feat(text): composite shared text rasters in output

Raster static text on UI-thread changes and reuse the same transparent BGRA frame in preview and all compositor paths. Cache text frame identity in the frame-pump signature and invalidate static bakes on edits. Follow OBS text-source conventions: https://obsproject.com/kb/text-sources
2026-11-04 15:01:47 -08:00
parent 58eb640c4e
commit 5c4acf141b
19 changed files with 622 additions and 81 deletions
@@ -0,0 +1,61 @@
+using System.Collections.Generic;
+using System.Linq;
+using ytLive.Models;
+using ytLive.Services;
+
+namespace ytLive.ViewModels;
+
+public partial class MainViewModel
+{
+    private readonly TextOverlayRenderer _textOverlayRenderer = new();
+    private readonly HashSet<Source> _wiredTextOverlays = new();
+
+    private void UpdateConfiguredTextOverlays()
+    {
+        var sources = Scenes.SelectMany(scene => scene.Elements).OfType<Source>()
+            .Where(source => source.Type == SourceType.TextOverlay).ToArray();
+        RetainTextOverlaySubscriptions();
+        _textOverlayRenderer.Retain(sources);
+        foreach (var source in sources)
+        {
+            if (source.Width <= 0) source.Width = 900;
+            if (source.Height <= 0) source.Height = 140;
+            WireTextOverlaySource(source);
+            _textOverlayRenderer.UpdatePreview(source);
+        }
+    }
+
+    private void WireTextOverlaySource(Source source)
+    {
+        if (_wiredTextOverlays.Add(source))
+            source.PropertyChanged += OnElementPropertyChanged;
+    }
+
+    private void UpdateTextOverlayPreview(Source source) => _textOverlayRenderer.UpdatePreview(source);
+
+    private void RemoveTextOverlayPreview(Source source)
+    {
+        if (_wiredTextOverlays.Remove(source))
+            source.PropertyChanged -= OnElementPropertyChanged;
+        _textOverlayRenderer.Remove(source);
+    }
+
+    private void RetainTextOverlaySubscriptions()
+    {
+        var active = Scenes.SelectMany(scene => scene.Elements).OfType<Source>()
+            .Where(source => source.Type == SourceType.TextOverlay).ToHashSet();
+        foreach (var source in _wiredTextOverlays.ToArray())
+            if (!active.Contains(source))
+                RemoveTextOverlayPreview(source);
+    }
+
+    private void OnTextOverlayPropertyChanged(Source source, string? propertyName)
+    {
+        if (propertyName is nameof(Source.TextContent) or nameof(Source.TextFontFamily)
+            or nameof(Source.TextFontSize) or nameof(Source.TextColor) or nameof(Source.TextBold)
+            or nameof(Source.TextItalic) or nameof(Source.TextUnderline) or nameof(Source.TextAlignment)
+            or nameof(Source.Width) or nameof(Source.Height))
+            UpdateTextOverlayPreview(source);
+    }
+
+}