/************************************************************************* * * * Open Dynamics Engine, Copyright (C) 2001-2003 Russell L. Smith. * * All rights reserved. Email: russ@q12.org Web: www.q12.org * * * * This library is free software; you can redistribute it and/or * * modify it under the terms of EITHER: * * (1) The GNU Lesser General Public License as published by the Free * * Software Foundation; either version 2.1 of the License, or (at * * your option) any later version. The text of the GNU Lesser * * General Public License is included with this library in the * * file LICENSE.TXT. * * (2) The BSD-style license that is included with this library in * * the file LICENSE-BSD.TXT. * * * * This library is distributed in the hope that it will be useful, * * but WITHOUT ANY WARRANTY; without even the implied warranty of * * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files * * LICENSE.TXT and LICENSE-BSD.TXT for more details. * * * *************************************************************************/ /* standard ODE geometry primitives: public API and pairwise collision functions. the rule is that only the low level primitive collision functions should set dContactGeom::g1 and dContactGeom::g2. */ #include "ode_common.hpp" #include "ode_collision.hpp" #include "ode_rotation.hpp" #include "matrix.h" #include "odemath.h" #include "collision_kernel.h" #include "collision_std.h" #include "collision_util.h" #ifdef _MSC_VER #pragma warning(disable:4291) // for VC++, no complaints about "no matching operator delete found" #endif //**************************************************************************** // box public API dxBox::dxBox (dSpaceID space, dReal lx, dReal ly, dReal lz) : dxGeom (space,1) { dAASSERT (lx >= 0 && ly >= 0 && lz >= 0); type = dBoxClass; side[0] = lx; side[1] = ly; side[2] = lz; updateZeroSizedFlag(!lx || !ly || !lz); } void dxBox::computeAABB() { const dMatrix3& R = final_posr->R; const dVector3& pos = final_posr->pos; dReal xrange = REAL(0.5) * (dFabs (R[0] * side[0]) + dFabs (R[1] * side[1]) + dFabs (R[2] * side[2])); dReal yrange = REAL(0.5) * (dFabs (R[4] * side[0]) + dFabs (R[5] * side[1]) + dFabs (R[6] * side[2])); dReal zrange = REAL(0.5) * (dFabs (R[8] * side[0]) + dFabs (R[9] * side[1]) + dFabs (R[10] * side[2])); aabb[0] = pos[0] - xrange; aabb[1] = pos[0] + xrange; aabb[2] = pos[1] - yrange; aabb[3] = pos[1] + yrange; aabb[4] = pos[2] - zrange; aabb[5] = pos[2] + zrange; } dGeomID dCreateBox (dSpaceID space, dReal lx, dReal ly, dReal lz) { return new dxBox (space,lx,ly,lz); } void dGeomBoxSetLengths (dGeomID g, dReal lx, dReal ly, dReal lz) { dUASSERT (g && g->type == dBoxClass,"argument not a box"); dAASSERT (lx >= 0 && ly >= 0 && lz >= 0); dxBox *b = (dxBox*) g; b->side[0] = lx; b->side[1] = ly; b->side[2] = lz; b->updateZeroSizedFlag(!lx || !ly || !lz); dGeomMoved (g); } void dGeomBoxGetLengths (dGeomID g, dVector3 result) { dUASSERT (g && g->type == dBoxClass,"argument not a box"); dxBox *b = (dxBox*) g; result[0] = b->side[0]; result[1] = b->side[1]; result[2] = b->side[2]; } dReal dGeomBoxPointDepth (dGeomID g, dReal x, dReal y, dReal z) { dUASSERT (g && g->type == dBoxClass,"argument not a box"); g->recomputePosr(); dxBox *b = (dxBox*) g; // Set p = (x,y,z) relative to box center // // This will be (0,0,0) if the point is at (side[0]/2,side[1]/2,side[2]/2) dVector3 p,q; p[0] = x - b->final_posr->pos[0]; p[1] = y - b->final_posr->pos[1]; p[2] = z - b->final_posr->pos[2]; // Rotate p into box's coordinate frame, so we can // treat the OBB as an AABB dMultiply1_331 (q,b->final_posr->R,p); // Record distance from point to each successive box side, and see // if the point is inside all six sides dReal dist[6]; int i; bool inside = true; for (i=0; i < 3; i++) { dReal side = b->side[i] * REAL(0.5); dist[i ] = side - q[i]; dist[i+3] = side + q[i]; if ((dist[i] < 0) || (dist[i+3] < 0)) { inside = false; } } // If point is inside the box, the depth is the smallest positive distance // to any side if (inside) { dReal smallest_dist = (dReal) (unsigned) -1; for (i=0; i < 6; i++) { if (dist[i] < smallest_dist) smallest_dist = dist[i]; } return smallest_dist; } // Otherwise, if point is outside the box, the depth is the largest // distance to any side. This is an approximation to the 'proper' // solution (the proper solution may be larger in some cases). dReal largest_dist = 0; for (i=0; i < 6; i++) { if (dist[i] > largest_dist) largest_dist = dist[i]; } return -largest_dist; } //**************************************************************************** // box-box collision utility // 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 intersectRectQuad (dReal h[2], dReal p[8], dReal ret[16]) { // q (and r) contain nq (and nr) coordinate points for the current (and // chopped) polygons int nq=4,nr; dReal buffer[16]; dReal *q = p; dReal *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] dReal *pq = q; dReal *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; } } dReal *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(dReal)); return nr; } // 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 cullPoints (int n, dReal p[], int m, int i0, int iret[]) { // compute the centroid of the polygon in cx,cy int i,j; dReal a,cx,cy,q; if (n==1) { cx = p[0]; cy = p[1]; } else if (n==2) { cx = REAL(0.5)*(p[0] + p[2]); cy = REAL(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]; a = dRecip(REAL(3.0)*(a+q)); 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 dReal A[8]; for (i=0; i M_PI) a -= (dReal)(2*M_PI); dReal maxdiff=1e9,diff; #ifndef dNODEBUG *iret = i0; // iret is not allowed to keep this value #endif for (i=0; i M_PI) diff = (dReal) (2*M_PI - diff); if (diff < maxdiff) { maxdiff = diff; *iret = i; } } } #ifndef dNODEBUG dIASSERT (*iret != i0); // ensure iret got set #endif avail[*iret] = 0; iret++; } } // 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. int dBoxBox (const dVector3 p1, const dMatrix3 R1, const dVector3 side1, const dVector3 p2, const dMatrix3 R2, const dVector3 side2, dVector3 normal, dReal *depth, int *return_code, int flags, dContactGeom *contact, int skip) { const dReal fudge_factor = REAL(1.05); dVector3 p,pp,normalC={0,0,0}; const dReal *normalR = 0; dReal 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,expr1_val; int i,j,invert_normal,code; // get vector from centers of box 1 to box 2, relative to box 1 p[0] = p2[0] - p1[0]; p[1] = p2[1] - p1[1]; p[2] = p2[2] - p1[2]; dMultiply1_331 (pp,R1,p); // get pp = p relative to body 1 // get side lengths / 2 A[0] = side1[0]*REAL(0.5); A[1] = side1[1]*REAL(0.5); A[2] = side1[2]*REAL(0.5); B[0] = side2[0]*REAL(0.5); B[1] = side2[1]*REAL(0.5); B[2] = side2[2]*REAL(0.5); // Rij is R1'*R2, i.e. the relative rotation between R1 and R2 R11 = dCalcVectorDot3_44(R1+0,R2+0); R12 = dCalcVectorDot3_44(R1+0,R2+1); R13 = dCalcVectorDot3_44(R1+0,R2+2); R21 = dCalcVectorDot3_44(R1+1,R2+0); R22 = dCalcVectorDot3_44(R1+1,R2+1); R23 = dCalcVectorDot3_44(R1+1,R2+2); R31 = dCalcVectorDot3_44(R1+2,R2+0); R32 = dCalcVectorDot3_44(R1+2,R2+1); R33 = dCalcVectorDot3_44(R1+2,R2+2); Q11 = dFabs(R11); Q12 = dFabs(R12); Q13 = dFabs(R13); Q21 = dFabs(R21); Q22 = dFabs(R22); Q23 = dFabs(R23); Q31 = dFabs(R31); Q32 = dFabs(R32); Q33 = dFabs(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. do { #define TST(expr1,expr2,norm,cc) \ expr1_val = (expr1); /* Avoid duplicate evaluation of expr1 */ \ s2 = dFabs(expr1_val) - (expr2); \ if (s2 > 0) return 0; \ if (s2 > s) { \ s = s2; \ normalR = norm; \ invert_normal = ((expr1_val) < 0); \ code = (cc); \ if (flags & CONTACTS_UNIMPORTANT) break; \ } 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 (dCalcVectorDot3_41(R2+0,p),(A[0]*Q11 + A[1]*Q21 + A[2]*Q31 + B[0]),R2+0,4); TST (dCalcVectorDot3_41(R2+1,p),(A[0]*Q12 + A[1]*Q22 + A[2]*Q32 + B[1]),R2+1,5); TST (dCalcVectorDot3_41(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) \ expr1_val = (expr1); /* Avoid duplicate evaluation of expr1 */ \ s2 = dFabs(expr1_val) - (expr2); \ if (s2 > 0) return 0; \ l = dSqrt ((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_val) < 0); \ code = (cc); \ if (flags & CONTACTS_UNIMPORTANT) break; \ } \ } // We only need to check 3 edges per box // since parallel edges are equivalent. // 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 } while (0); 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 dVector3 pa; dReal sign; // Copy p1 into pa for (i=0; i<3; i++) pa[i] = p1[i]; // why no memcpy? // Get world position of p2 into pa for (j=0; j<3; j++) { sign = (dCalcVectorDot3_14(normal,R1+j) > 0) ? REAL(1.0) : REAL(-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 dVector3 pb; // Copy p2 into pb for (i=0; i<3; i++) pb[i] = p2[i]; // why no memcpy? // Get world position of p2 into pb for (j=0; j<3; j++) { sign = (dCalcVectorDot3_14(normal,R2+j) > 0) ? REAL(-1.0) : REAL(1.0); for (i=0; i<3; i++) pb[i] += sign * B[j] * R2[i*4+j]; } dReal alpha,beta; dVector3 ua,ub; // Get direction of first edge for (i=0; i<3; i++) ua[i] = R1[((code)-7)/3 + i*4]; // Get direction of second edge for (i=0; i<3; i++) ub[i] = R2[((code)-7)%3 + i*4]; // Get closest points between edges (one at each) 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; // Set the contact point as halfway between the 2 closest points for (i=0; i<3; i++) contact[0].pos[i] = REAL(0.5)*(pa[i]+pb[i]); contact[0].depth = *depth; *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). // Note: Unmodified parameter values are being used here const dReal *Ra,*Rb,*pa,*pb,*Sa,*Sb; if (code <= 3) { // One of the faces of box 1 is the reference face Ra = R1; // Rotation of 'a' Rb = R2; // Rotation of 'b' pa = p1; // Center (location) of 'a' pb = p2; // Center (location) of 'b' Sa = A; // Side Lenght of 'a' Sb = B; // Side Lenght of 'b' } else { // One of the faces of box 2 is the reference face Ra = R2; // Rotation of 'a' Rb = R1; // Rotation of 'b' pa = p2; // Center (location) of 'a' pb = p1; // Center (location) of 'b' Sa = B; // Side Lenght of 'a' Sb = A; // Side Lenght of 'b' } // nr = normal vector of reference face dotted with axes of incident box. // anr = absolute values of nr. /* The normal is flipped if necessary so it always points outward from box 'a', box 'b' is thus always the incident box */ dVector3 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]; } // Rotate normal2 in incident box opposite direction dMultiply1_331 (nr,Rb,normal2); anr[0] = dFabs (nr[0]); anr[1] = dFabs (nr[1]); anr[2] = dFabs (nr[2]); // find the largest compontent of anr: this corresponds to the normal // for the incident face. the other axis numbers of the incident 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 dVector3 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 dReal quad[8]; // 2D coordinate of incident face (x,y pairs) dReal c1,c2,m11,m12,m21,m22; c1 = dCalcVectorDot3_14 (center,Ra+code1); c2 = dCalcVectorDot3_14 (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 = dCalcVectorDot3_44 (Ra+code1,Rb+a1); m12 = dCalcVectorDot3_44 (Ra+code1,Rb+a2); m21 = dCalcVectorDot3_44 (Ra+code2,Rb+a1); m22 = dCalcVectorDot3_44 (Ra+code2,Rb+a2); { dReal k1 = m11*Sb[a1]; dReal k2 = m21*Sb[a1]; dReal k3 = m12*Sb[a2]; dReal 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 dReal rect[2]; rect[0] = Sa[code1]; rect[1] = Sa[code2]; // intersect the incident and reference faces dReal ret[16]; int n = intersectRectQuad (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. dReal point[3*8]; // penetrating contact points dReal dep[8]; // depths for those points dReal det1 = dRecip(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++) { dReal k1 = m22*(ret[j*2]-c1) - m12*(ret[j*2+1]-c2); dReal 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] - dCalcVectorDot3(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 | CONTACTS_UNIMPORTANT) == (flags & (NUMC_MASK | CONTACTS_UNIMPORTANT))) { break; } } } if (cnum < 1) { return 0; // this should not happen, yet does at times (demo_plane2d single precision). } // we can't generate more contacts than we actually have int maxc = flags & NUMC_MASK; if (maxc > cnum) maxc = cnum; if (maxc < 1) maxc = 1; // Even though max count must not be zero this check is kept for backward compatibility as this is a public function if (cnum <= maxc) { // we have less contacts than we need, so we use them all for (j=0; j < cnum; j++) { 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]; } } else { dIASSERT(!(flags & CONTACTS_UNIMPORTANT)); // cnum should be generated not greater than maxc so that "then" clause is executed // 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; dReal maxdepth = dep[0]; for (i=1; i maxdepth) { maxdepth = dep[i]; i1 = i; } } int iret[8]; cullPoints (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]]; } cnum = maxc; } *return_code = code; return cnum; } int dCollideBoxBox (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dBoxClass); dIASSERT (o2->type == dBoxClass); dIASSERT ((flags & NUMC_MASK) >= 1); dVector3 normal; dReal depth; int code; dxBox *b1 = (dxBox*) o1; dxBox *b2 = (dxBox*) o2; int num = dBoxBox (o1->final_posr->pos,o1->final_posr->R,b1->side, o2->final_posr->pos,o2->final_posr->R,b2->side, normal,&depth,&code,flags,contact,skip); for (int i=0; inormal[0] = -normal[0]; currContact->normal[1] = -normal[1]; currContact->normal[2] = -normal[2]; currContact->g1 = o1; currContact->g2 = o2; currContact->side1 = -1; currContact->side2 = -1; } return num; } int dCollideBoxPlane (dxGeom *o1, dxGeom *o2, int flags, dContactGeom *contact, int skip) { dIASSERT (skip >= (int)sizeof(dContactGeom)); dIASSERT (o1->type == dBoxClass); dIASSERT (o2->type == dPlaneClass); dIASSERT ((flags & NUMC_MASK) >= 1); dxBox *box = (dxBox*) o1; dxPlane *plane = (dxPlane*) o2; contact->g1 = o1; contact->g2 = o2; contact->side1 = -1; contact->side2 = -1; int ret = 0; //@@@ problem: using 4-vector (plane->p) as 3-vector (normal). const dReal *R = o1->final_posr->R; // rotation of box const dReal *n = plane->p; // normal vector // project sides lengths along normal vector, get absolute values dReal Q1 = dCalcVectorDot3_14(n,R+0); dReal Q2 = dCalcVectorDot3_14(n,R+1); dReal Q3 = dCalcVectorDot3_14(n,R+2); dReal A1 = box->side[0] * Q1; dReal A2 = box->side[1] * Q2; dReal A3 = box->side[2] * Q3; dReal B1 = dFabs(A1); dReal B2 = dFabs(A2); dReal B3 = dFabs(A3); // early exit test dReal depth = plane->p[3] + REAL(0.5)*(B1+B2+B3) - dCalcVectorDot3(n,o1->final_posr->pos); if (depth < 0) return 0; // find number of contacts requested int maxc = flags & NUMC_MASK; // if (maxc < 1) maxc = 1; // an assertion is made on entry if (maxc > 4) maxc = 4; // not more than 4 contacts per box allowed // find deepest point dVector3 p; p[0] = o1->final_posr->pos[0]; p[1] = o1->final_posr->pos[1]; p[2] = o1->final_posr->pos[2]; #define FOO(i,op) \ p[0] op REAL(0.5)*box->side[i] * R[0+i]; \ p[1] op REAL(0.5)*box->side[i] * R[4+i]; \ p[2] op REAL(0.5)*box->side[i] * R[8+i]; #define BAR(i,iinc) if (A ## iinc > 0) { FOO(i,-=) } else { FOO(i,+=) } BAR(0,1); BAR(1,2); BAR(2,3); #undef FOO #undef BAR // the deepest point is the first contact point contact->pos[0] = p[0]; contact->pos[1] = p[1]; contact->pos[2] = p[2]; contact->depth = depth; ret = 1; // ret is number of contact points found so far if (maxc == 1) goto done; // get the second and third contact points by starting from `p' and going // along the two sides with the smallest projected length. #define FOO(i,j,op) \ CONTACT(contact,i*skip)->pos[0] = p[0] op box->side[j] * R[0+j]; \ CONTACT(contact,i*skip)->pos[1] = p[1] op box->side[j] * R[4+j]; \ CONTACT(contact,i*skip)->pos[2] = p[2] op box->side[j] * R[8+j]; #define BAR(ctact,side,sideinc) \ if (depth - B ## sideinc < 0) goto done; \ if (A ## sideinc > 0) { FOO(ctact,side,+); } else { FOO(ctact,side,-); } \ CONTACT(contact,ctact*skip)->depth = depth - B ## sideinc; \ ret++; if (B1 < B2) { if (B3 < B1) goto use_side_3; else { BAR(1,0,1); // use side 1 if (maxc == 2) goto done; if (B2 < B3) goto contact2_2; else goto contact2_3; } } else { if (B3 < B2) { use_side_3: // use side 3 BAR(1,2,3); if (maxc == 2) goto done; if (B1 < B2) goto contact2_1; else goto contact2_2; } else { BAR(1,1,2); // use side 2 if (maxc == 2) goto done; if (B1 < B3) goto contact2_1; else goto contact2_3; } } contact2_1: BAR(2,0,1); goto done; contact2_2: BAR(2,1,2); goto done; contact2_3: BAR(2,2,3); goto done; #undef FOO #undef BAR done: if (maxc == 4 && ret == 3) { // If user requested 4 contacts, and the first 3 were created... // Combine contacts 2 and 3 (vectorial sum) and get the fourth one // Result: if a box face is completely inside a plane, contacts are created for all the 4 vertices dReal d4 = CONTACT(contact,1*skip)->depth + CONTACT(contact,2*skip)->depth - depth; // depth is the depth for first contact if (d4 > 0) { CONTACT(contact,3*skip)->pos[0] = CONTACT(contact,1*skip)->pos[0] + CONTACT(contact,2*skip)->pos[0] - p[0]; // p is the position of first contact CONTACT(contact,3*skip)->pos[1] = CONTACT(contact,1*skip)->pos[1] + CONTACT(contact,2*skip)->pos[1] - p[1]; CONTACT(contact,3*skip)->pos[2] = CONTACT(contact,1*skip)->pos[2] + CONTACT(contact,2*skip)->pos[2] - p[2]; CONTACT(contact,3*skip)->depth = d4; ret++; } } for (int i=0; ig1 = o1; currContact->g2 = o2; currContact->side1 = -1; currContact->side2 = -1; currContact->normal[0] = n[0]; currContact->normal[1] = n[1]; currContact->normal[2] = n[2]; } return ret; }