diff --git a/lib/WellspringCS b/lib/WellspringCS
index ac63d6c9..f8872bae 160000
--- a/lib/WellspringCS
+++ b/lib/WellspringCS
@@ -1 +1 @@
-Subproject commit ac63d6c9b2d773792f8c3e5dafe760dd8769a4bf
+Subproject commit f8872bae59e394b0f8a35224bb39ab8fd041af97
diff --git a/src/Graphics/Font/Packer.cs b/src/Graphics/Font/Packer.cs
index 8f0fe665..3395a39b 100644
--- a/src/Graphics/Font/Packer.cs
+++ b/src/Graphics/Font/Packer.cs
@@ -12,6 +12,8 @@ namespace MoonWorks.Graphics.Font
 
 		public Font Font { get; }
 
+		private byte[] StringBytes;
+
 		private bool IsDisposed;
 
 		public unsafe Packer(GraphicsDevice graphicsDevice, Font font, float fontSize, uint textureWidth, uint textureHeight, uint padding = 1)
@@ -19,6 +21,7 @@ namespace MoonWorks.Graphics.Font
 			Font = font;
 			Handle = Wellspring.Wellspring_CreatePacker(Font.Handle, fontSize, textureWidth, textureHeight, 0, padding);
 			Texture = Texture.CreateTexture2D(graphicsDevice, textureWidth, textureHeight, TextureFormat.R8, TextureUsageFlags.Sampler);
+			StringBytes = new byte[128];
 		}
 
 		public unsafe bool PackFontRanges(params FontRange[] fontRanges)
@@ -43,6 +46,38 @@ namespace MoonWorks.Graphics.Font
 			commandBuffer.SetTextureData(Texture, pixelDataPointer, Texture.Width * Texture.Height);
 		}
 
+		public unsafe void TextBounds(
+			string text,
+			float x,
+			float y,
+			HorizontalAlignment horizontalAlignment,
+			VerticalAlignment verticalAlignment,
+			out Wellspring.Rectangle rectangle
+		) {
+			var byteCount = System.Text.Encoding.UTF8.GetByteCount(text);
+
+			if (StringBytes.Length < byteCount)
+			{
+				System.Array.Resize(ref StringBytes, byteCount);
+			}
+
+			fixed (char* chars = text)
+			fixed (byte* bytes = StringBytes)
+			{
+				System.Text.Encoding.UTF8.GetBytes(chars, text.Length, bytes, byteCount);
+				Wellspring.Wellspring_TextBounds(
+					Handle,
+					x,
+					y,
+					(Wellspring.HorizontalAlignment) horizontalAlignment,
+					(Wellspring.VerticalAlignment) verticalAlignment,
+					(IntPtr) bytes,
+					(uint) byteCount,
+					out rectangle
+				);
+			}
+		}
+
 		protected virtual void Dispose(bool disposing)
 		{
 			if (!IsDisposed)