compatibility checks for kitty, experimental windowsizing stuff.

Author: trackd

docs/en-US/ConvertTo-Sixel.md

@@ -132,7 +132,10 @@ Accept wildcard characters: False
 
 ### -Protocol
 
-Select the image protocol to output, supports Sixel & InlineImageProtocol (1337 xterm).  
+Select the image protocol to output.  
+Supports Sixel, InlineImageProtocol, KittyGraphicsProtocol  
+
+It will attempt to autoselect the supported image protocol for your terminal.  
 
 ```yaml
 Type: ImageProtocol

src/Sixel/Sixel.csproj

@@ -18,7 +18,7 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
-    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.5" />
+    <PackageReference Include="SixLabors.ImageSharp" Version="3.1.6" />
     <PackageReference Include="System.Management.Automation" Version="7.4.6" PrivateAssets="all" />
     <ProjectReference Include="../Sixel.Shared/Sixel.Shared.csproj" />
 </ItemGroup>

src/Sixel/Terminal/Compatibility.cs

@@ -1,4 +1,5 @@
 using Sixel.Terminal.Models;
+using System.Diagnostics;
 
 namespace Sixel.Terminal;
 
@@ -9,6 +10,11 @@ public static class Compatibility
   /// </summary>
   private static bool? _terminalSupportsSixel;
 
+  /// <summary>
+  /// Check if the terminal supports kitty graphics
+  /// </summary>
+  private static bool? _terminalSupportsKitty;
+
   /// <summary>
   /// Memory-caches the result of the terminal cell size.
   /// </summary>
@@ -17,8 +23,12 @@ public static class Compatibility
   /// <summary>
   /// get the terminal info
   /// </summary>
-
   private static TerminalInfo? _terminalInfo;
+
+  private static WindowSizePixels? _windowSizePixels;
+
+  private static WindowSizeCharacters? _windowSizeCharacters;
+
   /// <summary>
   /// Get the cell size of the terminal in pixel-sixel size.
   /// The response to the command will look like [6;20;10t where the 20 is height and 10 is width.
@@ -52,9 +62,55 @@ public static CellSize GetCellSize()
         PixelHeight = 20
       };
     }
-
     return _cellSize;
   }
+  public static WindowSizePixels GetWindowSizePixels()
+  {
+    // this class should be able to re-run, people can resize the terminal
+    // so should not cache the result.. hopefully this is not too slow
+    var response14 = GetControlSequenceResponse("[14t");
+    try
+    {
+      var parts14 = response14.Split(';', 't');
+      _windowSizePixels = new WindowSizePixels
+      {
+        PixelWidth = int.Parse(parts14[2]),
+        PixelHeight = int.Parse(parts14[1]),
+      };
+    }
+    catch
+    {
+      _windowSizePixels = new WindowSizePixels
+      {
+        PixelWidth = 0,
+        PixelHeight = 0
+      };
+    }
+    return _windowSizePixels;
+  }
+  public static WindowSizeCharacters GetWindowSizeCharacters()
+  {
+    // this class should be able to re-run, people can resize the terminal
+    // so should not cache the result.. hopefully this is not too slow
+    var response18 = GetControlSequenceResponse("[18t");
+    try
+    {
+      var parts18 = response18.Split(';', 't');
+      _windowSizeCharacters = new WindowSizeCharacters
+      {
+        CharacterWidth = int.Parse(parts18[2]),
+        CharacterHeight = int.Parse(parts18[1]),
+      };
+    }
+    catch {
+      _windowSizeCharacters = new WindowSizeCharacters
+      {
+        CharacterWidth = 0,
+        CharacterHeight = 0
+      };
+    }
+    return _windowSizeCharacters;
+  }
 
   /// <summary>
   /// Check if the terminal supports sixel graphics.
@@ -69,17 +125,28 @@ public static bool TerminalSupportsSixel()
     {
       return _terminalSupportsSixel.Value;
     }
-
     _terminalSupportsSixel = GetControlSequenceResponse("[c").Contains(";4;");
-
     return _terminalSupportsSixel.Value;
   }
 
   /// <summary>
-  /// Send a control sequence to the terminal and read back the response from STDIN.
+  /// Check if the terminal supports kitty graphics.
+  /// https://sw.kovidgoyal.net/kitty/graphics-protocol/
+  // response: ␛_Gi=31;OK␛\␛[?62;c
   /// </summary>
-  /// <param name="controlSequence"></param>
-  /// <returns>The response from the terminal.</returns>
+  /// <returns>True if the terminal supports sixel graphics, false otherwise.</returns>
+  public static bool TerminalSupportsKitty()
+  {
+    if (_terminalSupportsKitty.HasValue)
+    {
+      return _terminalSupportsKitty.Value;
+    }
+    // string kittyTest = $"_Gi=31,s=1,v=1,a=q,t=d,f=24;AAAA{Constants.ESC}\\{Constants.ESC}[c";
+    string kittyTest = $"_Gi=31,s=1,v=1,a=q,t=d,f=24;AAAA{Constants.ESC}\\";
+    _terminalSupportsKitty = GetControlSequenceResponse(kittyTest).Contains(";OK");
+    return _terminalSupportsKitty.Value;
+  }
+
   private static string GetControlSequenceResponse(string controlSequence)
   {
     char? c;

src/Sixel/Terminal/Load.cs

@@ -27,6 +27,10 @@ public static class Load
     }
     if (imageProtocol == ImageProtocol.KittyGraphicsProtocol)
     {
+      if (Compatibility.TerminalSupportsKitty() == false && Force == false)
+      {
+        throw new InvalidOperationException("Terminal does not support Kitty, override with -Force");
+      }
       if (width > 0)
       {
         // we need to resize the image to the target width

src/Sixel/Terminal/Models/WindowSizeCharacters.cs

@@ -0,0 +1,17 @@
+namespace Sixel.Terminal.Models;
+
+/// <summary>
+/// Represents the size of the terminal window in characters.
+/// </summary>
+public class WindowSizeCharacters
+{
+  /// <summary>
+  /// Gets the width of the terminal in characters.
+  /// </summary>
+  public int CharacterWidth { get; set; }
+
+  /// <summary>
+  /// Gets the height of the terminal in characters.
+  /// </summary>
+  public int CharacterHeight { get; set; }
+}

src/Sixel/Terminal/Models/WindowSizePixels.cs

@@ -0,0 +1,19 @@
+namespace Sixel.Terminal.Models;
+
+/// <summary>
+/// Represents the size of the terminal window in pixels
+/// not supported in all terminals.
+/// like WezTerm, Alacritty
+/// </summary>
+public class WindowSizePixels
+{
+  /// <summary>
+  /// Gets the width of the terminal in pixels.
+  /// </summary>
+  public int PixelWidth { get; set; }
+
+  /// <summary>
+  /// Gets the height of the terminal in pixels.
+  /// </summary>
+  public int PixelHeight { get; set; }
+}

src/Sixel/Terminal/Validate.cs

@@ -10,7 +10,7 @@ protected override void Validate(object arguments, EngineIntrinsics engineIntrin
   {
     var requestedWidth = (int)arguments;
     var hostWidth = engineIntrinsics.Host.UI.RawUI.WindowSize.Width;
-    if (requestedWidth > hostWidth) 
+    if (requestedWidth > hostWidth)
     {
       throw new ValidationMetadataException($"{requestedWidth} width is greater than terminal width ({hostWidth}).");
     }