implement new code, and remove deprecated old code. Overal optimisation.

this code is currently broken, but this'll be fixed in a subsequent
commit

src/main.c

@@ -1,62 +1,23 @@
 #include <SDL.h>
-#include <SDL_error.h>
-#include <SDL_events.h>
-#include <SDL_ttf.h>
+#include <stdlib.h>
 
 #include "error.h"
 #include "game/game.h"
-#include "game/paths.h"
-#include "io/render.h"
+#include "io/window.h"
 
-// initialized in init(), reading beforehand is undefined behaviour
-static gamedata gdat;
-static renderdata rdat;
-
-// initialize the game
-static void init(void) {
-	// initialize SDL
-	if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_AUDIO) < 0) fatal(ERROR_SDL_INIT, "SDL could not initialize! SDL Error: %s", SDL_GetError());
-	if (TTF_Init() != 0) fatal(ERROR_SDL_FONT_INIT, "the TTF module of SDL could not initialize! TTF Error: %s", TTF_GetError());
-
-	// initialize other game components
-	paths_init();
-	game_init(&gdat);
-	render_init(&rdat, &gdat);
-}
-
-// perform the updates to the game
-static void update(void) {
-	// update the input
-	{
-		SDL_Event e;
-		while (SDL_PollEvent(&e)) {
-			switch (e.type) {
-			case SDL_QUIT:
-				gdat.run = false;
-				break;
-			}
-		}
-	}
-
-	// perform updates
-	game_update(&gdat);
-	render_update(&rdat);
+static void stop(void) {
+	debug("stopping...", );
+	window_close();
+	SDL_Quit();
 }
 
 // entry-point of the application
 int main(int argc, char** argv) {
 	(void)argc, (void)argv;
+	// register stop as exit function
+	atexit(stop);
 
-	init();
-	debug("successfully initialized!", );
+	window_open(game_init());
 
-	while (gdat.run == true)
-		update();
-
-	debug("done! starting to free resources...", );
-	game_free(&gdat);
-	render_free(&rdat);
-	paths_free();
-	SDL_Quit();
 	return 0;
 }