From 013487bf778a5d26e0ef6e53bd53d8a9578fec09 Mon Sep 17 00:00:00 2001
From: zeromus <zeromus@zeromus.org>
Date: Thu, 2 Jun 2011 01:52:10 +0000
Subject: [PATCH] disc api: clarify 2048 vs 2352 sector accesses

---
 BizHawk.Emulation/Disc/Disc.API.cs | 20 +++++++++++++++++++-
 BizHawk.Emulation/Disc/Disc.cs     |  4 +++-
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/BizHawk.Emulation/Disc/Disc.API.cs b/BizHawk.Emulation/Disc/Disc.API.cs
index 3e3ab77c9f..09b0e31a5d 100644
--- a/BizHawk.Emulation/Disc/Disc.API.cs
+++ b/BizHawk.Emulation/Disc/Disc.API.cs
@@ -10,7 +10,7 @@ namespace BizHawk.Disc
 		//main API to read a 2352-byte LBA from a disc.
 		//this starts at the beginning of the disc (at the lead-in)
 		//so add 150 to get to a FAD-address in the user data area
-		public void ReadLBA(int lba, byte[] buffer, int offset)
+		public void ReadLBA_2352(int lba, byte[] buffer, int offset)
 		{
 			if (lba < 150)
 			{
@@ -23,6 +23,24 @@ namespace BizHawk.Disc
 			Sectors[lba - 150].Sector.Read(buffer, offset);
 		}
 
+		//main API to read a 2048-byte LBA from a disc.
+		//this starts at the beginning of the disc (at the lead-in)
+		//so add 150 to get to a FAD-address in the user data area
+		public void ReadLBA_2048(int lba, byte[] buffer, int offset)
+		{
+			if (lba < 150)
+			{
+				//lead-in area not supported yet
+				//in the future it will return something to mate with the 
+				//subchannel data which we will load or calculate from the TOC
+				return;
+			}
+
+			byte[] temp = new byte[2352];
+			Sectors[lba - 150].Sector.Read(temp, offset);
+			Array.Copy(temp, 16, buffer, offset, 2048);
+		}
+
 		//main API to determine how many LBA sectors are available
 		public int LBACount { get { return Sectors.Count + 150; } }
 
diff --git a/BizHawk.Emulation/Disc/Disc.cs b/BizHawk.Emulation/Disc/Disc.cs
index c91f89f8fd..26cbc9abe3 100644
--- a/BizHawk.Emulation/Disc/Disc.cs
+++ b/BizHawk.Emulation/Disc/Disc.cs
@@ -68,6 +68,8 @@ namespace BizHawk.Disc
 
 	public partial class Disc
 	{
+		//TODO - separate these into Read_2352 and Read_2048 (optimizations can be made by ISector implementors depending on what is requested)
+		//(for example, avoiding the 2048 byte sector creating the ECC data and then immediately discarding it)
 		public interface ISector
 		{
 			int Read(byte[] buffer, int offset);
@@ -278,7 +280,7 @@ namespace BizHawk.Disc
 			using(FileStream fs = new FileStream(binPath,FileMode.Create,FileAccess.Write,FileShare.None))
 				for (int i = 0; i < Sectors.Count; i++)
 				{
-					ReadLBA(i, temp, 0);
+					ReadLBA_2352(i, temp, 0);
 					fs.Write(temp, 0, 2352);
 				}
 		}