3 files changed, 49 insertions, 0 deletions
diff --git a/src/script/common/c_converter.h b/src/script/common/c_converter.h
index 2af726d16..f1e4e47ec 100644
--- a/src/script/common/c_converter.h
+++ b/src/script/common/c_converter.h
@@ -121,3 +121,12 @@ void                warn_if_field_exists(lua_State *L, int table,
 
 size_t write_array_slice_float(lua_State *L, int table_index, float *data,
 	v3u16 data_size, v3u16 slice_offset, v3u16 slice_size);
+
+// This must match the implementation in builtin/game/misc_s.lua
+// Note that this returns a floating point result as Lua integers are 32-bit
+inline lua_Number hash_node_position(v3s16 pos)
+{
+	return (((s64)pos.Z + 0x8000L) << 32)
+			| (((s64)pos.Y + 0x8000L) << 16)
+			| ((s64)pos.X + 0x8000L);
+}
diff --git a/src/script/cpp_api/s_env.cpp b/src/script/cpp_api/s_env.cpp
index e49113405..3cbb13cd2 100644
--- a/src/script/cpp_api/s_env.cpp
+++ b/src/script/cpp_api/s_env.cpp
@@ -299,3 +299,36 @@ void ScriptApiEnv::on_liquid_transformed(
 
 	runCallbacks(2, RUN_CALLBACKS_MODE_FIRST);
 }
+
+void ScriptApiEnv::on_mapblocks_changed(const std::unordered_set<v3s16> &set)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get core.registered_on_mapblocks_changed
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_mapblocks_changed");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	lua_remove(L, -2);
+
+	// Convert the set to a set of position hashes
+	lua_createtable(L, 0, set.size());
+	for(const v3s16 &p : set) {
+		lua_pushnumber(L, hash_node_position(p));
+		lua_pushboolean(L, true);
+		lua_rawset(L, -3);
+	}
+	lua_pushinteger(L, set.size());
+
+	runCallbacks(2, RUN_CALLBACKS_MODE_FIRST);
+}
+
+bool ScriptApiEnv::has_on_mapblocks_changed()
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get core.registered_on_mapblocks_changed
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_mapblocks_changed");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	return lua_objlen(L, -1) > 0;
+}
diff --git a/src/script/cpp_api/s_env.h b/src/script/cpp_api/s_env.h
index 9a50a01cc..bc4c4cd4d 100644
--- a/src/script/cpp_api/s_env.h
+++ b/src/script/cpp_api/s_env.h
@@ -22,6 +22,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "cpp_api/s_base.h"
 #include "irr_v3d.h"
 #include "mapnode.h"
+#include <unordered_set>
 #include <vector>
 
 class ServerEnvironment;
@@ -48,5 +49,11 @@ public:
 	// Called after liquid transform changes
 	void on_liquid_transformed(const std::vector<std::pair<v3s16, MapNode>> &list);
 
+	// Called after mapblock changes
+	void on_mapblocks_changed(const std::unordered_set<v3s16> &set);
+
+	// Determines whether there are any on_mapblocks_changed callbacks
+	bool has_on_mapblocks_changed();
+
 	void initializeEnvironment(ServerEnvironment *env);
 };