--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Halftone.php	Tue Mar 27 03:55:10 2012 -0400
@@ -0,0 +1,399 @@
+<?php
+
+/**!info**
+{
+  "Plugin Name"  : "Halftone",
+  "Plugin URI"   : "http://enanocms.org/plugin/halftone",
+  "Description"  : "Allows semantic input and transposition of chord sheets.",
+  "Author"       : "Dan Fuhry",
+  "Version"      : "0.1",
+  "Author URI"   : "http://enanocms.org/",
+  "Version list" : ['0.1']
+}
+**!*/
+
+$plugins->attachHook('render_wikiformat_posttemplates', 'halftone_process_tags($text);');
+$plugins->attachHook('html_attribute_whitelist', '$whitelist["halftone"] = array("title", "key");');
+$plugins->attachHook('session_started', 'register_special_page(\'HalftoneRender\', \'Halftone AJAX render handler\', false);');
+
+define('KEY_C', 0);
+define('KEY_D', 2);
+define('KEY_E', 4);
+define('KEY_F', 5);
+define('KEY_G', 7);
+define('KEY_A', 9);
+define('KEY_B', 11);
+define('KEY_C_SHARP', 1);
+define('KEY_E_FLAT', 3);
+define('KEY_F_SHARP', 6);
+define('KEY_G_SHARP', 8);
+define('KEY_B_FLAT', 10);
+
+define('ACC_FLAT', -1);
+define('ACC_SHARP', 1);
+
+$circle_of_fifths = array(KEY_C, KEY_G, KEY_D, KEY_A, KEY_E, KEY_B, KEY_F_SHARP, KEY_C_SHARP, KEY_G_SHARP, KEY_E_FLAT, KEY_B_FLAT, KEY_F);
+$accidentals = array(
+	KEY_C => ACC_FLAT,
+	KEY_G => ACC_SHARP,
+	KEY_D => ACC_SHARP,
+	KEY_A => ACC_SHARP,
+	KEY_E => ACC_SHARP,
+	KEY_B => ACC_SHARP,
+	KEY_F_SHARP => ACC_SHARP,
+	KEY_C_SHARP => ACC_SHARP,
+	KEY_G_SHARP => ACC_FLAT,
+	KEY_E_FLAT => ACC_FLAT,
+	KEY_B_FLAT => ACC_FLAT,
+	KEY_F => ACC_FLAT
+);
+
+function get_consonants($root_key)
+{
+	global $circle_of_fifths;
+	$first = $root_key;
+	$key = array_search($root_key, $circle_of_fifths);
+	$fourth = $circle_of_fifths[(($key - 1) + count($circle_of_fifths)) % count($circle_of_fifths)];
+	$fifth = $circle_of_fifths[($key + 1) % count($circle_of_fifths)];
+	
+	$minor1 = $circle_of_fifths[($key + 2) % count($circle_of_fifths)];
+	$minor2 = $circle_of_fifths[($key + 3) % count($circle_of_fifths)];
+	$minor3 = $circle_of_fifths[($key + 4) % count($circle_of_fifths)];
+	
+	$result = array(
+			'first' => $first,
+			'fourth' => $fourth,
+			'fifth' => $fifth,
+			'minors' => array($minor1, $minor2, $minor3)
+		);
+	return $result;
+}
+
+function get_sharp($chord)
+{
+	return key_to_name(name_to_key($chord), ACC_SHARP);
+}
+
+function detect_key($chord_list)
+{
+	$majors = array();
+	$minors = array();
+	$sharp_or_flat = ACC_SHARP;
+	// index which chords are used in the song
+	foreach ( $chord_list as $chord )
+	{
+		// discard bass note
+		list($chord) = explode('/', $chord);
+		$match = array();
+		preg_match('/((?:m?7?|2|add9|sus4|[Mm]aj[79])?)$/', $chord, $match);
+		if ( !empty($match[1]) )
+			$chord = str_replace_once($match[1], '', $chord);
+		$sharp_or_flat = get_sharp($chord) == $chord ? ACC_SHARP : ACC_FLAT;
+		$chord = get_sharp($chord);
+		if ( $match[1] == 'm' || $match[1] == 'm7' )
+		{
+			// minor chord
+			if ( !isset($minors[$chord]) )
+				$minors[$chord] = 0;
+			$minors[$chord]++;
+		}
+		else
+		{
+			// major chord
+			if ( !isset($majors[$chord]) )
+				$majors[$chord] = 0;
+			$majors[$chord]++;
+		}
+	}
+	// now we go through each of the detected major chords, calculate its consonants, and determine how many of its consonants are present in the song.
+	$scores = array();
+	foreach ( $majors as $key => $count )
+	{
+		$scores[$key] = 0;
+		$consonants = get_consonants(name_to_key($key));
+		if ( isset($majors[key_to_name($consonants['fourth'])]) )
+			$scores[$key] += 2;
+		if ( isset($majors[key_to_name($consonants['fifth'])]) )
+			$scores[$key] += 2;
+		if ( isset($majors[key_to_name($consonants['minors'][0])]) )
+			$scores[$key] += 1;
+		if ( isset($majors[key_to_name($consonants['minors'][1])]) )
+			$scores[$key] += 2;
+		if ( isset($majors[key_to_name($consonants['minors'][2])]) )
+			$scores[$key] += 1;
+	}
+	$winner_val = -1;
+	$winner_key = '';
+	foreach ( $scores as $key => $score )
+	{
+		if ( $score > $winner_val )
+		{
+			$winner_val = $score;
+			$winner_key = $key;
+		}
+	}
+	$winner_key = key_to_name(name_to_key($winner_key), $sharp_or_flat);
+	return $winner_key;
+}
+
+function key_to_name($root_key, $accidental = ACC_SHARP)
+{
+	switch($root_key)
+	{
+		case KEY_C:
+			return 'C';
+		case KEY_D:
+			return 'D';
+		case KEY_E:
+			return 'E';
+		case KEY_F:
+			return 'F';
+		case KEY_G:
+			return 'G';
+		case KEY_A:
+			return 'A';
+		case KEY_B:
+			return 'B';
+		case KEY_C_SHARP:
+			return $accidental == ACC_FLAT ? 'Db' : 'C#';
+		case KEY_E_FLAT:
+			return $accidental == ACC_FLAT ? 'Eb' : 'D#';
+		case KEY_F_SHARP:
+			return $accidental == ACC_FLAT ? 'Gb' : 'F#';
+		case KEY_G_SHARP:
+			return $accidental == ACC_FLAT ? 'Ab' : 'G#';
+		case KEY_B_FLAT:
+			return $accidental == ACC_FLAT ? 'Bb' : 'A#';
+		default:
+			return false;
+	}
+}
+
+function name_to_key($name)
+{
+	switch($name)
+	{
+		case 'C': return KEY_C;
+		case 'D': return KEY_D;
+		case 'E': return KEY_E;
+		case 'F': return KEY_F;
+		case 'G': return KEY_G;
+		case 'A': return KEY_A;
+		case 'B': return KEY_B;
+		case 'C#': case 'Db': return KEY_C_SHARP;
+		case 'D#': case 'Eb': return KEY_E_FLAT;
+		case 'F#': case 'Gb': return KEY_F_SHARP;
+		case 'G#': case 'Ab': return KEY_G_SHARP;
+		case 'A#': case 'Bb': return KEY_B_FLAT;
+		default: return false;
+	}
+}
+
+function prettify_accidentals($chord)
+{
+	if ( count(explode('/', $chord)) > 1 )
+	{
+		list($upper, $lower) = explode('/', $chord);
+		return prettify_accidentals($upper) . '/' . prettify_accidentals($lower);
+	}
+	
+	if ( strlen($chord) < 2 )
+		return $chord;
+	
+	if ( $chord{1} == 'b' )
+	{
+		$chord = $chord{0} . '&flat;' . substr($chord, 2);
+	}
+	else if ( $chord{1} == '#' )
+	{
+		$chord = $chord{0} . '&sharp;' . substr($chord, 2);
+	}
+	return $chord;
+}
+
+function transpose_chord($chord, $increment, $accidental = false)
+{
+	global $circle_of_fifths;
+	
+	if ( count(explode('/', $chord)) > 1 )
+	{
+		list($upper, $lower) = explode('/', $chord);
+		return transpose_chord($upper, $increment, $accidental) . '/' . transpose_chord($lower, $increment, $accidental);
+	}
+	// shave off any wacky things we're doing to the chord (minor, seventh, etc.)
+	preg_match('/((?:m?7?|2|add9|sus4|[Mm]aj[79])?)$/', $chord, $match);
+	// find base chord
+	if ( !empty($match[1]) )
+		$chord = str_replace($match[1], '', $chord);
+	// what's our accidental? allow it to be specified, and autodetect if it isn't
+	if ( !$accidental )
+		$accidental = strstr($chord, '#') ? ACC_SHARP : ACC_FLAT;
+	// convert to numeric value
+	$key = name_to_key($chord);
+	if ( $key === false )
+		// should never happen
+		return "[TRANSPOSITION FAILED: " . $chord . $match[1] . "]";
+	// transpose
+	$key = (($key + $increment) + count($circle_of_fifths)) % count($circle_of_fifths);
+	// return result
+	$kname = key_to_name($key, $accidental);
+	if ( !$kname )
+		// again, should never happen
+		return "[TRANSPOSITION FAILED: " . $chord . $match[1] . " + $increment (-&gt;$key)]";
+	$result = $kname . $match[1];
+	// echo "$chord{$match[1]} + $increment = $result<br />";
+	return $result;
+}
+
+function halftone_process_tags(&$text)
+{
+	static $css_added = false;
+	if ( !$css_added )
+	{
+		global $template;
+		$template->preload_js(array('jquery', 'jquery-ui'));
+		$template->add_header('
+			<style type="text/css">
+				h1.halftone-title {
+					page-break-before: always;
+				}
+				span.halftone-line {
+					display: block;
+					padding-top: 10pt;
+					position: relative; /* allows the absolute positioning in chords to work */
+				}
+				span.halftone-chord {
+					position: absolute;
+					top: 0pt;
+					color: rgb(27, 104, 184);
+				}
+				span.halftone-chord.sequential {
+					padding-left: 20pt;
+				}
+				div.halftone-key-select {
+					float: right;
+				}
+			</style>
+			<script type="text/javascript">
+				addOnloadHook(function()
+					{
+						$("select.halftone-key").change(function()
+							{
+								var me = this;
+								var src = $(this.parentNode.parentNode).attr("halftone:src");
+								ajaxPost(makeUrlNS("Special", "HalftoneRender", "transpose=" + $(this).val()) + "&tokey=" + $("option:selected", this).attr("halftone:abs"), "src=" + encodeURIComponent(src), function(ajax)
+									{
+										if ( ajax.readyState == 4 && ajax.status == 200 )
+										{
+											var $songbody = $("div.halftone-song", me.parentNode.parentNode);
+											$songbody.html(ajax.responseText);
+										}
+									});
+							});
+					});
+			</script>
+			');
+		$css_added = true;
+	}
+	if ( preg_match_all('/<halftone(.*?)>(.+?)<\/halftone>/s', $text, $matches) )
+	{
+		foreach ( $matches[0] as $i => $whole_match )
+		{
+			$attribs = decodeTagAttributes($matches[1][$i]);
+			$song_title = isset($attribs['title']) ? $attribs['title'] : 'Untitled song';
+			$chord_list = array();
+			$inner = trim($matches[2][$i]);
+			$song = halftone_render_body($inner, $chord_list);
+			$src = base64_encode($whole_match);
+			$key = name_to_key(detect_key($chord_list));
+			$select = '<select class="halftone-key">';
+			for ( $i = 0; $i < 12; $i++ )
+			{
+				$label = in_array($i, array(KEY_C_SHARP, KEY_E_FLAT, KEY_F_SHARP, KEY_G_SHARP, KEY_B_FLAT)) ? sprintf("%s/%s", key_to_name($i, ACC_SHARP), key_to_name($i, ACC_FLAT)) : key_to_name($i);
+				$label = prettify_accidentals($label);
+				$sel = $key == $i ? ' selected="selected"' : '';
+				$select .= sprintf("<option%s value=\"%d\" halftone:abs=\"%d\">%s</option>", $sel, $i - $key, $i, $label);
+			}
+			$select .= '</select>';
+			$text = str_replace_once($whole_match, "<div class=\"halftone\" halftone:src=\"$src\"><div class=\"halftone-key-select\">$select</div><h1 class=\"halftone-title\">$song_title</h1>\n\n<div class=\"halftone-song\">\n" . $song . "</div></div>", $text);
+		}
+	}
+}
+
+function halftone_render_body($inner, &$chord_list, $inkey = false)
+{
+	global $accidentals;
+	$song = '';
+	$chord_list = array();
+	$transpose = isset($_GET['transpose']) ? intval($_GET['transpose']) : 0;
+	$transpose_accidental = $inkey ? $accidentals[$inkey] : false;
+	foreach ( explode("\n", $inner) as $line )
+	{
+		$chordline = false;
+		$chords_regex = '/(\((?:[A-G][#b]?(?:m?7?|2|add9|sus4|[Mm]aj[79])?(?:\/[A-G][#b]?)?)\))/';
+		$line_split = preg_split($chords_regex, $line, -1, PREG_SPLIT_DELIM_CAPTURE);
+		if ( preg_match_all($chords_regex, $line, $chords) )
+		{
+			// this is a line with lyrics + chords
+			// echo out the line, adding spans around chords. here is where we also do transposition
+			// (if requested) and 
+			$line_final = array();
+			$last_was_chord = false;
+			foreach ( $line_split as $entry )
+			{
+				if ( preg_match($chords_regex, $entry) )
+				{
+					if ( $last_was_chord )
+					{
+						while ( !($pop = array_pop($line_final)) );
+						$new_entry = preg_replace('#</span>$#', '', $pop);
+						$new_entry .= str_repeat('&nbsp;', 4);
+						$new_entry .= prettify_accidentals($chord_list[] = transpose_chord(trim($entry, '()'), $transpose, $transpose_accidental)) . '</span>';
+						$line_final[] = $new_entry;
+					}
+					else
+					{
+						$line_final[] = '<span class="halftone-chord">' . prettify_accidentals($chord_list[] = transpose_chord(trim($entry, '()'), $transpose, $transpose_accidental)) . '</span>';
+					}
+					$last_was_chord = true;
+				}
+				else
+				{
+					if ( trim($entry) != "" )
+					{
+						$last_was_chord = false;
+						$line_final[] = $entry;
+					}
+				}
+			}
+			$song .= '<span class="halftone-line">' . implode("", $line_final) . "</span>\n";
+		}
+		else if ( preg_match('/^=\s*(.+?)\s*=$/', $line, $match) )
+		{
+			$song .= "== {$match[1]} ==\n";
+		} 
+		else if ( trim($line) == '' )
+		{
+			continue;
+		}
+		else
+		{
+			$song .= "$line<br />\n";
+		}
+	}
+	return $song;
+}
+
+function page_Special_HalftoneRender()
+{
+	global $accidentals;
+	$text = isset($_POST['src']) ? base64_decode($_POST['src']) : '';
+	if ( preg_match('/<halftone(.*?)>(.+?)<\/halftone>/s', $text, $match) )
+	{
+		require_once(ENANO_ROOT . '/includes/wikiformat.php');
+		$carp = new Carpenter();
+		$carp->exclusive_rule('heading');
+		$tokey = isset($_GET['tokey']) ? intval($_GET['tokey']) : false;
+		echo $carp->render(halftone_render_body($match[2], $chord_list, $tokey));
+	}
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/README	Tue Mar 27 03:55:10 2012 -0400
@@ -0,0 +1,27 @@
+chords2halftone.php is a completely standalone (non-Enano dependent) quick php
+script which turns ascii monospace chord sheets into halftone markup. You may
+or may not find it useful.
+
+Halftone markup example:
+
+<halftone title="Don't Stop Believing">
+Intro: (E) (B) (C#m) (A) (E) (B) (G#m) (A)
+
+Verse 1:
+(E)Just a (B)small town girl
+(C#m)Living in a (A)lonely world,
+(E)She took the (B)midnight train going
+(G#m)any - (A)where
+</halftone>
+
+You get the picture.
+
+Halftone will position the chords exactly in the right position above the text.
+You also (and this was the main reason I wrote this plugin) get automatic
+transposition with ajaxy-smooth sexiness.
+
+Note that the positioning-chords-above-text trick sometimes makes for overlaps
+if you put chords so close to each other. An example would be using
+"(G#m)any(A)where" in the sample verse above - depending on your theme/font
+G#m would be directly adjacent to A (confusing) or A would even overlap. So
+be sure to space out your lyrics accordingly.

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/chords2halftone.php	Tue Mar 27 03:55:10 2012 -0400
@@ -0,0 +1,113 @@
+<?php
+
+if ( isset($_POST['text']) )
+{
+	$text = explode("\n", str_replace("\r\n", "\n", trim($_POST['text'])));
+	$chordline = false;
+	echo "<pre>";
+	foreach ( $text as $i => $line )
+	{
+		if ( $i == 0 )
+		{
+			echo "&lt;halftone title=\"" . htmlspecialchars(htmlspecialchars($line)) . "\"&gt;\n";
+		}
+		else if ( trim($line) == "" )
+		{
+			// do nothing
+		}
+		else if ( preg_match('/^(.*?(?:Verse|Chorus|Bridge).*?):\s*$/i', $line, $match) )
+		{
+			if ( $chordline )
+			{
+				$chordstack = preg_split("/([ \t]+)/", $chordline);
+				echo '(' . implode(") (", $chordstack) . ")\n";
+				$chordline = false;
+			}
+			
+			if ( $i > 3 )
+				echo "\n";
+			echo "= {$match[1]} =\n";
+		}
+		else if ( preg_match('/^\((.*?(?:Verse|Chorus|Bridge).*?)\)$/i', $line, $match) )
+		{
+			if ( $chordline )
+			{
+				$chordstack = preg_split("/([ \t]+)/", $chordline);
+				echo '(' . implode(") (", $chordstack) . ")\n";
+				$chordline = false;
+			}
+			echo "\n[{$match[1]}]\n";
+		}
+		else if ( preg_match('/^(\s*([A-G][#b]?(?:m?7?|2|add9|sus4|[Mm]aj[79])?)(\/[A-G][#b]?)?\s*)*$/', $line) )
+		{
+			if ( $chordline )
+			{
+				// we have two chord lines in a row... treat the last one as a transition
+				$chordstack = preg_split("/([ \t]+)/", $chordline);
+				echo '(' . implode(") (", $chordstack) . ")\n";
+			}
+			
+			// chord line
+			$chordline = $line;
+		}
+		else if ( $chordline && trim($line) )
+		{
+			// combine chord line with text line
+			$chordline = preg_split('/([ \t]+)/', $chordline, -1, PREG_SPLIT_DELIM_CAPTURE);
+			
+			if ( count($chordline) >= 2 && preg_match('/^\s*$/', $chordline[0]) && preg_match('/^\s*$/', $chordline[1]) )
+			{
+				$merger = array_shift($chordline);
+				$chordline[0] .= $merger;
+			}
+			
+			$chordstack = array();
+			for ( $j = 0; $j < count($chordline); $j++ )
+			{
+				if ( $j == 0 && !preg_match('/^\s*$/', $chordline[$j]) )
+				{
+					$chordstack[] = "({$chordline[$j]})";
+					if ( isset($chordline[$j+1]) )
+					{
+						$chordline[$j+1] .= str_repeat(' ', strlen($chordline[$j]));
+					}
+					continue;
+				}
+				// insert line up until this chord
+				$chordstack[] = substr($line, 0, strlen($chordline[$j]));
+				// chomp off the front of the line
+				$line = substr($line, strlen($chordline[$j]));
+				// insert this chord
+				if ( isset($chordline[++$j]) )
+				{
+					if ( !empty($chordline[$j]) )
+					{
+						$chordstack[] = "({$chordline[$j]})";
+						if ( isset($chordline[$j+1]) )
+						{
+							$chordline[$j+1] .= str_repeat(' ', strlen($chordline[$j]));
+						}
+					}
+				}
+			}
+			$chordstack[] = $line;
+			echo implode("", $chordstack) . "\n";
+			$chordline = false;
+		}
+		else
+		{
+			// assume it's a lyric line without chords...?
+			echo "$line\n";
+		}
+	}
+	
+	echo "&lt;/halftone&gt;";
+	echo "</pre>";
+	exit;
+}
+
+?>
+<form method="post">
+<p><textarea name="text" rows="20" cols="100"></textarea></p>
+<p><input type="submit" value="Make Halftone" /></p>
+</form>