From 3783548c24b2e39c59cf25161521a76451a7bfda Mon Sep 17 00:00:00 2001
From: Bradley Bell <btb@icculus.org>
Date: Thu, 20 Mar 2003 04:05:12 +0000
Subject: [PATCH] starting d2 cd detection (cddb discid) support

---
 ChangeLog          |  3 +++
 arch/sdl/rbaudio.c | 42 +++++++++++++++++++++++++++++++++++++++++-
 include/rbaudio.h  |  3 +++
 3 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index a63ed4df..64f46b4f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2003-03-19  Bradley Bell  <btb@icculus.org>
 
+	* arch/sdl/rbaudio.c, include/rbaudio.h: starting d2 cd detection
+	(cddb discid) support
+
 	* arch/sdl/digi.c, main/kludge.c: implemented
 	digi_link_sound_to_object3 for looping sounds, other looping stuff
 
diff --git a/arch/sdl/rbaudio.c b/arch/sdl/rbaudio.c
index a53df1a8..33b20ccd 100644
--- a/arch/sdl/rbaudio.c
+++ b/arch/sdl/rbaudio.c
@@ -1,4 +1,4 @@
-/* $Id: rbaudio.c,v 1.6 2003-03-19 19:21:34 btb Exp $ */
+/* $Id: rbaudio.c,v 1.7 2003-03-20 04:05:12 btb Exp $ */
 /*
  *
  * SDL CD Audio functions
@@ -161,3 +161,43 @@ int CD_blast_mixer()
 {
 	return 0;
 }
+
+
+static int cddb_sum(int n)
+{
+	int ret;
+
+	/* For backward compatibility this algorithm must not change */
+
+	ret = 0;
+
+	while (n > 0) {
+		ret = ret + (n % 10);
+		n = n / 10;
+	}
+
+	return (ret);
+}
+
+
+unsigned long RBAGetDiscID()
+{
+	int i, t = 0, n = 0;
+
+	if (!initialised)
+		return 0;
+
+	/* For backward compatibility this algorithm must not change */
+
+	i = 0;
+
+	while (i < s_cd->numtracks) {
+		n = n + cddb_sum(s_cd->track[i].length / CD_FPS);
+		i++;
+	}
+
+	t = (s_cd->track[s_cd->numtracks].length / CD_FPS) -
+	    (s_cd->track[0].length / CD_FPS);
+
+	return ((n % 0xff) << 24 | t << 8 | s_cd->numtracks);
+}
diff --git a/include/rbaudio.h b/include/rbaudio.h
index d0834b12..216a61f2 100644
--- a/include/rbaudio.h
+++ b/include/rbaudio.h
@@ -54,4 +54,7 @@ extern int	RBAResume();
 //is called.  Returns 0 if no track playing, else track number
 int RBAGetTrackNum();
 
+// get the cddb discid for the current cd.
+unsigned long RBAGetDiscID();
+
 #endif
-- 
2.39.2