From b866ae24fac9dd066cfae9ab2871aa67b6f2390a Mon Sep 17 00:00:00 2001
From: Martin Mares <mj@ucw.cz>
Date: Sat, 25 Jan 2003 16:19:40 +0000
Subject: [PATCH] Added transpose mode.

---
 vs.pl | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 110 insertions(+), 4 deletions(-)

diff --git a/vs.pl b/vs.pl
index 0ac0fb5..ad9be12 100755
--- a/vs.pl
+++ b/vs.pl
@@ -134,6 +134,81 @@ for(;;) {
 	}
 }
 
+### Chords ###
+
+package VS::Chord;
+
+# Internal representation of chords: <base-tone>:<type> (so C="0:", C#="1:", Dmi="2:mi" etc.)
+# but usually they are accompanied by position info after a second colon
+
+our (%t2n, @n2t);
+
+BEGIN {
+%t2n = (
+	"C" => 0,
+	"C#" => 1,
+		"Db" => 1,
+	"D" => 2,
+	"D#" => 3,
+		"Eb" => 3,
+	"E" => 4,
+		"Fb" => 4,
+		"E#" => 5,
+	"F" => 5,
+	"F#" => 6,
+		"Gb" => 6,
+	"G" => 7,
+	"G#" => 8,
+		"Ab" => 8,
+	"A" => 9,
+		"Bb" => 9,
+	"A#" => 10,
+		"Hb" => 10,
+		"B" => 10,
+	"H" => 11,
+		"B#" => 11,
+		"Cb" => 11,
+		"H#" => 0
+);
+@n2t = ( "C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "B", "H" );
+}
+
+sub parse_line($) {
+	my $r = shift @_;
+	my @l = ();
+	my $pos = 0;
+	while (my ($spaces,$chord,$rest) = $r =~ /(\s*)(\S+)(.*)/) {
+		$pos += length $spaces;
+		if (my ($tone,$sh,$mod) = ($chord =~ /^([CDEFGABH](#|b|))(.*)$/)) {
+			my $k = $t2n{$tone};
+			push @l, "$k:$mod:$pos"
+		} else {
+			push @l, "0:?$chord:$pos";
+		}
+		$pos += length $chord;
+		$r = $rest;
+	}
+	return \@l;
+}
+
+sub synthesize_line($$) {
+	my ($l,$xpos) = @_;
+	my $pp = 0;
+	my $result = "";
+	for (my $i=0; $i<@$l; $i++) {
+		my ($tone,$mod,$pos) = split(/:/, $l->[$i]);
+		$tone = ($tone + $xpos) % 12;
+		my $chord = $n2t[$tone] . "$mod ";
+		if ($pp < $pos) {
+			$result .= " " x ($pos - $pp);
+			$pp = $pos;
+		}
+		$result .= $chord;
+		$pp += length $chord;
+	}
+	return $result;
+}
+
 ### Window Objects ###
 
 package VS::Window;
@@ -181,9 +256,12 @@ sub new($) {
 	$w->{"file"} = "";
 	$w->{"attrs"} = {};
 	$w->{"lines"} = ["", "", "   The Virtual Songbook 0.0\n", "   (c) 2003 Martin Mares <mj\@ucw.cz>"];
-	$w->{"linetype"} = [0,0,0,0];
+	$w->{"chords"} = [0,0,0,0];
 	$w->{"n"} = 4;
 	$w->{"top"} = 0;
+	$w->{"chords_analysed"} = 0;
+	$w->{"current_xpose"} = 0;
+	$w->{"requested_xpose"} = 0;
 	return bless $w;
 }
 
@@ -192,6 +270,8 @@ sub view($$$) {
 	if ($w->{"file"} ne $f) {
 		$w->{"file"} = $f;
 		$w->{"xfile"} = $x;
+		$w->{"current_xpose"} = 0;
+		$w->{"chords_analysed"} = 0;
 		$f =~ s@^./@@;
 		$x =~ s@^./@@;
 		if (open X, $f) {
@@ -204,16 +284,17 @@ sub view($$$) {
 				}
 			}
 			my @lines = ();
-			my @types = ();
+			my @chords = ();
 			while (<X>) {
 				chomp;
-				if (s/^!//) { push @types, 1; } else { push @types, 0; }
+				if (s/^!//) { push @chords, 1; } else { push @chords, 0; }
 				push @lines, $_;
 			}
 			close X;
 			$w->{"attrs"} = \%attrs;
 			$w->{"lines"} = \@lines;
-			$w->{"linetypes"} = \@types;
+			$w->{"chords"} = \@chords;
+			$w->{"chordtable"} = [];
 			$w->{"top"} = 0;
 			$w->{"n"} = scalar @lines;
 			$w->redraw;
@@ -228,6 +309,24 @@ sub view($$$) {
 	}
 }
 
+sub transpose($) {
+	my $w = shift @_;
+	if (!$w->{"chords_analysed"}) {
+		for (my $i=0; $i<$w->{"n"}; $i++) {
+			if ($w->{"chords"}->[$i]) {
+				$w->{"chordtable"}->[$i] = VS::Chord::parse_line($w->{"lines"}->[$i]);
+			}
+		}
+		$w->{"chords_analysed"} = 1;
+	}
+	for (my $i=0; $i<$w->{"n"}; $i++) {
+		if ($w->{"chords"}->[$i]) {
+			$w->{"lines"}->[$i] = VS::Chord::synthesize_line($w->{"chordtable"}->[$i], $w->{"requested_xpose"});
+		}
+	}
+	$w->{"current_xpose"} = $w->{"requested_xpose"};
+}
+
 sub redraw_line($$) {
 	my ($w,$i) = @_;
 	my $win = $w->{"win"};
@@ -244,6 +343,7 @@ sub redraw_line($$) {
 
 sub redraw($) {
 	my $w = shift @_;
+	$w->transpose if $w->{"current_xpose"} != $w->{"requested_xpose"};
 	my $win = $w->{"win"};
 	my $top = $w->{"top"};
 	my $cnt = $w->{"n"} - $w->{"top"};
@@ -294,6 +394,9 @@ sub key($$) {
 	elsif ($key eq KEY_NPAGE) { $w->go($w->{"h"}-1); }
 	elsif ($key eq KEY_HOME) { $w->go(-1000000000); }
 	elsif ($key eq KEY_END) { $w->go(1000000000); }
+	elsif ($key eq "+" || $key eq "=") { $w->{"requested_xpose"} = ($w->{"requested_xpose"}+1)%12; $status_window->redraw; $w->redraw; }
+	elsif ($key eq "-") { $w->{"requested_xpose"} = ($w->{"requested_xpose"}+11)%12; $status_window->redraw; $w->redraw; }
+	elsif ($key eq "0") { $w->{"requested_xpose"} = 0; $status_window->redraw; $w->redraw; }
 	else { $status_window->tell("Unknown key <$key>"); }
 }
 
@@ -463,6 +566,9 @@ sub redraw($) {
 	$win->bkgdset($attr_status);
 	$win->addstr(0, 0, $w->{"msg"});
 	$win->clrtoeol;
+	my $aux = "";
+	$aux = "T=" . $main_window->{"requested_xpose"} if ($main_window->{"requested_xpose"});
+	$win->addstr(0, $w->{"w"}-length $aux, $aux) if $aux ne "";
 	$win->refresh;
 }
 
-- 
2.39.2