Added functions to remove a part/gpart/spart from a cell.

src/cell.c

@@ -3202,6 +3202,69 @@ void cell_check_timesteps(struct cell *c) {
 #endif
 }
 
+/**
+ * @brief "Remove" a gas particle from the calculation.
+ *
+ * The particle is inhibited and will officially be removed at the next rebuild.
+ *
+ * @param c The #cell from which to remove the particle.
+ * @param p The #part to remove.
+ * @param xp The extended data of the particle to remove.
+ */
+void cell_remove_part(const struct engine *e, struct cell *c, struct part *p,
+                      struct xpart *xp) {
+
+  /* Quick cross-check */
+  if (c->nodeID != e->nodeID)
+    error("Can't remove a particle in a foreign cell.");
+
+  /* Mark the particle as inhibited */
+  p->time_bin = time_bin_inhibited;
+  if (p->gpart) p->gpart->time_bin = time_bin_inhibited;
+}
+
+/**
+ * @brief "Remove" a gravity particle from the calculation.
+ *
+ * The particle is inhibited and will officially be removed at the next rebuild.
+ *
+ * @param c The #cell from which to remove the particle.
+ * @param gp The #gpart to remove.
+ */
+void cell_remove_gpart(const struct engine *e, struct cell *c,
+                       struct gpart *gp) {
+
+  /* Quick cross-check */
+  if (c->nodeID != e->nodeID)
+    error("Can't remove a particle in a foreign cell.");
+
+  if (gp->type != swift_type_dark_matter)
+    error("Trying to remove a non-dark matter gpart.");
+
+  /* Mark the particle as inhibited */
+  gp->time_bin = time_bin_inhibited;
+}
+
+/**
+ * @brief "Remove" a star particle from the calculation.
+ *
+ * The particle is inhibited and will officially be removed at the next rebuild.
+ *
+ * @param c The #cell from which to remove the particle.
+ * @param sp The #spart to remove.
+ */
+void cell_remove_spart(const struct engine *e, struct cell *c,
+                       struct spart *sp) {
+
+  /* Quick cross-check */
+  if (c->nodeID != e->nodeID)
+    error("Can't remove a particle in a foreign cell.");
+
+  /* Mark the particle as inhibited */
+  sp->time_bin = time_bin_inhibited;
+  if (sp->gpart) sp->gpart->time_bin = time_bin_inhibited;
+}
+
 /**
  * @brief Can we use the MM interactions fo a given pair of cells?
  *

src/cell.h

@@ -616,6 +616,10 @@ void cell_activate_sorts(struct cell *c, int sid, struct scheduler *s);
 void cell_clear_drift_flags(struct cell *c, void *data);
 void cell_set_super_mapper(void *map_data, int num_elements, void *extra_data);
 int cell_has_tasks(struct cell *c);
+void cell_remove_part(const struct engine *e, struct cell *c, struct part *p,
+                      struct xpart *xp);
+void cell_remove_gpart(const struct engine *e, struct cell *c, struct gpart *gp);
+void cell_remove_spart(const struct engine *e, struct cell *c, struct spart *sp);
 int cell_can_use_pair_mm(const struct cell *ci, const struct cell *cj,
                          const struct engine *e, const struct space *s);
 int cell_can_use_pair_mm_rebuild(const struct cell *ci, const struct cell *cj,