添加壁纸功能

src/include/utils.h

@@ -5,6 +5,9 @@
 
 #define LENGTH(X) (sizeof(X) / sizeof(X)[0])
 
+#define MIN(a, b) (((a) < (b)) ? (a) : (b))
+#define MAX(a, b) (((a) > (b)) ? (a) : (b))
+
 void die(const char *format, ...);
 void *ecalloc(size_t number_of_member, size_t member_size);