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+//---------------------------------------------------------------------------//
+// Copyright (c) 2013-2014 Kyle Lutz <kyle.r.lutz@gmail.com>
+//
+// Distributed under the Boost Software License, Version 1.0
+// See accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt
+//
+// See http://boostorg.github.com/compute for more information.
+//---------------------------------------------------------------------------//
+
+#ifndef BOOST_COMPUTE_INTEROP_VTK_BOUNDS_HPP
+#define BOOST_COMPUTE_INTEROP_VTK_BOUNDS_HPP
+
+#include <vector>
+#include <iterator>
+
+#include <boost/compute/system.hpp>
+#include <boost/compute/command_queue.hpp>
+#include <boost/compute/algorithm/copy_n.hpp>
+#include <boost/compute/algorithm/reduce.hpp>
+#include <boost/compute/container/array.hpp>
+
+namespace boost {
+namespace compute {
+
+/// Calculates the bounds for the points in the range [\p first, \p last) and
+/// stores the result in \p bounds.
+///
+/// For example, this can be used to implement the GetBounds() method for a
+/// vtkMapper subclass.
+template<class PointIterator>
+inline void vtk_compute_bounds(PointIterator first,
+ PointIterator last,
+ double bounds[6],
+ command_queue &queue = system::default_queue())
+{
+ typedef typename std::iterator_traits<PointIterator>::value_type T;
+
+ const context &context = queue.get_context();
+
+ // compute min and max point
+ array<T, 2> extrema(context);
+ reduce(first, last, extrema.begin() + 0, min<T>(), queue);
+ reduce(first, last, extrema.begin() + 1, max<T>(), queue);
+
+ // copy results to host buffer
+ std::vector<T> buffer(2);
+ copy_n(extrema.begin(), 2, buffer.begin(), queue);
+
+ // copy to vtk-style bounds
+ bounds[0] = buffer[0][0]; bounds[1] = buffer[1][0];
+ bounds[2] = buffer[0][1]; bounds[3] = buffer[1][1];
+ bounds[4] = buffer[0][2]; bounds[5] = buffer[1][2];
+}
+
+} // end compute namespace
+} // end boost namespace
+
+#endif // BOOST_COMPUTE_INTEROP_VTK_BOUNDS_HPP