Simpler interface to the multipole-acceptance-criterion test function.

src/cell.c

@@ -1733,7 +1733,8 @@ void cell_activate_subcell_grav_tasks(struct cell *ci, struct cell *cj,
     const double r2 = dx * dx + dy * dy + dz * dz;
 
     /* Can we use multipoles ? */
-    if (gravity_multipole_accept(multi_i, multi_j, theta_crit2, r2)) {
+    if (gravity_multipole_accept(multi_i->r_max, multi_j->r_max, theta_crit2,
+                                 r2)) {
 
       /* Ok, no need to drift anything */
       return;

src/engine.c

@@ -1798,8 +1798,9 @@ void engine_make_self_gravity_tasks_mapper(void *map_data, int num_elements,
           const double r2 = dx * dx + dy * dy + dz * dz;
 
           /* Are the cells too close for a MM interaction ? */
-          if (!gravity_multipole_accept_rebuild(multi_i, multi_j, theta_crit2,
-                                                r2)) {
+          if (!gravity_multipole_accept(multi_i->r_max_rebuild,
+                                        multi_j->r_max_rebuild, theta_crit2,
+                                        r2)) {
 
             /* Ok, we need to add a direct pair calculation */
             scheduler_addtask(sched, task_type_pair, task_subtype_grav, 0, 0,

src/multipole.h

@@ -2390,52 +2390,20 @@ INLINE static void gravity_M2P(const struct multipole *ma,
 
 /**
  * @brief Checks whether a cell-cell interaction can be appromixated by a M-M
- * interaction using the CoM and cell radius at rebuild.
+ * interaction using the distance and cell radius.
  *
  * We use the multipole acceptance criterion of Dehnen, 2002, JCoPh, Volume 179,
  * Issue 1, pp.27-42, equation 10.
  *
- * @param ma The #multipole of the first #cell.
- * @param mb The #multipole of the second #cell.
- * @param theta_crit2 The square of the critical opening angle.
- * @param r2 Square of the distance (periodically wrapped) between the
- * multipoles.
- */
-__attribute__((always_inline)) INLINE static int
-gravity_multipole_accept_rebuild(const struct gravity_tensors *const ma,
-                                 const struct gravity_tensors *const mb,
-                                 double theta_crit2, double r2) {
-
-  const double r_crit_a = ma->r_max_rebuild;
-  const double r_crit_b = mb->r_max_rebuild;
-  const double size = r_crit_a + r_crit_b;
-  const double size2 = size * size;
-
-  // MATTHIEU: Make this mass-dependent ?
-
-  /* Multipole acceptance criterion (Dehnen 2002, eq.10) */
-  return (r2 * theta_crit2 > size2);
-}
-
-/**
- * @brief Checks whether a cell-cell interaction can be appromixated by a M-M
- * interaction using the CoM and cell radius at the current time.
- *
- * We use the multipole acceptance criterion of Dehnen, 2002, JCoPh, Volume 179,
- * Issue 1, pp.27-42, equation 10.
- *
- * @param ma The #multipole of the first #cell.
- * @param mb The #multipole of the second #cell.
+ * @param r_crit_a The size of the multipole A.
+ * @param r_crit_b The size of the multipole B.
  * @param theta_crit2 The square of the critical opening angle.
  * @param r2 Square of the distance (periodically wrapped) between the
  * multipoles.
  */
 __attribute__((always_inline)) INLINE static int gravity_multipole_accept(
-    const struct gravity_tensors *const ma,
-    const struct gravity_tensors *const mb, double theta_crit2, double r2) {
+    double r_crit_a, double r_crit_b, double theta_crit2, double r2) {
 
-  const double r_crit_a = ma->r_max;
-  const double r_crit_b = mb->r_max;
   const double size = r_crit_a + r_crit_b;
   const double size2 = size * size;
 

src/runner_doiact_grav.h

@@ -224,6 +224,9 @@ void runner_dopair_grav_pp_full(struct runner *r, struct cell *ci,
       const float h_inv_i = 1.f / h_i;
       const float h_inv3_i = h_inv_i * h_inv_i * h_inv_i;
 
+      ///* Can we use the multipole in cj ? */
+      // if
+
       /* Local accumulators for the acceleration */
       float a_x = 0.f, a_y = 0.f, a_z = 0.f;
 
@@ -1117,7 +1120,8 @@ void runner_dopair_grav(struct runner *r, struct cell *ci, struct cell *cj,
    * option... */
 
   /* Can we use M-M interactions ? */
-  if (gravity_multipole_accept(multi_i, multi_j, theta_crit2, r2)) {
+  if (gravity_multipole_accept(multi_i->r_max, multi_j->r_max, theta_crit2,
+                               r2)) {
 
     /* MATTHIEU: make a symmetric M-M interaction function ! */
     runner_dopair_grav_mm(r, ci, cj);
@@ -1341,7 +1345,8 @@ void runner_do_grav_long_range(struct runner *r, struct cell *ci, int timer) {
     }
 
     /* Check the multipole acceptance criterion */
-    if (gravity_multipole_accept(multi_i, multi_j, theta_crit2, r2)) {
+    if (gravity_multipole_accept(multi_i->r_max, multi_j->r_max, theta_crit2,
+                                 r2)) {
 
       /* Go for a (non-symmetric) M-M calculation */
       runner_dopair_grav_mm(r, ci, cj);
@@ -1364,8 +1369,9 @@ void runner_do_grav_long_range(struct runner *r, struct cell *ci, int timer) {
       const double r2_rebuild = dx * dx + dy * dy + dz * dz;
 
       /* Is the criterion violated now but was OK at the last rebuild ? */
-      if (gravity_multipole_accept_rebuild(multi_i, multi_j, theta_crit2,
-                                           r2_rebuild)) {
+      if (gravity_multipole_accept(multi_i->r_max_rebuild,
+                                   multi_j->r_max_rebuild, theta_crit2,
+                                   r2_rebuild)) {
 
         /* Alright, we have to take charge of that pair in a different way. */
         // MATTHIEU: We should actually open the tree-node here and recurse.