From 95d6f05a764ef646e733818301f0fd8c0d1e08bb Mon Sep 17 00:00:00 2001
From: Axel Kohlmeyer <akohlmey@gmail.com>
Date: Mon, 5 Jun 2017 12:41:37 -0400
Subject: [PATCH] add 3 APIs to Modify for checking if atoms overlap with any
 rigid fixes

---
 src/modify.cpp | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/modify.h   |  3 ++
 2 files changed, 95 insertions(+)

diff --git a/src/modify.cpp b/src/modify.cpp
index 7af4576038..4422ee6890 100644
--- a/src/modify.cpp
+++ b/src/modify.cpp
@@ -23,6 +23,7 @@
 #include "group.h"
 #include "update.h"
 #include "domain.h"
+#include "region.h"
 #include "input.h"
 #include "variable.h"
 #include "memory.h"
@@ -995,6 +996,97 @@ int Modify::check_package(const char *package_fix_name)
   return 1;
 }
 
+
+/* ----------------------------------------------------------------------
+   check if the group indicated by groupbit overlaps with any
+   currently existing rigid fixes. return 1 in this case otherwise 0
+------------------------------------------------------------------------- */
+
+int Modify::check_rigid_group_overlap(int groupbit)
+{
+  const int * const mask = atom->mask;
+  const int nlocal = atom->nlocal;
+
+  int n = 0;
+  for (int ifix = 0; ifix < nfix; ifix++) {
+    if (strncmp("rigid",fix[ifix]->style,5) == 0) {
+      const int bothbits = groupbit | fix[ifix]->groupbit;
+      for (int i=0; i < nlocal; ++i)
+        if (mask[i] & bothbits) {++n; break;}
+      if (n > 0) break;
+    }
+  }
+
+  int n_all = 0;
+  MPI_Allreduce(&n,&n_all,1,MPI_INT,MPI_SUM,world);
+
+  if (n_all > 0) return 1;
+  return 0;
+}
+
+/* ----------------------------------------------------------------------
+   check if the atoms in the region indicated by regionid overlap with any
+   currently existing rigid fixes. return 1 in this case otherwise 0
+------------------------------------------------------------------------- */
+
+int Modify::check_rigid_region_overlap(Region *reg)
+{
+  const int * const mask = atom->mask;
+  const double * const * const x = atom->x;
+  const int nlocal = atom->nlocal;
+
+  int n = 0;
+  reg->prematch();
+  for (int ifix = 0; ifix < nfix; ifix++) {
+    if (strncmp("rigid",fix[ifix]->style,5) == 0) {
+      const int groupbit = fix[ifix]->groupbit;
+      for (int i=0; i < nlocal; ++i)
+        if ((mask[i] & groupbit) && reg->match(x[i][0],x[i][1],x[i][2])) {
+          ++n;
+          break;
+        }
+      if (n > 0) break;
+    }
+  }
+
+  int n_all = 0;
+  MPI_Allreduce(&n,&n_all,1,MPI_INT,MPI_SUM,world);
+
+  if (n_all > 0) return 1;
+  return 0;
+}
+
+/* ----------------------------------------------------------------------
+   check if the atoms in the selection list (length atom->nlocal,
+   content: 1 if atom is contained, 0 if not) overlap with currently
+   existing rigid fixes. return 1 in this case otherwise 0
+------------------------------------------------------------------------- */
+
+int Modify::check_rigid_list_overlap(int *select)
+{
+  const int * const mask = atom->mask;
+  const int nlocal = atom->nlocal;
+
+  int n = 0;
+  for (int ifix = 0; ifix < nfix; ifix++) {
+    if (strncmp("rigid",fix[ifix]->style,5) == 0) {
+      const int groupbit = fix[ifix]->groupbit;
+      for (int i=0; i < nlocal; ++i)
+        if ((mask[i] & groupbit) && select[i]) {
+          ++n;
+          break;
+        }
+      if (n > 0) break;
+    }
+  }
+
+  int n_all = 0;
+  MPI_Allreduce(&n,&n_all,1,MPI_INT,MPI_SUM,world);
+
+  if (n_all > 0) return 1;
+  return 0;
+}
+
 /* ----------------------------------------------------------------------
    add a new compute
 ------------------------------------------------------------------------- */
diff --git a/src/modify.h b/src/modify.h
index 3ded3cbab6..2ad244f8fb 100644
--- a/src/modify.h
+++ b/src/modify.h
@@ -98,6 +98,9 @@ class Modify : protected Pointers {
   int find_fix(const char *);
   int find_fix_by_style(const char *);
   int check_package(const char *);
+  int check_rigid_group_overlap(int);
+  int check_rigid_region_overlap(class Region *);
+  int check_rigid_list_overlap(int *);
 
   void add_compute(int, char **, int trysuffix=1);
   void modify_compute(int, char **);