int hop(int step, t_QMrec *qm)
{
int
swap = 0;
real
d11=0.0,d12=0.0,d21=0.0,d22=0.0;
/* calculates the inproduct between the current Ci vector and the
* previous CI vector. A diabatic hop will be made if d12 and d21
* are much bigger than d11 and d22. In that case hop returns true,
* otherwise it returns false.
*/
if(step){ /* only go on if more than one step has been done */
d11 = inproduct(qm->CIvec1,qm->CIvec1old,qm->CIdim);
d12 = inproduct(qm->CIvec1,qm->CIvec2old,qm->CIdim);
d21 = inproduct(qm->CIvec2,qm->CIvec1old,qm->CIdim);
d22 = inproduct(qm->CIvec2,qm->CIvec2old,qm->CIdim);
}
fprintf(stderr,"-------------------\n");
fprintf(stderr,"d11 = %13.8f\n",d11);
fprintf(stderr,"d12 = %13.8f\n",d12);
fprintf(stderr,"d21 = %13.8f\n",d21);
fprintf(stderr,"d22 = %13.8f\n",d22);
fprintf(stderr,"-------------------\n");
if((fabs(d12)>0.5)&&(fabs(d21)>0.5))
swap = 1;
return(swap);
}
Vector IntersectBallTriangle(Ball ball, Triangle t, Vector* Intersect)
{
const double small = 1e-12;
const double large = 1e3;
Vector u, v, normal; // triangle vectors (u is V0->V1, v is V0->V2, n is the normal vector
Vector q0 , q1, dir, w0, w; // q0 and q1 will contain the points on the ball's surface that is closest to (q0) and farthest from (q1) the triangle;
// dir is twice the radius of the ball (a vector pointing towards the triangle
// in the direction of -n); w0 is the shortest distance between the bottom of the ball and V0;
// w is the vector between V0 and the intersection point
float r, a, b; // additional parameters
u = t.getCorner(1) - t.getCorner(0);
v = t.getCorner(2) - t.getCorner(0);
normal = crossproduct(u, v);
if (normal.getLength() < small) // triangle is degenerate
{
std::cerr << "degenerate triangle detected, fix your blender" << std::endl;
exit(1);
}
normal = normal / normal.getLength();
q0 = ball.getCenter() - ball.getRadius() * normal;
q1 = ball.getCenter() + ball.getRadius() * normal;
dir = q0 - q1;
w0 = q0 - t.getCorner(0);
a = -inproduct(normal, w0);
b = inproduct(normal, dir);
// ball vector is parallel to the triangle. This should never happen, as ortogonal lines are never parallel
if (std::abs(b) < small)
{
std::cerr << "degenerate ball detected, fix" <<std::endl;
exit(1);
}
// get intersect point of ray with triangle plane
r = a / b;
if (r < 0.0 || r > 1.0)
{
return {0, 0, 0}; // => no intersect
}
// intersection between ball radius and (extended) plane of triangle
Vector intersect = q0 + r * dir;
// is I inside T?
float uu, uv, vv, wu, wv, D;
uu = inproduct(u, u);
uv = inproduct(u, v);
vv = inproduct(v, v);
w = intersect - t.getCorner(0);
wu = inproduct(w, u);
wv = inproduct(w, v);
D = uv * uv - uu * vv;
// get and test parametric coords
float f, g;
f = (uv * wv - vv * wu) / D;
if (f < 0.0 || f > 1.0) // I is outside T
{
return {0, 0, 0};
}
g = (uv * wu - uu * wv) / D;
if (g < 0.0 || (f + g) > 1.0) // I is outside T
{
return {0, 0, 0};
}
Vector force;
float elasticity = large;
force = elasticity * (w0 - w);
return force;
}
