MSD Version 0.02

svn path=/trunk/externals/nusmuk/; revision=2795

1 files changed, 57 insertions, 47 deletions

diff --git a/msd/main.cpp b/msd/main.cpp
index b01bc5e..a9aad8a 100755
--- a/msd/main.cpp
+++ b/msd/main.cpp
@@ -101,7 +101,7 @@ public:
 protected:
 
 // ---------------------------------------------------------------  RESET 
-
+// ----------------------------------------------------------------------
 	void m_reset() 
 	{ 
 		t_int i;
@@ -121,6 +121,7 @@ protected:
 	}
 
 // --------------------------------------------------------------  COMPUTE 
+// -----------------------------------------------------------------------
 
 	void m_bang()
 	{
@@ -130,37 +131,37 @@ protected:
 	
 		for (i=0; i<nb_link; i++)	{

 		// compute link forces
-			distance = link[i]->mass1->posX-link[i]->mass2->posX;
-			F  = link[i]->K1 * (distance - link[i]->longueur) ;	// F = k1(x1-x2)
-			F += link[i]->D1 * (distance - link[i]->distance_old) ;	// F = F + D1(v1-v2)
+			distance = link[i]->mass1->posX-link[i]->mass2->posX;		// L[n] = x1 - x2
+			F  = link[i]->K1 * (distance - link[i]->longueur) ;		// F[n] = k1 (L[n] - L[0])
+			F += link[i]->D1 * (distance - link[i]->distance_old) ;		// F[n] = F[n] + D1 (L[n] - L[n-1])
 			if (distance != 0) 	{
-				Fx = F * (link[i]->mass1->posX - link[i]->mass2->posX)/distance;
+				Fx = F * (link[i]->mass1->posX - link[i]->mass2->posX)/distance; // Fx = F * Lx[n]/L[n]
 			}

-			link[i]->mass1->forceX -= Fx;
-			link[i]->mass1->forceX -= link[i]->D2*link[i]->mass1->speedX;

-			link[i]->mass2->forceX += Fx;
-			link[i]->mass2->forceX -= link[i]->D2*link[i]->mass2->speedX;
-			link[i]->distance_old = distance;
+			link[i]->mass1->forceX -= Fx;					// Fx1[n] = -Fx
+			link[i]->mass1->forceX -= link[i]->D2*link[i]->mass1->speedX; 	// Fx1[n] = Fx1[n] - D2 * vx1[n-1]

+			link[i]->mass2->forceX += Fx;					// Fx2[n] = Fx
+			link[i]->mass2->forceX -= link[i]->D2*link[i]->mass2->speedX; 	// Fx2[n] = Fx2[n] - D2 * vx2[n-1]
+			link[i]->distance_old = distance;				// L[n-1] = L[n]
 		}
 

 		for (i=0; i<nb_mass; i++)

 		// compute new masses position only if mobile = 1

 			if (mass[i]->mobile == 1)  		{

-				X_new = mass[i]->forceX * mass[i]->invM + 2*mass[i]->posX - mass[i]->posX2;
-				mass[i]->posX2 = mass[i]->posX;
-				mass[i]->posX = max(min(X_new,Xmax),Xmin);			// x = x + v
-				mass[i]->speedX = mass[i]->posX - mass[i]->posX2;	// v = v + F/M
+				X_new = mass[i]->forceX * mass[i]->invM + 2*mass[i]->posX - mass[i]->posX2; // x[n] =Fx[n]/M+2x[n]-x[n-1] 
+				mass[i]->posX2 = mass[i]->posX;				// x[n-2] = x[n-1]
+				mass[i]->posX = max(min(X_new,Xmax),Xmin);		// x[n-1] = x[n]	
+				mass[i]->speedX = mass[i]->posX - mass[i]->posX2;	// vx[n] = x[n] - x[n-1]
 				}
 
 		for (i=0; i<nb_mass; i++)	{

 		// clear forces
 			mass[i]->out_forceX = mass[i]->forceX;

-			mass[i]->forceX = 0;
+			mass[i]->forceX = 0;						// Fx[n] = 0
 		}

 	}
 
 // --------------------------------------------------------------  MASSES
-
+// ----------------------------------------------------------------------
 	void m_mass(int argc,t_atom *argv) 

 	// add a mass

 	// Id, nbr, mobile, invM, speedX, posX, forceX

@@ -168,18 +169,18 @@ protected:
 		t_atom sortie[5], aux[2];
 		t_float M;
 
-		mass[nb_mass] = new t_mass;			// new pointer

-		mass[nb_mass]->Id = GetSymbol(argv[0]);	// ID
+		mass[nb_mass] = new t_mass;			// new mass

+		mass[nb_mass]->Id = GetSymbol(argv[0]);		// ID
 		mass[nb_mass]->mobile = GetInt(argv[1]);	// mobile
 		if (GetFloat(argv[2])==0)
 			M=1;
 		else M = GetFloat(argv[2]);			
-		mass[nb_mass]->invM = 1/(M);			// invM
-		mass[nb_mass]->speedX = 0;			// vx

-		mass[nb_mass]->posX = GetFloat(argv[3]);		// x
-		mass[nb_mass]->posX2 = GetFloat(argv[3]);		// x

-		mass[nb_mass]->forceX = 0;			// Fx
-		mass[nb_mass]->nbr = id_mass;			// id_nbr
+		mass[nb_mass]->invM = 1/(M);			// 1/M
+		mass[nb_mass]->speedX = 0;			// vx[n]

+		mass[nb_mass]->posX = GetFloat(argv[3]);	// x[n]
+		mass[nb_mass]->posX2 = GetFloat(argv[3]);	// x[n-1]

+		mass[nb_mass]->forceX = 0;			// Fx[n]
+		mass[nb_mass]->nbr = id_mass;			// id number
 		nb_mass++ ;
 		id_mass++;

 		nb_mass = min ( nb_max_mass -1, nb_mass );
@@ -252,6 +253,8 @@ protected:
 	t_int i,nb_link_delete=0;
 	t_atom sortie[5], aux[nb_link];
 	
+
+	// Delete all associated links 
 	for (i=0; i<nb_link;i++)	{
 		if (link[i]->mass1->nbr == GetAInt(argv[0]) || link[i]->mass2->nbr == GetAInt(argv[0]))	{
 			SetFloat((aux[nb_link_delete]),link[i]->nbr);
@@ -261,7 +264,8 @@ protected:
 
 	for (i=0; i<nb_link_delete;i++)
 		m_delete_link(1,&aux[i]);
-
+	
+	// Delete mass
 	for (i=0; i<nb_mass;i++)
 		if (mass[i]->nbr == GetAInt(argv[0]))	{
 			SetFloat((sortie[0]),mass[i]->nbr);
@@ -270,7 +274,7 @@ protected:
 			SetFloat((sortie[3]),1/mass[i]->invM);
 			SetFloat((sortie[4]),mass[i]->posX);
 			delete mass[i];
-			mass[i] = mass[nb_mass-1];
+			mass[i] = mass[nb_mass-1]; 	// copy last mass instead 
 			nb_mass--;
 			ToOutAnything(1,S_Mass_deleted,5,sortie);
 			break;
@@ -281,17 +285,18 @@ protected:
 
 	void m_Xmax(int argc,t_atom *argv) 
 	{

-	// set damping of link(s) named Id
+	// set X max
 	Xmax = GetFloat(argv[0]);
 	}
 
 	void m_Xmin(int argc,t_atom *argv) 
 	{

-	// set damping of link(s) named Id
+	// set X min
 	Xmin = GetFloat(argv[0]);
 	}
 
 // --------------------------------------------------------------  LINKS 
+// ---------------------------------------------------------------------
 
 	void m_link(int argc,t_atom *argv) 
 	// add a link

@@ -300,20 +305,20 @@ protected:
 		t_atom sortie[7], aux[2];
 		t_int i;
 
-		link[nb_link] = new t_link;
-		link[nb_link]->Id = GetSymbol(argv[0]);
+		link[nb_link] = new t_link;			// New pointer
+		link[nb_link]->Id = GetSymbol(argv[0]);		// ID
 		for (i=0; i<nb_mass;i++)
-			if (mass[i]->nbr==GetAInt(argv[1]))
+			if (mass[i]->nbr==GetAInt(argv[1]))	// pointer to mass1
 				link[nb_link]->mass1 = mass[i];
-			else if(mass[i]->nbr==GetAInt(argv[2]))
+			else if(mass[i]->nbr==GetAInt(argv[2]))	// pointer to mass2
 				link[nb_link]->mass2 = mass[i];
-		link[nb_link]->K1 = GetFloat(argv[3]);

-		link[nb_link]->D1 = GetFloat(argv[4]);
-		link[nb_link]->D2 = GetFloat(argv[5]);
-		link[nb_link]->longx = link[nb_link]->mass1->posX - link[nb_link]->mass2->posX;
-		link[nb_link]->longueur = link[nb_link]->longx ;
-		link[nb_link]->nbr = id_link;
-		link[nb_link]->distance_old = link[nb_link]->longueur;
+		link[nb_link]->K1 = GetFloat(argv[3]);		// K1

+		link[nb_link]->D1 = GetFloat(argv[4]);		// D1
+		link[nb_link]->D2 = GetFloat(argv[5]);		// D2
+		link[nb_link]->longx = link[nb_link]->mass1->posX - link[nb_link]->mass2->posX;	// Lx[0]
+		link[nb_link]->longueur = link[nb_link]->longx ;// L[0]
+		link[nb_link]->nbr = id_link;			// id number
+		link[nb_link]->distance_old = link[nb_link]->longueur;	// L[n-1]
 		nb_link++;
 		id_link++;

 		nb_link = min ( nb_max_link -1, nb_link );
@@ -356,7 +361,7 @@ protected:
 					SetSymbol((arglist[0]),GetSymbol(argv[0]));
 					SetFloat((arglist[1]),mass[imass1[i]]->nbr);
 					SetFloat((arglist[2]),mass[imass2[j]]->nbr);
-					SetFloat((arglist[3]),GetInt(argv[3]));
+					SetFloat((arglist[3]),GetFloat(argv[3]));
 					SetFloat((arglist[4]),GetFloat(argv[4]));
 					SetFloat((arglist[5]),GetFloat(argv[5]));
 					m_link(6,arglist);
@@ -418,7 +423,7 @@ protected:
 			SetFloat((sortie[5]),link[i]->D1);
 			SetFloat((sortie[6]),link[i]->D2);
 			delete link[i];
-			link[i]=link[nb_link-1];
+			link[i]=link[nb_link-1];	// copy last link instead
 			nb_link--;
 			ToOutAnything(1,S_Link_deleted,7,sortie);
 			break;
@@ -427,6 +432,7 @@ protected:
 
 
 // --------------------------------------------------------------  GET 
+// -------------------------------------------------------------------
 
 	void m_get(int argc,t_atom *argv)
 	// get attributes
@@ -595,7 +601,7 @@ protected:
 	}
 
 	void m_force_dumpl()
-	// List of masses positions on first outlet
+	// List of masses forces on first outlet
 	{	
 		t_atom sortie[nb_mass];
 		t_int i;
@@ -607,7 +613,7 @@ protected:
 	}
 
 	void m_info_dumpl()
-	// List of masses positions on first outlet
+	// List of masses and links infos on first outlet
 	{	
 		t_atom sortie[7];
 		t_int i;
@@ -636,16 +642,19 @@ protected:
 
 
 // --------------------------------------------------------------  PROTECTED VARIABLES 
+// -----------------------------------------------------------------------------------
 
-	t_link * link[nb_max_link];

-	t_mass * mass[nb_max_mass];
-	t_float Xmin, Xmax, Ymin, Ymax;
+	t_link * link[nb_max_link];		// Pointer table on links

+	t_mass * mass[nb_max_mass];		// Pointer table on masses
+	t_float Xmin, Xmax;			// Limit values
 	int nb_link, nb_mass, id_mass, id_link;
 
 // --------------------------------------------------------------  SETUP
+// ---------------------------------------------------------------------
 
 private:
 
+	// Static symbols
 	const static t_symbol *S_Reset;
 	const static t_symbol *S_Mass;
 	const static t_symbol *S_Link;
@@ -721,7 +730,8 @@ private:
 	FLEXT_CALLBACK_V(m_delete_link)
 	FLEXT_CALLBACK_V(m_delete_mass)
 };
-
+// -------------------------------------------------------------- STATIC VARIABLES
+// -------------------------------------------------------------------------------
 
 	const t_symbol *msd::S_Reset = MakeSymbol("Reset");
 	const t_symbol *msd::S_Mass = MakeSymbol("Mass");