Merge

--HG--
branch : trunk

1 files changed, 70 insertions, 0 deletions

diff --git a/externals/g3dlite/G3D.lib/source/g3dmath.cpp b/externals/g3dlite/G3D.lib/source/g3dmath.cpp
new file mode 100644
index 00000000000..95c9e16cc24
--- /dev/null
+++ b/externals/g3dlite/G3D.lib/source/g3dmath.cpp
@@ -0,0 +1,70 @@
+/**
+ @file g3dmath.cpp
+ 
+ @author Morgan McGuire, graphics3d.com
+  
+ @created 2001-06-02
+ @edited  2004-02-24
+ */
+
+#include "G3D/g3dmath.h"
+#include <stdlib.h>
+
+namespace G3D {
+
+float gaussRandom(float mean, float stdev) {
+
+    // Using Box-Mueller method from http://www.taygeta.com/random/gaussian.html
+    // Modified to specify standard deviation and mean of distribution
+    float w, x1, x2;
+
+    // Loop until w is less than 1 so that log(w) is negative
+    do {
+        x1 = uniformRandom(-1.0, 1.0);
+        x2 = uniformRandom(-1.0, 1.0);
+
+        w = float(square(x1) + square(x2));
+    } while (w > 1.0f);
+
+    // Transform to gassian distribution
+    // Multiply by sigma (stdev ^ 2) and add mean.
+    return x2 * (float)square(stdev) * sqrtf((-2.0f * logf(w) ) / w) + mean; 
+}
+
+
+int highestBit(uint32 x) {
+    // Binary search.
+    int base = 0;
+
+	if (x & 0xffff0000)	{
+		base = 16;
+		x >>= 16;
+	}
+    if (x & 0x0000ff00) {
+		base += 8;
+		x >>= 8;
+	}
+    if (x & 0x000000f0) {
+		base += 4;
+		x >>= 4;
+	}
+
+	static const int lut[] = {-1,0,1,1,2,2,2,2,3,3,3,3,3,3,3,3};
+	return base + lut[x];
+}
+
+
+int iRandom(int low, int high) {
+	int r = iFloor(low + (high - low + 1) * (double)rand() / RAND_MAX);
+
+	// There is a *very small* chance of generating
+	// a number larger than high.
+	if (r > high) {
+		return high;
+	} else {
+		return r;
+	}
+}
+
+
+}