add text element text_fit options (#2441)

CHANGELOG.md

@@ -37,8 +37,13 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
       - `loop` - loop forever
       - `hold` - hold last frame forever, or `hold_seconds`
     - Draw order (`z_index`)
-- Add search fields to filter collections, schedules, playouts tables
+- Add search fields to filter collections, schedules and playouts tables
 - Add selected row background color to schedules and playouts tables
+- Graphics engine text element: add `width_percent` and `text_fit` to support wrapping and scaling text
+  - `text_fit: none` or unspecified will keep existing behavior (render text exactly as configured)
+  - `text_fit: wrap` will wrap text to the given `width_percent`
+  - `text_fit: scale` will scale text *smaller* to fit the given `width_percent`
+    - Text that already fits with the configured style will not be adjusted
 
 ### Fixed
 - Fix green output when libplacebo tonemapping is used with NVIDIA acceleration and 10-bit output in FFmpeg Profile

ErsatzTV.Core/Graphics/TextGraphicsElement.cs

@@ -19,14 +19,11 @@ public class TextGraphicsElement
     [YamlMember(Alias = "vertical_margin_percent", ApplyNamingConventions = false)]
     public double? VerticalMarginPercent { get; set; }
 
-    [YamlMember(Alias = "horizontal_alignment", ApplyNamingConventions = false)]
-    public string HorizontalAlignment { get; set; }
+    [YamlMember(Alias = "width_percent", ApplyNamingConventions = false)]
+    public double? WidthPercent { get; set; }
 
-    [YamlMember(Alias = "location_x", ApplyNamingConventions = false)]
-    public double? LocationX { get; set; }
-
-    [YamlMember(Alias = "location_y", ApplyNamingConventions = false)]
-    public double? LocationY { get; set; }
+    [YamlMember(Alias = "text_fit", ApplyNamingConventions = false)]
+    public TextFit Fit { get; set; } = TextFit.None;
 
     [YamlMember(Alias = "z_index", ApplyNamingConventions = false)]
     public int? ZIndex { get; set; }
@@ -45,6 +42,13 @@ public class TextGraphicsElement
     public string Text { get; set; }
 }
 
+public enum TextFit
+{
+    None,
+    Wrap,
+    Scale
+}
+
 public class StyleDefinition
 {
     public string Name { get; set; }

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

@@ -62,6 +62,21 @@ public partial class TextElement(
 
             RichTextKit.TextBlock textBlock = BuildTextBlock(textElement.Text);
 
+            if (textElement.WidthPercent.HasValue)
+            {
+                var maxWidth = (float)Math.Round(textElement.WidthPercent.Value / 100.0 * context.FrameSize.Width);
+
+                switch (textElement.Fit)
+                {
+                    case TextFit.Wrap:
+                        textBlock.MaxWidth = maxWidth;
+                        break;
+                    case TextFit.Scale:
+                        FitTextBlock(textBlock, maxWidth);
+                        break;
+                }
+            }
+
             _image = new SKBitmap(
                 (int)Math.Ceiling(textBlock.MeasuredWidth),
                 (int)Math.Ceiling(textBlock.MeasuredHeight));
@@ -216,6 +231,66 @@ public partial class TextElement(
         }
     }
 
+    private static void FitTextBlock(RichTextKit.TextBlock block, float maxWidth)
+    {
+        if (block.MeasuredWidth <= maxWidth)
+        {
+            return;
+        }
+
+        var originalContent = block.StyleRuns
+            .Select(run => (run.ToString(), run.Style))
+            .ToList();
+
+        float scale = maxWidth / block.MeasuredWidth;
+
+        const float MIN_FONT_SIZE = 5.0f;
+
+        while (true)
+        {
+            block.Clear();
+            var isAtMinSize = false;
+
+            foreach ((string text, RichTextKit.IStyle style) in originalContent)
+            {
+                var newStyle = new RichTextKit.Style
+                {
+                    FontFamily = style.FontFamily,
+                    FontItalic = style.FontItalic,
+                    FontSize = style.FontSize,
+                    FontWidth = style.FontWidth,
+                    FontWeight = style.FontWeight,
+                    LetterSpacing = style.LetterSpacing,
+                    TextColor = style.TextColor
+                };
+
+                float newSize = newStyle.FontSize * scale;
+
+                if (newSize < MIN_FONT_SIZE)
+                {
+                    newSize = MIN_FONT_SIZE;
+                    isAtMinSize = true;
+                }
+
+                newStyle.FontSize = newSize;
+                block.AddText(text, newStyle);
+            }
+
+            if (block.MeasuredWidth <= maxWidth)
+            {
+                break;
+            }
+
+            if (isAtMinSize)
+            {
+                break;
+            }
+
+            scale -= 0.01f;
+        }
+    }
+
+
     [GeneratedRegex(@"\[(\w+)\](.*?)\[/\1\]")]
     private static partial Regex StyleRegex();
 }