Add PseudoRandom in Lua API

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 3a5927e9cc0525c4b7c7d679de10872f7c5d659c..f66743a7deb158f3caae6a17fa26c359a321f58e 100644 (file)
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -599,6 +599,7 @@ methods:
     returns the items that were actually removed (as an ItemStack)
 
 ItemStack: A stack of items.
+- Can be created via ItemStack(itemstack or itemstring or table or nil)
 methods:
 - is_empty(): return true if stack is empty
 - get_name(): returns item name (e.g. "default:stone")
@@ -627,6 +628,11 @@ methods:
   ^ returns copied ItemStack
   ^ if n is omitted, n=1 is used
 
+PseudoRandom: A pseudorandom number generator
+- Can be created via PseudoRandom(seed)
+methods:
+- next(): return next random number [0...32767]
+
 Registered entities
 --------------------
 - Functions receive a "luaentity" as self:

diff --git a/games/minimal/mods/test/init.lua b/games/minimal/mods/test/init.lua
new file mode 100644 (file)
index 0000000..051b479
--- /dev/null
+++ b/games/minimal/mods/test/init.lua
@@ -0,0 +1,11 @@
+--
+-- Minimal Development Test
+-- Mod: test
+--
+
+-- Try out PseudoRandom
+pseudo = PseudoRandom(13)
+assert(pseudo:next() == 22290)
+assert(pseudo:next() == 13854)
+
+

diff --git a/src/scriptapi.cpp b/src/scriptapi.cpp
index 3c7b9bb3eed1c4c88938051a763a0c77a29bd87a..23c18473f3cd3b12cefa7f1b87f08f11cfe08dbc 100644 (file)
--- a/src/scriptapi.cpp
+++ b/src/scriptapi.cpp
@@ -47,6 +47,7 @@ extern "C" {
 #include "utility.h"
 #include "tool.h"
 #include "daynightratio.h"
+#include "noise.h" // PseudoRandom for LuaPseudoRandom
 
 static void stackDump(lua_State *L, std::ostream &o)
 {
@@ -3134,6 +3135,114 @@ const luaL_reg EnvRef::methods[] = {
        {0,0}
 };
 
+/*
+       LuaPseudoRandom
+*/
+
+class LuaPseudoRandom
+{
+private:
+       PseudoRandom m_pseudo;
+
+       static const char className[];
+       static const luaL_reg methods[];
+
+       // Exported functions
+       
+       // garbage collector
+       static int gc_object(lua_State *L)
+       {
+               LuaPseudoRandom *o = *(LuaPseudoRandom **)(lua_touserdata(L, 1));
+               delete o;
+               return 0;
+       }
+
+       // next(self) -> get next value
+       static int l_next(lua_State *L)
+       {
+               LuaPseudoRandom *o = checkobject(L, 1);
+               PseudoRandom &pseudo = o->m_pseudo;
+               lua_pushinteger(L, pseudo.next());
+               return 1;
+       }
+
+public:
+       LuaPseudoRandom(int seed):
+               m_pseudo(seed)
+       {
+       }
+
+       ~LuaPseudoRandom()
+       {
+       }
+
+       const PseudoRandom& getItem() const
+       {
+               return m_pseudo;
+       }
+       PseudoRandom& getItem()
+       {
+               return m_pseudo;
+       }
+       
+       // LuaPseudoRandom(seed)
+       // Creates an LuaPseudoRandom and leaves it on top of stack
+       static int create_object(lua_State *L)
+       {
+               int seed = luaL_checknumber(L, 1);
+               LuaPseudoRandom *o = new LuaPseudoRandom(seed);
+               *(void **)(lua_newuserdata(L, sizeof(void *))) = o;
+               luaL_getmetatable(L, className);
+               lua_setmetatable(L, -2);
+               return 1;
+       }
+
+       static LuaPseudoRandom* 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 *(LuaPseudoRandom**)ud;  // unbox pointer
+       }
+
+       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
+
+               // Can be created from Lua (LuaPseudoRandom(seed))
+               lua_register(L, className, create_object);
+       }
+};
+const char LuaPseudoRandom::className[] = "PseudoRandom";
+const luaL_reg LuaPseudoRandom::methods[] = {
+       method(LuaPseudoRandom, next),
+       {0,0}
+};
+
+/*
+       LuaABM
+*/
+
 class LuaABM : public ActiveBlockModifier
 {
 private:
@@ -3789,6 +3898,7 @@ void scriptapi_export(lua_State *L, Server *server)
        NodeMetaRef::Register(L);
        ObjectRef::Register(L);
        EnvRef::Register(L);
+       LuaPseudoRandom::Register(L);
 }
 
 bool scriptapi_loadmod(lua_State *L, const std::string &scriptpath,