From f3fe0b6bbe6c690540948b8f6d393f1bed437cef Mon Sep 17 00:00:00 2001
From: fallenoak <git@fallenoak.me>
Date: Mon, 30 Nov 2020 17:28:07 -0600
Subject: [PATCH] feat(matrix): add C44Matrix::RotateAroundZ

---
 tempest/matrix/C44Matrix.cpp |  4 ++++
 tempest/matrix/C44Matrix.hpp |  1 +
 test/Matrix.cpp              | 23 +++++++++++++++++++++++
 3 files changed, 28 insertions(+)

diff --git a/tempest/matrix/C44Matrix.cpp b/tempest/matrix/C44Matrix.cpp
index 823cfcc..d472ca2 100644
--- a/tempest/matrix/C44Matrix.cpp
+++ b/tempest/matrix/C44Matrix.cpp
@@ -60,6 +60,10 @@ C44Matrix C44Matrix::Inverse(float det) const {
     return this->Adjoint() * (1.0f / det);
 }
 
+void C44Matrix::RotateAroundZ(float angle) {
+    *this = C44Matrix::RotationAroundZ(angle) * *this;
+}
+
 C44Matrix operator*(const C44Matrix& l, float a) {
     float a0 = l.a0 * a;
     float a1 = l.a1 * a;
diff --git a/tempest/matrix/C44Matrix.hpp b/tempest/matrix/C44Matrix.hpp
index 7a65633..0b59ea8 100644
--- a/tempest/matrix/C44Matrix.hpp
+++ b/tempest/matrix/C44Matrix.hpp
@@ -46,6 +46,7 @@ class C44Matrix {
     C44Matrix Adjoint() const;
     float Determinant() const;
     C44Matrix Inverse(float det) const;
+    void RotateAroundZ(float angle);
 };
 
 C44Matrix operator*(const C44Matrix& l, float a);
diff --git a/test/Matrix.cpp b/test/Matrix.cpp
index 0fccf8a..93bde16 100644
--- a/test/Matrix.cpp
+++ b/test/Matrix.cpp
@@ -235,6 +235,29 @@ TEST_CASE("C44Matrix::Inverse", "[matrix]") {
     }
 }
 
+TEST_CASE("C44Matrix::RotateAroundZ", "[matrix]") {
+    SECTION("rotates around z-axis by given angle") {
+        auto matrix = C44Matrix(1.0f, 1.0f, 1.0f, 0.0f, 1.0f, 1.0f, -1.0f, 0.0f, 1.0f, -1.0f, 1.0f, 0.0f, 20.0f, 30.0f, 40.0f, 1.0f);
+        matrix.RotateAroundZ(3.1415927f);
+        CHECK(matrix.a0 == Approx(-1.0f));
+        CHECK(matrix.a1 == Approx(-1.0f));
+        CHECK(matrix.a2 == Approx(-1.0f));
+        CHECK(matrix.a3 == 0.0f);
+        CHECK(matrix.b0 == Approx(-1.0f));
+        CHECK(matrix.b1 == Approx(-1.0f));
+        CHECK(matrix.b2 == Approx(1.0f));
+        CHECK(matrix.b3 == 0.0f);
+        CHECK(matrix.c0 == Approx(1.0f));
+        CHECK(matrix.c1 == Approx(-1.0f));
+        CHECK(matrix.c2 == Approx(1.0f));
+        CHECK(matrix.c3 == 0.0f);
+        CHECK(matrix.d0 == 20.0f);
+        CHECK(matrix.d1 == 30.0f);
+        CHECK(matrix.d2 == 40.0f);
+        CHECK(matrix.d3 == 1.0f);
+    }
+}
+
 TEST_CASE("C44Matrix global operators", "[matrix]") {
     SECTION("C44Matrix * float") {
         auto matrix1 = C44Matrix(1.0f, 2.0f, 3.0f, 4.0f, 5.0f, 6.0f, 7.0f, 8.0f, 9.0f, 10.0f, 11.0f, 12.0f, 13.0f, 14.0f, 15.0f, 16.0f);