Merge pull request #4325 from tcoyvwac/fix/constexpr-simple-variables

Promote many simple const variables to constexpr

src/analyzer/analyzerebur128.cpp

@@ -8,7 +8,7 @@
 #include "util/timer.h"
 
 namespace {
-const double kReplayGain2ReferenceLUFS = -18;
+constexpr double kReplayGain2ReferenceLUFS = -18;
 } // anonymous namespace
 
 AnalyzerEbur128::AnalyzerEbur128(UserSettingsPointer pConfig)

src/analyzer/analyzerwaveform.cpp

@@ -54,9 +54,9 @@ bool AnalyzerWaveform::initialize(TrackPointer tio,
     createFilters(sampleRate);
 
     //TODO (vrince) Do we want to expose this as settings or whatever ?
-    const int mainWaveformSampleRate = 441;
+    constexpr int mainWaveformSampleRate = 441;
     // two visual sample per pixel in full width overview in full hd
-    const int summaryWaveformSamples = 2 * 1920;
+    constexpr int summaryWaveformSamples = 2 * 1920;
 
     m_waveform = WaveformPointer(new Waveform(
             sampleRate, totalSamples, mainWaveformSampleRate, -1));

src/controllers/controllerinputmappingtablemodel.cpp

@@ -160,7 +160,7 @@ int ControllerInputMappingTableModel::columnCount(const QModelIndex& parent) con
         return 0;
     }
     // Control and description.
-    const int kBaseColumns = 2;
+    constexpr int kBaseColumns = 2;
     if (m_pMidiMapping != nullptr) {
         // Channel, Opcode, Control, Options
         return kBaseColumns + 4;

src/controllers/controlleroutputmappingtablemodel.cpp

@@ -127,7 +127,7 @@ int ControllerOutputMappingTableModel::columnCount(const QModelIndex& parent) co
         return 0;
     }
     // Control and description
-    const int kBaseColumns = 2;
+    constexpr int kBaseColumns = 2;
     if (m_pMidiMapping != nullptr) {
         // Channel, Opcode, Control, On, Off, Min, Max
         return kBaseColumns + 7;

src/controllers/controlpickermenu.cpp

@@ -107,7 +107,7 @@ ControlPickerMenu::ControlPickerMenu(QWidget* pParent)
         // TODO: Although there is a mode with 4-band EQs, it's not feasible
         // right now to add support for learning both it and regular 3-band eqs.
         // Since 3-band is by far the most common, stick with that.
-        const int kMaxEqs = 3;
+        constexpr int kMaxEqs = 3;
         QList<QString> eqNames;
         eqNames.append(tr("Low EQ"));
         eqNames.append(tr("Mid EQ"));
@@ -769,7 +769,7 @@ ControlPickerMenu::ControlPickerMenu(QWidget* pParent)
 
     // When kNumEffectRacks is changed to >1 put effect unit actions into
     // separate "Effect Rack N" submenus.
-    const int kNumEffectRacks = 1;
+    constexpr int kNumEffectRacks = 1;
     for (int iRackNumber = 1; iRackNumber <= kNumEffectRacks; ++iRackNumber) {
         const QString rackGroup = StandardEffectRack::formatGroupString(
                 iRackNumber - 1);

src/controllers/scripting/legacy/controllerscriptinterfacelegacy.cpp

@@ -11,11 +11,11 @@
 #include "util/time.h"
 
 namespace {
-const int kDecks = 16;
+constexpr int kDecks = 16;
 
 // Use 1ms for the Alpha-Beta dt. We're assuming the OS actually gives us a 1ms
 // timer.
-const int kScratchTimerMs = 1;
+constexpr int kScratchTimerMs = 1;
 const double kAlphaBetaDt = kScratchTimerMs / 1000.0;
 } // anonymous namespace
 

src/coreservices.cpp

@@ -77,7 +77,7 @@ void clearHelper(std::shared_ptr<T>& ref_ptr, const char* name) {
 #if defined(Q_OS_LINUX)
 typedef Bool (*WireToErrorType)(Display*, XErrorEvent*, xError*);
 
-const int NUM_HANDLERS = 256;
+constexpr int NUM_HANDLERS = 256;
 WireToErrorType __oldHandlers[NUM_HANDLERS] = {nullptr};
 
 Bool __xErrorHandler(Display* display, XErrorEvent* event, xError* error) {

src/effects/builtin/autopaneffect.h

@@ -57,7 +57,7 @@ class RampedSample {
     bool initialized;
 };
 
-static const int panMaxDelay = 3300; // allows a 30 Hz filter at 97346;
+static constexpr int panMaxDelay = 3300; // allows a 30 Hz filter at 97346;
 // static const int panMaxDelay = 50000; // high for debug;
 
 class AutoPanGroupState : public EffectState {

src/effects/builtin/balanceeffect.cpp

@@ -3,8 +3,8 @@
 #include "util/defs.h"
 
 namespace {
-    const double kMaxCornerHz = 500;
-    const double kMinCornerHz = 16;
+constexpr double kMaxCornerHz = 500;
+constexpr double kMinCornerHz = 16;
 } // anonymous namespace
 
 // static

src/effects/builtin/filtereffect.cpp

@@ -2,8 +2,8 @@
 #include "util/math.h"
 
 namespace {
-const double kMinCorner = 13; // Hz
-const double kMaxCorner = 22050; // Hz
+constexpr double kMinCorner = 13;    // Hz
+constexpr double kMaxCorner = 22050; // Hz
 } // anonymous namespace
 
 // static

src/effects/builtin/linkwitzriley8eqeffect.cpp

@@ -3,9 +3,9 @@
 #include "effects/builtin/equalizer_util.h"
 #include "util/math.h"
 
-static const unsigned int kStartupSamplerate = 44100;
-static const unsigned int kStartupLoFreq = 246;
-static const unsigned int kStartupHiFreq = 2484;
+static constexpr unsigned int kStartupSamplerate = 44100;
+static constexpr unsigned int kStartupLoFreq = 246;
+static constexpr unsigned int kStartupHiFreq = 2484;
 
 // static
 QString LinkwitzRiley8EQEffect::getId() {

src/effects/builtin/loudnesscontoureffect.cpp

@@ -4,12 +4,12 @@
 namespace {
 
 // The defaults are tweaked to match the TEA6320 IC
-static const double kLoPeakFreq = 20.0;
-static const double kHiShelveFreq = 3000.0;
-static const double kMaxLoGain = 30.0;
-static const double kHiShelveGainDiv = 3.0;
-static const double kLoPleakQ = 0.2;
-static const double kHiShelveQ = 0.7;
+static constexpr double kLoPeakFreq = 20.0;
+static constexpr double kHiShelveFreq = 3000.0;
+static constexpr double kMaxLoGain = 30.0;
+static constexpr double kHiShelveGainDiv = 3.0;
+static constexpr double kLoPleakQ = 0.2;
+static constexpr double kHiShelveQ = 0.7;
 
 } // anonymous namespace
 

src/effects/builtin/metronomeclick.h

@@ -5,8 +5,8 @@
 // This is a new recording from a real metronome
 // it was converted from *.wav to plain text using Audacity
 
-const SINT kClickSize44100 = 1024;
-const CSAMPLE kClick44100[kClickSize44100] = {
+constexpr SINT kClickSize44100 = 1024;
+constexpr CSAMPLE kClick44100[kClickSize44100] = {
         0.03459f,
         0.09436f,
         0.13646f,
@@ -1032,8 +1032,8 @@ const CSAMPLE kClick44100[kClickSize44100] = {
         0.00039f,
         0.00139f};
 
-const unsigned int kClickSize48000 = 1116;
-const CSAMPLE kClick48000[kClickSize48000] = {
+constexpr unsigned int kClickSize48000 = 1116;
+constexpr CSAMPLE kClick48000[kClickSize48000] = {
         0.01534f,
         0.05623f,
         0.10618f,
@@ -2151,8 +2151,8 @@ const CSAMPLE kClick48000[kClickSize48000] = {
         0.00132f,
         0.00021f};
 
-const unsigned int kClickSize96000 = 2231;
-const CSAMPLE kClick96000[kClickSize96000] = {
+constexpr unsigned int kClickSize96000 = 2231;
+constexpr CSAMPLE kClick96000[kClickSize96000] = {
         0.01534f,
         0.03123f,
         0.05623f,

src/effects/builtin/moogladder4filtereffect.cpp

@@ -1,9 +1,8 @@
 #include "effects/builtin/moogladder4filtereffect.h"
 #include "util/math.h"
 
-
-static const double kMinCorner = 0.0003; // 13 Hz @ 44100
-static const double kMaxCorner = 0.5; // 22050 Hz @ 44100
+static constexpr double kMinCorner = 0.0003; // 13 Hz @ 44100
+static constexpr double kMaxCorner = 0.5;    // 22050 Hz @ 44100
 
 // static
 QString MoogLadder4FilterEffect::getId() {

src/effects/builtin/threebandbiquadeqeffect.cpp

@@ -7,17 +7,17 @@ namespace {
 
 // The defaults are tweaked to match the Xone:23 EQ
 // but allow 12 dB boost instead of just 6 dB
-static const int kStartupSamplerate = 44100;
-static const double kMinimumFrequency = 10.0;
-static const double kMaximumFrequency = kStartupSamplerate / 2;
-static const double kStartupLoFreq = 50.0;
-static const double kStartupMidFreq = 1100.0;
-static const double kStartupHiFreq = 12000.0;
-static const double kQBoost = 0.3;
-static const double kQKill = 0.9;
-static const double kQKillShelve = 0.4;
-static const double kBoostGain = 12;
-static const double kKillGain = -26;
+static constexpr int kStartupSamplerate = 44100;
+static constexpr double kMinimumFrequency = 10.0;
+static constexpr double kMaximumFrequency = kStartupSamplerate / 2;
+static constexpr double kStartupLoFreq = 50.0;
+static constexpr double kStartupMidFreq = 1100.0;
+static constexpr double kStartupHiFreq = 12000.0;
+static constexpr double kQBoost = 0.3;
+static constexpr double kQKill = 0.9;
+static constexpr double kQKillShelve = 0.4;
+static constexpr double kBoostGain = 12;
+static constexpr double kKillGain = -26;
 
 
 double getCenterFrequency(double low, double high) {

src/effects/effectchainmanager.h

@@ -63,7 +63,7 @@ class EffectChainManager : public QObject {
     // Reloads all effect to the slots to update parameter assignments
     void refeshAllRacks();
 
-    static const int kNumStandardEffectChains = 4;
+    static constexpr int kNumStandardEffectChains = 4;
 
     bool isAdoptMetaknobValueEnabled() const;
 

src/effects/effectslot.cpp

@@ -11,7 +11,7 @@
 #include "util/xml.h"
 
 // The maximum number of effect parameters we're going to support.
-const unsigned int kDefaultMaxParameters = 16;
+constexpr unsigned int kDefaultMaxParameters = 16;
 
 EffectSlot::EffectSlot(const QString& group,
                        const unsigned int iChainNumber,

src/effects/effectsmanager.cpp

@@ -19,7 +19,7 @@ const QString EffectsManager::kNoEffectString = QStringLiteral("---");
 namespace {
 constexpr QChar kEffectGroupSeparator = '_';
 constexpr QChar kGroupClose = ']';
-const unsigned int kEffectMessagPipeFifoSize = 2048;
+constexpr unsigned int kEffectMessagPipeFifoSize = 2048;
 const QRegularExpression kIntRegex(QStringLiteral(".*(\\d+).*"));
 } // anonymous namespace
 

src/effects/effectxmlelements.h

@@ -1,7 +1,7 @@
 namespace EffectXml {
 // Version history:
 // 0 (Mixxx 2.1.0): initial support for saving state of effects
-const int kXmlSchemaVersion = 0;
+constexpr int kXmlSchemaVersion = 0;
 
 const QString Root("MixxxEffects");
 const QString SchemaVersion("SchemaVersion");

src/encoder/encoderfdkaac.cpp

@@ -15,7 +15,7 @@
 
 namespace {
 // recommended in encoder documentation, section 2.4.1
-const int kOutBufferBits = 6144;
+constexpr int kOutBufferBits = 6144;
 const mixxx::Logger kLogger("EncoderFdkAac");
 } // namespace
 

src/encoder/encoderfdkaac.h

@@ -22,9 +22,9 @@ class EncoderFdkAac : public Encoder {
     QString buttWindowsFdkAac();
 
     // libfdk-aac common AOTs
-    static const int AOT_AAC_LC = 2; // AAC-LC: Low Complexity (iTunes)
-    static const int AOT_SBR = 5;    // HE-AAC: with Spectral Band Replication
-    static const int AOT_PS = 29;    // HE-AACv2: Parametric Stereo (includes SBR)
+    static constexpr int AOT_AAC_LC = 2; // AAC-LC: Low Complexity (iTunes)
+    static constexpr int AOT_SBR = 5;    // HE-AAC: with Spectral Band Replication
+    static constexpr int AOT_PS = 29;    // HE-AACv2: Parametric Stereo (includes SBR)
 
     // libfdk-aac types and structs
     typedef signed int INT;

src/encoder/encoderfdkaacsettings.cpp

@@ -4,7 +4,7 @@
 #include "util/logger.h"
 
 namespace {
-const int kDefaultQualityIndex = 6;
+constexpr int kDefaultQualityIndex = 6;
 const char* kQualityKey = "FdkAac_Quality";
 const mixxx::Logger kLogger("EncoderFdkAacSettings");
 } // namespace

src/encoder/encoderopus.cpp

@@ -220,7 +220,7 @@ void EncoderOpus::pushHeaderPacket() {
     // - Mapping family: 1 byte
     // - Channel mapping table: ignored
     // Total: 19 bytes
-    const int frameSize = 19;
+    constexpr int frameSize = 19;
     QByteArray frame;
 
     // Magic signature (8 bytes)

src/encoder/encoderopussettings.cpp

@@ -5,7 +5,7 @@
 #include "util/logger.h"
 
 namespace {
-const int kDefaultQualityIndex = 6;
+constexpr int kDefaultQualityIndex = 6;
 const char* kQualityKey = "Opus_Quality";
 const mixxx::Logger kLogger("EncoderOpusSettings");
 } // namespace

src/engine/bufferscalers/enginebufferscalelinear.h

@@ -4,7 +4,7 @@
 #include "engine/readaheadmanager.h"
 
 /** Number of samples to read ahead */
-const int kiLinearScaleReadAheadLength = 10240;
+constexpr int kiLinearScaleReadAheadLength = 10240;
 
 
 class EngineBufferScaleLinear : public EngineBufferScale  {

src/engine/bufferscalers/enginebufferscalerubberband.cpp

@@ -54,7 +54,7 @@ void EngineBufferScaleRubberBand::setScaleParameters(double base_rate,
     // References:
     // https://bugs.launchpad.net/ubuntu/+bug/1263233
     // https://bitbucket.org/breakfastquay/rubberband/issue/4/sigfpe-zero-division-with-high-time-ratios
-    const double kMinSeekSpeed = 1.0 / 128.0;
+    constexpr double kMinSeekSpeed = 1.0 / 128.0;
     double speed_abs = fabs(*pTempoRatio);
     if (speed_abs < kMinSeekSpeed) {
         // Let the caller know we ignored their speed.

src/engine/bufferscalers/enginebufferscalest.cpp

@@ -22,7 +22,7 @@ namespace {
 // 0.918 (upscaling 44.1 kHz to 48 kHz) will produce an additional offset of 3 Frames
 // 0.459 (upscaling 44.1 kHz to 96 kHz) will produce an additional offset of 18 Frames
 // (Rubberband does not suffer this issue)
-const SINT kSeekOffsetFrames = 519;
+constexpr SINT kSeekOffsetFrames = 519;
 
 }  // namespace
 

src/engine/cachingreader/cachingreader.cpp

@@ -20,7 +20,7 @@ mixxx::Logger kLogger("CachingReader");
 // This is the default hint frameCount that is adopted in case of Hint::kFrameCountForward and
 // Hint::kFrameCountBackward count is provided. It matches 23 ms @ 44.1 kHz
 // TODO() Do we suffer cache misses if we use an audio buffer of above 23 ms?
-const SINT kDefaultHintFrames = 1024;
+constexpr SINT kDefaultHintFrames = 1024;
 
 // With CachingReaderChunk::kFrames = 8192 each chunk consumes
 // 8192 frames * 2 channels/frame * 4-bytes per sample = 65 kB.
@@ -37,7 +37,7 @@ const SINT kDefaultHintFrames = 1024;
 // (kNumberOfCachedChunksInMemory = 1, 2, 3, ...) for testing purposes
 // to verify that the MRU/LRU cache works as expected. Even though
 // massive drop outs are expected to occur Mixxx should run reliably!
-const SINT kNumberOfCachedChunksInMemory = 80;
+constexpr SINT kNumberOfCachedChunksInMemory = 80;
 
 } // anonymous namespace
 

src/engine/cachingreader/cachingreaderchunk.cpp

@@ -13,7 +13,7 @@ namespace {
 
 mixxx::Logger kLogger("CachingReaderChunk");
 
-const SINT kInvalidChunkIndex = -1;
+constexpr SINT kInvalidChunkIndex = -1;
 
 } // anonymous namespace
 

src/engine/channelhandle.h

@@ -167,7 +167,7 @@ typedef std::shared_ptr<ChannelHandleFactory> ChannelHandleFactoryPointer;
 // integer value.
 template <class T>
 class ChannelHandleMap {
-    static const int kMaxExpectedGroups = 256;
+    static constexpr int kMaxExpectedGroups = 256;
     typedef QVarLengthArray<T, kMaxExpectedGroups> container_type;
   public:
     typedef typename QVarLengthArray<T, kMaxExpectedGroups>::const_iterator const_iterator;

src/engine/controls/bpmcontrol.cpp

@@ -514,16 +514,16 @@ double BpmControl::calcSyncAdjustment(bool userTweakingSync) {
         // Threshold above which sync is really, really bad, so much so that we
         // don't even know if we're ahead or behind.  This can occur when quantize was
         // off, but then it gets turned on.
-        const double kTrainWreckThreshold = 0.2;
-        const double kSyncAdjustmentCap = 0.05;
+        constexpr double kTrainWreckThreshold = 0.2;
+        constexpr double kSyncAdjustmentCap = 0.05;
         if (fabs(error) > kTrainWreckThreshold) {
             // Assume poor reflexes (late button push) -- speed up to catch the other track.
             adjustment = 1.0 + kSyncAdjustmentCap;
         } else if (fabs(error) > kErrorThreshold) {
             // Proportional control constant. The higher this is, the more we
             // influence sync.
-            const double kSyncAdjustmentProportional = 0.7;
-            const double kSyncDeltaCap = 0.02;
+            constexpr double kSyncAdjustmentProportional = 0.7;
+            constexpr double kSyncDeltaCap = 0.02;
 
             // TODO(owilliams): There are a lot of "1.0"s in this code -- can we eliminate them?
             const double adjust = 1.0 + (-error * kSyncAdjustmentProportional);

src/engine/controls/enginecontrol.h

@@ -17,7 +17,7 @@
 class EngineMaster;
 class EngineBuffer;
 
-const int kNoTrigger = -1;
+constexpr int kNoTrigger = -1;
 static_assert(
         mixxx::audio::FramePos::kLegacyInvalidEnginePosition == kNoTrigger,
         "Invalid engine position value mismatch");