/*!
 * 07_making_scene.cpp
 *
 * Copyright (c) 2015-2024, NADAL Jean-Baptiste. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301 USA
 *
 * @Author:  NADAL Jean-Baptiste
 * @Date: 14/02/2024
 *
 */

/*---------------------------------------------------------------------------*/

#include <catch.hpp>

#include "raytracing.h"

using namespace Raytracer;

/* ------------------------------------------------------------------------- */

SCENARIO("Creating a world", "[features/world.feature]")
{
    GIVEN("w <- world()")
    {
        World w;
        THEN("w contains no objects")
        {
            REQUIRE(w.objects_count() == 0);
        }
        AND_THEN("w has no light source")
        {
            REQUIRE(w.has_light() == false);
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("The default world", "[features/world.feature]")
{
    GIVEN("light <- point_light(point(-10, 10, 10), color(1, 1, 1))")
    {
        PointLight light = PointLight(Tuple::Point(-10, 10, 10), Color(1, 1, 1));
        AND_GIVEN("s1 <- sphere")
        // with:
        //  |  material.color    | (0.8, 1.0, 0.6) |
        //  |  material.diffuse  |  0.7            |
        //  |  material.specular |  0.2            |
        {
            Sphere s1;
            s1.material().set_color(Color(0.8, 1.0, 0.6));
            s1.material().set_diffuse(0.7);
            s1.material().set_specular(0.2);
            AND_GIVEN("s2 <- sphere")
            // with:
            //  |  transform    | scaling(0.5, 0.5, 0.5) |
            {
                Sphere s2;
                s2.set_transform(Matrix::scaling(0.5, 0.5, 0.5));
                WHEN("w <- default_world")
                {
                    World w = World::default_world();
                    THEN("w.light = light")
                    {
                        REQUIRE(w.light() == light);
                    }
                    AND_THEN("w contains s1")
                    {
                        REQUIRE(w.contains(s1) == true);
                    }
                    AND_THEN("w contains s2")
                    {
                        REQUIRE(w.contains(s2) == true);
                    }
                }
            }
        }
    }
}

/* ------------------------------------------------------------------------- */

SCENARIO("Intersect a world with a ray", "[features/world.feature]")
{
    GIVEN("w <- default_world()")
    {
        World w = World::default_world();
        AND_GIVEN("r <- ray(point(0, 0, -5), vector(0, 0, 1))")
        {
            Ray r(Tuple::Point(0, 0, -5), Tuple::Vector(0, 0, 1));
            WHEN("xs <- intersect_world(w,r)")
            {
                Intersections xs = w.intersect_world(r);
                THEN("xs.count = 4")
                {
                    REQUIRE(xs.count() == 4);
                }
                AND_THEN("xs[0].t = 4")
                {
                    REQUIRE(xs[0].distance_t() == 4);
                }
                AND_THEN("xs[1].t = 4.5")
                {
                    REQUIRE(xs[1].distance_t() == 4.5);
                }
                AND_THEN("xs[2].t = 5.5")
                {
                    REQUIRE(xs[2].distance_t() == 5.5);
                }
                AND_THEN("xs[3].t = 6")
                {
                    REQUIRE(xs[3].distance_t() == 6);
                }
            }
        }
    }
}