QoL: Don't let user pan out of more than half of the video frame and reset pan+zoom when zooming completely out

FlyleafLib/Engine/Config.cs

@@ -300,6 +300,16 @@ public ThreadPriority
         /// </summary>
         public Usage    Usage                       { get; set; } = Usage.AVS;
 
+        /// <summary>
+        /// Restrict panning of the video outside of half the video width or height
+        /// </summary>
+        public bool RestrictPanning                 { get; set; } = false;
+
+        /// <summary>
+        /// Reset pan and zoom level when zooming out to less than 100%
+        /// </summary>
+        public bool ResetPanOnZoomedOut             { get; set; } = false;
+
         // Offsets
         public long     AudioDelayOffset            { get; set; } =  100 * 10000;
         public long     AudioDelayOffset2           { get; set; } = 1000 * 10000;

FlyleafLib/MediaFramework/MediaRenderer/Renderer.SwapChain.cs

@@ -325,8 +325,43 @@ public void SetViewport(bool refresh = true)
             yZoomPixels = newHeight - (ControlHeight - SideYPixels);
         }
 
+        if (Config.Player.RestrictPanning)
+        {
+            // Don't let the user pan or zoom outside of half the video's height
+            int newY = (int)(y - yZoomPixels * (float)zoomCenter.Y);
+            int bottom = newHeight + newY;
+            if (newY > ControlHeight / 2d)
+            {
+                y = (int)((ControlHeight / 2d) + yZoomPixels * (float)zoomCenter.Y);
+                panYOffset = y - SideYPixels / 2;
+            }
+            else if (bottom < ControlHeight / 2d)
+            {
+                int newBottom = (int)(ControlHeight / 2d);
+                int newNewY = newBottom - newHeight;
+                y = (int)(newNewY + yZoomPixels * (float)zoomCenter.Y);
+                panYOffset = y - SideYPixels / 2;
+            }
+
+            // Don't let the user pan or zoom outside of half the video's width
+            int newX = (int)(x - xZoomPixels * (float)zoomCenter.X);
+            int right = newWidth + newX;
+            if (newX > ControlWidth / 2d)
+            {
+                x = (int)((ControlWidth / 2d) + xZoomPixels * (float)zoomCenter.X);
+                panXOffset = x - SideXPixels / 2;
+            }
+            else if (right < ControlWidth / 2d)
+            {
+                int newRight = (int)(ControlWidth / 2d);
+                int newNewX = newRight - newWidth;
+                x = (int)(newNewX + xZoomPixels * (float)zoomCenter.X);
+                panXOffset = x - SideXPixels / 2;
+            }
+        }
+
         GetViewport = new(x - xZoomPixels * (float)zoomCenter.X, y - yZoomPixels * (float)zoomCenter.Y, newWidth, newHeight);
-        ViewportChanged?.Invoke(this, new());
+        ViewportChanged?.Invoke(this, EventArgs.Empty);
 
         if (videoProcessor == VideoProcessors.D3D11)
         {

FlyleafLib/MediaFramework/MediaRenderer/Renderer.cs

@@ -122,6 +122,15 @@ public void SetZoom(double zoom, bool refresh = true)
     {
         lock(lockDevice)
         {
+            if (Config.Player.ResetPanOnZoomedOut)
+            {
+                if (zoom < 1)
+                {
+                    ResetPanAndZoom(refresh);
+                    return;
+                }
+            }
+
             this.zoom = zoom;
 
             if (Disposed)
@@ -151,6 +160,15 @@ public void SetZoomAndCenter(double zoom, Point p, bool refresh = true)
     {
         lock(lockDevice)
         {
+            if (Config.Player.ResetPanOnZoomedOut)
+            {
+                if (zoom < 1)
+                {
+                    ResetPanAndZoom(refresh);
+                    return;
+                }
+            }
+
             this.zoom = zoom;
             zoomCenter = p;
 
@@ -179,6 +197,19 @@ public void SetPanAll(int panX, int panY, uint rotation, double zoom, Point p, b
         }
     }
 
+    private void ResetPanAndZoom(bool refresh = true)
+    {
+        panXOffset = panYOffset = 0;
+        zoom = 1;
+        zoomCenter = ZoomCenterPoint;
+
+        if (Disposed)
+            return;
+
+        if (refresh)
+            SetViewport();
+    }
+
     public int              UniqueId        { get; private set; }
     public bool             HasFLFilters    { get; private set; }
     public VideoFrame       LastFrame       { get; set; }