我正在OpenGL项目上的Linux中工作。但是，当我尝试使用SDL2创建窗口时，我得到的输出是：
g++ -lGL -lGLEW -lSDL2 main.cpp display.cpp
/tmp/cchQfbLR.o: In function `Display::Display(unsigned long, unsigned long, std::string const&)':
display.cpp:(.text+0x21): undefined reference to `SDL_Init'
display.cpp:(.text+0x30): undefined reference to `SDL_GL_SetAttribute'
display.cpp:(.text+0x3f): undefined reference to `SDL_GL_SetAttribute'
display.cpp:(.text+0x4e): undefined reference to `SDL_GL_SetAttribute'
display.cpp:(.text+0x5d): undefined reference to `SDL_GL_SetAttribute'
display.cpp:(.text+0x6c): undefined reference to `SDL_GL_SetAttribute'
/tmp/cchQfbLR.o:display.cpp:(.text+0x7b): more undefined references to `SDL_GL_SetAttribute' follow
/tmp/cchQfbLR.o: In function `Display::Display(unsigned long, unsigned long, std::string const&)':
display.cpp:(.text+0xb1): undefined reference to `SDL_CreateWindow'
display.cpp:(.text+0xc9): undefined reference to `SDL_GL_CreateContext'
display.cpp:(.text+0xd6): undefined reference to `glewInit'
/tmp/cchQfbLR.o: In function `Display::update()':
display.cpp:(.text+0x152): undefined reference to `SDL_PollEvent'
/tmp/cchQfbLR.o: In function `Display::swapBuffers()':
display.cpp:(.text+0x18e): undefined reference to `SDL_GL_SwapWindow'
/tmp/cchQfbLR.o: In function `Display::clearScreen(float, float, float, float)':
display.cpp:(.text+0x1e1): undefined reference to `glClearColor'
display.cpp:(.text+0x1eb): undefined reference to `glClear'
/tmp/cchQfbLR.o: In function `Display::~Display()':
display.cpp:(.text+0x20a): undefined reference to `SDL_GL_DeleteContext'
display.cpp:(.text+0x21a): undefined reference to `SDL_DestroyWindow'
display.cpp:(.text+0x21f): undefined reference to `SDL_Quit'
collect2: error: ld returned 1 exit status
关键是我之前在code :: blocks中使用了完全相同的代码，并且有效。我在其他主题中搜索了相同的错误，发现它可能与链接有关。但是我看不到我在做什么错。这是我编译项目的方式：
g++ -lGL -lGLEW -lSDL2 main.cpp display.cpp -o main.o
这是文件：
main.cpp
#include <iostream>
#include "display.h"
int main(int argc, char** argv){
Display display(800, 600, "engine");
while(!display.isClosed()){
display.clearScreen(.1f,.1f,.6f,1.f);
display.update();
}
std::cout << "Hello world !" << std::endl;
return 0;
}
display.h
#ifndef DISPLAY_H
#define DISPLAY_H
#include <string>
#include <SDL2/SDL.h>
class Display
{
public:
Display(size_t _width, size_t _height, const std::string& _title);
void update();
void swapBuffers();
void clearScreen(float _r, float _g, float _b, float _a);
~Display();
bool isClosed() const {return closed;}
private:
bool closed;
SDL_Window* mWindow;
SDL_GLContext mContext;
};
#endif
display.cpp
#include "display.h"
#include <GL/glew.h>
#include <iostream>
Display::Display(size_t _width, size_t _height, const std::string& _title){
SDL_Init(SDL_INIT_EVERYTHING);
SDL_GL_SetAttribute(SDL_GL_RED_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_GREEN_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BLUE_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_ALPHA_SIZE, 8);
SDL_GL_SetAttribute(SDL_GL_BUFFER_SIZE, 32);
SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
mWindow = SDL_CreateWindow(_title.c_str(), SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, _width, _height, SDL_WINDOW_OPENGL);
mContext = SDL_GL_CreateContext(mWindow);
GLuint status = glewInit();
if (status != GLEW_OK){
std::cerr << "Failed to link the glew library..." << std::endl;
}
closed = false;
}
void Display::update(){
swapBuffers();
SDL_Event e;
while(SDL_PollEvent(&e)){
if(e.type == SDL_QUIT)
closed = true;
}
}
void Display::swapBuffers(){
SDL_GL_SwapWindow(mWindow);
}
void Display::clearScreen(float _r, float _g, float _b, float _a){
glClearColor(_r, _g, _b, _a);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
}
Display::~Display(){
SDL_GL_DeleteContext(mContext);
SDL_DestroyWindow(mWindow);
SDL_Quit();
}
谢谢您的时间！
最佳答案
将各种-l标志放在命令行末尾。
关于c++ - C++ ld返回1个退出状态，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/27474067/