New TextPaintProperties for Font edging, hinting and sub-pixel positioning

Sandbox/Form1.cs

@@ -122,6 +122,21 @@ namespace Sandbox
                     Invalidate();
                     break;
 
+                case Keys.F1:
+                    _driver.SubpixelPositioning = !_driver.SubpixelPositioning;
+                    Invalidate();
+                    break;
+
+                case Keys.F2:
+                    _driver.Hinting = (SKFontHinting)(((int)_driver.Hinting + 1) % 4);
+                    Invalidate();
+                    break;
+
+                case Keys.F3:
+                    _driver.Edging = (SKFontEdging)(((int)_driver.Edging + 1) % 3);
+                    Invalidate();
+                    break;
+
             }
         }
 

SandboxDriver/SandboxDriver.cs

@@ -238,6 +238,9 @@ namespace SandboxDriver
             var options = new TextPaintOptions()
             {
                 SelectionColor = new SKColor(0x60FF0000),
+                Hinting = Hinting,
+                Edging = Edging,
+                SubpixelPositioning = SubpixelPositioning,
             };
 
             HitTestResult? htr = null;
@@ -313,7 +316,7 @@ namespace SandboxDriver
                 }
             }
 
-            var state = $"Size: {width} x {height} Base Direction: {BaseDirection} Alignment: {TextAlignment} Content: {ContentMode} scale: {Scale} time: {elapsed}";
+            var state = $"Size: {width} x {height} Base Direction: {BaseDirection} Alignment: {TextAlignment} Content: {ContentMode} scale: {Scale} time: {elapsed} subpixel: {SubpixelPositioning} hinting: {Hinting} edging: {Edging}";
             canvas.DrawText(state, margin, 20, new SKPaint()
             {
                 Typeface = SKTypeface.FromFamilyName("Arial"),
@@ -345,6 +348,10 @@ namespace SandboxDriver
         float _hitTestY;
         bool _showHitTest;
 
+        public SKFontEdging Edging = SKFontEdging.Antialias;
+        public SKFontHinting Hinting = SKFontHinting.Normal;
+        public bool SubpixelPositioning = true;
+
         public void HitTest(float x, float y)
         {
             _hitTestX = x;

Topten.RichTextKit/FontRun.cs

@@ -619,9 +619,6 @@ namespace Topten.RichTextKit
 
                 // Setup SKPaint
                 paint.Color = Style.TextColor;
-                paint.IsAntialias = ctx.Options.IsAntialias;
-                paint.LcdRenderText = ctx.Options.LcdRenderText;
-                paint.HintingLevel = ctx.Options.HintingLevel;
 
                 unsafe
                 {
@@ -634,8 +631,10 @@ namespace Topten.RichTextKit
                         if (_font == null)
                         {
                             _font = new SKFont(this.Typeface, this.Style.FontSize * glyphScale);
-                            _font.Subpixel = true;
                         }
+                        _font.Hinting = ctx.Options.Hinting;
+                        _font.Edging = ctx.Options.Edging;
+                        _font.Subpixel = ctx.Options.SubpixelPositioning;
 
                         // Create the SKTextBlob (if necessary)
                         if (_textBlob == null)

Topten.RichTextKit/TextPaintOptions.cs

@@ -14,6 +14,7 @@
 // under the License.
 
 using SkiaSharp;
+using System;
 
 namespace Topten.RichTextKit
 {
@@ -26,7 +27,7 @@ namespace Topten.RichTextKit
         /// Constructs a new text paint options
         /// </summary>
         public TextPaintOptions()
-        { 
+        {
         }
 
 
@@ -81,32 +82,53 @@ namespace Topten.RichTextKit
         } = 0;
 
         /// <summary>
-        /// Controls whether text is rendered with anti-aliasing.
+        /// Controls how font edges are drawn
         /// </summary>
-        public bool IsAntialias
+        public SKFontEdging Edging
+        {
+            get;
+            set;
+        } = SKFontEdging.Antialias;
+
+
+        /// <summary>
+        /// Requests text be drawn at sub-pixel offsets
+        /// </summary>
+        public bool SubpixelPositioning
         {
             get;
             set;
         } = true;
 
+        /// <summary>
+        /// Controls whether text is rendered with anti-aliasing.
+        /// </summary>
+        [Obsolete("Use Edging property instead of IsAntialias")]
+        public bool IsAntialias
+        {
+            get => Edging != SKFontEdging.Alias;
+            set => Edging = value ? SKFontEdging.Antialias : SKFontEdging.Alias;
+        }
+
         /// <summary>
         /// Controls whether text is rendered using LCD sub-pixel rendering.
         /// </summary>
+        [Obsolete("Use Edging property instead of LcdRenderText")]
         public bool LcdRenderText
         {
-            get;
-            set;
-        } = false;
+            get => Edging == SKFontEdging.SubpixelAntialias;
+            set => Edging = value ? SKFontEdging.SubpixelAntialias : SKFontEdging.Antialias;
+        }
 
 
         /// <summary>
         /// Controls the font hint used when rendering text
         /// </summary>
-        public SKPaintHinting HintingLevel
+        public SKFontHinting Hinting
         {
             get;
             set;
-        } = SKPaintHinting.Normal;
+        } = SKFontHinting.Normal;
 
         /// <summary>
         /// A default set of paint options that renders text blocks without