From a67460db8ba2c3c50e75866fa85091fbebdc7386 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Sun, 28 Aug 2016 21:18:41 +0200
Subject: [PATCH] More tweaks to the dB formatting.

---
 mainwindow.cpp | 68 ++++++++++++++++++++++++++++----------------------
 1 file changed, 38 insertions(+), 30 deletions(-)

diff --git a/mainwindow.cpp b/mainwindow.cpp
index 7d2a2d5..9ed7d3e 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -49,32 +49,40 @@ void quit_signal(int ignored)
 	global_mainwindow->close();
 }
 
-string format_db_with_sign(double db)
-{
-	if (isfinite(db)) {
-		char buf[256];
-		snprintf(buf, sizeof(buf), "%+.1f dB", db);
-		return buf;
-	} else if (db < 0.0) {
-		return "-∞ dB";
-	} else {
-		// Should never happen, really.
-		return "+∞ dB";
-	}
-}
+constexpr unsigned DB_NO_FLAGS = 0x0;
+constexpr unsigned DB_WITH_SIGN = 0x1;
+constexpr unsigned DB_BARE = 0x2;
 
-string format_db(double db)
+string format_db(double db, unsigned flags)
 {
-	if (isfinite(db)) {
-		char buf[256];
-		snprintf(buf, sizeof(buf), "%.1f dB", db);
-		return buf;
-	} else if (db < 0.0) {
-		return "-∞ dB";
+	string text;
+	if (flags & DB_WITH_SIGN) {
+		if (isfinite(db)) {
+			char buf[256];
+			snprintf(buf, sizeof(buf), "%+.1f", db);
+			text = buf;
+		} else if (db < 0.0) {
+			text = "-∞";
+		} else {
+			// Should never happen, really.
+			text = "+∞";
+		}
 	} else {
-		// Should never happen, really.
-		return "+∞ dB";
+		if (isfinite(db)) {
+			char buf[256];
+			snprintf(buf, sizeof(buf), "%.1f", db);
+			text = buf;
+		} else if (db < 0.0) {
+			text = "-∞";
+		} else {
+			// Should never happen, really.
+			text = "∞";
+		}
+	}
+	if (!(flags & DB_BARE)) {
+		text += " dB";
 	}
+	return text;
 }
 
 }  // namespace
@@ -166,9 +174,9 @@ void MainWindow::mixer_created(Mixer *mixer)
 	ui->makeup_gain_auto_checkbox->setChecked(global_mixer->get_final_makeup_gain_auto());
 
 	ui->limiter_threshold_db_display->setText(
-		QString::fromStdString(format_db(mixer->get_limiter_threshold_dbfs())));
+		QString::fromStdString(format_db(mixer->get_limiter_threshold_dbfs(), DB_WITH_SIGN)));
 	ui->compressor_threshold_db_display->setText(
-		QString::fromStdString(format_db(mixer->get_compressor_threshold_dbfs())));
+		QString::fromStdString(format_db(mixer->get_compressor_threshold_dbfs(), DB_WITH_SIGN)));
 
 	connect(ui->locut_cutoff_knob, &QDial::valueChanged, this, &MainWindow::cutoff_knob_changed);
 	cutoff_knob_changed(ui->locut_cutoff_knob->value());
@@ -280,7 +288,7 @@ void MainWindow::limiter_threshold_knob_changed(int value)
 	float threshold_dbfs = value * 0.1f;
 	global_mixer->set_limiter_threshold_dbfs(threshold_dbfs);
 	ui->limiter_threshold_db_display->setText(
-		QString::fromStdString(format_db(threshold_dbfs)));
+		QString::fromStdString(format_db(threshold_dbfs, DB_WITH_SIGN)));
 }
 
 void MainWindow::compressor_threshold_knob_changed(int value)
@@ -288,13 +296,13 @@ void MainWindow::compressor_threshold_knob_changed(int value)
 	float threshold_dbfs = value * 0.1f;
 	global_mixer->set_compressor_threshold_dbfs(threshold_dbfs);
 	ui->compressor_threshold_db_display->setText(
-		QString::fromStdString(format_db(threshold_dbfs)));
+		QString::fromStdString(format_db(threshold_dbfs, DB_WITH_SIGN)));
 }
 
 void MainWindow::reset_meters_button_clicked()
 {
 	global_mixer->reset_meters();
-	ui->peak_display->setText("-inf");
+	ui->peak_display->setText(QString::fromStdString(format_db(-HUGE_VAL, DB_WITH_SIGN | DB_BARE)));
 	ui->peak_display->setStyleSheet("");
 }
 
@@ -320,7 +328,7 @@ void MainWindow::audio_level_callback(float level_lufs, float peak_db, float glo
 		ui->lra_meter->set_levels(global_level_lufs, range_low_lufs, range_high_lufs);
 		ui->correlation_meter->set_correlation(correlation);
 
-		ui->peak_display->setText(QString::fromStdString(format_db(peak_db)));
+		ui->peak_display->setText(QString::fromStdString(format_db(peak_db, DB_BARE)));
 		if (peak_db > -0.1f) {  // -0.1 dBFS is EBU peak limit.
 			ui->peak_display->setStyleSheet("QLabel { background-color: red; color: white; }");
 		} else {
@@ -331,13 +339,13 @@ void MainWindow::audio_level_callback(float level_lufs, float peak_db, float glo
 		ui->gainstaging_knob->setValue(lrintf(gain_staging_db * 10.0f));
 		ui->gainstaging_knob->blockSignals(false);
 		ui->gainstaging_db_display->setText(
-			QString::fromStdString(format_db_with_sign(gain_staging_db)));
+			QString::fromStdString(format_db(gain_staging_db, DB_WITH_SIGN)));
 
 		ui->makeup_gain_knob->blockSignals(true);
 		ui->makeup_gain_knob->setValue(lrintf(final_makeup_gain_db * 10.0f));
 		ui->makeup_gain_knob->blockSignals(false);
 		ui->makeup_gain_db_display->setText(
-			QString::fromStdString(format_db_with_sign(final_makeup_gain_db)));
+			QString::fromStdString(format_db(final_makeup_gain_db, DB_WITH_SIGN)));
 	});
 }
 
-- 
2.39.2