add freeing code to the different modules

src/game/game.c

@@ -24,5 +24,5 @@ void game_update(gamedata* dat) {
 }
 
 void game_free(gamedata* dat) {
-    (void)dat;
+    *dat = (gamedata){0};
 }

src/main.c

@@ -51,8 +51,6 @@ int32_t main(int32_t argc, char** argv) {
 
     game_free(&gdat);
     render_free(&rdat);
-    gdat = (gamedata){0};
-    rdat = (renderdata){0};
     SDL_Quit();
 
     return get_gamestatus();

src/window/render.c

@@ -37,6 +37,7 @@ void render_update(renderdata const* const rdat) {
 }
 
 void render_free(renderdata* const rdat) {
-    (void)rdat;
-    error(STATUS_ERROR, "function render_free(render_data*) not implemented");
+    SDL_DestroyRenderer(rdat->renderer);
+    SDL_DestroyWindow(rdat->window);
+    *rdat = (renderdata){0};
 }