Lua on each mapgen thread (#13092)

src/script/cpp_api/CMakeLists.txt

@@ -5,6 +5,7 @@ set(common_SCRIPT_CPP_API_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/s_env.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/s_inventory.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/s_item.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/s_mapgen.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/s_modchannels.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/s_node.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/s_nodemeta.cpp

src/script/cpp_api/s_base.h

@@ -61,13 +61,15 @@ enum class ScriptingType: u8 {
 	Async, // either mainmenu (client) or ingame (server)
 	Client,
 	MainMenu,
-	Server
+	Server,
+	Emerge
 };
 
 class Server;
 #ifndef SERVER
 class Client;
 #endif
+class EmergeThread;
 class IGameDef;
 class Environment;
 class GUIEngine;
@@ -158,6 +160,9 @@ protected:
 	void setGuiEngine(GUIEngine* guiengine) { m_guiengine = guiengine; }
 #endif
 
+	EmergeThread* getEmergeThread() { return m_emerge; }
+	void setEmergeThread(EmergeThread *emerge) { m_emerge = emerge; }
+
 	void objectrefGetOrCreate(lua_State *L, ServerActiveObject *cobj);
 
 	void pushPlayerHPChangeReason(lua_State *L, const PlayerHPChangeReason& reason);
@@ -180,5 +185,7 @@ private:
 #ifndef SERVER
 	GUIEngine      *m_guiengine = nullptr;
 #endif
+	EmergeThread   *m_emerge = nullptr;
+
 	ScriptingType  m_type;
 };

src/script/cpp_api/s_mapgen.cpp

@@ -0,0 +1,76 @@
+/*
+Minetest
+Copyright (C) 2022 sfan5 <sfan5@live.de>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "cpp_api/s_mapgen.h"
+#include "cpp_api/s_internal.h"
+#include "common/c_converter.h"
+#include "lua_api/l_vmanip.h"
+#include "emerge.h"
+
+void ScriptApiMapgen::on_mods_loaded()
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get registered shutdown hooks
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_mods_loaded");
+	// Call callbacks
+	runCallbacks(0, RUN_CALLBACKS_MODE_FIRST);
+}
+
+void ScriptApiMapgen::on_shutdown()
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	// Get registered shutdown hooks
+	lua_getglobal(L, "core");
+	lua_getfield(L, -1, "registered_on_shutdown");
+	// Call callbacks
+	runCallbacks(0, RUN_CALLBACKS_MODE_FIRST);
+}
+
+void ScriptApiMapgen::on_generated(BlockMakeData *bmdata)
+{
+	SCRIPTAPI_PRECHECKHEADER
+
+	v3s16 minp = bmdata->blockpos_min * MAP_BLOCKSIZE;
+	v3s16 maxp = bmdata->blockpos_max * MAP_BLOCKSIZE +
+				 v3s16(1,1,1) * (MAP_BLOCKSIZE - 1);
+
+	LuaVoxelManip::create(L, bmdata->vmanip, true);
+	const int vmanip = lua_gettop(L);
+
+	// Store vmanip globally (used by helpers)
+	lua_getglobal(L, "core");
+	lua_pushvalue(L, vmanip);
+	lua_setfield(L, -2, "vmanip");
+
+	// Call callbacks
+	lua_getfield(L, -1, "registered_on_generateds");
+	lua_pushvalue(L, vmanip);
+	push_v3s16(L, minp);
+	push_v3s16(L, maxp);
+	lua_pushnumber(L, bmdata->seed);
+	runCallbacks(4, RUN_CALLBACKS_MODE_FIRST);
+	lua_pop(L, 1); // return val
+
+	// Unset core.vmanip again
+	lua_pushnil(L);
+	lua_setfield(L, -2, "vmanip");
+}

src/script/cpp_api/s_mapgen.h

@@ -0,0 +1,40 @@
+/*
+Minetest
+Copyright (C) 2022 sfan5 <sfan5@live.de>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#pragma once
+
+#include "cpp_api/s_base.h"
+
+struct BlockMakeData;
+
+/*
+ * Note that this is the class defining the functions called inside the emerge
+ * Lua state, not the server one.
+ */
+
+class ScriptApiMapgen : virtual public ScriptApiBase
+{
+public:
+
+	void on_mods_loaded();
+	void on_shutdown();
+
+	// Called after generating a piece of map before writing it to the map
+	void on_generated(BlockMakeData *bmdata);
+};