entitymanager.cpp

#include "entitymanager.h"

#include <iostream>
#include <vector>
#include <string>
#include "raylib.h"
#include "raymath.h"
#ifdef _WIN32
    #include <lua.hpp>
#else
    #include <luajit-2.1/lua.hpp>
#endif

#include "entitydefinition.h"

extern std::vector<Entity> entities_scene;
extern int next_entity_id;
extern lua_State* L;
extern Camera camera;

void entity_add_lua_table_int(lua_State* Ls, int push, std::string lua_var){
    lua_pushinteger(Ls,push);
    lua_setfield(Ls,-2,lua_var.c_str());
}
void entity_add_lua_table_float(lua_State* Ls, float push, std::string lua_var){
    lua_pushnumber(Ls,push);
    lua_setfield(Ls,-2,lua_var.c_str());
}
void entity_add_lua_table_bool(lua_State* Ls, bool push, std::string lua_var){
    lua_pushboolean(Ls,push);
    lua_setfield(Ls,-2,lua_var.c_str());
}
void entity_add_lua_table_string(lua_State* Ls, std::string push, std::string lua_var){
    lua_pushstring(Ls,push.c_str());
    lua_setfield(Ls,-2,lua_var.c_str());
}

void entity_get_lua_table_int(lua_State* Ls, int& ret, std::string lua_var){
    lua_getfield(Ls,-1,lua_var.c_str());
    ret = lua_tointeger(Ls,-1);
    lua_pop(Ls,1);
}
void entity_get_lua_table_float(lua_State* Ls, float& ret, std::string lua_var){
    lua_getfield(Ls,-1,lua_var.c_str());
    ret = lua_tonumber(Ls,-1);
    lua_pop(Ls,1);
}
void entity_get_lua_table_bool(lua_State* Ls, bool& ret, std::string lua_var){
    lua_getfield(Ls,-1,lua_var.c_str());
    ret = lua_toboolean(Ls,-1);
    lua_pop(Ls,1);
}
void entity_get_lua_table_string(lua_State* Ls, std::string& ret, std::string lua_var){
    lua_getfield(Ls,-1,lua_var.c_str());
    ret = std::string(lua_tostring(Ls,-1));
    lua_pop(Ls,1);
}

void entity_set_table(lua_State* Ls, Entity e){
    entity_add_lua_table_float(Ls,e.position.x,"x");
    entity_add_lua_table_float(Ls,e.position.y,"y");
    entity_add_lua_table_float(Ls,e.position.z,"z");
    entity_add_lua_table_float(Ls,e.culling_radius,"culling_radius");
    entity_add_lua_table_bool(Ls,e.persistent,"is_persistent");
}
void entity_get_table(lua_State* Ls, Entity& e){
    entity_get_lua_table_float(Ls,e.position.x,"x");
    entity_get_lua_table_float(Ls,e.position.y,"y");
    entity_get_lua_table_float(Ls,e.position.z,"z");
    entity_get_lua_table_float(Ls,e.culling_radius,"culling_radius");
    entity_get_lua_table_bool(Ls,e.persistent,"is_persistent");
}
int CreateEntity(std::string entity_lua, Vector3 position){
    Entity new_entity;
    next_entity_id ++;

    new_entity.id = next_entity_id;
    new_entity.position = position;
    new_entity.script = entity_lua;

    lua_newtable(L);

    entity_set_table(L,new_entity);

    lua_newtable(L);
    lua_getglobal(L,"_G");
    lua_setfield(L,-2,"__index");
    lua_setmetatable(L,-2);
    lua_setfield(L, LUA_REGISTRYINDEX, std::to_string(next_entity_id).c_str());

    luaL_loadfile(L,entity_lua.c_str());
    lua_getfield(L,LUA_REGISTRYINDEX, std::to_string(next_entity_id).c_str());
    lua_setfenv(L,-2);

    int result = lua_pcall(L,0,0,0);

    if(result != LUA_OK){
        printf("[ART] Error loading %s: %s\n",entity_lua.c_str(), lua_tostring(L,-1));
        lua_pop(L,1);
        return -1;
    }

    lua_getfield(L,LUA_REGISTRYINDEX, std::to_string(new_entity.id).c_str());
    lua_getfield(L,-1,"init");
    if(lua_isfunction(L,-1)){
        lua_pushvalue(L,-2);
        lua_pcall(L,1,0,0);
        entity_get_table(L,new_entity);
    }else{
        lua_pop(L,1);
    }
    lua_pop(L,1);

    entities_scene.push_back(new_entity);
    return next_entity_id;
}

bool DeleteEntity(int id){
    for(auto it = entities_scene.begin(); it != entities_scene.end();it++){
        if(it->id == id){
            lua_pushnil(L);
            lua_setfield(L,LUA_REGISTRYINDEX, std::to_string(id).c_str());

            entities_scene.erase(it);
            return true;
        }
    }
    return false;
}

void UpdateEntities(float dt){
    for(auto& e : entities_scene){
        lua_getfield(L,LUA_REGISTRYINDEX, std::to_string(e.id).c_str());

        entity_set_table(L,e);

        lua_getfield(L,-1,"update");
        if(lua_isfunction(L,-1)){
            lua_pushvalue(L,-2);
            lua_pushnumber(L,dt);
            int result = lua_pcall(L,2,0,0);

            if(result != LUA_OK){
                printf("[ART] Error on update %d: %s\n",e.id,lua_tostring(L,-1));
                lua_pop(L,1);
            }
        }else{
            lua_pop(L,1);
        }

        entity_get_table(L,e);

        lua_pop(L,1);
    }
}

void DrawEntities(){
    for(auto& e : entities_scene){
        float dist = Vector3Distance(camera.position,e.position);
        if(dist > e.culling_radius && e.culling_radius > 0.0) continue;

        lua_getfield(L,LUA_REGISTRYINDEX, std::to_string(e.id).c_str());

        lua_getfield(L,-1,"draw");
        if(lua_isfunction(L,-1)){
            lua_pushvalue(L,-2);
            int result = lua_pcall(L,1,0,0);
            if(result != LUA_OK){
                printf("[ART] Error on draw %d: %s\n",e.id,lua_tostring(L,-1));
                lua_pop(L,1);
            }
        }else{
            lua_pop(L,1);
        }
        lua_pop(L,1);
    }
}

void DrawScreenEntities(){
    for(auto& e : entities_scene){
        lua_getfield(L,LUA_REGISTRYINDEX, std::to_string(e.id).c_str());

        lua_getfield(L,-1,"draw_screen");
        if(lua_isfunction(L,-1)){
            int result = lua_pcall(L,0,0,0);
            if(result != LUA_OK){
                printf("[ART] Error on draw screen %d: %s\n",e.id,lua_tostring(L,-1));
                lua_pop(L,1);
            }
        }else{
            lua_pop(L,1);
        }
        lua_pop(L,1);
    }
}