twn_filewatch.c: file and directory change api, initial support for texture reload

src/twn_filewatch_c.h

@@ -0,0 +1,23 @@
+#ifndef TWN_FILEWATCH_C_H
+#define TWN_FILEWATCH_C_H
+
+#include <stdbool.h>
+
+#define FILEWATCH_MODIFIED_TICKS_MERGED 10
+
+enum FilewatchAction {
+    FILEWATCH_ACTION_FILE_NONE,
+    FILEWATCH_ACTION_FILE_CREATED,
+    FILEWATCH_ACTION_FILE_DELETED,
+    FILEWATCH_ACTION_FILE_MODIFIED,
+};
+
+typedef void (*FileatchCallback)(char const *path, enum FilewatchAction action);
+
+bool filewatch_add_directory(char *dir, FileatchCallback callback);
+
+bool filewatch_add_file(char *file, FileatchCallback callback);
+
+void filewatch_poll(void);
+
+#endif