luanti-org · Mar 5, 2020
diff --git a/‎builtin/game/features.lua
+1 b/‎builtin/game/features.lua
+1
diff --git a/‎doc/lua_api.txt
+16-5 b/‎doc/lua_api.txt
+16-5
diff --git a/‎src/pathfinder.cpp
+336-245 b/‎src/pathfinder.cpp
+336-245
diff --git a/‎src/script/lua_api/l_env.cpp
+1-1 b/‎src/script/lua_api/l_env.cpp
+1-1
@@ -15,6 +15,7 @@ core.features = {
 	httpfetch_binary_data = true,
 	formspec_version_element = true,
 	area_store_persistent_ids = true,
+	pathfinder_works = true,
 }
 
 function core.has_feature(arg)
 
@@ -4045,6 +4045,8 @@ Utilities
           formspec_version_element = true,
           -- Whether AreaStore's IDs are kept on save/load (5.1.0)
           area_store_persistent_ids = true,
+          -- Whether minetest.find_path is functional (5.2.0)
+          pathfinder_works = true,
       }
 
 * `minetest.has_feature(arg)`: returns `boolean, missing_features`
@@ -4709,16 +4711,25 @@ Environment access
     * `objects`: if false, only nodes will be returned. Default is `true`.
     * `liquids`: if false, liquid nodes won't be returned. Default is `false`.
 * `minetest.find_path(pos1,pos2,searchdistance,max_jump,max_drop,algorithm)`
-    * returns table containing path
+    * returns table containing path that can be walked on
     * returns a table of 3D points representing a path from `pos1` to `pos2` or
-      `nil`.
+      `nil` on failure.
+    * Reasons for failure:
+        * No path exists at all
+        * No path exists within `searchdistance` (see below)
+        * Start or end pos is buried in land
     * `pos1`: start position
     * `pos2`: end position
-    * `searchdistance`: number of blocks to search in each direction using a
-      maximum metric.
+    * `searchdistance`: maximum distance from the search positions to search in.
+      In detail: Path must be completely inside a cuboid. The minimum
+      `searchdistance` of 1 will confine search between `pos1` and `pos2`.
+      Larger values will increase the size of this cuboid in all directions
     * `max_jump`: maximum height difference to consider walkable
     * `max_drop`: maximum height difference to consider droppable
-    * `algorithm`: One of `"A*_noprefetch"` (default), `"A*"`, `"Dijkstra"`
+    * `algorithm`: One of `"A*_noprefetch"` (default), `"A*"`, `"Dijkstra"`.
+      Difference between `"A*"` and `"A*_noprefetch"` is that
+      `"A*"` will pre-calculate the cost-data, the other will calculate it
+      on-the-fly
 * `minetest.spawn_tree (pos, {treedef})`
     * spawns L-system tree at given `pos` with definition in `treedef` table
 * `minetest.transforming_liquid_add(pos)`
 
@@ -1194,7 +1194,7 @@ int ModApiEnvMod::l_find_path(lua_State *L)
 	unsigned int max_jump       = luaL_checkint(L, 4);
 	unsigned int max_drop       = luaL_checkint(L, 5);
 	PathAlgorithm algo          = PA_PLAIN_NP;
-	if (!lua_isnil(L, 6)) {
+	if (!lua_isnoneornil(L, 6)) {
 		std::string algorithm = luaL_checkstring(L,6);
 
 		if (algorithm == "A*")
Original file line number	Diff line number	Diff line change
`@@ -15,6 +15,7 @@ core.features = {`
`15`	`15`	`httpfetch_binary_data = true,`
`16`	`16`	`formspec_version_element = true,`
`17`	`17`	`area_store_persistent_ids = true,`
	`18`	`+ pathfinder_works = true,`
`18`	`19`	`}`
`19`	`20`
`20`	`21`	`function core.has_feature(arg)`