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表。但是我在执行程序时遇到了问题。当我执行二进制文件时,程序窗口会自动关闭;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();
}
答案 0 :(得分:3)
如果任何 while
发生,您的代码将退出SDL_PollEvent
- 循环:
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);
}