From a6424b254d2e16b2d3bb03e9079f2c8ed16ac0f4 Mon Sep 17 00:00:00 2001
From: Fawn <rubiefawn@gmail.com>
Date: Sun, 22 Mar 2026 19:27:23 -0600
Subject: [PATCH] Use std::formatted_size(), remove numDigitsAsInt()

Resolves a TODO in lmms_math.h by removing numDigitsAsInt() and using
std::formatted_size() instead.

This also removes MathTest.cpp, since its only purpose was to test the
now removed numDigitsAsInt().
---
 include/lmms_math.h         | 25 -----------------
 src/gui/Lv2ViewBase.cpp     | 10 ++++---
 tests/CMakeLists.txt        |  1 -
 tests/src/core/MathTest.cpp | 53 -------------------------------------
 4 files changed, 6 insertions(+), 83 deletions(-)
 delete mode 100644 tests/src/core/MathTest.cpp

diff --git a/include/lmms_math.h b/include/lmms_math.h
index a0f43c3e6f9..c68af071942 100644
--- a/include/lmms_math.h
+++ b/include/lmms_math.h
@@ -323,31 +323,6 @@ inline float safeDbfsToAmp(float dbfs)
 }
 
 
-// TODO C++20: use std::formatted_size
-// @brief Calculate number of digits which LcdSpinBox would show for a given number
-inline int numDigitsAsInt(float f)
-{
-	// use rounding:
-	// LcdSpinBox sometimes uses std::round(), sometimes cast rounding
-	// we use rounding to be on the "safe side"
-	int asInt = static_cast<int>(std::round(f));
-	int digits = 1; // always at least 1
-	if(asInt < 0)
-	{
-		++digits;
-		asInt = -asInt;
-	}
-	// "asInt" is positive from now
-	int power = 1;
-	for (int i = 1; i < 10; ++i)
-	{
-		power *= 10;
-		if (asInt >= power) { ++digits; } // 2 digits for >=10, 3 for >=100
-		else { break; }
-	}
-	return digits;
-}
-
 template <typename T>
 class LinearMap
 {
diff --git a/src/gui/Lv2ViewBase.cpp b/src/gui/Lv2ViewBase.cpp
index 0cd6a0ee4b7..44ea4c08d10 100644
--- a/src/gui/Lv2ViewBase.cpp
+++ b/src/gui/Lv2ViewBase.cpp
@@ -26,6 +26,7 @@
 
 #ifdef LMMS_HAVE_LV2
 
+#include <format>
 #include <QGridLayout>
 #include <QPushButton>
 #include <QHBoxLayout>
@@ -74,10 +75,11 @@ Lv2ViewProc::Lv2ViewProc(QWidget* parent, Lv2Proc* proc, int colNum) :
 						break;
 					case PortVis::Integer:
 					{
-						sample_rate_t sr = Engine::audioEngine()->outputSampleRate();
-						auto pMin = port.min(sr);
-						auto pMax = port.max(sr);
-						int numDigits = std::max(numDigitsAsInt(pMin), numDigitsAsInt(pMax));
+						const sample_rate_t sr = Engine::audioEngine()->outputSampleRate();
+						const auto numDigits = std::max(
+							std::formatted_size("{}", static_cast<long>(std::round(port.min(sr)))),
+							std::formatted_size("{}", static_cast<long>(std::round(port.max(sr))))
+						);
 						m_control = new LcdControl(numDigits, m_parent);
 						break;
 					}
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index b70d9fde9eb..1193acd6cf3 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -7,7 +7,6 @@ set(LMMS_TESTS
 	src/core/ArrayVectorTest.cpp
 	src/core/AudioBufferTest.cpp
 	src/core/AutomatableModelTest.cpp
-	src/core/MathTest.cpp
 	src/core/ProjectVersionTest.cpp
 	src/core/RelativePathsTest.cpp
 	src/core/TimelineTest.cpp
diff --git a/tests/src/core/MathTest.cpp b/tests/src/core/MathTest.cpp
deleted file mode 100644
index 544f04f4da5..00000000000
--- a/tests/src/core/MathTest.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-/*
- * MathTest.cpp
- *
- * Copyright (c) 2023 Johannes Lorenz <jlsf2013$users.sourceforge.net, $=@>
- *
- * This file is part of LMMS - https://lmms.io
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public
- * License as published by the Free Software Foundation; either
- * version 2 of the License, or (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public
- * License along with this program (see COPYING); if not, write to the
- * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
- * Boston, MA 02110-1301 USA.
- *
- */
-
-#include <QObject>
-#include <QtTest>
-
-#include "lmms_math.h"
-
-class MathTest : public QObject
-{
-	Q_OBJECT
-private slots:
-	void NumDigitsTest()
-	{
-		using namespace lmms;
-		QCOMPARE(numDigitsAsInt(1.f), 1);
-		QCOMPARE(numDigitsAsInt(9.9f), 2);
-		QCOMPARE(numDigitsAsInt(10.f), 2);
-		QCOMPARE(numDigitsAsInt(0.f), 1);
-		QCOMPARE(numDigitsAsInt(-100.f), 4);
-		QCOMPARE(numDigitsAsInt(-99.f), 3);
-		QCOMPARE(numDigitsAsInt(-0.4f), 1); // there is no "-0" for LED spinbox
-		QCOMPARE(numDigitsAsInt(-0.99f), 2);
-		QCOMPARE(numDigitsAsInt(1000000000), 10);
-		QCOMPARE(numDigitsAsInt(-1000000000), 11);
-		QCOMPARE(numDigitsAsInt(900000000), 9);
-		QCOMPARE(numDigitsAsInt(-900000000), 10);
-	}
-};
-
-QTEST_GUILESS_MAIN(MathTest)
-#include "MathTest.moc"