Pushed v1.24 code

- BPM is now slightly more accurate to CIA specifications, and also more accurate in vblank (VBL) timing mode using the true Amiga PAL vblank rate. NOTE: We're speaking tiny variations in BPM here...
- Vblank (VBL) timing mode: Fixed a bug with setting a speed of FF (255) on the first row. The tick duration would be about twice as long...
- Small code cleanup

src/pt2_audio.c

@@ -116,19 +116,6 @@ void setSyncTickTimeLen(uint32_t timeLen, uint32_t timeLenFrac)
 	tickTimeLenFrac = timeLenFrac;
 }
 
-static void generateBpmTables(void)
-{
-	for (int32_t i = 32; i <= 255; i++)
-	{
-		const double dBpmHz = i / 2.5;
-
-		audio.bpmTab[i-32] = audio.outputRate / dBpmHz;
-		audio.bpmTab28kHz[i-32] = PAT2SMP_HI_FREQ / dBpmHz; // PAT2SMP hi quality
-		audio.bpmTab22kHz[i-32] = PAT2SMP_LO_FREQ / dBpmHz; // PAT2SMP low quality
-		audio.bpmTabMod2Wav[i-32] = MOD2WAV_FREQ / dBpmHz; // MOD2WAV
-	}
-}
-
 void lockAudio(void)
 {
 	if (dev != 0)
@@ -788,6 +775,69 @@ void mixerCalcVoicePans(uint8_t stereoSeparation) // 0..100 (percentage)
 	setVoicePan(3, panL);
 }
 
+static double ciaBpm2Hz(int32_t bpm)
+{
+	if (bpm == 0)
+		return 0.0;
+
+	const uint32_t ciaPeriod = 1773447 / bpm; // yes, PT truncates here
+	return (double)CIA_PAL_CLK / ciaPeriod;
+}
+
+static void generateBpmTables(bool vblankTimingFlag)
+{
+	for (int32_t bpm = 32; bpm <= 255; bpm++)
+	{
+		double dHz;
+
+		if (vblankTimingFlag)
+			dHz = AMIGA_PAL_VBLANK_HZ;
+		else
+			dHz = ciaBpm2Hz(bpm);
+
+		audio.bpmTable[bpm-32] = audio.outputRate / dHz;
+		audio.bpmTable28kHz[bpm-32] = PAT2SMP_HI_FREQ / dHz; // PAT2SMP hi quality
+		audio.bpmTable22kHz[bpm-32] = PAT2SMP_LO_FREQ / dHz; // PAT2SMP low quality
+		audio.bpmTableMod2Wav[bpm-32] = MOD2WAV_FREQ / dHz; // MOD2WAV
+	}
+}
+
+static void generateTickLengthTable(bool vblankTimingFlag)
+{
+	for (int32_t bpm = 32; bpm <= 255; bpm++)
+	{
+		double dHz;
+
+		if (vblankTimingFlag)
+			dHz = AMIGA_PAL_VBLANK_HZ;
+		else
+			dHz = ciaBpm2Hz(bpm);
+
+		// BPM -> Hz -> tick length for performance counter (syncing visuals to audio)
+		double dTimeInt;
+		double dTimeFrac = modf(editor.dPerfFreq / dHz, &dTimeInt);
+		const int32_t timeInt = (int32_t)dTimeInt;
+
+		dTimeFrac = floor((UINT32_MAX+1.0) * dTimeFrac); // fractional part (scaled to 0..2^32-1)
+
+		audio.tickLengthTable[bpm-32] = ((uint64_t)timeInt << 32) | (uint32_t)dTimeFrac;
+	}
+}
+
+void updateReplayerTimingMode(void)
+{
+	const bool audioWasntLocked = !audio.locked;
+	if (audioWasntLocked)
+		lockAudio();
+
+	const bool vblankTimingMode = (editor.timingMode == TEMPO_MODE_VBLANK);
+	generateBpmTables(vblankTimingMode);
+	generateTickLengthTable(vblankTimingMode);
+
+	if (audioWasntLocked)
+		unlockAudio();
+}
+
 bool setupAudio(void)
 {
 	SDL_AudioSpec want, have;
@@ -822,12 +872,12 @@ bool setupAudio(void)
 	audio.audioBufferSize = have.samples;
 	audio.dPeriodToDeltaDiv = (double)PAULA_PAL_CLK / audio.outputRate;
 
-	generateBpmTables();
+	updateReplayerTimingMode();
 
 	const int32_t lowestBPM = 32;
-	const int32_t pat2SmpMaxSamples = (int32_t)ceil(audio.bpmTab22kHz[lowestBPM-32]);
-	const int32_t mod2WavMaxSamples = (int32_t)ceil(audio.bpmTabMod2Wav[lowestBPM-32]);
-	const int32_t renderMaxSamples = (int32_t)ceil(audio.bpmTab[lowestBPM-32]);
+	const int32_t pat2SmpMaxSamples = (int32_t)ceil(audio.bpmTable22kHz[lowestBPM-32]);
+	const int32_t mod2WavMaxSamples = (int32_t)ceil(audio.bpmTableMod2Wav[lowestBPM-32]);
+	const int32_t renderMaxSamples = (int32_t)ceil(audio.bpmTable[lowestBPM-32]);
 
 	const int32_t maxSamplesToMix = MAX(pat2SmpMaxSamples, MAX(mod2WavMaxSamples, renderMaxSamples));
 
@@ -850,24 +900,13 @@ bool setupAudio(void)
 	ledFilterEnabled = false;
 	calculateFilterCoeffs();
 
-	audio.dSamplesPerTick = audio.bpmTab[125-32]; // BPM 125
+	audio.dSamplesPerTick = audio.bpmTable[125-32]; // BPM 125
 	audio.dTickSampleCounter = 0.0;
 
 	calcAudioLatencyVars(audio.audioBufferSize, audio.outputRate);
 
-	for (int32_t i = 32; i <= 255; i++)
-	{
-		const double dBpmHz = i / 2.5;
 
-		// BPM -> Hz -> tick length for performance counter (syncing visuals to audio)
-		double dTimeInt;
-		double dTimeFrac = modf(editor.dPerfFreq / dBpmHz, &dTimeInt);
-		const int32_t timeInt = (int32_t)dTimeInt;
 
-		dTimeFrac *= UINT32_MAX+1.0; // fractional part (scaled to 0..2^32-1)
-
-		audio.tickTimeLengthTab[i-32] = ((uint64_t)timeInt << 32) | (uint32_t)dTimeFrac;
-	}
 
 	audio.resetSyncTickTimeFlag = true;
 	SDL_PauseAudioDevice(dev, false);

src/pt2_audio.h

@@ -9,7 +9,7 @@ typedef struct audio_t
 	volatile bool locked, isSampling;
 
 	bool forceMixerOff;
-	double bpmTab[256-32], bpmTab28kHz[256-32], bpmTab22kHz[256-32], bpmTabMod2Wav[256-32];
+	double bpmTable[256-32], bpmTable28kHz[256-32], bpmTable22kHz[256-32], bpmTableMod2Wav[256-32];
 	uint32_t outputRate, audioBufferSize;
 	double dPeriodToDeltaDiv;
 
@@ -20,7 +20,7 @@ typedef struct audio_t
 
 	// for audio/video syncing
 	bool resetSyncTickTimeFlag;
-	uint64_t tickTimeLengthTab[224];
+	uint64_t tickLengthTable[224];
 } audio_t;
 
 typedef struct voice_t
@@ -39,6 +39,8 @@ typedef struct voice_t
 	const int8_t *syncTriggerData;
 } paulaVoice_t;
 
+void updateReplayerTimingMode(void);
+
 void setSyncTickTimeLen(uint32_t timeLen, uint32_t timeLenFrac);
 void resetCachedMixerPeriod(void);
 void resetAudioDithering(void);

src/pt2_header.h

@@ -14,7 +14,7 @@
 #include "pt2_unicode.h"
 #include "pt2_palette.h"
 
-#define PROG_VER_STR "1.23"
+#define PROG_VER_STR "1.24"
 
 #ifdef _WIN32
 #define DIR_DELIMITER '\\'
@@ -225,8 +225,8 @@ void modStop(void);
 void doStopIt(bool resetPlayMode);
 void playPattern(int8_t startRow);
 void modPlay(int16_t patt, int16_t order, int8_t row);
-void modSetSpeed(uint8_t speed);
-void modSetTempo(uint16_t bpm, bool doLockAudio);
+void modSetSpeed(int32_t speed);
+void modSetTempo(int32_t bpm, bool doLockAudio);
 void modFree(void);
 bool setupAudio(void);
 void audioClose(void);

src/pt2_keyboard.c

@@ -699,17 +699,26 @@ void keyDownHandler(SDL_Scancode scancode, SDL_Keycode keycode)
 		{
 			if (keyb.leftCtrlPressed)
 			{
+				const bool audioWasntLocked = !audio.locked;
+				if (audioWasntLocked)
+					lockAudio();
+
 				editor.timingMode ^= 1;
+				updateReplayerTimingMode();
+
 				if (editor.timingMode == TEMPO_MODE_VBLANK)
 				{
 					editor.oldTempo = song->currBPM;
-					modSetTempo(125, true);
+					modSetTempo(125, false);
 				}
 				else
 				{
-					modSetTempo(editor.oldTempo, true);
+					modSetTempo(editor.oldTempo, false);
 				}
 
+				if (audioWasntLocked)
+					unlockAudio();
+
 				ui.updateSongTiming = true;
 			}
 			else if (keyb.shiftPressed)
@@ -3452,10 +3461,7 @@ void handleKeyRepeat(SDL_Scancode scancode)
 		break;
 	}
 
-	// repeat keys at 49.92Hz (Amiga PAL) rate
-	const uint64_t keyRepeatDelta = (uint64_t)(((UINT32_MAX+1.0) * (AMIGA_PAL_VBLANK_HZ / (double)VBLANK_HZ)) + 0.5);
-
-	keyb.repeatFrac += keyRepeatDelta; // 32.32 fixed-point counter
+	keyb.repeatFrac += keyb.repeatDelta; // 32.32 fixed-point counter
 	if (keyb.repeatFrac > 0xFFFFFFFF)
 	{
 		keyb.repeatFrac &= 0xFFFFFFFF;

src/pt2_main.c

@@ -471,6 +471,10 @@ static bool initializeVars(void)
 
 	editor.repeatKeyFlag = (SDL_GetModState() & KMOD_CAPS) ? true : false;
 
+	// set key repeat rate to 49.9204Hz (Amiga PAL vblank rate)
+	const double dVblankHzRatio = AMIGA_PAL_VBLANK_HZ / (double)VBLANK_HZ;
+	keyb.repeatDelta = (uint64_t)floor((UINT32_MAX+1.0) * dVblankHzRatio);
+
 	strcpy(editor.mixText, "MIX 01+02 TO 03");
 
 	// allocate some memory

src/pt2_mod2wav.c

@@ -157,7 +157,8 @@ bool renderToWav(char *fileName, bool checkIfFileExist)
 		return false;
 	}
 
-	const int32_t maxSamplesToMix = (int32_t)ceil(TICKS_PER_RENDER_CHUNK * audio.bpmTabMod2Wav[32-32]); // BPM 32, stereo
+	const int32_t lowestBPM = 32;
+	const int32_t maxSamplesToMix = (int32_t)ceil(TICKS_PER_RENDER_CHUNK * audio.bpmTableMod2Wav[lowestBPM-32]); // stereo
 
 	mod2WavBuffer = (int16_t *)malloc(maxSamplesToMix * (2 * sizeof (int16_t)));
 	if (mod2WavBuffer == NULL)

src/pt2_module_loader.c

@@ -946,6 +946,7 @@ void setupLoadedMod(void)
 	updateWindowTitle(MOD_NOT_MODIFIED);
 
 	editor.timingMode = TEMPO_MODE_CIA;
+	updateReplayerTimingMode();
 
 	modSetSpeed(6);
 	modSetTempo(song->header.initialTempo, false); // 125 for normal MODs, custom value for certain STK/UST MODs

src/pt2_mouse.c

@@ -1048,7 +1048,7 @@ void sampleRepeatLengthDownButton(bool fast)
 
 void tempoUpButton(void)
 {
-	int16_t val;
+	int32_t val;
 
 	if (editor.timingMode == TEMPO_MODE_VBLANK)
 		return;
@@ -1069,7 +1069,7 @@ void tempoUpButton(void)
 
 void tempoDownButton(void)
 {
-	int16_t val;
+	int32_t val;
 
 	if (editor.timingMode == TEMPO_MODE_VBLANK)
 		return;