问题描述
我尝试编译我的allegro 5程序,但是由于某种原因我得到了它
我想制作一种类似于引擎的结构,所以我制作了一个应用类,以使其更容易制作像ludum dare这样的游戏
所以您将创建一个类并使其继承自应用程序,只需填写更新init和draw方法
我真的是从终端进行编译的初学者(我使用linux)
我的构建脚本如下
gcc src / *。cpp build / Game $(pkg-config allegro-5 allegro_font-5 --libs --cflags) ./build/Game 暂停
希望我得到答案
/usr/bin/ld: /tmp/ccbdAHA8.o: in function `Pislify::DefaultwindowConfig()':
main.cpp:(.text+0x0): multiple deFinition of `Pislify::DefaultwindowConfig()'; /tmp/ccwYzbn9.o:Engine.cpp:(.text+0x0): first defined here
/usr/bin/ld: /tmp/ccwYzbn9.o:(.data.rel.ro._ZTIN7Pislify4GameE[_ZTIN7Pislify4GameE]+0x0): undefined reference to `vtable for __cxxabiv1::__class_type_info'
collect2: error: ld returned 1 exit status
我的代码: Engine.hpp
#ifndef ENGINE_HPP
#define ENGINE_HPP
#include <allegro5/allegro5.h>
#include <allegro5/allegro_font.h>
namespace Pislify
{
struct WindowConfiguration
{
int WindowWidth;
int WindowHeight;
char* WindowTitle;
int FPS;
};
WindowConfiguration DefaultwindowConfig()
{
WindowConfiguration conf;
conf.WindowWidth = 1280;
conf.WindowHeight = 720;
conf.FPS = 60;
conf.WindowTitle = "game";
}
class Game
{
WindowConfiguration config;
void Start();
ALLEGRO_TIMER* timer;
ALLEGRO_EVENT_QUEUE* queue;
ALLEGRO_disPLAY* disp;
ALLEGRO_FONT* font;
public:
ALLEGRO_EVENT event;
Game(WindowConfiguration c);
Game(int w,int h,char* t);
virtual void Init(){}
virtual void Update(){}
virtual void Draw(){}
};
}
#endif
engine.cpp
#include "Engine.hpp"
using namespace Pislify;
void Game::Start()
{
//Initialize allegro
al_init();
al_install_keyboard();
//initalize Allegro's Vars
timer = al_create_timer(1.0 / config.FPS);
queue = al_create_event_queue();
disp = al_create_display(config.WindowWidth,config.WindowHeight);
font = al_create_builtin_font();
//some more al config
al_register_event_source(queue,al_get_keyboard_event_source());
al_register_event_source(queue,al_get_display_event_source(disp));
al_register_event_source(queue,al_get_timer_event_source(timer));
//game loop
Init();
bool ShouldClose;
al_start_timer(timer);
while(!ShouldClose)
{
al_wait_for_event(queue,&event);
Update();
//time to draw? draw!
if(event.type == ALLEGRO_EVENT_TIMER)
{
Draw();
}
//close Window?
if((event.type == ALLEGRO_EVENT_disPLAY_CLOSE))
{
break;
}
}
al_destroy_font(font);
al_destroy_display(disp);
al_destroy_timer(timer);
al_destroy_event_queue(queue);
}
Game::Game(WindowConfiguration c)
{
config = c;
Start();
}
main.cpp
#include "Engine.hpp"
using namespace Pislify;
int main()
{
Game g(DefaultwindowConfig());
return 0;
}
解决方法
由于要在多个源文件中包含Engine.hpp
,因此必须将其标记为inline
。这样可以多次定义该功能。
namespace Pislify
{
//...
inline WindowConfiguration DefaultWindowConfig()
{
WindowConfiguration conf;
conf.WindowWidth = 1280;
conf.WindowHeight = 720;
conf.FPS = 60;
conf.WindowTitle = "game";
}
//...
引用https://www.cplusplus.com/articles/2LywvCM9/ 5. By marking it as inline,you can put a function definition in a header file (i.e. it can be included in multiple compilation unit,without the linker complaining)