Question

我正在开发一个简单的C ++游戏，SDL作为我的API。我把我的图像bliting函数放在一个单独的文档中，这样我的主文件就不那么杂乱了。但是，当我尝试使用类的对象调用函数时，我的IDE说我正在对函数进行未定义的引用。这是主文件：

#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
#include "imageBlitingFunctions.h"
#include <iostream>
#include <string>
#include <sstream>

int screenW = 640;
int screenH = 480;
int screenBPP = 32;

SDL_Surface* window = SDL_SetVideoMode(screenW, screenH, screenBPP, SDL_SWSURFACE);

imageBlitingFunctions IBFobject;

SDL_Surface* background1;
SDL_Surface* player1;

int main(int argc, char* args[])
{
    SDL_Init(SDL_INIT_EVERYTHING);
    TTF_Init();

    background1 = IBFobject.loadIMG("background.png");
    player1 = IBFobject.loadIMG("swordtest.png");

    IBFobject.blitIMG(0, 0, window, background1, 0, 0, 1000, 1000);
    IBFobject.blitIMG(0, 0, window, player1, 100, 0, 100, 300);

    SDL_FreeSurface(background1);
    SDL_FreeSurface(player1);

    SDL_Quit();

    return 0;
}

以下是该课程的标题：

#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
#include <iostream>
#include <string>
#ifndef IMAGEBLITINGFUNCTIONS_H
#define IMAGEBLITINGFUNCTIONS_H


class imageBlitingFunctions
{
    public:
        SDL_Surface *loadIMG(std::string filename);

        void blitIMG(int pX, int pY, SDL_Surface *window, SDL_Surface *image, int cpX, int cpY, int cpH, int cpW);

        SDL_Surface *loadText(int red, int blue, int green, std::string fontname, int fontSize, std::string text);
};

#endif // IMAGEBLITINGFUNCTIONS_H

这是班级：

#include "imageBlitingFunctions.h"
#include "SDL/SDL.h"
#include "SDL/SDL_image.h"
#include "SDL/SDL_ttf.h"
#include <iostream>
#include <string>

SDL_Surface* imageBlitingFunctions::loadIMG(std::string filename)
{
    SDL_Surface *img = IMG_Load(filename.c_str());

    SDL_Surface *imgOPT = SDL_DisplayFormat(img);

    SDL_FreeSurface(img);

    return imgOPT;
}

void imageBlitingFunctions::blitIMG(int pX, int pY, SDL_Surface *window, SDL_Surface *image, int cpX, int cpY, int cpH, int cpW)
{
    SDL_Rect positionIMG;
    positionIMG.x = pX;
    positionIMG.y = pY;

    SDL_Rect clipP;
    clipP.x = cpX;
    clipP.y = cpY;
    clipP.h = cpH;
    clipP.w = cpW;

    SDL_BlitSurface(image, &clipP, window, &positionIMG);

    SDL_Flip(window);
}

SDL_Surface* imageBlitingFunctions::loadText(int red, int blue, int green, std::string fontname, int fontSize, std::string text)
{
    int color1 = red;
    int color2 = blue;
    int color3 = green;

    SDL_Color textColor = {color1, color2, color3};

    TTF_Font *font1 = TTF_OpenFont(fontname.c_str(), fontSize);

    SDL_Surface *message1 = TTF_RenderText_Solid(font1, text.c_str(), textColor);

    return message1;
}

任何帮助将不胜感激。

Answer 1

对函数的未定义引用意味着链接器无法找到函数定义。函数的定义就是你在代码中的含义＆＃34;这里是类：＆＃34; （也许你称之为imageBlitingFunctions.cpp或类似的东西？）所以问题是你的IDE无法找到这个文件。

要解决此问题，您需要修复项目配置。

在SDL中不起作用的对象（C ++）

1 个答案: