use renDoRenderLoop() in hello_world example

examples/hello_world/main.cpp

@@ -1,40 +1,16 @@
 
-#include <SDL2/SDL.h>
-
 #include "renderer.h"
 
 
 int
 main()
 {
-	render_state* rs = renInit();
+	render_state* rs = renInit("Hello World");
 
 	if (rs == nullptr)
 		return 1;
 
-	const uint TARGET_FPS = 60;
-	const uint FRAME_DELAY = 1000 / TARGET_FPS;
-	uint frameStart, frameTime;
-	bool running = true;
-	SDL_Event e;
-
-	while (running) {
-		frameStart = SDL_GetTicks();
-
-		while (SDL_PollEvent(&e)) {
-			if ((e.type == SDL_KEYDOWN && e.key.keysym.sym == SDLK_ESCAPE)
-				|| e.type == SDL_QUIT) {
-				running = false;
-			}
-		}
-
-		renRenderFrame(rs);
-		SDL_GL_SwapWindow(rs->handles.window);
-		frameTime = SDL_GetTicks() - frameStart;
-
-		if (FRAME_DELAY > frameTime)
-			SDL_Delay(FRAME_DELAY - frameTime);
-	}
+	renDoRenderLoop(rs);
 
 	return 0;
 }