add graphics engine text halo (#2528)

CHANGELOG.md

@@ -14,6 +14,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
     - Positive and negative margins can be used to offset from center as desired
   - Add `line_height` property to text element style definition
     - This is a multiplier that defaults to 1.0 when unspecified
+  - Add `halo_color`, `halo_width` and `halo_blur` properties to text element style definition
+    - These can be used to "outline" text with the configured color (e.g. `#000000`), width (e.g. `10`) and amount of blur (e.g. `2`)
 - Add `Block Playout Troubleshooting` tool to help investigate block playout history
 - Add sequential schedule file and scripted schedule file names to playouts table
 - Add empty (but already up-to-date) sqlite3 database to greatly speed up initial startup for fresh installs

ErsatzTV.Core/Graphics/TextGraphicsElement.cs

@@ -83,4 +83,13 @@ public class StyleDefinition
 
     [YamlMember(Alias = "line_height", ApplyNamingConventions = false)]
     public float? LineHeight { get; set; }
+
+    [YamlMember(Alias = "halo_color", ApplyNamingConventions = false)]
+    public string HaloColor { get; set; }
+
+    [YamlMember(Alias = "halo_width", ApplyNamingConventions = false)]
+    public float? HaloWidth { get; set; }
+
+    [YamlMember(Alias = "halo_blur", ApplyNamingConventions = false)]
+    public float? HaloBlur { get; set; }
 }

ErsatzTV.Infrastructure/Streaming/Graphics/Text/TextElement.cs

@@ -223,6 +223,21 @@ public partial class TextElement(
                 TextColor = SKColor.TryParse(def.TextColor, out SKColor color) ? color : SKColors.White
             };
 
+            if (SKColor.TryParse(def.HaloColor, out SKColor parsedHaloColor))
+            {
+                style.HaloColor = parsedHaloColor;
+            }
+
+            foreach (float haloWidth in Optional(def.HaloWidth))
+            {
+                style.HaloWidth = haloWidth;
+            }
+
+            foreach (float haloBlur in Optional(def.HaloBlur))
+            {
+                style.HaloBlur = haloBlur;
+            }
+
             foreach (float fontSize in Optional(def.FontSize))
             {
                 style.FontSize = fontSize;