"atomic bomb" commit. Reorganized OpenCV directory structure

3rdparty/include/flann/random.h

@@ -0,0 +1,134 @@
+/***********************************************************************
+ * Software License Agreement (BSD License)
+ *
+ * Copyright 2008-2009  Marius Muja (mariusm@cs.ubc.ca). All rights reserved.
+ * Copyright 2008-2009  David G. Lowe (lowe@cs.ubc.ca). All rights reserved.
+ *
+ * THE BSD LICENSE
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *************************************************************************/
+
+#ifndef RANDOM_H
+#define RANDOM_H
+
+#include <algorithm>
+#include <cstdlib>
+#include <cassert>
+
+using namespace std;
+
+namespace flann
+{
+
+/**
+ * Seeds the random number generator
+ */
+void seed_random(unsigned int seed);
+
+/*
+ * Generates a random double value.
+ */
+double rand_double(double high = 1.0, double low=0);
+
+/*
+ * Generates a random integer value.
+ */
+int rand_int(int high = RAND_MAX, int low = 0);
+
+
+/**
+ * Random number generator that returns a distinct number from
+ * the [0,n) interval each time.
+ *
+ * TODO: improve on this to use a generator function instead of an
+ * array of randomly permuted numbers
+ */
+class UniqueRandom
+{
+	int* vals;
+    int size;
+	int counter;
+
+public:
+	/**
+	 * Constructor.
+	 * Params:
+	 *     n = the size of the interval from which to generate
+	 *     		random numbers.
+	 */
+	UniqueRandom(int n) : vals(NULL) {
+		init(n);
+	}
+
+	~UniqueRandom()
+	{
+		delete[] vals;
+	}
+
+	/**
+	 * Initializes the number generator.
+	 * Params:
+	 * 		n = the size of the interval from which to generate
+	 *     		random numbers.
+	 */
+	void init(int n)
+	{
+    	// create and initialize an array of size n
+		if (vals == NULL || n!=size) {
+            delete[] vals;
+	        size = n;
+            vals = new int[size];
+    	}
+    	for(int i=0;i<size;++i) {
+			vals[i] = i;
+		}
+
+		// shuffle the elements in the array
+        // Fisher-Yates shuffle
+		for (int i=size;i>0;--i) {
+// 			int rand = cast(int) (drand48() * n);
+			int rnd = rand_int(i);
+			assert(rnd >=0 && rnd < i);
+			swap(vals[i-1], vals[rnd]);
+		}
+
+		counter = 0;
+	}
+
+	/**
+	 * Return a distinct random integer in greater or equal to 0 and less
+	 * than 'n' on each call. It should be called maximum 'n' times.
+	 * Returns: a random integer
+	 */
+	int next() {
+		if (counter==size) {
+			return -1;
+		} else {
+			return vals[counter++];
+		}
+	}
+};
+
+}
+
+#endif //RANDOM_H