new command "BoundingBox GeoEntity { tag }" to retrieve the bbox of an entity

Parser/Gmsh.tab.hpp

@@ -496,7 +496,7 @@
 
 #if ! defined YYSTYPE && ! defined YYSTYPE_IS_DECLARED
 typedef union YYSTYPE
-#line 164 "Gmsh.y"
+#line 165 "Gmsh.y"
 {
   char *c;
   int i;

Parser/Gmsh.y

@@ -129,6 +129,7 @@ void getAllPhysicalTags(int dim, List_T *in);
 void getElementaryTagsForPhysicalGroups(int dim, List_T *in, List_T *out);
 void getElementaryTagsInBoundingBox(int dim, double x1, double y1, double z1,
                                     double x2, double y2, double z2, List_T *out);
+void getBoundingBox(int dim, int tag, List_T *out);
 void setVisibility(int dim, int visible, bool recursive);
 void setVisibility(const std::vector<std::pair<int, int> > &dimTags, int visible,
                    bool recursive);
@@ -5361,6 +5362,11 @@ FExpr_Multi :
       $$ = List_Create(10, 10, sizeof(double));
       getElementaryTagsInBoundingBox($1, $5, $7, $9, $11, $13, $15, $$);
     }
+   | tBoundingBox GeoEntity '{' FExpr '}'
+    {
+      $$ = List_Create(10, 10, sizeof(double));
+      getBoundingBox($2, (int)$4, $$);
+    }
   | Transform
     {
       $$ = List_Create(List_Nbr($1), 1, sizeof(double));
@@ -6651,6 +6657,25 @@ void getElementaryTagsInBoundingBox(int dim, double x1, double y1, double z1,
   }
 }
 
+void getBoundingBox(int dim, int tag, List_T *out)
+{
+  if(GModel::current()->getOCCInternals() &&
+     GModel::current()->getOCCInternals()->getChanged())
+    GModel::current()->getOCCInternals()->synchronize(GModel::current());
+  if(GModel::current()->getGEOInternals()->getChanged())
+    GModel::current()->getGEOInternals()->synchronize(GModel::current());
+
+  GEntity *ge = GModel::current()->getEntityByTag(dim, tag);
+  SBoundingBox3d box;
+  if(ge) box = ge->bounds();
+  if(!box.empty()){
+    double b[6] = {box.min().x(), box.min().y(), box.min().z(),
+                   box.max().x(), box.max().y(), box.max().z()};
+    for(int i = 0; i < 6; i++)
+      List_Add(out, &b[i]);
+  }
+}
+
 void setVisibility(int dim, int visible, bool recursive)
 {
   if(GModel::current()->getOCCInternals() &&