // it returns the number of contacts generated. |
| // `normal' returns the contact normal. |
| // `depth' returns the maximum penetration depth along that normal. |
| // `return_code' returns a number indicating the type of contact that was |
| // detected: |
| // 1,2,3 = box 2 intersects with a face of box 1 |
| // 4,5,6 = box 1 intersects with a face of box 2 |
| // 7..15 = edge-edge contact |
| // `maxc' is the maximum number of contacts allowed to be generated, i.e. |
| // the size of the `contact' array. |
| // `contact' and `skip' are the contact array information provided to the |
| // collision functions. this function only fills in the position and depth |
| // fields. |
| struct dContactGeom; |
| #define dDOTpq(a,b,p,q) ((a)[0]*(b)[0] + (a)[p]*(b)[q] + (a)[2*(p)]*(b)[2*(q)]) |
| #define dInfinity FLT_MAX |
| |
| |
| /*PURE_INLINE btScalar dDOT (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,1,1); } |
| PURE_INLINE btScalar dDOT13 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,1,3); } |
| PURE_INLINE btScalar dDOT31 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,3,1); } |
| PURE_INLINE btScalar dDOT33 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,3,3); } |
| */ |
| static btScalar dDOT (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,1,1); } |
| static btScalar dDOT44 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,4,4); } |
| static btScalar dDOT41 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,4,1); } |
| static btScalar dDOT14 (const btScalar *a, const btScalar *b) { return dDOTpq(a,b,1,4); } |
| #define dMULTIPLYOP1_331(A,op,B,C) \ |
| {\ |
| (A)[0] op dDOT41((B),(C)); \ |
| (A)[1] op dDOT41((B+1),(C)); \ |
| (A)[2] op dDOT41((B+2),(C)); \ |
| } |
| |
| #define dMULTIPLYOP0_331(A,op,B,C) \ |
| { \ |
| (A)[0] op dDOT((B),(C)); \ |
| (A)[1] op dDOT((B+4),(C)); \ |
| (A)[2] op dDOT((B+8),(C)); \ |
| } |
| |
| #define dMULTIPLY1_331(A,B,C) dMULTIPLYOP1_331(A,=,B,C) |
| #define dMULTIPLY0_331(A,B,C) dMULTIPLYOP0_331(A,=,B,C) |
| |
| typedef btScalar dMatrix3[4*3]; |
| |
| void dLineClosestApproach (const btVector3& pa, const btVector3& ua, |
| const btVector3& pb, const btVector3& ub, |
| btScalar *alpha, btScalar *beta); |
| void dLineClosestApproach (const btVector3& pa, const btVector3& ua, |
| const btVector3& pb, const btVector3& ub, |
| btScalar *alpha, btScalar *beta) |
| { |
| btVector3 p; |
| p[0] = pb[0] - pa[0]; |
| p[1] = pb[1] - pa[1]; |
| p[2] = pb[2] - pa[2]; |
| btScalar uaub = dDOT(ua,ub); |
| btScalar q1 = dDOT(ua,p); |
| btScalar q2 = -dDOT(ub,p); |
| btScalar d = 1-uaub*uaub; |
| if (d <= btScalar(0.0001f)) { |
| // @@@ this needs to be made more robust |
| *alpha = 0; |
| *beta = 0; |
| } |
| else { |
| d = 1.f/d; |
| *alpha = (q1 + uaub*q2)*d; |
| *beta = (uaub*q1 + q2)*d; |
| } |
| } |
| |
| |
| |
| // find all the intersection points between the 2D rectangle with vertices |
| // at (+/-h[0],+/-h[1]) and the 2D quadrilateral with vertices (p[0],p[1]), |
| // (p[2],p[3]),(p[4],p[5]),(p[6],p[7]). |
| // |
| // the intersection points are returned as x,y pairs in the 'ret' array. |
| // the number of intersection points is returned by the function (this will |
| // be in the range 0 to 8). |
| |
| static int intersectRectQuad2 (btScalar h[2], btScalar p[8], btScalar ret[16]) |
| { |
| // q (and r) contain nq (and nr) coordinate points for the current (and |
| // chopped) polygons |
| int nq=4,nr=0; |
| btScalar buffer[16]; |
| btScalar *q = p; |
| btScalar *r = ret; |
| for (int dir=0; dir <= 1; dir++) { |
| // direction notation: xy[0] = x axis, xy[1] = y axis |
| for (int sign=-1; sign <= 1; sign += 2) { |
| // chop q along the line xy[dir] = sign*h[dir] |
| btScalar *pq = q; |
| btScalar *pr = r; |
| nr = 0; |
| for (int i=nq; i > 0; i--) { |
| // go through all points in q and all lines between adjacent points |
| if (sign*pq[dir] < h[dir]) { |
| // this point is inside the chopping line |
| pr[0] = pq[0]; |
| pr[1] = pq[1]; |
| pr += 2; |
| nr++; |
| if (nr & 8) { |
| q = r; |
| goto done; |
| } |
| } |
| btScalar *nextq = (i > 1) ? pq+2 : q; |
| if ((sign*pq[dir] < h[dir]) ^ (sign*nextq[dir] < h[dir])) { |
| // this line crosses the chopping line |
| pr[1-dir] = pq[1-dir] + (nextq[1-dir]-pq[1-dir]) / |
| (nextq[dir]-pq[dir]) * (sign*h[dir]-pq[dir]); |
| pr[dir] = sign*h[dir]; |
| pr += 2; |
| nr++; |
| if (nr & 8) { |
| q = r; |
| goto done; |
| } |
| } |
| pq += 2; |
| } |
| q = r; |
| r = (q==ret) ? buffer : ret; |
| nq = nr; |
| } |
| } |
| done: |
| if (q != ret) memcpy (ret,q,nr*2*sizeof(btScalar)); |
| return nr; |
| } |
| |
| |
| #define M__PI 3.14159265f |
| |
| // given n points in the plane (array p, of size 2*n), generate m points that |
| // best represent the whole set. the definition of 'best' here is not |
| // predetermined - the idea is to select points that give good box-box |
| // collision detection behavior. the chosen point indexes are returned in the |
| // array iret (of size m). 'i0' is always the first entry in the array. |
| // n must be in the range [1..8]. m must be in the range [1..n]. i0 must be |
| // in the range [0..n-1]. |
| |
| void cullPoints2 (int n, btScalar p[], int m, int i0, int iret[]); |
| void cullPoints2 (int n, btScalar p[], int m, int i0, int iret[]) |
| { |
| // compute the centroid of the polygon in cx,cy |
| int i,j; |
| btScalar a,cx,cy,q; |
| if (n==1) { |
| cx = p[0]; |
| cy = p[1]; |
| } |
| else if (n==2) { |
| cx = btScalar(0.5)*(p[0] + p[2]); |
| cy = btScalar(0.5)*(p[1] + p[3]); |
| } |
| else { |
| a = 0; |
| cx = 0; |
| cy = 0; |
| for (i=0; i<(n-1); i++) { |
| q = p[i*2]*p[i*2+3] - p[i*2+2]*p[i*2+1]; |
| a += q; |
| cx += q*(p[i*2]+p[i*2+2]); |
| cy += q*(p[i*2+1]+p[i*2+3]); |
| } |
| q = p[n*2-2]*p[1] - p[0]*p[n*2-1]; |
| if (btFabs(a+q) > SIMD_EPSILON) |
| { |
| a = 1.f/(btScalar(3.0)*(a+q)); |
| } else |
| { |
| a=BT_LARGE_FLOAT; |
| } |
| cx = a*(cx + q*(p[n*2-2]+p[0])); |
| cy = a*(cy + q*(p[n*2-1]+p[1])); |
| } |
| |
| // compute the angle of each point w.r.t. the centroid |
| btScalar A[8]; |
| for (i=0; i<n; i++) A[i] = btAtan2(p[i*2+1]-cy,p[i*2]-cx); |
| |
| // search for points that have angles closest to A[i0] + i*(2*pi/m). |
| int avail[8]; |
| for (i=0; i<n; i++) avail[i] = 1; |
| avail[i0] = 0; |
| iret[0] = i0; |
| iret++; |
| for (j=1; j<m; j++) { |
| a = btScalar(j)*(2*M__PI/m) + A[i0]; |
| if (a > M__PI) a -= 2*M__PI; |
| btScalar maxdiff=1e9,diff; |
| |
| *iret = i0; // iret is not allowed to keep this value, but it sometimes does, when diff=#QNAN0 |
| |
| for (i=0; i<n; i++) { |
| if (avail[i]) { |
| diff = btFabs (A[i]-a); |
| if (diff > M__PI) diff = 2*M__PI - diff; |
| if (diff < maxdiff) { |
| maxdiff = diff; |
| *iret = i; |
| } |
| } |
| } |
| #if defined(DEBUG) || defined (_DEBUG) |
| btAssert (*iret != i0); // ensure iret got set |
| #endif |
| avail[*iret] = 0; |
| iret++; |
| } |
| } |
| |
| |
| |
| int dBoxBox2 (const btVector3& p1, const dMatrix3 R1, |
| const btVector3& side1, const btVector3& p2, |
| const dMatrix3 R2, const btVector3& side2, |
| btVector3& normal, btScalar *depth, int *return_code, |
| int maxc, dContactGeom * /*contact*/, int /*skip*/,btDiscreteCollisionDetectorInterface::Result& output); |
| int dBoxBox2 (const btVector3& p1, const dMatrix3 R1, |
| const btVector3& side1, const btVector3& p2, |
| const dMatrix3 R2, const btVector3& side2, |
| btVector3& normal, btScalar *depth, int *return_code, |
| int maxc, dContactGeom * /*contact*/, int /*skip*/,btDiscreteCollisionDetectorInterface::Result& output) |
| { |
| const btScalar fudge_factor = btScalar(1.05); |
| btVector3 p,pp,normalC(0.f,0.f,0.f); |
| const btScalar *normalR = 0; |
| btScalar A[3],B[3],R11,R12,R13,R21,R22,R23,R31,R32,R33, |
| Q11,Q12,Q13,Q21,Q22,Q23,Q31,Q32,Q33,s,s2,l; |
| int i,j,invert_normal,code; |
| |
| // get vector from centers of box 1 to box 2, relative to box 1 |
| p = p2 - p1; |
| dMULTIPLY1_331 (pp,R1,p); // get pp = p relative to body 1 |
| |
| // get side lengths / 2 |
| A[0] = side1[0]*btScalar(0.5); |
| A[1] = side1[1]*btScalar(0.5); |
| A[2] = side1[2]*btScalar(0.5); |
| B[0] = side2[0]*btScalar(0.5); |
| B[1] = side2[1]*btScalar(0.5); |
| B[2] = side2[2]*btScalar(0.5); |
| |
| // Rij is R1'*R2, i.e. the relative rotation between R1 and R2 |
| R11 = dDOT44(R1+0,R2+0); R12 = dDOT44(R1+0,R2+1); R13 = dDOT44(R1+0,R2+2); |
| R21 = dDOT44(R1+1,R2+0); R22 = dDOT44(R1+1,R2+1); R23 = dDOT44(R1+1,R2+2); |
| R31 = dDOT44(R1+2,R2+0); R32 = dDOT44(R1+2,R2+1); R33 = dDOT44(R1+2,R2+2); |
| |
| Q11 = btFabs(R11); Q12 = btFabs(R12); Q13 = btFabs(R13); |
| Q21 = btFabs(R21); Q22 = btFabs(R22); Q23 = btFabs(R23); |
| Q31 = btFabs(R31); Q32 = btFabs(R32); Q33 = btFabs(R33); |
| |
| // for all 15 possible separating axes: |
| // * see if the axis separates the boxes. if so, return 0. |
| // * find the depth of the penetration along the separating axis (s2) |
| // * if this is the largest depth so far, record it. |
| // the normal vector will be set to the separating axis with the smallest |
| // depth. note: normalR is set to point to a column of R1 or R2 if that is |
| // the smallest depth normal so far. otherwise normalR is 0 and normalC is |
| // set to a vector relative to body 1. invert_normal is 1 if the sign of |
| // the normal should be flipped. |
| |
| #define TST(expr1,expr2,norm,cc) \ |
| s2 = btFabs(expr1) - (expr2); \ |
| if (s2 > 0) return 0; \ |
| if (s2 > s) { \ |
| s = s2; \ |
| normalR = norm; \ |
| invert_normal = ((expr1) < 0); \ |
| code = (cc); \ |
| } |
| |
| s = -dInfinity; |
| invert_normal = 0; |
| code = 0; |
| |
| // separating axis = u1,u2,u3 |
| TST (pp[0],(A[0] + B[0]*Q11 + B[1]*Q12 + B[2]*Q13),R1+0,1); |
| TST (pp[1],(A[1] + B[0]*Q21 + B[1]*Q22 + B[2]*Q23),R1+1,2); |
| TST (pp[2],(A[2] + B[0]*Q31 + B[1]*Q32 + B[2]*Q33),R1+2,3); |
| |
| // separating axis = v1,v2,v3 |
| TST (dDOT41(R2+0,p),(A[0]*Q11 + A[1]*Q21 + A[2]*Q31 + B[0]),R2+0,4); |
| TST (dDOT41(R2+1,p),(A[0]*Q12 + A[1]*Q22 + A[2]*Q32 + B[1]),R2+1,5); |
| TST (dDOT41(R2+2,p),(A[0]*Q13 + A[1]*Q23 + A[2]*Q33 + B[2]),R2+2,6); |
| |
| // note: cross product axes need to be scaled when s is computed. |
| // normal (n1,n2,n3) is relative to box 1. |
| #undef TST |
| #define TST(expr1,expr2,n1,n2,n3,cc) \ |
| s2 = btFabs(expr1) - (expr2); \ |
| if (s2 > 0) return 0; \ |
| l = btSqrt((n1)*(n1) + (n2)*(n2) + (n3)*(n3)); \ |
| if (l > 0) { \ |
| s2 /= l; \ |
| if (s2*fudge_factor > s) { \ |
| s = s2; \ |
| normalR = 0; \ |
| normalC[0] = (n1)/l; normalC[1] = (n2)/l; normalC[2] = (n3)/l; \ |
| invert_normal = ((expr1) < 0); \ |
| code = (cc); \ |
| } \ |
| } |
| |
| // separating axis = u1 x (v1,v2,v3) |
| TST(pp[2]*R21-pp[1]*R31,(A[1]*Q31+A[2]*Q21+B[1]*Q13+B[2]*Q12),0,-R31,R21,7); |
| TST(pp[2]*R22-pp[1]*R32,(A[1]*Q32+A[2]*Q22+B[0]*Q13+B[2]*Q11),0,-R32,R22,8); |
| TST(pp[2]*R23-pp[1]*R33,(A[1]*Q33+A[2]*Q23+B[0]*Q12+B[1]*Q11),0,-R33,R23,9); |
| |
| // separating axis = u2 x (v1,v2,v3) |
| TST(pp[0]*R31-pp[2]*R11,(A[0]*Q31+A[2]*Q11+B[1]*Q23+B[2]*Q22),R31,0,-R11,10); |
| TST(pp[0]*R32-pp[2]*R12,(A[0]*Q32+A[2]*Q12+B[0]*Q23+B[2]*Q21),R32,0,-R12,11); |
| TST(pp[0]*R33-pp[2]*R13,(A[0]*Q33+A[2]*Q13+B[0]*Q22+B[1]*Q21),R33,0,-R13,12); |
| |
| // separating axis = u3 x (v1,v2,v3) |
| TST(pp[1]*R11-pp[0]*R21,(A[0]*Q21+A[1]*Q11+B[1]*Q33+B[2]*Q32),-R21,R11,0,13); |
| TST(pp[1]*R12-pp[0]*R22,(A[0]*Q22+A[1]*Q12+B[0]*Q33+B[2]*Q31),-R22,R12,0,14); |
| TST(pp[1]*R13-pp[0]*R23,(A[0]*Q23+A[1]*Q13+B[0]*Q32+B[1]*Q31),-R23,R13,0,15); |
| |
| #undef TST |
| |
| if (!code) return 0; |
| |
| // if we get to this point, the boxes interpenetrate. compute the normal |
| // in global coordinates. |
| if (normalR) { |
| normal[0] = normalR[0]; |
| normal[1] = normalR[4]; |
| normal[2] = normalR[8]; |
| } |
| else { |
| dMULTIPLY0_331 (normal,R1,normalC); |
| } |
| if (invert_normal) { |
| normal[0] = -normal[0]; |
| normal[1] = -normal[1]; |
| normal[2] = -normal[2]; |
| } |
| *depth = -s; |
| |
| // compute contact point(s) |
| |
| if (code > 6) { |
| // an edge from box 1 touches an edge from box 2. |
| // find a point pa on the intersecting edge of box 1 |
| btVector3 pa; |
| btScalar sign; |
| for (i=0; i<3; i++) pa[i] = p1[i]; |
| for (j=0; j<3; j++) { |
| sign = (dDOT14(normal,R1+j) > 0) ? btScalar(1.0) : btScalar(-1.0); |
| for (i=0; i<3; i++) pa[i] += sign * A[j] * R1[i*4+j]; |
| } |
| |
| // find a point pb on the intersecting edge of box 2 |
| btVector3 pb; |
| for (i=0; i<3; i++) pb[i] = p2[i]; |
| for (j=0; j<3; j++) { |
| sign = (dDOT14(normal,R2+j) > 0) ? btScalar(-1.0) : btScalar(1.0); |
| for (i=0; i<3; i++) pb[i] += sign * B[j] * R2[i*4+j]; |
| } |
| |
| btScalar alpha,beta; |
| btVector3 ua,ub; |
| for (i=0; i<3; i++) ua[i] = R1[((code)-7)/3 + i*4]; |
| for (i=0; i<3; i++) ub[i] = R2[((code)-7)%3 + i*4]; |
| |
| dLineClosestApproach (pa,ua,pb,ub,&alpha,&beta); |
| for (i=0; i<3; i++) pa[i] += ua[i]*alpha; |
| for (i=0; i<3; i++) pb[i] += ub[i]*beta; |
| |
| { |
| |
| //contact[0].pos[i] = btScalar(0.5)*(pa[i]+pb[i]); |
| //contact[0].depth = *depth; |
| btVector3 pointInWorld; |
| |
| #ifdef USE_CENTER_POINT |
| for (i=0; i<3; i++) |
| pointInWorld[i] = (pa[i]+pb[i])*btScalar(0.5); |
| output.addContactPoint(-normal,pointInWorld,-*depth); |
| #else |
| output.addContactPoint(-normal,pb,-*depth); |
| #endif // |
| *return_code = code; |
| } |
| return 1; |
| } |
| |
| // okay, we have a face-something intersection (because the separating |
| // axis is perpendicular to a face). define face 'a' to be the reference |
| // face (i.e. the normal vector is perpendicular to this) and face 'b' to be |
| // the incident face (the closest face of the other box). |
| |
| const btScalar *Ra,*Rb,*pa,*pb,*Sa,*Sb; |
| if (code <= 3) { |
| Ra = R1; |
| Rb = R2; |
| pa = p1; |
| pb = p2; |
| Sa = A; |
| Sb = B; |
| } |
| else { |
| Ra = R2; |
| Rb = R1; |
| pa = p2; |
| pb = p1; |
| Sa = B; |
| Sb = A; |
| } |
| |
| // nr = normal vector of reference face dotted with axes of incident box. |
| // anr = absolute values of nr. |
| btVector3 normal2,nr,anr; |
| if (code <= 3) { |
| normal2[0] = normal[0]; |
| normal2[1] = normal[1]; |
| normal2[2] = normal[2]; |
| } |
| else { |
| normal2[0] = -normal[0]; |
| normal2[1] = -normal[1]; |
| normal2[2] = -normal[2]; |
| } |
| dMULTIPLY1_331 (nr,Rb,normal2); |
| anr[0] = btFabs (nr[0]); |
| anr[1] = btFabs (nr[1]); |
| anr[2] = btFabs (nr[2]); |
| |
| // find the largest compontent of anr: this corresponds to the normal |
| // for the indident face. the other axis numbers of the indicent face |
| // are stored in a1,a2. |
| int lanr,a1,a2; |
| if (anr[1] > anr[0]) { |
| if (anr[1] > anr[2]) { |
| a1 = 0; |
| lanr = 1; |
| a2 = 2; |
| } |
| else { |
| a1 = 0; |
| a2 = 1; |
| lanr = 2; |
| } |
| } |
| else { |
| if (anr[0] > anr[2]) { |
| lanr = 0; |
| a1 = 1; |
| a2 = 2; |
| } |
| else { |
| a1 = 0; |
| a2 = 1; |
| lanr = 2; |
| } |
| } |
| |
| // compute center point of incident face, in reference-face coordinates |
| btVector3 center; |
| if (nr[lanr] < 0) { |
| for (i=0; i<3; i++) center[i] = pb[i] - pa[i] + Sb[lanr] * Rb[i*4+lanr]; |
| } |
| else { |
| for (i=0; i<3; i++) center[i] = pb[i] - pa[i] - Sb[lanr] * Rb[i*4+lanr]; |
| } |
| |
| // find the normal and non-normal axis numbers of the reference box |
| int codeN,code1,code2; |
| if (code <= 3) codeN = code-1; else codeN = code-4; |
| if (codeN==0) { |
| code1 = 1; |
| code2 = 2; |
| } |
| else if (codeN==1) { |
| code1 = 0; |
| code2 = 2; |
| } |
| else { |
| code1 = 0; |
| code2 = 1; |
| } |
| |
| // find the four corners of the incident face, in reference-face coordinates |
| btScalar quad[8]; // 2D coordinate of incident face (x,y pairs) |
| btScalar c1,c2,m11,m12,m21,m22; |
| c1 = dDOT14 (center,Ra+code1); |
| c2 = dDOT14 (center,Ra+code2); |
| // optimize this? - we have already computed this data above, but it is not |
| // stored in an easy-to-index format. for now it's quicker just to recompute |
| // the four dot products. |
| m11 = dDOT44 (Ra+code1,Rb+a1); |
| m12 = dDOT44 (Ra+code1,Rb+a2); |
| m21 = dDOT44 (Ra+code2,Rb+a1); |
| m22 = dDOT44 (Ra+code2,Rb+a2); |
| { |
| btScalar k1 = m11*Sb[a1]; |
| btScalar k2 = m21*Sb[a1]; |
| btScalar k3 = m12*Sb[a2]; |
| btScalar k4 = m22*Sb[a2]; |
| quad[0] = c1 - k1 - k3; |
| quad[1] = c2 - k2 - k4; |
| quad[2] = c1 - k1 + k3; |
| quad[3] = c2 - k2 + k4; |
| quad[4] = c1 + k1 + k3; |
| quad[5] = c2 + k2 + k4; |
| quad[6] = c1 + k1 - k3; |
| quad[7] = c2 + k2 - k4; |
| } |
| |
| // find the size of the reference face |
| btScalar rect[2]; |
| rect[0] = Sa[code1]; |
| rect[1] = Sa[code2]; |
| |
| // intersect the incident and reference faces |
| btScalar ret[16]; |
| int n = intersectRectQuad2 (rect,quad,ret); |
| if (n < 1) return 0; // this should never happen |
| |
| // convert the intersection points into reference-face coordinates, |
| // and compute the contact position and depth for each point. only keep |
| // those points that have a positive (penetrating) depth. delete points in |
| // the 'ret' array as necessary so that 'point' and 'ret' correspond. |
| btScalar point[3*8]; // penetrating contact points |
| btScalar dep[8]; // depths for those points |
| btScalar det1 = 1.f/(m11*m22 - m12*m21); |
| m11 *= det1; |
| m12 *= det1; |
| m21 *= det1; |
| m22 *= det1; |
| int cnum = 0; // number of penetrating contact points found |
| for (j=0; j < n; j++) { |
| btScalar k1 = m22*(ret[j*2]-c1) - m12*(ret[j*2+1]-c2); |
| btScalar k2 = -m21*(ret[j*2]-c1) + m11*(ret[j*2+1]-c2); |
| for (i=0; i<3; i++) point[cnum*3+i] = |
| center[i] + k1*Rb[i*4+a1] + k2*Rb[i*4+a2]; |
| dep[cnum] = Sa[codeN] - dDOT(normal2,point+cnum*3); |
| if (dep[cnum] >= 0) { |
| ret[cnum*2] = ret[j*2]; |
| ret[cnum*2+1] = ret[j*2+1]; |
| cnum++; |
| } |
| } |
| if (cnum < 1) return 0; // this should never happen |
| |
| // we can't generate more contacts than we actually have |
| if (maxc > cnum) maxc = cnum; |
| if (maxc < 1) maxc = 1; |
| |
| if (cnum <= maxc) { |
| // we have less contacts than we need, so we use them all |
| for (j=0; j < cnum; j++) { |
| |
| //AddContactPoint... |
| |
| //dContactGeom *con = CONTACT(contact,skip*j); |
| //for (i=0; i<3; i++) con->pos[i] = point[j*3+i] + pa[i]; |
| //con->depth = dep[j]; |
| |
| btVector3 pointInWorld; |
| for (i=0; i<3; i++) |
| pointInWorld[i] = point[j*3+i] + pa[i]; |
| output.addContactPoint(-normal,pointInWorld,-dep[j]); |
| |
| } |
| } |
| else { |
| // we have more contacts than are wanted, some of them must be culled. |
| // find the deepest point, it is always the first contact. |
| int i1 = 0; |
| btScalar maxdepth = dep[0]; |
| for (i=1; i<cnum; i++) { |
| if (dep[i] > maxdepth) { |
| maxdepth = dep[i]; |
| i1 = i; |
| } |
| } |
| |
| int iret[8]; |
| cullPoints2 (cnum,ret,maxc,i1,iret); |
| |
| for (j=0; j < maxc; j++) { |
| // dContactGeom *con = CONTACT(contact,skip*j); |
| // for (i=0; i<3; i++) con->pos[i] = point[iret[j]*3+i] + pa[i]; |
| // con->depth = dep[iret[j]]; |
| |
| btVector3 posInWorld; |
| for (i=0; i<3; i++) |
| posInWorld[i] = point[iret[j]*3+i] + pa[i]; |
| output.addContactPoint(-normal,posInWorld,-dep[iret[j]]); |
| } |
| cnum = maxc; |
| } |
| |
| *return_code = code; |
| return cnum; |
| } |
| |
| void btBoxBoxDetector::getClosestPoints(const ClosestPointInput& input,Result& output,class btIDebugDraw* /*debugDraw*/,bool /*swapResults*/) |
| { |
| |
| const btTransform& transformA = input.m_transformA; |
| const btTransform& transformB = input.m_transformB; |
| |
| int skip = 0; |
| dContactGeom *contact = 0; |
| |
| dMatrix3 R1; |
| dMatrix3 R2; |
| |
| for (int j=0;j<3;j++) |
| { |
| R1[0+4*j] = transformA.getBasis()[j].x(); |
| R2[0+4*j] = transformB.getBasis()[j].x(); |
| |
| R1[1+4*j] = transformA.getBasis()[j].y(); |
| R2[1+4*j] = transformB.getBasis()[j].y(); |
| |
| |
| R1[2+4*j] = transformA.getBasis()[j].z(); |
| R2[2+4*j] = transformB.getBasis()[j].z(); |
| |
| } |
| |
| |
| |
| btVector3 normal; |
| btScalar depth; |
| int return_code; |
| int maxc = 4; |
| |
| |
| dBoxBox2 (transformA.getOrigin(), |
| R1, |
| 2.f*m_box1->getHalfExtentsWithMargin(), |
| transformB.getOrigin(), |
| R2, |
| 2.f*m_box2->getHalfExtentsWithMargin(), |
| normal, &depth, &return_code, |
| maxc, contact, skip, |
| output |
| ); |
| |
| } |