Diff: include/opencv2/flann/dynamic_bitset.h

Revision:

0:0e0631af0305

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+++ b/include/opencv2/flann/dynamic_bitset.h	Fri Jan 29 04:53:38 2021 +0000
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+/***********************************************************************
+ * 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.
+ *************************************************************************/
+
+/***********************************************************************
+ * Author: Vincent Rabaud
+ *************************************************************************/
+
+#ifndef OPENCV_FLANN_DYNAMIC_BITSET_H_
+#define OPENCV_FLANN_DYNAMIC_BITSET_H_
+
+#ifndef FLANN_USE_BOOST
+#  define FLANN_USE_BOOST 0
+#endif
+//#define FLANN_USE_BOOST 1
+#if FLANN_USE_BOOST
+#include <boost/dynamic_bitset.hpp>
+typedef boost::dynamic_bitset<> DynamicBitset;
+#else
+
+#include <limits.h>
+
+#include "dist.h"
+
+namespace cvflann {
+
+/** Class re-implementing the boost version of it
+ * This helps not depending on boost, it also does not do the bound checks
+ * and has a way to reset a block for speed
+ */
+class DynamicBitset
+{
+public:
+    /** default constructor
+     */
+    DynamicBitset()
+    {
+    }
+
+    /** only constructor we use in our code
+     * @param sz the size of the bitset (in bits)
+     */
+    DynamicBitset(size_t sz)
+    {
+        resize(sz);
+        reset();
+    }
+
+    /** Sets all the bits to 0
+     */
+    void clear()
+    {
+        std::fill(bitset_.begin(), bitset_.end(), 0);
+    }
+
+    /** @brief checks if the bitset is empty
+     * @return true if the bitset is empty
+     */
+    bool empty() const
+    {
+        return bitset_.empty();
+    }
+
+    /** set all the bits to 0
+     */
+    void reset()
+    {
+        std::fill(bitset_.begin(), bitset_.end(), 0);
+    }
+
+    /** @brief set one bit to 0
+     * @param index
+     */
+    void reset(size_t index)
+    {
+        bitset_[index / cell_bit_size_] &= ~(size_t(1) << (index % cell_bit_size_));
+    }
+
+    /** @brief sets a specific bit to 0, and more bits too
+     * This function is useful when resetting a given set of bits so that the
+     * whole bitset ends up being 0: if that's the case, we don't care about setting
+     * other bits to 0
+     * @param index
+     */
+    void reset_block(size_t index)
+    {
+        bitset_[index / cell_bit_size_] = 0;
+    }
+
+    /** resize the bitset so that it contains at least sz bits
+     * @param sz
+     */
+    void resize(size_t sz)
+    {
+        size_ = sz;
+        bitset_.resize(sz / cell_bit_size_ + 1);
+    }
+
+    /** set a bit to true
+     * @param index the index of the bit to set to 1
+     */
+    void set(size_t index)
+    {
+        bitset_[index / cell_bit_size_] |= size_t(1) << (index % cell_bit_size_);
+    }
+
+    /** gives the number of contained bits
+     */
+    size_t size() const
+    {
+        return size_;
+    }
+
+    /** check if a bit is set
+     * @param index the index of the bit to check
+     * @return true if the bit is set
+     */
+    bool test(size_t index) const
+    {
+        return (bitset_[index / cell_bit_size_] & (size_t(1) << (index % cell_bit_size_))) != 0;
+    }
+
+private:
+    std::vector<size_t> bitset_;
+    size_t size_;
+    static const unsigned int cell_bit_size_ = CHAR_BIT * sizeof(size_t);
+};
+
+} // namespace cvflann
+
+#endif
+
+#endif // OPENCV_FLANN_DYNAMIC_BITSET_H_