Function RenderScript_Predicate

engine/render/src/render/render_script.cpp:2683–2710

creates a new render predicate * * This function returns a new render predicate for objects with materials matching * the provided material tags. The provided tags are combined into a bit mask * for the predicate. If multiple tags are provided, the predicate matches materials * with all tags ANDed together. * * The current limit to the number of tags that can be

     * ```
     */
    static int RenderScript_Predicate(lua_State* L)
    {
        int top = lua_gettop(L);
        (void) top;

        RenderScriptInstance* i = RenderScriptInstance_Check(L);
        (void)i;
        luaL_checktype(L, 1, LUA_TTABLE);

        HPredicate* p_predicate = (HPredicate*) lua_newuserdata(L, sizeof(HPredicate*));
        *p_predicate = NewPredicate();

        luaL_getmetatable(L, RENDER_SCRIPT_PREDICATE);
        lua_setmetatable(L, -2);

        lua_pushnil(L);  /* first key */
        while (lua_next(L, 1) != 0)
        {
            dmhash_t tag = dmScript::CheckHashOrString(L, -1);
            if (RESULT_OK != AddPredicateTag(*p_predicate, tag))
            {
                dmLogWarning("Unable to add predicate tag. Max number of tags (%i) reached?", dmRender::Predicate::MAX_TAG_COUNT);
            }
            lua_pop(L, 1);
        }
        assert(top + 1 == lua_gettop(L));
        return 1;
    }

    /*# enables a material
     * If another material was already enabled, it will be automatically disabled