From 80cf87158ec494dd0a5c57ee37fb63b000e11194 Mon Sep 17 00:00:00 2001
From: iwubcode <iwubcode@users.noreply.github.com>
Date: Fri, 12 Mar 2021 00:02:06 -0600
Subject: [PATCH] VideoCommon: update FreeLook camera to add quaternion based
 rotation, fix orbital and fps implementations

---
 Source/Core/VideoCommon/FreeLookCamera.cpp | 28 +++++++++++++++++-----
 Source/Core/VideoCommon/FreeLookCamera.h   |  1 +
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/Source/Core/VideoCommon/FreeLookCamera.cpp b/Source/Core/VideoCommon/FreeLookCamera.cpp
index 5526ff50f0..25eb2a7c89 100644
--- a/Source/Core/VideoCommon/FreeLookCamera.cpp
+++ b/Source/Core/VideoCommon/FreeLookCamera.cpp
@@ -102,15 +102,20 @@ public:
 
   void Rotate(const Common::Vec3& amt) override
   {
+    if (amt.Length() == 0)
+      return;
+
     m_rotation += amt;
 
     using Common::Quaternion;
-    const auto quat =
+    m_rotate_quat =
         (Quaternion::RotateX(m_rotation.x) * Quaternion::RotateY(m_rotation.y)).Normalized();
-    Rotate(quat);
   }
 
-  void Rotate(const Common::Quaternion& quat) override { m_rotate_quat = quat; }
+  void Rotate(const Common::Quaternion& quat) override
+  {
+    Rotate(Common::FromQuaternionToEuler(quat));
+  }
 
   void Reset() override
   {
@@ -153,15 +158,20 @@ public:
 
   void Rotate(const Common::Vec3& amt) override
   {
+    if (amt.Length() == 0)
+      return;
+
     m_rotation += amt;
 
     using Common::Quaternion;
-    const auto quat =
+    m_rotate_quat =
         (Quaternion::RotateX(m_rotation.x) * Quaternion::RotateY(m_rotation.y)).Normalized();
-    Rotate(quat);
   }
 
-  void Rotate(const Common::Quaternion& quat) override { m_rotate_quat = quat; }
+  void Rotate(const Common::Quaternion& quat) override
+  {
+    Rotate(Common::FromQuaternionToEuler(quat));
+  }
 
   void Reset() override
   {
@@ -246,6 +256,12 @@ void FreeLookCamera::Rotate(const Common::Vec3& amt)
   m_dirty = true;
 }
 
+void FreeLookCamera::Rotate(const Common::Quaternion& amt)
+{
+  m_camera_controller->Rotate(amt);
+  m_dirty = true;
+}
+
 void FreeLookCamera::IncreaseFovX(float fov)
 {
   m_fov_x += fov;
diff --git a/Source/Core/VideoCommon/FreeLookCamera.h b/Source/Core/VideoCommon/FreeLookCamera.h
index f4a3242905..389c4cc5cf 100644
--- a/Source/Core/VideoCommon/FreeLookCamera.h
+++ b/Source/Core/VideoCommon/FreeLookCamera.h
@@ -52,6 +52,7 @@ public:
   void MoveForward(float amt);
 
   void Rotate(const Common::Vec3& amt);
+  void Rotate(const Common::Quaternion& amt);
 
   void IncreaseFovX(float fov);
   void IncreaseFovY(float fov);