From dc0bca14c50a1b6adb72d9be5f1494d5cb85d4d9 Mon Sep 17 00:00:00 2001
From: Orange <orange-cpp@yandex.ru>
Date: Thu, 2 Jan 2025 12:52:34 +0300
Subject: [PATCH] added method + tests

---
 include/omath/Vector3.hpp         | 20 ++++++++++++++++++++
 tests/general/UnitTestVector3.cpp |  9 +++++++++
 2 files changed, 29 insertions(+)

diff --git a/include/omath/Vector3.hpp b/include/omath/Vector3.hpp
index b24ad660..7d3ff50d 100644
--- a/include/omath/Vector3.hpp
+++ b/include/omath/Vector3.hpp
@@ -7,9 +7,18 @@
 #include <cstdint>
 #include <functional>
 #include "omath/Vector2.hpp"
+#include "omath/Angle.hpp"
+#include <expected>
+
 
 namespace omath
 {
+
+    enum class Vector3Error
+    {
+        IMPOSSIBLE_BETWEEN_ANGLE,
+    };
+
     class Vector3 : public Vector2
     {
     public:
@@ -208,6 +217,17 @@ namespace omath
             return Sum2D() + z;
         }
 
+        [[nodiscard]] std::expected<Angle<float, 0.f, 180.f, AngleFlags::Clamped>, Vector3Error>
+        AngleBetween(const Vector3& other) const
+        {
+            const auto bottom = Length() * other.Length();
+
+            if (bottom == 0.f)
+                return std::unexpected(Vector3Error::IMPOSSIBLE_BETWEEN_ANGLE);
+
+            return Angle<float, 0.f, 180.f, AngleFlags::Clamped>::FromRadians(std::acos(Dot(other) / bottom));
+        }
+
         [[nodiscard]] constexpr float Sum2D() const
         {
             return Vector2::Sum();
diff --git a/tests/general/UnitTestVector3.cpp b/tests/general/UnitTestVector3.cpp
index f08a35f8..14002d34 100644
--- a/tests/general/UnitTestVector3.cpp
+++ b/tests/general/UnitTestVector3.cpp
@@ -387,6 +387,15 @@ TEST_F(UnitTestVector3, AsTuple)
     EXPECT_FLOAT_EQ(std::get<2>(tuple), v1.z);
 }
 
+// Test AsTuple method
+TEST_F(UnitTestVector3, AngleBeatween)
+{
+    EXPECT_EQ(Vector3(0.0f, 0.0f, 1.0f).AngleBetween({1, 0 ,0}).value().AsDegrees(), 90.0f);
+    EXPECT_EQ(Vector3(0.0f, 0.0f, 1.0f).AngleBetween({0.0f, 0.0f, 1.0f}).value().AsDegrees(), 0.0f);
+    EXPECT_FALSE(Vector3(0.0f, 0.0f, 0.0f).AngleBetween({0.0f, 0.0f, 1.0f}).has_value());
+}
+
+
 // Static assertions (compile-time checks)
 static_assert(Vector3(1.0f, 2.0f, 3.0f).LengthSqr() == 14.0f, "LengthSqr should be 14");
 static_assert(Vector3(1.0f, 2.0f, 3.0f).Dot(Vector3(4.0f, 5.0f, 6.0f)) == 32.0f, "Dot product should be 32");