Add support for richer console colors and FontWeight and Bold TextDecorator

src/Consolonia.Core/Consolonia.Core.csproj

@@ -5,6 +5,7 @@
         <PackageReference Include="Avalonia" Version="$(AvaloniaVersion)" />
         <PackageReference Include="Avalonia.FreeDesktop" Version="$(AvaloniaVersion)" />
         <PackageReference Include="Avalonia.Controls.DataGrid" Version="$(AvaloniaVersion)" />
+        <PackageReference Include="Crayon" Version="2.0.69" />
         <PackageReference Include="NullLib.ConsoleEx" Version="1.0.4.4" />
     </ItemGroup>
 

src/Consolonia.Core/Drawing/ConsoleBrush.cs

@@ -0,0 +1,214 @@
+using System;
+using Avalonia;
+using Avalonia.Media;
+using Consolonia.Core.Drawing.PixelBufferImplementation;
+using Consolonia.Core.Infrastructure;
+
+namespace Consolonia.Core.Drawing
+{
+    public class ConsoleBrush : AvaloniaObject, IImmutableBrush
+    {
+        public static readonly StyledProperty<Color> ColorProperty =
+            AvaloniaProperty.Register<ConsoleBrush, Color>(nameof(Color));
+
+        public static readonly StyledProperty<PixelBackgroundMode> ModeProperty =
+            AvaloniaProperty.Register<ConsoleBrush, PixelBackgroundMode>(nameof(Mode));
+
+        // ReSharper disable once UnusedMember.Global
+        public ConsoleBrush(Color color, PixelBackgroundMode mode) : this(color)
+        {
+            Mode = mode;
+        }
+
+        public ConsoleBrush(Color color)
+        {
+            Color = color;
+        }
+
+        public ConsoleBrush()
+        {
+        }
+
+        /// <summary>
+        /// Convert a IBrush to a Brush. 
+        /// </summary>
+        /// <remarks>
+        /// NOTE: If it's a ConsoleBrush it will be passed through unchanged, unless mode is set then it will convert consolebrush to mode
+        /// </remarks>
+        /// <param name="brush"></param>
+        /// <param name="mode">Default is Colored.</param>
+        /// <returns></returns>
+        public static ConsoleBrush FromBrush(IBrush brush, PixelBackgroundMode? mode = null)
+        {
+            ArgumentNullException.ThrowIfNull(brush, nameof(brush));
+
+            switch (brush)
+            {
+                case ConsoleBrush consoleBrush:
+                    if (mode != null && consoleBrush.Mode != mode)
+                    {
+                        return new ConsoleBrush(consoleBrush.Color, mode.Value);
+                    }
+                    return consoleBrush;
+
+                case LineBrush lineBrush:
+                    switch (lineBrush.Brush)
+                    {
+                        case ConsoleBrush consoleBrush:
+                            return consoleBrush;
+                        case ISolidColorBrush br:
+                            return new ConsoleBrush(br.Color, mode ?? PixelBackgroundMode.Colored);
+                        default:
+                            ConsoloniaPlatform.RaiseNotSupported(6);
+                            return null;
+                    }
+
+                case ISolidColorBrush solidBrush:
+                    return new ConsoleBrush(solidBrush.Color, mode ?? PixelBackgroundMode.Colored);
+
+                default:
+                    ConsoloniaPlatform.RaiseNotSupported(6);
+                    return null;
+            }
+        }
+
+        public static ConsoleBrush FromPosition(IBrush brush, int x, int y, int width, int height)
+        {
+            ArgumentNullException.ThrowIfNull(brush);
+            if (x < 0 || x > width)
+                throw new ArgumentOutOfRangeException(nameof(x), "x is out bounds");
+            if (y < 0 || y > height)
+                throw new ArgumentOutOfRangeException(nameof(y), "y is out bounds");
+            if (width <= 0)
+                throw new ArgumentOutOfRangeException(nameof(width), "Width must be positive");
+            if (height <= 0)
+                throw new ArgumentOutOfRangeException(nameof(height), "Height must be positive");
+
+            switch (brush)
+            {
+                case ILinearGradientBrush gradientBrush:
+                    {
+                        // Calculate the relative position within the gradient
+                        double horizontalRelativePosition = (double)x / width;
+                        double verticalRelativePosition = (double)y / height;
+
+                        // Interpolate horizontal and vertical colors
+                        var horizontalColor = InterpolateColor(gradientBrush, horizontalRelativePosition);
+                        var verticalColor = InterpolateColor(gradientBrush, verticalRelativePosition);
+
+                        // Average the two colors to get the final color
+                        var color = BlendColors(horizontalColor, verticalColor);
+                        return new ConsoleBrush(color);
+                    }
+                case IRadialGradientBrush radialBrush:
+                    {
+                        // Calculate the normalized center coordinates
+                        double centerX = radialBrush.Center.Point.X * width;
+                        double centerY = radialBrush.Center.Point.Y * height;
+
+                        // Calculate the distance from the center
+                        double dx = x - centerX;
+                        double dy = y - centerY;
+                        double distance = Math.Sqrt(dx * dx + dy * dy);
+
+                        // Normalize the distance based on the brush radius
+                        double normalizedDistance = distance / (Math.Min(width, height) * radialBrush.Radius);
+
+                        // Clamp the normalized distance to [0, 1]
+                        normalizedDistance = Math.Min(Math.Max(normalizedDistance, 0), 1);
+
+                        // Interpolate the color based on the normalized distance
+                        var color = InterpolateColor(radialBrush, normalizedDistance);
+                        return new ConsoleBrush(color);
+                    }
+                    case IConicGradientBrush conicBrush:
+                    {
+                        // Calculate the relative position within the gradient
+                        double horizontalRelativePosition = (double)x / width;
+                        double verticalRelativePosition = (double)y / height;
+
+                        // Interpolate horizontal and vertical colors
+                        var horizontalColor = InterpolateColor(conicBrush, horizontalRelativePosition);
+                        var verticalColor = InterpolateColor(conicBrush, verticalRelativePosition);
+
+                        // Average the two colors to get the final color
+                        var color = BlendColors(horizontalColor, verticalColor);
+                        return new ConsoleBrush(color);
+                    }
+
+                default:
+                    return FromBrush(brush);
+            }
+        }
+
+        public PixelBackgroundMode Mode
+        {
+            get => GetValue(ModeProperty);
+            set => SetValue(ModeProperty, value);
+        }
+
+        public Color Color
+        {
+            get => GetValue(ColorProperty);
+            set => SetValue(ColorProperty, value);
+        }
+
+        // ReSharper disable once UnusedMember.Global used by Avalonia
+        // ReSharper disable once UnusedParameter.Global
+        public IBrush ProvideValue(IServiceProvider _)
+        {
+            return this;
+        }
+
+        public double Opacity => 1;
+        public ITransform Transform => null;
+        public RelativePoint TransformOrigin => RelativePoint.TopLeft;
+
+        private static Color InterpolateColor(IGradientBrush brush, double relativePosition)
+        {
+            IGradientStop before = null;
+            IGradientStop after = null;
+
+            foreach (var stop in brush.GradientStops)
+            {
+                if (stop.Offset <= relativePosition)
+                {
+                    before = stop;
+                }
+                else if (stop.Offset >= relativePosition)
+                {
+                    after = stop;
+                    break;
+                }
+            }
+            if (before == null && after == null)
+                throw new ArgumentException("no gradientstops defined");
+
+            if (before == null)
+            {
+                return after.Color;
+            }
+            if (after == null)
+            {
+                return before.Color;
+            }
+
+            double ratio = (relativePosition - before.Offset) / (after.Offset - before.Offset);
+            byte r = (byte)(before.Color.R + ratio * (after.Color.R - before.Color.R));
+            byte g = (byte)(before.Color.G + ratio * (after.Color.G - before.Color.G));
+            byte b = (byte)(before.Color.B + ratio * (after.Color.B - before.Color.B));
+            byte a = (byte)(before.Color.A + ratio * (after.Color.A - before.Color.A));
+
+            return Color.FromArgb(a, r, g, b);
+        }
+
+        private static Color BlendColors(Color color1, Color color2)
+        {
+            int r = (color1.R + color2.R) / 2;
+            int g = (color1.G + color2.G) / 2;
+            int b = (color1.B + color2.B) / 2;
+            int a = (color1.A + color2.A) / 2;
+            return Color.FromArgb((byte)a, (byte)r, (byte)g, (byte)b);
+        }
+    }
+}

src/Consolonia.Core/Drawing/ConsoloniaRenderInterface.cs

@@ -107,7 +107,7 @@ IBitmapImpl IPlatformRenderInterface.ResizeBitmap(IBitmapImpl bitmapImpl, PixelS
         {
             throw new NotImplementedException();
         }
-
+        
         public IBitmapImpl LoadBitmap(
             PixelFormat format,
             AlphaFormat alphaFormat,