编译SDL测试期间出错

Question

我正在学习使用SDL2进行编程。目前，我正在做一个基本的练习。我的程序加载背景图像，并在背景上加载完整的精灵图。但是我在执行程序时遇到问题。当我执行二进制文件时，程序窗口会立即自动关闭;我看不到任何东西。我认为这是主循环的一个问题，但它看起来适合我。这是我的代码

#include "SDL.h" 


void main() { 

int gameover = 0; 


SDL_Init(SDL_INIT_VIDEO); 

SDL_Window* TheWindow; 
SDL_Renderer* RenderEngine; 
SDL_Surface* LoadedSurface; 
SDL_Surface* LoadedImage; 
SDL_Texture* CharacterImg; 
SDL_Texture* BackgroundImg; 

TheWindow = SDL_CreateWindow("Character Test", 
    SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 580, SDL_WINDOW_RESIZABLE); 

RenderEngine = SDL_CreateRenderer(TheWindow, -1, SDL_RENDERER_ACCELERATED); 

LoadedSurface= SDL_LoadBMP("./maptest.bmp"); 
BackgroundImg = SDL_CreateTextureFromSurface(RenderEngine, LoadedSurface); 
SDL_FreeSurface(LoadedSurface); 

LoadedImage = SDL_LoadBMP("./sprite.bmp"); 
CharacterImg = SDL_CreateTextureFromSurface(RenderEngine, LoadedImage); 
SDL_FreeSurface(LoadedImage); 



SDL_Event event; 

while (!gameover) 
{ 

    if (SDL_PollEvent(&event)) { 

    switch (event.type) { 

     case SDL_QUIT: 
     gameover = 1; 
     break; 

     case SDL_KEYDOWN: 
     switch (event.key.keysym.sym) { 
     case SDLK_ESCAPE: 
     case SDLK_q: 
     gameover = 1; 
       break; 
      } 
     } 
     break; 
     } 

    SDL_RenderClear(RenderEngine); 
    SDL_RenderCopy(RenderEngine, BackgroundImg, NULL, NULL); 
    SDL_RenderCopy(RenderEngine, CharacterImg, 120, 80); 
    SDL_RenderPresent(RenderEngine); 


    } 



    SDL_Quit(); 



} 

Answer 1

您的代码将退出while -loop如果任何SDL_PollEvent情况：

while (!gameover) 
    { 
    if (SDL_PollEvent(&event)) //Any SDL_PollEvent that gets into if... 
     { 
     switch (event.type) 
      {  
      case SDL_QUIT: 
      gameover = 1; 
      break; 
      case SDL_KEYDOWN: 
      switch (event.key.keysym.sym) 
       { 
       case SDLK_ESCAPE: 
       case SDLK_q: 
       gameover = 1; 
       break; 
       } 
      } 
     break;  //...will eventually hit this break if it didn't break before 
     } 
    SDL_RenderClear(RenderEngine); 
    SDL_RenderCopy(RenderEngine, BackgroundImg, NULL, NULL); 
    SDL_RenderCopy(RenderEngine, CharacterImg, 120, 80); 
    SDL_RenderPresent(RenderEngine); 
    }