From bc51c34a962aa314e3326487d0dd60e621ab69a4 Mon Sep 17 00:00:00 2001
From: spycrab <spycrab@users.noreply.github.com>
Date: Sun, 29 Apr 2018 13:35:43 +0200
Subject: [PATCH] Qt: Implement "Free look"

---
 Source/Core/DolphinQt2/RenderWidget.cpp | 27 +++++++++++++++++++++++++
 Source/Core/DolphinQt2/RenderWidget.h   |  5 +++++
 2 files changed, 32 insertions(+)

diff --git a/Source/Core/DolphinQt2/RenderWidget.cpp b/Source/Core/DolphinQt2/RenderWidget.cpp
index c2bbec0d4b..0d82a40372 100644
--- a/Source/Core/DolphinQt2/RenderWidget.cpp
+++ b/Source/Core/DolphinQt2/RenderWidget.cpp
@@ -6,12 +6,16 @@
 #include <QDesktopWidget>
 #include <QGuiApplication>
 #include <QKeyEvent>
+#include <QMouseEvent>
 #include <QPalette>
 #include <QScreen>
 #include <QTimer>
 
 #include "Core/ConfigManager.h"
 #include "Core/Core.h"
+#include "VideoCommon/VertexShaderManager.h"
+#include "VideoCommon/VideoConfig.h"
+
 #include "DolphinQt2/Host.h"
 #include "DolphinQt2/RenderWidget.h"
 #include "DolphinQt2/Settings.h"
@@ -120,6 +124,10 @@ bool RenderWidget::event(QEvent* event)
     break;
   }
   case QEvent::MouseMove:
+    if (g_Config.bFreeLook)
+      OnFreeLookMouseMove(static_cast<QMouseEvent*>(event));
+
+  // [[fallthrough]]
   case QEvent::MouseButtonPress:
     if (!Settings::Instance().GetHideCursor() && isActiveWindow())
     {
@@ -162,3 +170,22 @@ bool RenderWidget::event(QEvent* event)
   }
   return QWidget::event(event);
 }
+
+void RenderWidget::OnFreeLookMouseMove(QMouseEvent* event)
+{
+  if (event->buttons() & Qt::MidButton)
+  {
+    // Mouse Move
+    VertexShaderManager::TranslateView((event->x() - m_last_mouse[0]) / 50.0f,
+                                       (event->y() - m_last_mouse[1]) / 50.0f);
+  }
+  else if (event->buttons() & Qt::RightButton)
+  {
+    // Mouse Look
+    VertexShaderManager::RotateView((event->x() - m_last_mouse[0]) / 200.0f,
+                                    (event->y() - m_last_mouse[1]) / 200.0f);
+  }
+
+  m_last_mouse[0] = event->x();
+  m_last_mouse[1] = event->y();
+}
diff --git a/Source/Core/DolphinQt2/RenderWidget.h b/Source/Core/DolphinQt2/RenderWidget.h
index 0c89363fa0..6122fc8633 100644
--- a/Source/Core/DolphinQt2/RenderWidget.h
+++ b/Source/Core/DolphinQt2/RenderWidget.h
@@ -4,9 +4,12 @@
 
 #pragma once
 
+#include <array>
+
 #include <QEvent>
 #include <QWidget>
 
+class QMouseEvent;
 class QTimer;
 
 class RenderWidget final : public QWidget
@@ -31,7 +34,9 @@ private:
   void OnHideCursorChanged();
   void OnKeepOnTopChanged(bool top);
   void SetFillBackground(bool fill);
+  void OnFreeLookMouseMove(QMouseEvent* event);
 
   static constexpr int MOUSE_HIDE_DELAY = 3000;
   QTimer* m_mouse_timer;
+  std::array<float, 2> m_last_mouse{};
 };