merged with master and seems to work

src/gravity/Default/gravity.h

@@ -28,9 +28,12 @@
 
 __attribute__((always_inline))
     INLINE static float gravity_compute_timestep(struct gpart* gp) {
+  float dt = FLT_MAX;
 
-  /* Currently no limit is imposed */
-  return FLT_MAX;
+#ifdef EXTERNAL_POTENTIAL_POINTMASS
+  dt = fminf(dt, external_gravity_pointmass_timestep(gp));
+#endif
+  return dt;
 }
 
 /**
@@ -66,6 +69,7 @@ __attribute__((always_inline)) INLINE static void external_gravity(struct gpart
 #ifdef EXTERNAL_POTENTIAL_POINTMASS
   external_gravity_pointmass(g);
 #endif
+}
 
 /**
  * @brief Kick the additional variables
@@ -76,3 +80,6 @@ __attribute__((always_inline)) INLINE static void external_gravity(struct gpart
  */
 __attribute__((always_inline)) INLINE static void gravity_kick_extra(
     struct gpart* gp, float dt, float half_dt) {}
+
+__attribute__((always_inline)) INLINE static void gravity_end_force(
+    struct gpart* gp) {}

src/gravity/Default/gravity_part.h

@@ -31,9 +31,6 @@ struct gpart {
   /* Particle acceleration. */
   float a_grav[3];
 
-  /* Gravity acceleration */
-  float a_grav_external[3];
-
   /* Particle mass. */
   float mass;
 

src/gravity/Default/potentials.h

@@ -25,7 +25,7 @@ __attribute__((always_inline)) INLINE static float external_gravity_pointmass_ti
   const float dota_y = const_G * External_Potential_Mass * rinv * rinv * rinv * (-g->v_full[1] + 3.f * rinv * rinv * drdv * dy);
   const float dota_z = const_G * External_Potential_Mass * rinv * rinv * rinv * (-g->v_full[2] + 3.f * rinv * rinv * drdv * dz);
   const float dota_2 = dota_x * dota_x + dota_y * dota_y + dota_z * dota_z;
-  const float a_2    = g->a_grav_external[0] * g->a_grav_external[0] + g->a_grav_external[1] * g->a_grav_external[1] + g->a_grav_external[2] * g->a_grav_external[2];
+  const float a_2    = g->a_grav[0] * g->a_grav[0] + g->a_grav[1] * g->a_grav[1] + g->a_grav[2] * g->a_grav[2];
   
   return 0.03f * sqrtf(a_2/dota_2);
 }
@@ -38,9 +38,9 @@ __attribute__((always_inline)) INLINE static void external_gravity_pointmass(str
   const float rinv = 1.f / sqrtf(dx*dx + dy*dy + dz*dz);
   
 
-  g->a_grav_external[0] += - const_G *  External_Potential_Mass * dx * rinv * rinv * rinv;
-  g->a_grav_external[1] += - const_G *  External_Potential_Mass * dy * rinv * rinv * rinv;
-  g->a_grav_external[2] += - const_G *  External_Potential_Mass * dz * rinv * rinv * rinv;
+  g->a_grav[0] += - const_G *  External_Potential_Mass * dx * rinv * rinv * rinv;
+  g->a_grav[1] += - const_G *  External_Potential_Mass * dy * rinv * rinv * rinv;
+  g->a_grav[2] += - const_G *  External_Potential_Mass * dz * rinv * rinv * rinv;
 }
 
 

src/runner.c

@@ -139,16 +139,16 @@ void runner_dograv_external(struct runner *r, struct cell *c) {
       const float rinv = 1.f / sqrtf(dx*dx + dy*dy + dz*dz);
 
 		/* /\* current acceleration *\/ */
-      /* g->a_grav_external[0] = - const_G *  External_Potential_Mass * dx * rinv * rinv * rinv; */
-      /* g->a_grav_external[1] = - const_G *  External_Potential_Mass * dy * rinv * rinv * rinv; */
-      /* g->a_grav_external[2] = - const_G *  External_Potential_Mass * dz * rinv * rinv * rinv; */
+      /* g->a_grav[0] = - const_G *  External_Potential_Mass * dx * rinv * rinv * rinv; */
+      /* g->a_grav[1] = - const_G *  External_Potential_Mass * dy * rinv * rinv * rinv; */
+      /* g->a_grav[2] = - const_G *  External_Potential_Mass * dz * rinv * rinv * rinv; */
 
 
 		const int current_dti = g->ti_end - g->ti_begin;
 		const float dt = 0.5f * current_dti * r->e->timeBase;
-		const float vx = g->v_full[0] + dt * g->a_grav_external[0];
-		const float vy = g->v_full[1] + dt * g->a_grav_external[1];
-		const float vz = g->v_full[2] + dt * g->a_grav_external[2];
+		const float vx = g->v_full[0] + dt * g->a_grav[0];
+		const float vy = g->v_full[1] + dt * g->a_grav[1];
+		const float vz = g->v_full[2] + dt * g->a_grav[2];
 
 		/* E/L */
       E = 0.5 * ((vx*vx) + (vy*vy) + (vz*vz)) - const_G *  External_Potential_Mass * rinv;
@@ -158,7 +158,7 @@ void runner_dograv_external(struct runner *r, struct cell *c) {
       if(abs(g->id) == 1) {
         float v2  = vx*vx + vy*vy + vz*vz;
         float fg  = const_G * External_Potential_Mass * rinv;
-		  float fga = sqrtf((g->a_grav_external[0]*g->a_grav_external[0]) + (g->a_grav_external[1]*g->a_grav_external[1]) + (g->a_grav_external[2]*g->a_grav_external[2])) * dr;
+		  float fga = sqrtf((g->a_grav[0]*g->a_grav[0]) + (g->a_grav[1]*g->a_grav[1]) + (g->a_grav[2]*g->a_grav[2])) * dr;
         //message("grav_external time= %f\t V_c^2= %f GM/r= %f E= %f L[2]= %f x= %f y= %f vx= %f vy= %f\n", r->e->time, v2, fg, E, L[2], g->x[0], g->x[1], vx, vy);
         message("%f\t %f %f %f %f %f %f %f %f %f %f %f %f\n", r->e->time, g->tx, g->tv, dt, v2, fg, fga, E, L[2], g->x[0], g->x[1], vx, vy);
         // message(" G=%e M=%e\n", const_G, External_Potential_Mass);
@@ -955,6 +955,10 @@ void runner_dokick(struct runner *r, struct cell *c, int timer) {
         const double dt = (ti_end - ti_start) * timeBase;
         const double half_dt = (ti_end - gp->ti_end) * timeBase;
 
+       /* Move particle forward in time */
+        gp->ti_begin = gp->ti_end;
+        gp->ti_end = gp->ti_begin + new_dti;
+
         /* Kick particles in momentum space */
         gp->v_full[0] += gp->a_grav[0] * dt;
         gp->v_full[1] += gp->a_grav[1] * dt;
@@ -966,6 +970,11 @@ void runner_dokick(struct runner *r, struct cell *c, int timer) {
         /* Number of updated g-particles */
         g_updated++;
       }
+
+		/* Minimal time for next end of time-step */
+		ti_end_min = min(gp->ti_end, ti_end_min);
+		ti_end_max = max(gp->ti_end, ti_end_max);
+
     }
 
     /* Now do the hydro ones... */