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-rwxr-xr-xmsd2D/main.cpp80
1 files changed, 38 insertions, 42 deletions
diff --git a/msd2D/main.cpp b/msd2D/main.cpp
index d911a14..4313bba 100755
--- a/msd2D/main.cpp
+++ b/msd2D/main.cpp
@@ -87,6 +87,9 @@ typedef struct _link {
t_float distance_old;
} t_link;
+
+inline t_float sqr(t_float x) { return x*x; }
+
class msd2D:
public flext_base
{
@@ -136,57 +139,50 @@ protected:
void m_bang()
{
- t_float F=0,Fx=0,Fy=0,distance,vitesse, X_new, Y_new;
- t_int i;
- t_mass **mi;
- t_link **li;
-
- for (i=0, li=link; i<nb_link; li++, i++) {
+ t_int i;
+ for (i=0; i<nb_link; i++) {
+ t_link *li = link[i];
+ t_mass *m1 = li->mass1,*m2 = li->mass2;
// compute link forces
- distance = sqrt(pow((*li)->mass1->posX-(*li)->mass2->posX,2) +
- pow((*li)->mass1->posY-(*li)->mass2->posY,2)); // L[n] = sqrt( (x1-x2)² +(y1-y2)²)
- if (distance < (*li)->long_min || distance > (*li)->long_max) {
- Fx = 0;
- Fy = 0;
- }
+ t_float distance = sqrt(sqr(m1->posX-m2->posX) + sqr(m1->posY-m2->posY)); // L[n] = sqrt( (x1-x2)² +(y1-y2)²)
+
+ t_float Fx,Fy;
+ if (distance < li->long_min || distance > li->long_max || distance == 0)
+ Fx = Fy = 0;
else {
- F = (*li)->K1 * (distance - (*li)->longueur) ; // F[n] = k1 (L[n] - L[0])
- F += (*li)->D1 * (distance - (*li)->distance_old) ; // F[n] = F[n] + D1 (L[n] - L[n-1])
- if (distance != 0) {
- Fx = F * ((*li)->mass1->posX - (*li)->mass2->posX)/distance; // Fx = F * Lx[n]/L[n]
- Fy = F * ((*li)->mass1->posY - (*li)->mass2->posY)/distance; // Fy = F * Ly[n]/L[n]
- }
+ t_float F = (li->K1 * (distance - li->longueur) + li->D1 * (distance - li->distance_old))/distance; // F[n] = k1 (L[n] - L[0])/L[n]+ D1 (L[n] - L[n-1])/L[n]
+ Fx = F * (m1->posX - m2->posX); // Fx = F * Lx[n]/L[n]
+ Fy = F * (m1->posY - m2->posY); // Fy = F * Ly[n]/L[n]
}
- (*li)->mass1->forceX -= Fx; // Fx1[n] = -Fx
- (*li)->mass1->forceX -= (*li)->D2*(*li)->mass1->speedX; // Fx1[n] = Fx1[n] - D2 * vx1[n-1]
- (*li)->mass2->forceX += Fx; // Fx2[n] = Fx
- (*li)->mass2->forceX -= (*li)->D2*(*li)->mass2->speedX; // Fx2[n] = Fx2[n] - D2 * vx2[n-1]
- (*li)->mass1->forceY -= Fy; // Fy1[n] = -Fy
- (*li)->mass1->forceY -= (*li)->D2*(*li)->mass1->speedY; // Fy1[n] = Fy1[n] - D2 * vy1[n-1]
- (*li)->mass2->forceY += Fy; // Fy2[n] = Fy
- (*li)->mass2->forceY -= (*li)->D2*(*li)->mass2->speedY; // Fy1[n] = Fy1[n] - D2 * vy1[n-1]
- (*li)->distance_old = distance; // L[n-1] = L[n]
+
+ m1->forceX -= Fx+li->D2*m1->speedX; // Fx1[n] = -Fx,Fx1[n] = Fx1[n] - D2 * vx1[n-1]
+ m1->forceY -= Fy+li->D2*m1->speedY; // Fy1[n] = -Fy,Fy1[n] = Fy1[n] - D2 * vy1[n-1]
+ m2->forceX += Fx-li->D2*m2->speedX; // Fx2[n] = Fx,Fx2[n] = Fx2[n] - D2 * vx2[n-1]
+ m2->forceY += Fy-li->D2*m2->speedY; // Fy2[n] = Fy,Fy1[n] = Fy1[n] - D2 * vy1[n-1]
+ li->distance_old = distance; // L[n-1] = L[n]
}
- for (i=0, mi=mass; i<nb_mass; mi++, i++)
+ for (i=0; i<nb_mass; i++) {
+ t_mass *mi = mass[i];
// compute new masses position only if mobile = 1
- if ((*mi)->mobile == 1) {
- X_new = (*mi)->forceX * (*mi)->invM + 2*(*mi)->posX - (*mi)->posX2; // x[n] =Fx[n]/M+2x[n]-x[n-1]
- (*mi)->posX2 = (*mi)->posX; // x[n-2] = x[n-1]
- (*mi)->posX = max(min(X_new,Xmax),Xmin); // x[n-1] = x[n]
- (*mi)->speedX = (*mi)->posX - (*mi)->posX2; // vx[n] = x[n] - x[n-1]
- Y_new = (*mi)->forceY * (*mi)->invM + 2*(*mi)->posY - (*mi)->posY2; // x[n] =Fx[n]/M+2x[n]-x[n-1]
- (*mi)->posY2 = (*mi)->posY; // x[n-2] = x[n-1]
- (*mi)->posY = max(min(Y_new,Ymax),Ymin); // x[n-1] = x[n]
- (*mi)->speedY = (*mi)->posY - (*mi)->posY2; // vx[n] = x[n] - x[n-1]
+ if (mi->mobile == 1) {
+ t_float X_new = mi->forceX * mi->invM + 2*mi->posX - mi->posX2; // x[n] =Fx[n]/M+2x[n]-x[n-1]
+ mi->posX2 = mi->posX; // x[n-2] = x[n-1]
+ mi->posX = max(min(X_new,Xmax),Xmin); // x[n-1] = x[n]
+ mi->speedX = mi->posX - mi->posX2; // vx[n] = x[n] - x[n-1]
+ t_float Y_new = mi->forceY * mi->invM + 2*mi->posY - mi->posY2; // x[n] =Fx[n]/M+2x[n]-x[n-1]
+ mi->posY2 = mi->posY; // x[n-2] = x[n-1]
+ mi->posY = max(min(Y_new,Ymax),Ymin); // x[n-1] = x[n]
+ mi->speedY = mi->posY - mi->posY2; // vx[n] = x[n] - x[n-1]
}
+ }
- for (i=0, mi=mass; i<nb_mass; mi++, i++) {
+ for (i=0; i<nb_mass; i++) {
+ t_mass *mi = mass[i];
// clear forces
- (*mi)->out_forceX = (*mi)->forceX;
- (*mi)->forceX = 0; // Fx[n] = 0
- (*mi)->out_forceY = (*mi)->forceY;
- (*mi)->forceY = 0; // Fy[n] = 0
+ mi->out_forceX = mi->forceX;
+ mi->out_forceY = mi->forceY;
+ mi->forceX = mi->forceY = 0; // Fx[n] = 0,Fy[n] = 0
}
}