程序接收到的信号SIGSEGV，吸气方法中的分段错误

Question

I was making a game using Code::Blocks, and came across the Segmentation fault error. I have looked through other questions here and couldn't find anything that helped. I have a Sprite class that represents the basic objects in the game and a Window class that controls the display to the screen of the game. I ran the debugger and it gave me the error at the line return image; from the getImage() method below.

SDL_Surface* Sprite::getImage() {
    return image;
}

I call the following setImage() method in the constructor for Sprite , and I verified that SDL_ConvertSurface did not return NULL .

void Sprite::setImage(string path) {
    SDL_Surface* loadedSurface = IMG_Load( path.c_str() );
    if( loadedSurface == NULL ) {
        printf( "Unable to load image %s! SDL_image Error: %s\n", path.c_str(), IMG_GetError() );
    } else {
        image = SDL_ConvertSurface( loadedSurface, surface->format, NULL );
        if( image == NULL ) {
            printf( "Unable to optimize image %s! SDL Error: %s\n", path.c_str(), SDL_GetError() );
        }

        SDL_FreeSurface( loadedSurface );
    }
}

I call the method getImage() in mainloop() of Window , as shown below, where sprites is declared as Sprite* sprites[10]; :

void Window::mainloop() {
    bool quit = false;
    SDL_Event e;

    while( !quit ) {
        while( SDL_PollEvent( &e ) != 0 ) {
            if( e.type == SDL_QUIT ) {
                quit = true;
            }
        }

        SDL_FillRect( screenSurface, NULL, SDL_MapRGB( screenSurface->format, red, green, blue ) );

        for (int i = 0; i < spritesNum; i++) {
            SDL_BlitScaled( sprites[spritesNum]->getImage() , NULL, screenSurface, sprites[spritesNum]->getRect() );
        }

        SDL_UpdateWindowSurface( window );
    }
}

Answer 1

You are probably indexing out of range here

for (int i = 0; i < spritesNum; i++) {
    SDL_BlitScaled( sprites[spritesNum]->getImage() , NULL, screenSurface, sprites[spritesNum]->getRect() );
}

I assume you wanted to use your counter i ?

for (int i = 0; i < spritesNum; i++) {
    SDL_BlitScaled( sprites[i]->getImage() , NULL, screenSurface, sprites[i]->getRect() );
}

Otherwise if your array sprites is of length spritesNum you are indexing out of range, and doing so spritesNum number of times.

In any case, you should at least confirm you aren't dereferencing a null pointer here

sprites[i]->getImage()