//
// Copyright 2019 Miral Shah <miralshah2211@gmail.com>
//
// Use, modification and distribution are subject to 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)
//
#include <boost/gil/image_processing/threshold.hpp>
#include <boost/gil/image_view.hpp>
#include <boost/gil/algorithm.hpp>
#include <boost/gil/gray.hpp>
#include <boost/core/lightweight_test.hpp>


namespace gil = boost::gil;

int main()
{
    int height = 4;
    int width = 4;
    gil::gray8_image_t original(width, height), threshold(width, height),
        expected(width, height);

    //filling original view's upper half part with gray pixels of value 50
    //filling original view's lower half part with gray pixels of value 150
    gil::fill_pixels(gil::subimage_view(gil::view(original), 0, 0, original.width(),
        original.height() / 2), gil::gray8_pixel_t(50));
    gil::fill_pixels(gil::subimage_view(gil::view(original), 0, original.height() / 2,
        original.width(), original.height() / 2), gil::gray8_pixel_t(150));
    

    /*--------------------------------Mode Threshold------------------------------------*/
    /*-------------------------------Direction Regular----------------------------------*/

    //expected view after thresholding of the original view with threshold value of 100
    //filling expected view's upper half part with gray pixels of value 50
    //filling expected view's lower half part with gray pixels of value 100
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, 0, original.width(),
        original.height() / 2), gil::gray8_pixel_t(50));
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, original.height() / 2,
        original.width(), original.height() / 2), gil::gray8_pixel_t(100));

    gil::threshold_truncate(gil::view(original), gil::view(threshold), 100);

    //comparing threshold view generated by the function with the expected view
    BOOST_TEST(gil::equal_pixels(gil::view(threshold), gil::view(expected)));

    /*--------------------------------Mode Threshold------------------------------------*/
    /*-------------------------------Direction Inverse----------------------------------*/

    //expected view after thresholding of the original view with threshold value of 100
    //filling expected view's upper half part with gray pixels of value 100
    //filling expected view's lower half part with gray pixels of value 150
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, 0, original.width(),
        original.height() / 2), gil::gray8_pixel_t(100));
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, original.height() / 2,
        original.width(), original.height() / 2), gil::gray8_pixel_t(150));

    gil::threshold_truncate
    (
        gil::view(original),
        gil::view(threshold),
        100,
        gil::threshold_truncate_mode::threshold,
        gil::threshold_direction::inverse
    );

    //comparing threshold view generated by the function with the expected view
    BOOST_TEST(gil::equal_pixels(gil::view(threshold), gil::view(expected)));

    /*-----------------------------------Mode Zero--------------------------------------*/
    /*-------------------------------Direction Regular----------------------------------*/

    //expected view after thresholding of the original view with threshold value of 100
    //filling expected view's upper half part with gray pixels of value 0
    //filling expected view's lower half part with gray pixels of value 150
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, 0, original.width(),
        original.height() / 2), gil::gray8_pixel_t(0));
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, original.height() / 2,
        original.width(), original.height() / 2), gil::gray8_pixel_t(150));

    gil::threshold_truncate
    (
        gil::view(original),
        gil::view(threshold),
        100,
        gil::threshold_truncate_mode::zero,
        gil::threshold_direction::regular
    );

    //comparing threshold view generated by the function with the expected view
    BOOST_TEST(gil::equal_pixels(gil::view(threshold), gil::view(expected)));

    /*-----------------------------------Mode Zero--------------------------------------*/
    /*-------------------------------Direction Inverse----------------------------------*/

    //expected view after thresholding of the original view with threshold value of 100
    //filling expected view's upper half part with gray pixels of value 50
    //filling expected view's lower half part with gray pixels of value 0
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, 0, original.width(),
        original.height() / 2), gil::gray8_pixel_t(50));
    gil::fill_pixels(gil::subimage_view(gil::view(expected), 0, original.height() / 2,
        original.width(), original.height() / 2), gil::gray8_pixel_t(0));

    gil::threshold_truncate
    (
        gil::view(original),
        gil::view(threshold),
        100,
        gil::threshold_truncate_mode::zero,
        gil::threshold_direction::inverse
    );

    //comparing threshold view generated by the function with the expected view
    BOOST_TEST(gil::equal_pixels(gil::view(threshold), gil::view(expected)));

    return boost::report_errors();
}