1 files changed, 28 insertions, 0 deletions

diff --git a/source/base/base_rand.h b/source/base/base_rand.h
new file mode 100644
index 0000000..bfdab0f
--- /dev/null
+++ b/source/base/base_rand.h
@@ -0,0 +1,28 @@
+#ifndef BASE_RAND_H
+#define BASE_RAND_H
+
+// source: https://rosettacode.org/wiki/Pseudo-random_numbers/Splitmix64
+
+#define RAND_CONSTANT 6364136223846793005
+#define GEN_RAND() _generate_random_u64(RAND_CONSTANT)
+
+#endif  /* BASE_RAND_H  */
+
+#ifdef BASE_RAND_IMPLEMENTATION
+internal u64
+generate_random_u64(u64 constant)
+{
+    time_t current_time = time(0);
+    constant = current_time ^ constant;
+
+    constant += 0x9e3779b97f4a7c15;
+
+    u64 z  = constant;
+    z = (z ^ (z >> 30)) * 0xbf58476d1ce4e5b9;
+    z = (z ^ (z >> 27)) * 0x94d049bb133111eb;
+    z = z ^ (z >> 31);
+
+    return z;
+}
+
+#endif