/* ** Command & Conquer Renegade(tm) ** Copyright 2025 Electronic Arts Inc. ** ** This program is free software: you can redistribute it and/or modify ** it under the terms of the GNU General Public License as published by ** the Free Software Foundation, either version 3 of the License, or ** (at your option) any later version. ** ** This program 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 ** GNU General Public License for more details. ** ** You should have received a copy of the GNU General Public License ** along with this program. If not, see . */ #include "col.h" // The eight box vertices of the box at time zero are // center+extent[i]*basis[i] // center-extent[i]*basis[i] // for i = 0,1,2,3. The vertices after a time step of dt are // center+dt*velocity+extent[i]*basis[i] // center+dt*velocity-extent[i]*basis[i] // for i = 0,1,2,3. //--------------------------------------------------------------------------- IntersectType BoxesIntersect (float dt, const Box& box0, const Box& box1) { // Comments indicate where additional speed is gained for orthonormal bases // for both boxes. If a box is known to be flat (a[i] = 0 for some i OR // b[j] = 0 for some j), then more terms can be eliminated. const Vector* A = box0.basis; const Vector* B = box1.basis; const float* a = box0.extent; const float* b = box1.extent; // memoized values for Dot(A[i],A[j]), Dot(A[i],B[j]), Dot(B[i],B[j]) float AA[3][3], AB[3][3], BB[3][3]; // calculate difference of centers Vector C, V; Sub(box1.center,box0.center,C); Sub(box1.velocity,box0.velocity,V); float ra, rb, rsum, u0, u1; // L = A0 AA[0][0] = Dot(A[0],A[0]); // = 1 for orthonormal basis AA[0][1] = Dot(A[0],A[1]); // = 0 for orthonormal basis AA[0][2] = Dot(A[0],A[2]); // = 0 for orthonormal basis AB[0][0] = Dot(A[0],B[0]); AB[0][1] = Dot(A[0],B[1]); AB[0][2] = Dot(A[0],B[2]); ra = FABS(a[0]*AA[0][0])+FABS(a[1]*AA[0][1])+FABS(a[2]*AA[0][2]); // = FABS(a[0]) for orthonormal basis rb = FABS(b[0]*AB[0][0])+FABS(b[1]*AB[0][1])+FABS(b[2]*AB[0][2]); rsum = ra+rb; u0 = Dot(C,A[0]); u1 = u0+dt*Dot(V,A[0]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA0; // L = A1 AA[1][1] = Dot(A[1],A[1]); // = 1 for orthonormal basis AA[1][2] = Dot(A[1],A[2]); // = 0 for orthonormal basis AB[1][0] = Dot(A[1],B[0]); AB[1][1] = Dot(A[1],B[1]); AB[1][2] = Dot(A[1],B[2]); ra = FABS(a[0]*AA[0][1])+FABS(a[1]*AA[1][1])+FABS(a[2]*AA[1][2]); // = FABS(a[1]) for orthonormal basis rb = FABS(b[0]*AB[1][0])+FABS(b[1]*AB[1][1])+FABS(b[2]*AB[1][2]); rsum = ra+rb; u0 = Dot(C,A[1]); u1 = u0+dt*Dot(V,A[1]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA1; // L = A2 AA[2][2] = Dot(A[2],A[2]); // = 1 for orthonormal basis AB[2][0] = Dot(A[2],B[0]); AB[2][1] = Dot(A[2],B[1]); AB[2][2] = Dot(A[2],B[2]); ra = FABS(a[0]*AA[0][2])+FABS(a[1]*AA[1][2])+FABS(a[2]*AA[2][2]); // = FABS(a[2]) for orthonormal basis rb = FABS(b[0]*AB[2][0])+FABS(b[1]*AB[2][1])+FABS(b[2]*AB[2][2]); rsum = ra+rb; u0 = Dot(C,A[2]); u1 = u0+dt*Dot(V,A[2]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA2; // L = B0 BB[0][0] = Dot(B[0],B[0]); // = 1 for orthonormal basis BB[0][1] = Dot(B[0],B[1]); // = 0 for orthonormal basis BB[0][2] = Dot(B[0],B[2]); // = 0 for orthonormal basis ra = FABS(a[0]*AB[0][0])+FABS(a[1]*AB[1][0])+FABS(a[2]*AB[2][0]); rb = FABS(b[0]*BB[0][0])+FABS(b[1]*BB[0][1])+FABS(b[2]*BB[0][2]); // = FABS(b[0]) for orthonormal basis rsum = ra+rb; u0 = Dot(C,B[0]); u1 = u0+dt*Dot(V,B[0]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itB0; // L = B1 BB[1][1] = Dot(B[1],B[1]); // = 1 for orthonormal basis BB[1][2] = Dot(B[1],B[2]); // = 0 for orthonormal basis ra = FABS(a[0]*AB[0][1])+FABS(a[1]*AB[1][1])+FABS(a[2]*AB[2][1]); rb = FABS(b[0]*BB[0][1])+FABS(b[1]*BB[1][1])+FABS(b[2]*BB[1][2]); // = FABS(b[1]) for orthonormal basis rsum = ra+rb; u0 = Dot(C,B[1]); u1 = u0+dt*Dot(V,B[1]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itB1; // L = B2 BB[2][2] = Dot(B[2],B[2]); // = 1 for orthonormal basis ra = FABS(a[0]*AB[0][2])+FABS(a[1]*AB[1][2])+FABS(a[2]*AB[2][2]); rb = FABS(b[0]*BB[0][2])+FABS(b[1]*BB[1][2])+FABS(b[2]*BB[2][2]); // = FABS(b[2]) for orthonormal basis rsum = ra+rb; u0 = Dot(C,B[2]); u1 = u0+dt*Dot(V,B[2]); if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itB2; // check separating axes which are cross products of box edges float Ainv[3][3], coeff[3][3]; Invert3x3(A,Ainv); // Ainv = Transpose(A) for orthonormal basis, no need to invert MultiplyMM(B,Ainv,coeff); // coeff[i][j] = AB[j][i] for orthonormal basis, no need to multiply // memoize minors of coefficient matrix float minor[3][3]; // difference of centers in A-basis Vector d0, d1, product; MultiplyVM(C,Ainv,d0); // Ainv = Transpose(A) for orthonormal basis MultiplyVM(V,Ainv,d1); // Ainv = Transpose(A) for orthonormal basis ScalarMult(dt,d1,product); Add(d0,product,d1); // L = A0xB0 minor[0][1] = coeff[0][1]*coeff[2][2]-coeff[2][1]*coeff[0][2]; // = -coeff[1][0] for orthonormal bases minor[0][2] = coeff[0][1]*coeff[1][2]-coeff[1][1]*coeff[0][2]; // = +coeff[2][0] for orthonormal bases ra = FABS(a[1]*coeff[0][2])+FABS(a[2]*coeff[0][1]); rb = FABS(b[1]*minor[0][2])+FABS(b[2]*minor[0][1]); // = FABS(b[1]*coeff[2][0])+FABS(b[2]*coeff[1][0]) for orthonormal bases rsum = ra+rb; u0 = d0[2]*coeff[1][0]-d0[1]*coeff[2][0]; u1 = d1[2]*coeff[1][0]-d1[1]*coeff[2][0]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA0B0; // L = A0xB1 minor[0][0] = coeff[1][1]*coeff[2][2]-coeff[2][1]*coeff[1][2]; // = +coeff[0][0] for orthonormal bases ra = FABS(a[1]*coeff[1][2])+FABS(a[2]*coeff[1][1]); rb = FABS(b[0]*minor[0][2])+FABS(b[2]*minor[0][0]); // = FABS(b[0]*coeff[2][0])+FABS(b[2]*coeff[0][0]) for orthonormal bases rsum = ra+rb; u0 = d0[2]*coeff[1][1]-d0[1]*coeff[1][2]; u1 = d1[2]*coeff[1][1]-d1[1]*coeff[1][2]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA0B1; // L = A0xB2 ra = FABS(a[1]*coeff[2][2])+FABS(a[2]*coeff[2][1]); rb = FABS(b[0]*minor[0][1])+FABS(b[1]*minor[0][0]); // = FABS(b[0]*coeff[1][0])+FABS(b[1]*coeff[0][0]) for orthonormal bases rsum = ra+rb; u0 = d0[2]*coeff[2][1]-d0[1]*coeff[2][2]; u1 = d1[2]*coeff[2][1]-d1[1]*coeff[2][2]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA0B2; // L = A1xB0 minor[1][1] = coeff[0][0]*coeff[2][2]-coeff[2][0]*coeff[0][2]; // = +coeff[1][1] for orthonormal bases minor[1][2] = coeff[0][0]*coeff[1][2]-coeff[1][0]*coeff[0][2]; // = -coeff[2][1] for orthonormal bases ra = FABS(a[0]*coeff[0][2])+FABS(a[2]*coeff[0][0]); rb = FABS(b[1]*minor[1][2])+FABS(b[2]*minor[1][1]); // = FABS(b[1]*coeff[2][1])+FABS(b[2]*coeff[1][1]) for orthonormal bases rsum = ra+rb; u0 = d0[0]*coeff[0][2]-d0[2]*coeff[0][0]; u1 = d1[0]*coeff[0][2]-d1[2]*coeff[0][0]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA1B0; // L = A1xB1 minor[1][0] = coeff[1][0]*coeff[2][2]-coeff[2][0]*coeff[1][2]; // = -coeff[0][1] for orthonormal bases ra = FABS(a[0]*coeff[1][2])+FABS(a[2]*coeff[1][0]); rb = FABS(b[0]*minor[1][2])+FABS(b[2]*minor[1][0]); // = FABS(b[0]*coeff[2][1])+FABS(b[2]*coeff[0][1]) for orthonormal bases rsum = ra+rb; u0 = d0[0]*coeff[1][2]-d0[2]*coeff[1][0]; u1 = d1[0]*coeff[1][2]-d1[2]*coeff[1][0]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA1B1; // L = A1xB2 ra = FABS(a[0]*coeff[2][2])+FABS(a[2]*coeff[2][0]); rb = FABS(b[0]*minor[1][1])+FABS(b[1]*minor[1][0]); // = FABS(b[0]*coeff[1][1])+FABS(b[1]*coeff[0][1]) for orthonormal bases rsum = ra+rb; u0 = d0[0]*coeff[2][2]-d0[2]*coeff[2][0]; u1 = d1[0]*coeff[2][2]-d1[2]*coeff[2][0]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA1B2; // L = A2xB0 minor[2][1] = coeff[0][0]*coeff[2][1]-coeff[2][0]*coeff[0][1]; // = -coeff[2][1] for orthonormal bases minor[2][2] = coeff[0][0]*coeff[1][1]-coeff[1][0]*coeff[0][1]; // = +coeff[2][2] for orthonormal bases ra = FABS(a[0]*coeff[0][1])+FABS(a[1]*coeff[0][0]); rb = FABS(b[1]*minor[2][2])+FABS(b[2]*minor[2][1]); // = FABS(b[1]*coeff[2][2])+FABS(b[2]*coeff[1][2]) for orthonormal bases rsum = ra+rb; u0 = d0[1]*coeff[0][0]-d0[0]*coeff[0][1]; u1 = d1[1]*coeff[0][0]-d1[0]*coeff[0][1]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA2B0; // L = A2xB1 minor[2][0] = coeff[1][0]*coeff[2][1]-coeff[2][0]*coeff[1][1]; // = +coeff[0][2] for orthonormal bases ra = FABS(a[0]*coeff[1][1])+FABS(a[1]*coeff[1][0]); rb = FABS(b[0]*minor[2][2])+FABS(b[2]*minor[2][0]); // = FABS(b[0]*coeff[2][2])+FABS(b[2]*coeff[0][2]) for orthonormal bases rsum = ra+rb; u0 = d0[1]*coeff[1][0]-d0[0]*coeff[1][1]; u1 = d1[1]*coeff[1][0]-d1[0]*coeff[1][1]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA2B1; // L = A2xB2 ra = FABS(a[0]*coeff[2][1])+FABS(a[1]*coeff[2][0]); rb = FABS(b[0]*minor[2][1])+FABS(b[1]*minor[2][0]); // = FABS(b[0]*coeff[1][2])+FABS(b[1]*coeff[0][2]) for orthonormal bases rsum = ra+rb; u0 = d0[1]*coeff[2][0]-d0[0]*coeff[2][1]; u1 = d1[1]*coeff[2][0]-d1[0]*coeff[2][1]; if ((u0 > rsum && u1 > rsum) || (u0 < -rsum && u1 < -rsum) ) return itA2B2; return itIntersects; }