refactors & viewport fix

util.h

@@ -0,0 +1,22 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#include <stdint.h>
+
+#define MAX(A, B) ((A) > (B) ? (A) : (B))
+#define MIN(A, B) ((A) < (B) ? (A) : (B))
+#define CLAMP(X, A, B) (MIN((B), MAX((A), (X))))
+#define SATURATE(X) (CLAMP((X), 0, 1))
+
+typedef struct { int w, h; } size;
+typedef struct { int x, y, w, h; } rect;
+
+#define MKGREY(L, A) (uint32_t)( \
+	(((L) << 24) & 0xFF000000) | \
+	(((L) << 16) & 0x00FF0000) | \
+	(((L) <<  8) & 0x0000FF00) | \
+	((A) & 0x000000FF))
+
+#define WHITE 0xFFFFFFFF
+
+#endif//UTIL_H