Adding back text-based blobs (#2545)

binding/SkiaSharp/SKRunBuffer.cs

@@ -63,4 +63,55 @@ public Span<SKRotationScaleMatrix> GetRotationScaleSpan () =>
 		public void SetRotationScale (ReadOnlySpan<SKRotationScaleMatrix> positions) =>
 			positions.CopyTo (GetRotationScaleSpan ());
 	}
+
+	public unsafe class SKTextRunBuffer : SKRunBuffer
+	{
+		internal SKTextRunBuffer (SKRunBufferInternal buffer, int count, int textSize)
+			: base (buffer, count)
+		{
+			TextSize = textSize;
+		}
+
+		public int TextSize { get; }
+
+		public Span<byte> GetTextSpan () =>
+			new Span<byte> (internalBuffer.utf8text, internalBuffer.utf8text == null ? 0 : TextSize);
+
+		public Span<uint> GetClusterSpan () =>
+			new Span<uint> (internalBuffer.clusters, internalBuffer.clusters == null ? 0 : Size);
+
+		public void SetText (ReadOnlySpan<byte> text) =>
+			text.CopyTo (GetTextSpan ());
+
+		public void SetClusters (ReadOnlySpan<uint> clusters) =>
+			clusters.CopyTo (GetClusterSpan ());
+	}
+
+	public sealed unsafe class SKHorizontalTextRunBuffer : SKTextRunBuffer
+	{
+		internal SKHorizontalTextRunBuffer (SKRunBufferInternal buffer, int count, int textSize)
+			: base (buffer, count, textSize)
+		{
+		}
+
+		public Span<float> GetPositionSpan () =>
+			new Span<float> (internalBuffer.pos, internalBuffer.pos == null ? 0 : Size);
+
+		public void SetPositions (ReadOnlySpan<float> positions) =>
+			positions.CopyTo (GetPositionSpan ());
+	}
+
+	public sealed unsafe class SKPositionedTextRunBuffer : SKTextRunBuffer
+	{
+		internal SKPositionedTextRunBuffer (SKRunBufferInternal buffer, int count, int textSize)
+			: base (buffer, count, textSize)
+		{
+		}
+
+		public Span<SKPoint> GetPositionSpan () =>
+			new Span<SKPoint> (internalBuffer.pos, internalBuffer.pos == null ? 0 : Size);
+
+		public void SetPositions (ReadOnlySpan<SKPoint> positions) =>
+			positions.CopyTo (GetPositionSpan ());
+	}
 }

binding/SkiaSharp/SKTextBlob.cs

@@ -404,6 +404,20 @@ public SKRunBuffer AllocateRun (SKFont font, int count, float x, float y, SKRect
 			return new SKRunBuffer (runbuffer, count);
 		}
 
+		public SKTextRunBuffer AllocateTextRun (SKFont font, int count, float x, float y, int textByteCount, SKRect? bounds = null)
+		{
+			if (font == null)
+				throw new ArgumentNullException (nameof (font));
+
+			SKRunBufferInternal runbuffer;
+			if (bounds is SKRect b)
+				SkiaApi.sk_textblob_builder_alloc_run_text (Handle, font.Handle, count, x, y, textByteCount, &b, &runbuffer);
+			else
+				SkiaApi.sk_textblob_builder_alloc_run_text (Handle, font.Handle, count, x, y, textByteCount, null, &runbuffer);
+
+			return new SKTextRunBuffer (runbuffer, count, textByteCount);
+		}
+
 		// AllocateHorizontalRun
 
 		public SKHorizontalRunBuffer AllocateHorizontalRun (SKFont font, int count, float y, SKRect? bounds = null)
@@ -420,6 +434,20 @@ public SKHorizontalRunBuffer AllocateHorizontalRun (SKFont font, int count, floa
 			return new SKHorizontalRunBuffer (runbuffer, count);
 		}
 
+		public SKHorizontalTextRunBuffer AllocateHorizontalTextRun (SKFont font, int count, float y, int textByteCount, SKRect? bounds = null)
+		{
+			if (font == null)
+				throw new ArgumentNullException (nameof (font));
+
+			SKRunBufferInternal runbuffer;
+			if (bounds is SKRect b)
+				SkiaApi.sk_textblob_builder_alloc_run_text_pos_h (Handle, font.Handle, count, y, textByteCount, &b, &runbuffer);
+			else
+				SkiaApi.sk_textblob_builder_alloc_run_text_pos_h (Handle, font.Handle, count, y, textByteCount, null, &runbuffer);
+
+			return new SKHorizontalTextRunBuffer (runbuffer, count, textByteCount);
+		}
+
 		// AllocatePositionedRun
 
 		public SKPositionedRunBuffer AllocatePositionedRun (SKFont font, int count, SKRect? bounds = null)
@@ -436,6 +464,20 @@ public SKPositionedRunBuffer AllocatePositionedRun (SKFont font, int count, SKRe
 			return new SKPositionedRunBuffer (runbuffer, count);
 		}
 
+		public SKPositionedTextRunBuffer AllocatePositionedTextRun (SKFont font, int count, int textByteCount, SKRect? bounds = null)
+		{
+			if (font == null)
+				throw new ArgumentNullException (nameof (font));
+
+			SKRunBufferInternal runbuffer;
+			if (bounds is SKRect b)
+				SkiaApi.sk_textblob_builder_alloc_run_text_pos (Handle, font.Handle, count, textByteCount, &b, &runbuffer);
+			else
+				SkiaApi.sk_textblob_builder_alloc_run_text_pos (Handle, font.Handle, count, textByteCount, null, &runbuffer);
+
+			return new SKPositionedTextRunBuffer (runbuffer, count, textByteCount);
+		}
+
 		// AllocateRotationScaleRun
 
 		public SKRotationScaleRunBuffer AllocateRotationScaleRun (SKFont font, int count)

tests/Tests/SkiaSharp/SKTextBlobTest.cs

@@ -16,6 +16,23 @@ public void TestEmptyBuilderReturnsNull()
 			Assert.Null(blob);
 		}
 
+		[SkippableFact]
+		public void NonGlyphTextEncodingDoesNotThrow()
+		{
+			using var paint = new SKPaint { TextEncoding = SKTextEncoding.Utf16 };
+
+			using var builder = new SKTextBlobBuilder();
+
+			var run = builder.AllocateTextRun(paint.GetFont(), 100, 0, 0, 50);
+			Assert.Equal(100, run.GetGlyphSpan().Length);
+			Assert.Equal(50, run.GetTextSpan().Length);
+
+			using var blob = builder.Build();
+			Assert.NotNull(blob);
+
+			Assert.Equal(SKTextEncoding.Utf16, paint.TextEncoding);
+		}
+
 		[SkippableFact]
 		public void TestExplicitBounds()
 		{