Scripting WIP

src/scriptapi.cpp

@@ -0,0 +1,422 @@
+/*
+Minetest-c55
+Copyright (C) 2011 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 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 General Public License for more details.
+
+You should have received a copy of the GNU 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 "scriptapi.h"
+
+#include <iostream>
+extern "C" {
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+}
+
+#include "log.h"
+#include "server.h"
+#include "porting.h"
+#include "filesys.h"
+#include "serverobject.h"
+#include "script.h"
+//#include "luna.h"
+
+static void stackDump(lua_State *L, std::ostream &o)
+{
+  int i;
+  int top = lua_gettop(L);
+  for (i = 1; i <= top; i++) {  /* repeat for each level */
+	int t = lua_type(L, i);
+	switch (t) {
+
+	  case LUA_TSTRING:  /* strings */
+	  	o<<"\""<<lua_tostring(L, i)<<"\"";
+		break;
+
+	  case LUA_TBOOLEAN:  /* booleans */
+		o<<(lua_toboolean(L, i) ? "true" : "false");
+		break;
+
+	  case LUA_TNUMBER:  /* numbers */ {
+	  	char buf[10];
+		snprintf(buf, 10, "%g", lua_tonumber(L, i));
+		o<<buf;
+		break; }
+
+	  default:  /* other values */
+		o<<lua_typename(L, t);
+		break;
+
+	}
+	o<<" ";
+  }
+  o<<std::endl;
+}
+
+static void realitycheck(lua_State *L)
+{
+	int top = lua_gettop(L);
+	if(top >= 30){
+		dstream<<"Stack is over 30:"<<std::endl;
+		stackDump(L, dstream);
+		script_error(L, "Stack is over 30 (reality check)");
+	}
+}
+
+// Register new object prototype (must be based on entity)
+static int l_register_object(lua_State *L)
+{
+	const char *name = luaL_checkstring(L, 1);
+	luaL_checkany(L, 2);
+	infostream<<"register_object: "<<name<<std::endl;
+	// Get the minetest table
+	lua_getglobal(L, "minetest");
+	// Get field "registered_objects"
+	lua_getfield(L, -1, "registered_objects");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	// Object is in param 2
+	lua_pushvalue(L, 2); // Copy object to top of stack
+	lua_setfield(L, objectstable, name); // registered_objects[name] = object
+
+	return 0; /* number of results */
+}
+
+static int l_new_entity(lua_State *L)
+{
+	/* o = o or {}
+	   setmetatable(o, self)
+	   self.__index = self
+	   return o */
+	if(lua_isnil(L, -1))
+		lua_newtable(L);
+	luaL_checktype(L, -1, LUA_TTABLE);
+	luaL_getmetatable(L, "minetest.entity");
+	lua_pushvalue(L, -1); // duplicate metatable
+	lua_setfield(L, -2, "__index");
+	lua_setmetatable(L, -2);
+	// return table
+	return 1;
+}
+
+static const struct luaL_Reg minetest_f [] = {
+	{"register_object", l_register_object},
+	{"new_entity", l_new_entity},
+	{NULL, NULL}
+};
+
+static int l_entity_set_deleted(lua_State *L)
+{
+	return 0;
+}
+
+static const struct luaL_Reg minetest_entity_m [] = {
+	{"set_deleted", l_entity_set_deleted},
+	{NULL, NULL}
+};
+
+class ObjectRef
+{
+private:
+	ServerActiveObject *m_object;
+
+	static const char className[];
+	static const luaL_reg methods[];
+
+	static ObjectRef *checkobject(lua_State *L, int narg)
+	{
+		luaL_checktype(L, narg, LUA_TUSERDATA);
+		void *ud = luaL_checkudata(L, narg, className);
+		if(!ud) luaL_typerror(L, narg, className);
+		return *(ObjectRef**)ud;  // unbox pointer
+	}
+	
+	// Exported functions
+
+	static int l_remove(lua_State *L)
+	{
+		ObjectRef *o = checkobject(L, 1);
+		ServerActiveObject *co = o->m_object;
+		if(co == NULL) return 0;
+		infostream<<"ObjectRef::l_remove(): id="<<co->getId()<<std::endl;
+		co->m_removed = true;
+		return 0;
+	}
+
+	static int gc_object(lua_State *L) {
+		//ObjectRef *o = checkobject(L, 1);
+		ObjectRef *o = *(ObjectRef **)(lua_touserdata(L, 1));
+		//infostream<<"ObjectRef::gc_object: o="<<o<<std::endl;
+		delete o;
+		return 0;
+	}
+
+public:
+	ObjectRef(ServerActiveObject *object):
+		m_object(object)
+	{
+		infostream<<"ObjectRef created for id="<<m_object->getId()<<std::endl;
+	}
+
+	~ObjectRef()
+	{
+		if(m_object)
+			infostream<<"ObjectRef destructing for id="<<m_object->getId()<<std::endl;
+		else
+			infostream<<"ObjectRef destructing for id=unknown"<<std::endl;
+	}
+
+	// Creates an ObjectRef and leaves it on top of stack
+	// Not callable from Lua; all references are created on the C side.
+	static void create(lua_State *L, ServerActiveObject *object)
+	{
+		ObjectRef *o = new ObjectRef(object);
+		//infostream<<"ObjectRef::create: o="<<o<<std::endl;
+		*(void **)(lua_newuserdata(L, sizeof(void *))) = o;
+		luaL_getmetatable(L, className);
+		lua_setmetatable(L, -2);
+	}
+
+	static void set_null(lua_State *L)
+	{
+		ObjectRef *o = checkobject(L, -1);
+		ServerActiveObject *co = o->m_object;
+		if(co == NULL)
+			return;
+		o->m_object = NULL;
+	}
+	
+	static void Register(lua_State *L)
+	{
+		lua_newtable(L);
+		int methodtable = lua_gettop(L);
+		luaL_newmetatable(L, className);
+		int metatable = lua_gettop(L);
+
+		lua_pushliteral(L, "__metatable");
+		lua_pushvalue(L, methodtable);
+		lua_settable(L, metatable);  // hide metatable from Lua getmetatable()
+
+		lua_pushliteral(L, "__index");
+		lua_pushvalue(L, methodtable);
+		lua_settable(L, metatable);
+
+		lua_pushliteral(L, "__gc");
+		lua_pushcfunction(L, gc_object);
+		lua_settable(L, metatable);
+
+		lua_pop(L, 1);  // drop metatable
+
+		luaL_openlib(L, 0, methods, 0);  // fill methodtable
+		lua_pop(L, 1);  // drop methodtable
+
+		// Cannot be created from Lua
+		//lua_register(L, className, create_object);
+	}
+};
+
+const char ObjectRef::className[] = "ObjectRef";
+
+#define method(class, name) {#name, class::l_##name}
+
+const luaL_reg ObjectRef::methods[] = {
+	method(ObjectRef, remove),
+	{0,0}
+};
+
+void scriptapi_export(lua_State *L, Server *server)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_export"<<std::endl;
+	
+	// Register global functions in table minetest
+	lua_newtable(L);
+	luaL_register(L, NULL, minetest_f);
+	lua_setglobal(L, "minetest");
+	
+	// Get the main minetest table
+	lua_getglobal(L, "minetest");
+
+	// Add registered_objects table in minetest
+	lua_newtable(L);
+	lua_setfield(L, -2, "registered_objects");
+
+	// Add object_refs table in minetest
+	lua_newtable(L);
+	lua_setfield(L, -2, "object_refs");
+
+	// Add luaentities table in minetest
+	lua_newtable(L);
+	lua_setfield(L, -2, "luaentities");
+
+	// Load and run some base Lua stuff
+	/*script_load(L, (porting::path_data + DIR_DELIM + "scripts"
+			+ DIR_DELIM + "base.lua").c_str());*/
+	
+	// Create entity reference metatable
+	luaL_newmetatable(L, "minetest.entity_reference");
+	lua_pop(L, 1);
+	
+	// Create entity prototype
+	luaL_newmetatable(L, "minetest.entity");
+	// metatable.__index = metatable
+	lua_pushvalue(L, -1); // Duplicate metatable
+	lua_setfield(L, -2, "__index");
+	// Put functions in metatable
+	luaL_register(L, NULL, minetest_entity_m);
+	// Put other stuff in metatable
+
+	// Entity C reference
+	ObjectRef::Register(L);
+}
+
+void scriptapi_luaentity_register(lua_State *L, u16 id, const char *name,
+		const char *init_state)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_luaentity_register: id="<<id<<std::endl;
+	
+	// Create object as a dummy string (TODO: Create properly)
+	lua_pushstring(L, "dummy object string");
+	int object = lua_gettop(L);
+
+	// Get minetest.luaentities table
+	lua_getglobal(L, "minetest");
+	lua_getfield(L, -1, "luaentities");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	
+	// luaentities[id] = object
+	lua_pushnumber(L, id); // Push id
+	lua_pushvalue(L, object); // Copy object to top of stack
+	lua_settable(L, objectstable);
+	
+	lua_pop(L, 3); // pop luaentities, minetest and the object
+}
+
+void scriptapi_luaentity_deregister(lua_State *L, u16 id)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_luaentity_deregister: id="<<id<<std::endl;
+
+	// Get minetest.luaentities table
+	lua_getglobal(L, "minetest");
+	lua_getfield(L, -1, "luaentities");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	
+	/*// Get luaentities[id]
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_gettable(L, objectstable);
+	// Object is at stack top
+	lua_pop(L, 1); // pop object*/
+
+	// Set luaentities[id] = nil
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_pushnil(L);
+	lua_settable(L, objectstable);
+	
+	lua_pop(L, 2); // pop luaentities, minetest
+}
+
+void scriptapi_luaentity_step(lua_State *L, u16 id,
+		float dtime, bool send_recommended)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_luaentity_step: id="<<id<<std::endl;
+
+	// Get minetest.luaentities table
+	lua_getglobal(L, "minetest");
+	lua_getfield(L, -1, "luaentities");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	
+	// Get luaentities[id]
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_gettable(L, objectstable);
+
+	// TODO: Call step function
+
+	lua_pop(L, 1); // pop object
+	lua_pop(L, 2); // pop luaentities, minetest
+}
+
+std::string scriptapi_luaentity_get_state(lua_State *L, u16 id)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_luaentity_get_state: id="<<id<<std::endl;
+	
+	return "";
+}
+
+void scriptapi_add_object_reference(lua_State *L, ServerActiveObject *cobj)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_add_object_reference: id="<<cobj->getId()<<std::endl;
+
+	// Create object on stack
+	ObjectRef::create(L, cobj); // Puts ObjectRef (as userdata) on stack
+	int object = lua_gettop(L);
+
+	// Get minetest.object_refs table
+	lua_getglobal(L, "minetest");
+	lua_getfield(L, -1, "object_refs");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	
+	// object_refs[id] = object
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_pushvalue(L, object); // Copy object to top of stack
+	lua_settable(L, objectstable);
+	
+	// pop object_refs, minetest and the object
+	lua_pop(L, 3);
+}
+
+void scriptapi_rm_object_reference(lua_State *L, ServerActiveObject *cobj)
+{
+	realitycheck(L);
+	assert(lua_checkstack(L, 20));
+	infostream<<"scriptapi_rm_object_reference: id="<<cobj->getId()<<std::endl;
+
+	// Get minetest.object_refs table
+	lua_getglobal(L, "minetest");
+	lua_getfield(L, -1, "object_refs");
+	luaL_checktype(L, -1, LUA_TTABLE);
+	int objectstable = lua_gettop(L);
+	
+	// Get object_refs[id]
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_gettable(L, objectstable);
+	// Set object reference to NULL
+	ObjectRef::set_null(L);
+	lua_pop(L, 1); // pop object
+
+	// Set object_refs[id] = nil
+	lua_pushnumber(L, cobj->getId()); // Push id
+	lua_pushnil(L);
+	lua_settable(L, objectstable);
+	
+	// pop object_refs, minetest
+	lua_pop(L, 2);
+}
+