From b531e0b7146689b9ffa62deb2d4f3f2f71dec397 Mon Sep 17 00:00:00 2001
From: NADAL Jean-Baptiste <jbnadal@cabassegroup.com>
Date: Mon, 5 Feb 2024 17:02:42 +0100
Subject: [PATCH] [FEAT]Add maxtrix translation

---
 raytracing/src/matrix.cpp    | 14 ++++++++
 raytracing/src/matrix.h      |  1 +
 tests/04_transformations.cpp | 63 ++++++++++++++++++++++++++++++++++++
 tests/CMakeLists.txt         |  1 +
 4 files changed, 79 insertions(+)
 create mode 100644 tests/04_transformations.cpp

diff --git a/raytracing/src/matrix.cpp b/raytracing/src/matrix.cpp
index 3f24caf..3e8b968 100644
--- a/raytracing/src/matrix.cpp
+++ b/raytracing/src/matrix.cpp
@@ -312,6 +312,20 @@ Matrix Matrix::identity(void)
 
 /* ------------------------------------------------------------------------- */
 
+Matrix Matrix::translation(double an_x, double an_y, double an_z)
+{
+    Matrix the_translation = {
+        {1, 0, 0, an_x},
+        {0, 1, 0, an_y},
+        {0, 0, 1, an_z},
+        {0, 0, 0,    1}
+    };
+
+    return the_translation;
+}
+
+/* ------------------------------------------------------------------------- */
+
 bool Matrix::validate_dimensions(const std::initializer_list<std::initializer_list<double>> &a_values) const
 {
     for (const auto &the_row : a_values)
diff --git a/raytracing/src/matrix.h b/raytracing/src/matrix.h
index 138a181..bfaf2a3 100644
--- a/raytracing/src/matrix.h
+++ b/raytracing/src/matrix.h
@@ -71,6 +71,7 @@ namespace Raytracer
         Matrix inverse(void) const;
 
         static Matrix identity(void);
+        static Matrix translation(double an_x, double an_y, double an_z);
 
     private:
         bool validate_dimensions(const std::initializer_list<std::initializer_list<double>> &a_values) const;
diff --git a/tests/04_transformations.cpp b/tests/04_transformations.cpp
new file mode 100644
index 0000000..418e6ac
--- /dev/null
+++ b/tests/04_transformations.cpp
@@ -0,0 +1,63 @@
+/*!
+ * 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);
+}
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 3042c83..a35c2fa 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -14,6 +14,7 @@ add_executable(main_test
     02_1_colors.cpp
     02_2_canvas.cpp
     03_matrix.cpp
+    04_transformations.cpp
 )
 
 include_directories("${CMAKE_SOURCE_DIR}/tests")