From b68fc2dd5afc223d339097e72831d73920b9cd81 Mon Sep 17 00:00:00 2001
From: Matthias Neeracher <neeri@users.sourceforge.net>
Date: Sun, 6 Jul 2008 11:07:41 +0000
Subject: [PATCH] Track tempo while playing

---
 Sources/VLDocument.h  |  1 +
 Sources/VLDocument.mm | 20 +++++++++++++++++---
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/Sources/VLDocument.h b/Sources/VLDocument.h
index 11b18b4..6a33d7e 100644
--- a/Sources/VLDocument.h
+++ b/Sources/VLDocument.h
@@ -53,6 +53,7 @@ enum {
 	PDFDocument *		printDoc;
 	NSRange				previewRange;
 	float				playRate;
+	float				baseTempo;
 }
 
 - (VLSong *)	song;
diff --git a/Sources/VLDocument.mm b/Sources/VLDocument.mm
index a081a5c..2e92a4e 100644
--- a/Sources/VLDocument.mm
+++ b/Sources/VLDocument.mm
@@ -80,6 +80,7 @@
 		songArranger		= @"";
 		songGroove			= @"Swing";
 		songTempo			= [[NSNumber alloc] initWithInt:120];
+		baseTempo			= 120.0f;
 		chordSize			= 6.0f;
 		lyricSize			= 0.0f;
 		staffSize			= 20.0f;
@@ -266,6 +267,16 @@
 	[self didChangeSong];
 }
 
+- (void) setSongTempo:(int)tempo
+{
+	[self willChangeSong];
+	[songTempo autorelease];
+	songTempo = [[NSNumber numberWithInt:tempo] retain];
+	if (VLSoundOut::Instance()->Playing()) 
+		VLSoundOut::Instance()->SetPlayRate(playRate*tempo/baseTempo);
+	[self didChangeSong];
+}
+
 - (void) setGroove:(NSString *)groove inSections:(NSRange)sections
 {
 	const char * grv = [groove UTF8String];
@@ -523,8 +534,10 @@
 		VLMIDIWriter annotate(music, countIn);
 		annotate.Visit(*song);
 	
-		hasMusicSequence = true;
+		hasMusicSequence 	= true;
 		[sheetWin willPlaySequence:music];
+		baseTempo			= [songTempo floatValue];
+		VLSoundOut::Instance()->SetPlayRate(playRate);
 		VLSoundOut::Instance()->PlaySequence(music);
 	}
 }
@@ -568,7 +581,8 @@
 	const float kMinRate	= 0.2f;
 	const float kUpScale	= 1.1f;
 	const float kDownScale  = 1.0f/kUpScale;
-	bool nowPlaying = VLSoundOut::Instance()->Playing();
+	bool 		nowPlaying 	= VLSoundOut::Instance()->Playing();
+	const float	tempoRate 	= [songTempo floatValue] / baseTempo;
 	switch (int tag = [sender tag]) {
 	case 0: // Play
 		VLSoundOut::Instance()->SetPlayRate(playRate = 1.0f);
@@ -587,7 +601,7 @@
 			playRate *= kUpScale;
 		else
 			playRate *= kDownScale;
-		VLSoundOut::Instance()->SetPlayRate(playRate);
+		VLSoundOut::Instance()->SetPlayRate(playRate*tempoRate);
 		break;
 	case -2: 	// To Start
 		VLSoundOut::Instance()->SetTime(0);