User/paulm/fps (#198)

* added FPS counters

* handle FPS less than 0

* PR feedback

Author: walrusmcd

Samples/FNSCandyStyleTransfer/UWP/cs/MainPage.xaml

@@ -180,14 +180,30 @@ Copyright (C) Microsoft Corporation. All rights reserved.
                 </StackPanel>
 
             <Border x:Name="UIStatusBorder" Grid.Row="2">
-                <ScrollViewer VerticalScrollMode="Auto"  VerticalScrollBarVisibility="Auto" MaxHeight="200">
+                <StackPanel Orientation="Horizontal">
                     <TextBlock x:Name="StatusBlock" 
-                               Text="Select a style to begin"
-                               FontWeight="Bold" 
-                               MaxWidth="{Binding ElementName=Splitter, Path=ActualWidth}" 
-                               Margin="10,10,10,20" 
-                               TextWrapping="Wrap"  />
-                </ScrollViewer>
+                        Text="Select a style to begin"
+                        FontWeight="Bold" 
+                        Width="700" 
+                        Margin="10,2,0,0"
+                        TextWrapping="Wrap" />
+                    <TextBlock 
+                        Text="Capture FPS"
+                        Margin="10,2,0,0"
+                        FontWeight="Bold" />
+                    <TextBlock x:Name="CaptureFPS" 
+                        Text="0 fps"
+                        Margin="10,2,0,0"
+                        TextWrapping="Wrap" />
+                    <TextBlock 
+                        Text="Render FPS" 
+                        Margin="10,2,0,0"
+                        FontWeight="Bold"/>
+                    <TextBlock x:Name="RenderFPS"
+                        Text="0 fps"
+                        Margin="10,2,0,0"
+                        TextWrapping="Wrap" />
+                </StackPanel>
             </Border>
 
         </Grid>

Samples/FNSCandyStyleTransfer/UWP/cs/MainPage.xaml.cs

@@ -80,6 +80,10 @@ public sealed partial class MainPage : Page
 
         // Debug
         private Stopwatch _perfStopwatch = new Stopwatch(); // performance Stopwatch used throughout
+        private DispatcherTimer _FramesPerSecondTimer = new DispatcherTimer();
+        private long _CaptureFPS = 0;
+        public static long _RenderFPS = 0;
+        private int _LastFPSTick = 0;
 
         public MainPage()
         {
@@ -110,6 +114,47 @@ protected override void OnNavigatedTo(NavigationEventArgs e)
 
             // Select first style
             UIStyleList.SelectedIndex = 0;
+
+            // Create a 1 second timer
+            _FramesPerSecondTimer.Tick += _FramesPerSecond_Tick;
+            _FramesPerSecondTimer.Interval = new TimeSpan(0, 0, 1);
+            _FramesPerSecondTimer.Start();
+        }
+
+        private void _FramesPerSecond_Tick(object sender, object e)
+        {
+            // how many seconds has it been?
+            // Note: we do this math since even though we asked for the event to be 
+            // dispatched every 1s , due to timing and delays, it might not come
+            // exactly every second.   and on a busy system it could even be a couple of
+            // seconds until it is delivered.
+            int fpsTick = System.Environment.TickCount;
+
+            if (_LastFPSTick > 0)
+            {
+                float numberOfSeconds = ((float)(fpsTick - _LastFPSTick)) / (float)1000;
+
+                // how many frames did we capture?
+                float intervalFPS = ((float)_CaptureFPS) / numberOfSeconds;
+                if (intervalFPS == 0.0)
+                    return;
+                NotifyUser(CaptureFPS, $"{intervalFPS:F1}", NotifyType.StatusMessage);
+
+                // how many frames did we render
+                intervalFPS = ((float)_RenderFPS) / numberOfSeconds;
+                if (intervalFPS == 0.0)
+                    return;
+                NotifyUser(RenderFPS, $"{intervalFPS:F1}", NotifyType.StatusMessage);
+            }
+
+            _CaptureFPS = 0;
+            _RenderFPS = 0;
+            _LastFPSTick = fpsTick;
+        }
+
+        public void NotifyUser(string strMessage, NotifyType type)
+        {
+            NotifyUser(StatusBlock, strMessage, type);
         }
 
         /// <summary>
@@ -118,17 +163,17 @@ protected override void OnNavigatedTo(NavigationEventArgs e)
         /// </summary>
         /// <param name="strMessage"></param>
         /// <param name="type"></param>
-        public void NotifyUser(string strMessage, NotifyType type)
+        public void NotifyUser(TextBlock block, string strMessage, NotifyType type)
         {
             // If called from the UI thread, then update immediately.
             // Otherwise, schedule a task on the UI thread to perform the update.
             if (Dispatcher.HasThreadAccess)
             {
-                UpdateStatus(strMessage, type);
+                UpdateStatus(block, strMessage, type);
             }
             else
             {
-                var task = Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => UpdateStatus(strMessage, type));
+                var task = Dispatcher.RunAsync(CoreDispatcherPriority.Normal, () => UpdateStatus(block, strMessage, type));
                 task.AsTask().Wait();
             }
         }
@@ -138,7 +183,7 @@ public void NotifyUser(string strMessage, NotifyType type)
         /// </summary>
         /// <param name="strMessage"></param>
         /// <param name="type"></param>
-        private void UpdateStatus(string strMessage, NotifyType type)
+        private void UpdateStatus(TextBlock block, string strMessage, NotifyType type)
         {
             switch (type)
             {
@@ -150,11 +195,11 @@ private void UpdateStatus(string strMessage, NotifyType type)
                     break;
             }
 
-            StatusBlock.Text = strMessage;
+            block.Text = strMessage;
 
-            // Collapse the StatusBlock if it has no text to conserve real estate.
-            UIStatusBorder.Visibility = (StatusBlock.Text != String.Empty) ? Visibility.Visible : Visibility.Collapsed;
-            if (StatusBlock.Text != String.Empty)
+            // Collapse the TextBlock if it has no text to conserve real estate.
+            UIStatusBorder.Visibility = (block.Text != String.Empty) ? Visibility.Visible : Visibility.Collapsed;
+            if (block.Text != String.Empty)
             {
                 UIStatusBorder.Visibility = Visibility.Visible;
                 UIStatusPanel.Visibility = Visibility.Visible;
@@ -816,6 +861,8 @@ private async void _modelInputFrameReader_FrameArrived(MediaFrameReader sender,
             // Do not attempt processing of more than 1 frame at a time
             _frameAquisitionLock.Wait();
             {
+                _CaptureFPS += 1;
+
                 if (_isProcessingFrames)
                 {
                     _frameAquisitionLock.Release();
@@ -1059,6 +1106,8 @@ public void RenderFrame(SoftwareBitmap softwareBitmap)
                         {
                             var imageSource = (SoftwareBitmapSource)_imageElement.Source;
                             await imageSource.SetBitmapAsync(_backBuffer);
+
+                            MainPage._RenderFPS += 1;
                         }
                         catch (Exception ex)
                         {