第四节：事件驱动的编程

创建窗口 绘制图片

…

获得图片宽高

	int iW, iH;SDL_QueryTexture(image, NULL, NULL, &iW, &iH);int x = SCREEN_WIDTH / 2 - iW / 2;int y = SCREEN_HEIGHT / 2 - iH / 2;

开始事件循环

创建SDL_Event　然后等待事件

当点击退出／按下键盘／点击鼠标　马上退出图片渲染　退出程序

	//Our event unionSDL_Event e;//For tracking if we want to quitbool quit = false;while (!quit) {//Read any events that occured, for now we'll just quit if any event occurswhile (SDL_PollEvent(&e)) {//If user closes the windowif (e.type == SDL_QUIT) {quit = true;}//If user presses any keyif (e.type == SDL_KEYDOWN) {quit = true;}//If user clicks the mouseif (e.type == SDL_MOUSEBUTTONDOWN) {quit = true;}}//RenderingSDL_RenderClear(renderer);//Draw the imagerenderTexture(image, renderer, x, y);//Update the screenSDL_RenderPresent(renderer);}

总结

SDL_PollEvent和SDL_WaitEvent区别

demo地址