/*!
 * 04_transformations.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: 05/02/2024
 *
 */

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

#include <catch.hpp>

#include "raytracing.h"

using namespace Raytracer;

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

TEST_CASE("[04][TRANSFORMATION] Multiplying by a translation matrix", "[Matrix]")
{
    Matrix transform = Matrix::translation(5, -3, 2);
    Tuple p = Tuple::Point(-3, 4, 5);

    REQUIRE(transform * p == Tuple::Point(2, 1, 7));
}

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

TEST_CASE("[04][TRANSFORMATION] Multiplying by the inverse of a translation matrix", "[Matrix]")
{
    Matrix transform = Matrix::translation(5, -3, 2);
    Matrix inv = transform.inverse();
    Tuple p = Tuple::Point(-3, 4, 5);

    REQUIRE(inv * p == Tuple::Point(-8, 7, 3));
}

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

TEST_CASE("[04][TRANSFORMATION] Translation does not affect vectors", "[Matrix]")
{
    Matrix transform = Matrix::translation(5, -3, 2);
    Tuple v = Tuple::Vector(-3, 4, 5);

    REQUIRE(transform * v == v);
}

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

TEST_CASE("[04][TRANSFORMATION] A scaling matrix applied to a point", "[Matrix]")
{
    Matrix transform = Matrix::scaling(2, 3, 4);
    Tuple p = Tuple::Point(-4, 6, 8);

    REQUIRE(transform * p == Tuple::Point(-8, 18, 32));
}

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

TEST_CASE("[04][TRANSFORMATION] A scaling matrix applied to a vector", "[Matrix]")
{
    Matrix transform = Matrix::scaling(2, 3, 4);
    Tuple v = Tuple::Vector(-4, 6, 8);

    REQUIRE(transform * v == Tuple::Vector(-8, 18, 32));
}

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

TEST_CASE("[04][TRANSFORMATION] Multiplying by the inverse of a scaling matrix", "[Matrix]")
{
    Matrix transform = Matrix::scaling(2, 3, 4);
    Matrix inv = transform.inverse();
    Tuple v = Tuple::Vector(-4, 6, 8);

    REQUIRE(inv * v == Tuple::Vector(-2, 2, 2));
}

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

TEST_CASE("[04][TRANSFORMATION] Reflection is scaling by a negative value", "[Matrix]")
{
    Matrix transform = Matrix::scaling(-1, 1, 1);
    Tuple p = Tuple::Point(2, 3, 4);

    REQUIRE(transform * p == Tuple::Point(-2, 3, 4));
}