Improve group-based connection between raillike nodes

2 files changed, 15 insertions, 27 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index d73fb7721..e2589d226 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1053,8 +1053,8 @@ Another example: Make red wool from white wool and red dye:
   dropped as an item. If the node is wallmounted the wallmounted direction is
   checked.
 * `soil`: saplings will grow on nodes in this group
-* `connect_to_raillike`: makes nodes of raillike drawtype connect to
-  other group members with same drawtype
+* `connect_to_raillike`: makes nodes of raillike drawtype with same group value
+  connect to each other
 
 ### Known damage and digging time defining groups
 * `crumbly`: dirt, sand
diff --git a/src/content_mapblock.cpp b/src/content_mapblock.cpp
index 5bb787d01..3428f85f9 100644
--- a/src/content_mapblock.cpp
+++ b/src/content_mapblock.cpp
@@ -1421,77 +1421,65 @@ void mapblock_mesh_generate_special(MeshMakeData *data,
 
 			content_t thiscontent = n.getContent();
 			std::string groupname = "connect_to_raillike"; // name of the group that enables connecting to raillike nodes of different kind
-			bool self_connect_to_raillike = ((ItemGroupList) nodedef->get(n).groups)[groupname] != 0;
+			int self_group = ((ItemGroupList) nodedef->get(n).groups)[groupname];
 
 			if ((nodedef->get(n_minus_x).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_x).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_x).groups)[groupname] != self_group)
 					|| n_minus_x.getContent() == thiscontent)
 				is_rail_x[0] = true;
 
 			if ((nodedef->get(n_minus_x_minus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_x_minus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_x_minus_y).groups)[groupname] != self_group)
 					|| n_minus_x_minus_y.getContent() == thiscontent)
 				is_rail_x_minus_y[0] = true;
 
 			if ((nodedef->get(n_minus_x_plus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_x_plus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_x_plus_y).groups)[groupname] != self_group)
 					|| n_minus_x_plus_y.getContent() == thiscontent)
 				is_rail_x_plus_y[0] = true;
 
 			if ((nodedef->get(n_plus_x).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_x).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_x).groups)[groupname] != self_group)
 					|| n_plus_x.getContent() == thiscontent)
 				is_rail_x[1] = true;
 
 			if ((nodedef->get(n_plus_x_minus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_x_minus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_x_minus_y).groups)[groupname] != self_group)
 					|| n_plus_x_minus_y.getContent() == thiscontent)
 				is_rail_x_minus_y[1] = true;
 
 			if ((nodedef->get(n_plus_x_plus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_x_plus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_x_plus_y).groups)[groupname] != self_group)
 					|| n_plus_x_plus_y.getContent() == thiscontent)
 				is_rail_x_plus_y[1] = true;
 
 			if ((nodedef->get(n_minus_z).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_z).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_z).groups)[groupname] != self_group)
 					|| n_minus_z.getContent() == thiscontent)
 				is_rail_z[0] = true;
 
 			if ((nodedef->get(n_minus_z_minus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_z_minus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_z_minus_y).groups)[groupname] != self_group)
 					|| n_minus_z_minus_y.getContent() == thiscontent)
 				is_rail_z_minus_y[0] = true;
 
 			if ((nodedef->get(n_minus_z_plus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_minus_z_plus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_minus_z_plus_y).groups)[groupname] != self_group)
 					|| n_minus_z_plus_y.getContent() == thiscontent)
 				is_rail_z_plus_y[0] = true;
 
 			if ((nodedef->get(n_plus_z).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_z).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_z).groups)[groupname] != self_group)
 					|| n_plus_z.getContent() == thiscontent)
 				is_rail_z[1] = true;
 
 			if ((nodedef->get(n_plus_z_minus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_z_minus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_z_minus_y).groups)[groupname] != self_group)
 					|| n_plus_z_minus_y.getContent() == thiscontent)
 				is_rail_z_minus_y[1] = true;
 
 			if ((nodedef->get(n_plus_z_plus_y).drawtype == NDT_RAILLIKE
-					&& ((ItemGroupList) nodedef->get(n_plus_z_plus_y).groups)[groupname] != 0
-					&& self_connect_to_raillike)
+					&& ((ItemGroupList) nodedef->get(n_plus_z_plus_y).groups)[groupname] != self_group)
 					|| n_plus_z_plus_y.getContent() == thiscontent)
 				is_rail_z_plus_y[1] = true;