问题描述
我正在跟踪YouTube上有关C ++和SDL2的教程,该教程于2017年完成,由于此错误,我无法继续学习。我是Mac上的新手,并假设错误是由于CMake或使用VS Code所致,所以我安装了Qt creator,但仍然遇到相同的错误。我已经研究了此错误,但我无法理解问题所在,希望有人可以帮助我理解。我的假设是,它与Game.cpp中的新GameObject和新Map的行有关。
感谢任何帮助。
错误:
18:19:19: Running steps for project cpp...
18:19:19: Starting: "/Users/m/Qt/Tools/CMake/CMake.app/Contents/bin/cmake" --build . --target all
[1/6 2.1/sec] Building CXX object CMakeFiles/cpp.dir/GameObject.cpp.o
[2/6 4.2/sec] Building CXX object CMakeFiles/cpp.dir/TextureManager.cpp.o
[3/6 6.2/sec] Building CXX object CMakeFiles/cpp.dir/main.cpp.o
[4/6 8.3/sec] Building CXX object CMakeFiles/cpp.dir/Map.cpp.o
[5/6 10.2/sec] Building CXX object CMakeFiles/cpp.dir/Game.cpp.o
[6/6 8.8/sec] Linking CXX executable cpp
Failed: cpp
: && /usr/bin/clang++ -g -isysroot /Library/Developer/CommandLinetools/SDKs/MacOSX10.15.sdk -Wl,-search_paths_first -Wl,-headerpad_max_install_names CMakeFiles/cpp.dir/main.cpp.o CMakeFiles/cpp.dir/Game.cpp.o CMakeFiles/cpp.dir/GameObject.cpp.o CMakeFiles/cpp.dir/Map.cpp.o CMakeFiles/cpp.dir/TextureManager.cpp.o -o cpp -F/Library/Frameworks -Wl,-rpath,/Library/Frameworks -framework SDL2 -framework Cocoa -framework SDL2_image && :
duplicate symbol 'TextureManager::Draw(SDL_Texture*,SDL_Rect,SDL_Rect)' in:
CMakeFiles/cpp.dir/Game.cpp.o
CMakeFiles/cpp.dir/GameObject.cpp.o
duplicate symbol 'TextureManager::Draw(SDL_Texture*,SDL_Rect)' in:
CMakeFiles/cpp.dir/Game.cpp.o
CMakeFiles/cpp.dir/Map.cpp.o
duplicate symbol 'TextureManager::Draw(SDL_Texture*,SDL_Rect)' in:
CMakeFiles/cpp.dir/Game.cpp.o
CMakeFiles/cpp.dir/TextureManager.cpp.o
ld: 3 duplicate symbols for architecture x86_64
clang: error: linker command Failed with exit code 1 (use -v to see invocation)
ninja: build stopped: subcommand Failed.
18:19:20: The process "/Users/m/Qt/Tools/CMake/CMake.app/Contents/bin/cmake" exited with code 1.
Error while building/deploying project cpp (kit: Desktop Qt 5.15.1 clang 64bit)
When executing step "CMake Build"
18:19:20: Elapsed time: 00:01.
TextureManager.cpp:
#include "TextureManager.h"
SDL_Texture* TextureManager::LoadTexture(const char* texture)
{
SDL_Surface* tempSurface = IMG_Load(texture);
SDL_Texture* tex = SDL_CreateTextureFromSurface(Game::renderer,tempSurface);
SDL_FreeSurface(tempSurface);
return tex;
}
TextureManager.h:
#include "Game.h"
class TextureManager {
public:
static SDL_Texture* LoadTexture(const char* fileName);
static void Draw(SDL_Texture* tex,SDL_Rect src,SDL_Rect dest);
};
void TextureManager::Draw(SDL_Texture * tex,SDL_Rect dest)
{
SDL_Rendercopy(Game::renderer,tex,&src,&dest);
}
Game.cpp:
#include "Game.h"
#include "TextureManager.h"
#include "GameObject.h"
#include "Map.h"
GameObject* player;
GameObject* enemy;
MaP* map;
SDL_Renderer* Game::renderer = nullptr;
Game::Game()
{}
Game::~Game()
{}
void Game::init(const char *title,int xpos,int ypos,int width,int height,bool fullscreen)
{
int flags = 0;
if(fullscreen)
{
flags = SDL_WINDOW_FULLSCREEN;
}
if(SDL_Init(SDL_INIT_EVERYTHING) == 0)
{
std::cout << "Subsystems Initialized..." << std::endl;
window = SDL_CreateWindow(title,xpos,ypos,width,height,flags);
if(window)
{
std::cout << "Window created..." << std::endl;
}
renderer = SDL_CreateRenderer(window,-1,0);
if(renderer)
{
SDL_SetRenderDrawColor(renderer,255,255);
std::cout << "Renderer created..." << std::endl;
}
isRunning = true;
} else {
isRunning = false;
}
player = new GameObject("../assets/player.png",0);
enemy = new GameObject("../assets/enemy.png",50,50);
map = new Map();
}
void Game::handleEvents()
{
SDL_Event event;
SDL_PollEvent(&event);
switch (event.type)
{
case SDL_QUIT:
isRunning = false;
break;
default:
break;
}
}
void Game::update()
{
player->Update();
enemy->Update();
}
void Game::render()
{
SDL_RenderClear(renderer);
map->DrawMap();
player->Render();
enemy->Render();
SDL_RenderPresent(renderer);
}
void Game::clean()
{
SDL_DestroyWindow(window);
SDL_DestroyRenderer(renderer);
SDL_Quit();
std::cout << "Game cleaned..." << std::endl;
}
Game.h:
#ifndef Game_hpp
#define Game_hpp
#include <SDL2/SDL.h>
#include "SDL_image.h"
#include <iostream>
class Game {
public:
Game();
~Game();
void init(const char* title,int x,int y,bool fullscreen);
void handleEvents();
void update();
void render();
void clean();
bool running() { return isRunning; }
static SDL_Renderer *renderer;
private:
int cnt = 0;
bool isRunning;
SDL_Window *window;
};
#endif /* Game_hpp */
GameObject.cpp:
#include "GameObject.h"
#include "TextureManager.h"
GameObject::GameObject(const char* texturesheet,int y)
{
objTexture = TextureManager::LoadTexture(texturesheet);
xpos = x;
ypos = y;
}
void GameObject::Update()
{
xpos++;
ypos++;
srcRect.h = 32;
srcRect.w = 32;
srcRect.x = 0;
srcRect.y = 0;
destRect.x = xpos;
destRect.y = ypos;
destRect.h = srcRect.h * 2;
destRect.w = srcRect.w * 2;
}
void GameObject::Render()
{
SDL_Rendercopy(Game::renderer,objTexture,&srcRect,&destRect);
}
GameObject.h:
#pragma once
#include "Game.h"
class GameObject {
public:
GameObject(const char* texturesheet,int y);
~GameObject();
void Update();
void Render();
private:
int xpos;
int ypos;
SDL_Texture* objTexture;
SDL_Rect srcRect,destRect;
};
Map.cpp:
#include "Map.h"
#include "TextureManager.h"
int lvl1[20][25] = {
{ 0,1,0 },{ 0,0 }
};
Map::Map()
{
dirt = TextureManager::LoadTexture("../assets/dirt.png");
grass = TextureManager::LoadTexture("../assets/grass.png");
water = TextureManager::LoadTexture("../assets/water.png");
LoadMap(lvl1);
src.x = src.y = 0;
src.w = dest.w = 32;
src.h = dest.h = 32;
dest.x = dest.y = 0;
}
void Map::LoadMap(int arr[20][25])
{
for (int row = 0; row < 20; row++)
{
for (int column = 0; column < 25; column++)
{
map[row][column] = arr[row][column];
}
}
}
void Map::DrawMap()
{
int type = 0;
for (int row = 0; row < 20; row++)
{
for (int column = 0; column < 25; column++)
{
type = map[row][column];
dest.x = column * 32;
dest.y = row * 32;
switch (type)
{
case 0:
TextureManager::Draw(water,src,dest);
break;
case 1:
TextureManager::Draw(grass,dest);
break;
case 2:
TextureManager::Draw(dirt,dest);
break;
default:
break;
}
}
}
}
Map.h:
#pragma once
#include "Game.h"
class Map
{
public:
Map();
~Map();
void LoadMap(int arr[20][25]);
void DrawMap();
private:
SDL_Rect src,dest;
SDL_Texture* dirt;
SDL_Texture* grass;
SDL_Texture* water;
int map[20][25];
};
main.cpp:
#include "Game.h"
Game *game = nullptr;
int main(int argc,const char * argv[]) {
const int FPS = 60;
const int frameDelay = 1000 / FPS;
Uint32 frameStart;
int frameTime;
game = new Game();
game->init("2D Engine",SDL_WINDOWPOS_CENTERED,800,640,false);
while (game->running())
{
frameStart = SDL_GetTicks();
game->handleEvents();
game->update();
game->render();
frameTime = SDL_GetTicks() - frameStart;
if(frameDelay > frameTime)
{
SDL_Delay(frameDelay - frameTime);
}
}
game->clean();
return 0;
}
解决方法
此问题已通过drescherjm的评论解决。
通过在TextureManager.h中添加inline
:
#include "Game.h"
class TextureManager {
public:
static SDL_Texture* LoadTexture(const char* fileName);
static void Draw(SDL_Texture* tex,SDL_Rect src,SDL_Rect dest);
};
void inline TextureManager::Draw(SDL_Texture * tex,SDL_Rect dest)
{
SDL_RenderCopy(Game::renderer,tex,&src,&dest);
}
或者通过在TextureManager.h中删除该功能并将其添加到TextureManager.cpp中:
#include "TextureManager.h"
SDL_Texture* TextureManager::LoadTexture(const char* texture)
{
SDL_Surface* tempSurface = IMG_Load(texture);
SDL_Texture* tex = SDL_CreateTextureFromSurface(Game::renderer,tempSurface);
SDL_FreeSurface(tempSurface);
return tex;
}
void TextureManager::Draw(SDL_Texture * tex,&dest);
}