Create RNG module

rng.c

@@ -0,0 +1,32 @@
+#include "rng.h"
+
+#include <assert.h>
+#include <sys/time.h>
+
+static uint32_t state;
+
+void rng_init()
+{
+	struct timeval tv;
+	const int res = gettimeofday(&tv, nullptr);
+	assert(res == 0);
+	state = tv.tv_usec;
+}
+
+uint32_t rng_uint32()
+{
+	state ^= state << 13;
+	state ^= state >> 17;
+	state ^= state << 5;
+	return state;
+}
+
+float rng_canon()
+{
+	return (float)rng_uint32() / UINT32_MAX;
+}
+
+float rng_plusminus()
+{
+	return 2.0 * rng_canon() - 1.0;
+}