opt: animations logic all use the int type

avoid the coordinates being forcibly limited to positive numbers

mmsg/arg.h

@@ -8,13 +8,13 @@
 
 extern char *argv0;
 
-/* use main(int argc, char *argv[]) */
+/* use main(int32_t argc, char *argv[]) */
 #define ARGBEGIN                                                               \
 	for (argv0 = *argv, argv++, argc--;                                        \
 		 argv[0] && argv[0][0] == '-' && argv[0][1]; argc--, argv++) {         \
 		char argc_;                                                            \
 		char **argv_;                                                          \
-		int brk_;                                                              \
+		int32_t brk_;                                                          \
 		if (argv[0][1] == '-' && argv[0][2] == '\0') {                         \
 			argv++;                                                            \
 			argc--;                                                            \