bool MFCollision_TriTriTest(const MFVector& V0, const MFVector& V1, const MFVector& V2, const MFVector& U0, const MFVector& U1, const MFVector& U2)
{
MFVector E1, E2;
MFVector N1, N2;
MFVector D;
float d1,d2;
float du0,du1,du2,dv0,dv1,dv2;
float isect1[2], isect2[2];
float du0du1,du0du2,dv0dv1,dv0dv2;
short index;
float vp0,vp1,vp2;
float up0,up1,up2;
float bb,cc,max;
float a,b,c,x0,x1;
float d,e,f,y0,y1;
float xx,yy,xxyy,tmp;
/* compute plane equation of triangle(V0,V1,V2) */
E1 = V1-V0;
E2 = V2-V0;
N1.Cross3(E1, E2);
d1 = -N1.Dot3(V0);
/* plane equation 1: N1.X+d1=0 */
/* put U0,U1,U2 into plane equation 1 to compute signed distances to the plane*/
du0 = N1.Dot3(U0) + d1;
du1 = N1.Dot3(U1) + d1;
du2 = N1.Dot3(U2) + d1;
/* coplanarity robustness check */
if(fabsf(du0)<MFALMOST_ZERO) du0=0.0f;
if(fabsf(du1)<MFALMOST_ZERO) du1=0.0f;
if(fabsf(du2)<MFALMOST_ZERO) du2=0.0f;
du0du1 = du0*du1;
du0du2 = du0*du2;
if(du0du1>0.0f && du0du2>0.0f) /* same sign on all of them + not equal 0 ? */
return false; /* no intersection occurs */
/* compute plane of triangle (U0,U1,U2) */
E1 = U1 - U0;
E2 = U2 - U0;
N2.Cross3(E1, E2);
d2 = -N2.Dot3(U0);
/* plane equation 2: N2.X+d2=0 */
/* put V0,V1,V2 into plane equation 2 */
dv0 = N2.Dot3(V0) + d2;
dv1 = N2.Dot3(V1) + d2;
dv2 = N2.Dot3(V2) + d2;
if(fabsf(dv0)<MFALMOST_ZERO) dv0=0.0;
if(fabsf(dv1)<MFALMOST_ZERO) dv1=0.0;
if(fabsf(dv2)<MFALMOST_ZERO) dv2=0.0;
dv0dv1 = dv0*dv1;
dv0dv2 = dv0*dv2;
if(dv0dv1>0.0f && dv0dv2>0.0f) /* same sign on all of them + not equal 0 ? */
return false; /* no intersection occurs */
/* compute direction of intersection line */
D.Cross3(N1, N2);
/* compute and index to the largest component of D */
max = fabsf(D.x);
index = 0;
bb = fabsf(D.y);
cc = fabsf(D.z);
if(bb>max) max = bb, index = 1;
if(cc>max) max = cc, index = 2;
/* this is the simplified projection onto L*/
vp0 = V0[index];
vp1 = V1[index];
vp2 = V2[index];
up0 = U0[index];
up1 = U1[index];
up2 = U2[index];
/* compute interval for triangle 1 */
NEWCOMPUTE_INTERVALS(vp0,vp1,vp2,dv0,dv1,dv2,dv0dv1,dv0dv2,a,b,c,x0,x1);
/* compute interval for triangle 2 */
NEWCOMPUTE_INTERVALS(up0,up1,up2,du0,du1,du2,du0du1,du0du2,d,e,f,y0,y1);
xx=x0*x1;
yy=y0*y1;
xxyy=xx*yy;
tmp=a*xxyy;
isect1[0]=tmp+b*x1*yy;
isect1[1]=tmp+c*x0*yy;
tmp=d*xxyy;
isect2[0]=tmp+e*xx*y1;
isect2[1]=tmp+f*xx*y0;
SORT(isect1[0],isect1[1]);
SORT(isect2[0],isect2[1]);
if(isect1[1]<isect2[0] || isect2[1]<isect1[0]) return false;
return true;
}
