ilimination of system code, removal of x-watcher and replacement of it by dmon, fixes in audio code, dynamic asset reload

src/twn_timer.c

@@ -0,0 +1,38 @@
+#include "twn_timer_c.h"
+#include "twn_engine_context_c.h"
+
+#include <SDL2/SDL.h>
+
+static SDL_TimerID sanity_timer;
+
+#define SANITY_TIMER_MESSAGE_FMT "Game tick exeeded its allocated time (%u milliseconds), application is closing"
+
+/* stop application */
+static uint32_t sanity_timer_handler(uint32_t interval, void *data) {
+    (void)data;
+
+    size_t text_str_len = snprintf(NULL, 0, SANITY_TIMER_MESSAGE_FMT, interval) + 1;
+    char *text_str = SDL_malloc(text_str_len);
+    snprintf(text_str, text_str_len, SANITY_TIMER_MESSAGE_FMT, interval);
+    SDL_ShowSimpleMessageBox(SDL_MESSAGEBOX_ERROR, "sanity timer", text_str, ctx.window);
+    SDL_free(text_str);
+
+    /* TODO: figure out the most portable way to do it */
+    /* TODO: different type of behavior is possible, especially for debugging */
+    quick_exit(EXIT_FAILURE);
+}
+
+
+bool start_sanity_timer(uint32_t milliseconds_to_expire) {
+    if (!sanity_timer) {
+        sanity_timer = SDL_AddTimer(milliseconds_to_expire, sanity_timer_handler, NULL);
+    }
+
+    return sanity_timer != 0;
+}
+
+
+bool end_sanity_timer(void) {
+    SDL_RemoveTimer(sanity_timer);
+    sanity_timer = 0;
+}