From bba64c17960c370cc833805b4f5e9f2f5fbccd1a Mon Sep 17 00:00:00 2001
From: cosmonaut <evan@moonside.games>
Date: Fri, 15 Dec 2023 09:23:46 -0800
Subject: [PATCH] make text batches use less memory by defualt

---
 src/Graphics/Font/TextBatch.cs | 28 +++++++++++++++++++++-------
 1 file changed, 21 insertions(+), 7 deletions(-)

diff --git a/src/Graphics/Font/TextBatch.cs b/src/Graphics/Font/TextBatch.cs
index cccbd59..7aef845 100644
--- a/src/Graphics/Font/TextBatch.cs
+++ b/src/Graphics/Font/TextBatch.cs
@@ -6,9 +6,9 @@ namespace MoonWorks.Graphics.Font
 {
 	public unsafe class TextBatch : GraphicsResource
 	{
-		public const int MAX_CHARS = 4096;
-		public const int MAX_VERTICES = MAX_CHARS * 4;
-		public const int MAX_INDICES = MAX_CHARS * 6;
+		public const int INITIAL_CHAR_COUNT = 64;
+		public const int INITIAL_VERTEX_COUNT = INITIAL_CHAR_COUNT * 4;
+		public const int INITIAL_INDEX_COUNT = INITIAL_CHAR_COUNT * 6;
 
 		private GraphicsDevice GraphicsDevice { get; }
 		public IntPtr Handle { get; }
@@ -30,10 +30,11 @@ namespace MoonWorks.Graphics.Font
 			StringBytesLength = 128;
 			StringBytes = (byte*) NativeMemory.Alloc((nuint) StringBytesLength);
 
-			VertexBuffer = Buffer.Create<Vertex>(GraphicsDevice, BufferUsageFlags.Vertex, MAX_VERTICES);
-			IndexBuffer = Buffer.Create<uint>(GraphicsDevice, BufferUsageFlags.Index, MAX_INDICES);
+			VertexBuffer = Buffer.Create<Vertex>(GraphicsDevice, BufferUsageFlags.Vertex, INITIAL_VERTEX_COUNT);
+			IndexBuffer = Buffer.Create<uint>(GraphicsDevice, BufferUsageFlags.Index, INITIAL_INDEX_COUNT);
 		}
 
+		// Call this to initialize or reset the batch.
 		public void Start(Font font)
 		{
 			Wellspring.Wellspring_StartTextBatch(Handle, font.Handle);
@@ -41,6 +42,7 @@ namespace MoonWorks.Graphics.Font
 			PrimitiveCount = 0;
 		}
 
+		// Add text with size and color to the batch
 		public unsafe bool Add(
 			string text,
 			int pixelSize,
@@ -79,7 +81,7 @@ namespace MoonWorks.Graphics.Font
 			return true;
 		}
 
-		// Call this after you have made all the Draw calls you want.
+		// Call this after you have made all the Add calls you want, but before beginning a render pass.
 		public unsafe void UploadBufferData(CommandBuffer commandBuffer)
 		{
 			Wellspring.Wellspring_GetBufferData(
@@ -91,13 +93,25 @@ namespace MoonWorks.Graphics.Font
 				out uint indexDataLengthInBytes
 			);
 
+			if (VertexBuffer.Size < vertexDataLengthInBytes)
+			{
+				VertexBuffer.Dispose();
+				VertexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Vertex, vertexDataLengthInBytes);
+			}
+
+			if (IndexBuffer.Size < indexDataLengthInBytes)
+			{
+				IndexBuffer.Dispose();
+				IndexBuffer = new Buffer(GraphicsDevice, BufferUsageFlags.Vertex, vertexDataLengthInBytes);
+			}
+
 			if (vertexDataLengthInBytes > 0 && indexDataLengthInBytes > 0)
 			{
 				commandBuffer.SetBufferData(VertexBuffer, vertexDataPointer, 0, vertexDataLengthInBytes);
 				commandBuffer.SetBufferData(IndexBuffer, indexDataPointer, 0, indexDataLengthInBytes);
 			}
 
-			PrimitiveCount = vertexCount / 2; // FIXME: is this jank?
+			PrimitiveCount = vertexCount / 2;
 		}
 
 		// Call this AFTER binding your text pipeline!