Implement basic font rendering tuning for code editor.

Ability to disable anti-aliasing for 'pixel-perfect' fonts like Courier
New.
Ability to disable hinting to forget about jagged default WPF rendering.

Author: 13-beta2

ICSharpCode.AvalonEdit/Rendering/TextView.cs

@@ -165,7 +165,41 @@ void RecreateCachedElements()
 				cachedElements = new TextViewCachedElements();
 			}
 		}
-		
+
+		void SetupTextRendering()
+		{
+			if (Options.EnableTextAntialiasing)
+			{
+				if (Options.EnableTextHinting)
+				{
+					if (CurrentZoom == 1.0)
+					{
+						TextOptions.SetTextFormattingMode(this, TextFormattingMode.Display);
+						TextOptions.SetTextRenderingMode(this, TextRenderingMode.ClearType);
+						TextOptions.SetTextHintingMode(this, TextHintingMode.Auto);
+					}
+					else
+					{
+						TextOptions.SetTextFormattingMode(this, TextFormattingMode.Ideal);
+						TextOptions.SetTextRenderingMode(this, TextRenderingMode.Grayscale);
+						TextOptions.SetTextHintingMode(this, TextHintingMode.Auto);
+					}
+				}
+				else
+				{
+					TextOptions.SetTextFormattingMode(this, TextFormattingMode.Ideal);
+					TextOptions.SetTextRenderingMode(this, TextRenderingMode.Grayscale);
+					TextOptions.SetTextHintingMode(this, TextHintingMode.Animated);
+				}
+			}
+			else
+			{
+				TextOptions.SetTextFormattingMode(this, TextFormattingMode.Display);
+				TextOptions.SetTextRenderingMode(this, TextRenderingMode.Aliased);
+				TextOptions.SetTextHintingMode(this, TextHintingMode.Auto);
+			}
+		}
+
 		/// <inheritdoc cref="IWeakEventListener.ReceiveWeakEvent"/>
 		protected virtual bool ReceiveWeakEvent(Type managerType, object sender, EventArgs e)
 		{
@@ -224,7 +258,8 @@ protected virtual void OnOptionChanged(PropertyChangedEventArgs e)
 				columnRulerRenderer.SetRuler(Options.ColumnRulerPosition, ColumnRulerPen);
 			else
 				columnRulerRenderer.SetRuler(-1, ColumnRulerPen);
-			
+
+			SetupTextRendering();
 			UpdateBuiltinElementGeneratorsFromOptions();
 			Redraw();
 		}
@@ -1424,7 +1459,26 @@ void SetScrollOffset(Vector vector)
 		}
 
 		ScrollViewer IScrollInfo.ScrollOwner { get; set; }
-		
+
+		/// <summary>
+		/// Gets the zoom level;
+		/// </summary>
+		public double CurrentZoom
+		{
+			get
+			{
+				dynamic scrollOwner = ((IScrollInfo) this).ScrollOwner;
+
+				if (scrollOwner != null
+				&& scrollOwner.GetType().GetProperty("CurrentZoom") != null)
+				{
+					return scrollOwner.CurrentZoom;
+				}
+
+				return 1.0;
+			}
+		}
+
 		void IScrollInfo.LineUp()
 		{
 			((IScrollInfo)this).SetVerticalOffset(scrollOffset.Y - DefaultLineHeight);
@@ -2005,6 +2059,9 @@ public DocumentLine GetDocumentLineByVisualTop(double visualTop)
 		protected override void OnPropertyChanged(DependencyPropertyChangedEventArgs e)
 		{
 			base.OnPropertyChanged(e);
+			if (e.Property == TextView.ActualHeightProperty) {
+				SetupTextRendering();
+			}
 			if (TextFormatterFactory.PropertyChangeAffectsTextFormatter(e.Property)) {
 				// first, create the new text formatter:
 				RecreateTextFormatter();
@@ -2113,4 +2170,4 @@ public virtual double EmptyLineSelectionWidth
 			get { return 1; }
 		}
 	}
-}
+}

ICSharpCode.AvalonEdit/TextEditorOptions.cs

@@ -493,5 +493,49 @@ public bool AllowToggleOverstrikeMode {
 				}
 			}
 		}
+
+		bool enableTextAntialiasing = true;
+
+		/// <summary>
+		/// Gets/Sets if anti-aliasing should be applied while text rendering.
+		/// </summary>
+		[DefaultValue(true)]
+		public bool EnableTextAntialiasing
+		{
+			get
+			{
+				return enableTextAntialiasing;
+			}
+			set
+			{
+				if (enableTextAntialiasing != value)
+				{
+					enableTextAntialiasing = value;
+					OnPropertyChanged("EnableTextAntialiasing");
+				}
+			}
+		}
+
+		bool enableTextHinting = true;
+
+		/// <summary>
+		/// Gets/Sets if TrueType hinting should be applied while text rendering.
+		/// </summary>
+		[DefaultValue(true)]
+		public bool EnableTextHinting
+		{
+			get
+			{
+				return enableTextHinting;
+			}
+			set
+			{
+				if (enableTextHinting != value)
+				{
+					enableTextHinting = value;
+					OnPropertyChanged("EnableTextHinting");
+				}
+			}
+		}
 	}
 }