Initial commit: client source

source/EterBase/Random.cpp

@@ -0,0 +1,48 @@
+#include "StdAfx.h"
+
+#include <assert.h>
+
+static unsigned long randseed = 1;
+
+void srandom(unsigned long seed)
+{
+	randseed = seed;
+}
+
+/*
+ * Pseudo-random number generator for randomizing the profiling clock,
+ * and whatever else we might use it for.  The result is uniform on
+ * [0, 2^31 - 1].
+ */
+unsigned long random()
+{       
+	long x, hi, lo, t;
+	
+	/*
+	* Compute x[n + 1] = (7^5 * x[n]) mod (2^31 - 1).
+	* From "Random number generators: good ones are hard to find",
+	* Park and Miller, Communications of the ACM, vol. 31, no. 10,
+	* October 1988, p. 1195.
+	*/ 
+	x = randseed;
+	hi = x / 127773;
+	lo = x % 127773; 
+	t = 16807 * lo - 2836 * hi;
+	if (t <= 0)
+		t += 0x7fffffff;
+	randseed = t;
+	return (t);
+}
+
+
+float frandom(float flLow, float flHigh)
+{
+	float fl = float(random()) / float(2147483648.0f); // float in [0,1)
+	return (fl * (flHigh - flLow)) + flLow; // float in [low,high)
+}
+
+long random_range(long from, long to)
+{
+	assert(from <= to);
+	return ((random() % (to - from + 1)) + from);
+}