//---------------------------------------------------------------------------//
// Copyright (c) 2013 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://kylelutz.github.com/compute for more information.
//---------------------------------------------------------------------------//

#include <iostream>
#include <boost/compute.hpp>

// this example demonstrates how to use Boost.Compute's STL
// implementation to add two vectors on the GPU
int main()
{
    // get the default device
    boost::compute::device gpu =
        boost::compute::system::default_device();

    // create a context for the device
    boost::compute::context context(gpu);

    // create a command queue for the device
    boost::compute::command_queue queue(context, gpu);

    // setup input arrays
    float a[] = { 1, 2, 3, 4 };
    float b[] = { 5, 6, 7, 8 };

    // make space for the output
    float c[] = { 0, 0, 0, 0 };

    // create vectors and transfer data for the input arrays 'a' and 'b'
    boost::compute::vector<float> vector_a(a, a + 4, context);
    boost::compute::vector<float> vector_b(b, b + 4, context);

    // create vector for the output array
    boost::compute::vector<float> vector_c(4, context);

    // add the vectors together
    boost::compute::transform(vector_a.begin(),
                              vector_a.end(),
                              vector_b.begin(),
                              vector_c.begin(),
                              boost::compute::plus<float>(),
                              queue);

    // transfer results back to the host array 'c'
    boost::compute::copy(vector_c.begin(), vector_c.end(), c, queue);

    // print out results in 'c'
    std::cout << "c: [" << c[0] << ", "
                        << c[1] << ", "
                        << c[2] << ", "
                        << c[3] << "]" << std::endl;

    return 0;
}