Everyone loves random

1 files changed, 41 insertions, 0 deletions

diff --git a/src/rand_sys.c b/src/rand_sys.c
new file mode 100644
index 0000000..679ac94
--- /dev/null
+++ b/src/rand_sys.c
@@ -0,0 +1,41 @@
+#include "rand_sys.h"
+
+#define WIN32_LEAN_AND_MEAN
+#define NOSERVICE
+#define NOMCX
+#define NOIME
+#include <windows.h>
+
+static u32 state[2];
+
+void rand_seed(void)
+{
+	FILETIME t; 
+	GetSystemTimeAsFileTime(&t);
+	
+	u32 val = t.dwLowDateTime;
+	val ^= val >> 16;
+    val *= 0x85ebca6b;
+    val ^= val >> 13;
+    val *= 0xc2b2ae35;
+    val ^= val >> 16;
+	
+	state[0] = val;
+	state[1] = val ^ 0x49616e42U;
+}
+
+u32 rand_u32(void)
+{
+	state[0] = (state[0] << 16) + (state[0] >> 16);
+    state[0] += state[1];
+    state[1] += state[0];
+    return state[0];
+}
+
+i32 rand_range(i32 min, i32 max)
+{
+	u32 range = (u32)(max - min + 1);
+    u32 num = rand_u32() % range;
+
+    return min + (i32)num;
+}
\ No newline at end of file