From 4815e77f1f032c649e0db1095dc6fe3d5839239d Mon Sep 17 00:00:00 2001
From: Eric Wasylishen <ewasylishen@gmail.com>
Date: Sun, 21 May 2023 12:46:53 -0600
Subject: [PATCH] lightpreview: reduce stuttering when using WASD + mouselook
 together

---
 lightpreview/glview.cpp | 22 +++++++++++++++-------
 lightpreview/glview.h   |  3 +++
 2 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/lightpreview/glview.cpp b/lightpreview/glview.cpp
index 755ccf9c..a89bb03d 100644
--- a/lightpreview/glview.cpp
+++ b/lightpreview/glview.cpp
@@ -332,7 +332,7 @@ void GLView::mouseMoveEvent(QMouseEvent *event)
     // now rotate m_cameraFwd and m_cameraUp by mouseRotation
     m_cameraFwd = mouseRotation * m_cameraFwd;
 
-    repaint();
+    update();
 }
 
 static keys_t Qt_Key_To_keys_t(int key)
@@ -351,7 +351,8 @@ void GLView::startMovementTimer()
     if (m_keymoveUpdateTimer)
         return;
 
-    m_keymoveUpdateTimer = startTimer(10); // repaint timer, calls timerEvent()
+    m_lastKeymoveFrame = I_FloatTime();
+    m_keymoveUpdateTimer = startTimer(1); // repaint timer, calls timerEvent()
 }
 
 void GLView::stopMovementTimer()
@@ -390,16 +391,23 @@ void GLView::wheelEvent(QWheelEvent *event)
 
 void GLView::timerEvent(QTimerEvent *event)
 {
-    const float speed = 10;
+    // update frame time
+    auto current_time = I_FloatTime();
+    auto duration = current_time - m_lastKeymoveFrame;
+    m_lastKeymoveFrame = current_time;
+
+    // qDebug() << "timer event: duration: " << duration.count();
+
+    const float distance = 1000 * duration.count();
 
     if (m_keysPressed & static_cast<uint32_t>(keys_t::up))
-        m_cameraOrigin += m_cameraFwd * speed;
+        m_cameraOrigin += m_cameraFwd * distance;
     if (m_keysPressed & static_cast<uint32_t>(keys_t::down))
-        m_cameraOrigin -= m_cameraFwd * speed;
+        m_cameraOrigin -= m_cameraFwd * distance;
     if (m_keysPressed & static_cast<uint32_t>(keys_t::left))
-        m_cameraOrigin -= cameraRight() * speed;
+        m_cameraOrigin -= cameraRight() * distance;
     if (m_keysPressed & static_cast<uint32_t>(keys_t::right))
-        m_cameraOrigin += cameraRight() * speed;
+        m_cameraOrigin += cameraRight() * distance;
 
     update(); // schedule a repaint
 }
diff --git a/lightpreview/glview.h b/lightpreview/glview.h
index f2a96cd1..bb516fdd 100644
--- a/lightpreview/glview.h
+++ b/lightpreview/glview.h
@@ -31,6 +31,8 @@ See file, 'COPYING', for details.
 
 #include <vector>
 
+#include <common/cmdlib.hh>
+
 enum class keys_t : uint32_t
 {
     none = 0,
@@ -47,6 +49,7 @@ class GLView : public QOpenGLWidget, protected QOpenGLFunctions
 private:
     uint32_t m_keysPressed;
     int m_keymoveUpdateTimer;
+    time_point m_lastKeymoveFrame;
     QPointF m_lastMouseDownPos;
 
     // camera stuff