2 files changed, 115 insertions, 34 deletions
diff --git a/src/chips/dosbox/dbopl.cpp b/src/chips/dosbox/dbopl.cpp
index 4eb79f8..2d31708 100644
--- a/src/chips/dosbox/dbopl.cpp
+++ b/src/chips/dosbox/dbopl.cpp
@@ -37,6 +37,7 @@
 #include <math.h>
 #include <stdlib.h>
 #include <string.h>
+#include <vector>
 #include "dbopl.h"
 
 #if defined(__GNUC__) && __GNUC__ > 3
@@ -70,6 +71,36 @@
 #define PI 3.14159265358979323846
 #endif
 
+struct NoCopy {
+	NoCopy() {}
+private:
+	NoCopy(const NoCopy &);
+	NoCopy &operator=(const NoCopy &);
+};
+#if !defined(_WIN32)
+#include <pthread.h>
+struct Mutex : NoCopy {
+	Mutex() : m(PTHREAD_MUTEX_INITIALIZER) {}
+	void lock() { pthread_mutex_lock(&m); }
+	void unlock() { pthread_mutex_unlock(&m); }
+	pthread_mutex_t m;
+};
+#else
+#include <windows.h>
+struct Mutex : NoCopy {
+	Mutex() { InitializeCriticalSection(&m); }
+	~Mutex() { DeleteCriticalSection(&m); }
+	void lock() { EnterCriticalSection(&m); }
+	void unlock() { LeaveCriticalSection(&m); }
+	CRITICAL_SECTION m;
+};
+#endif
+struct MutexHolder : NoCopy {
+	explicit MutexHolder(Mutex &m) : m(m) { m.lock(); }
+	~MutexHolder() { m.unlock(); }
+	Mutex &m;
+};
+
 namespace DBOPL {
 
 #define OPLRATE		((double)(14318180.0 / 288.0))
@@ -222,24 +253,24 @@ static const Bit8u KslShiftTable[4] = {
 // Pan law table
 static const Bit16u PanLawTable[] =
 {
-    65535, 65529, 65514, 65489, 65454, 65409, 65354, 65289,
-    65214, 65129, 65034, 64929, 64814, 64689, 64554, 64410,
-    64255, 64091, 63917, 63733, 63540, 63336, 63123, 62901,
-    62668, 62426, 62175, 61914, 61644, 61364, 61075, 60776,
-    60468, 60151, 59825, 59489, 59145, 58791, 58428, 58057,
-    57676, 57287, 56889, 56482, 56067, 55643, 55211, 54770,
-    54320, 53863, 53397, 52923, 52441, 51951, 51453, 50947,
-    50433, 49912, 49383, 48846, 48302, 47750, 47191,
-    46340, /* Center left */
-    46340, /* Center right */
-    45472, 44885, 44291, 43690, 43083, 42469, 41848, 41221,
-    40588, 39948, 39303, 38651, 37994, 37330, 36661, 35986,
-    35306, 34621, 33930, 33234, 32533, 31827, 31116, 30400,
-    29680, 28955, 28225, 27492, 26754, 26012, 25266, 24516,
-    23762, 23005, 22244, 21480, 20713, 19942, 19169, 18392,
-    17613, 16831, 16046, 15259, 14469, 13678, 12884, 12088,
-    11291, 10492, 9691, 8888, 8085, 7280, 6473, 5666,
-    4858, 4050, 3240, 2431, 1620, 810, 0
+	65535, 65529, 65514, 65489, 65454, 65409, 65354, 65289,
+	65214, 65129, 65034, 64929, 64814, 64689, 64554, 64410,
+	64255, 64091, 63917, 63733, 63540, 63336, 63123, 62901,
+	62668, 62426, 62175, 61914, 61644, 61364, 61075, 60776,
+	60468, 60151, 59825, 59489, 59145, 58791, 58428, 58057,
+	57676, 57287, 56889, 56482, 56067, 55643, 55211, 54770,
+	54320, 53863, 53397, 52923, 52441, 51951, 51453, 50947,
+	50433, 49912, 49383, 48846, 48302, 47750, 47191,
+	46340, /* Center left */
+	46340, /* Center right */
+	45472, 44885, 44291, 43690, 43083, 42469, 41848, 41221,
+	40588, 39948, 39303, 38651, 37994, 37330, 36661, 35986,
+	35306, 34621, 33930, 33234, 32533, 31827, 31116, 30400,
+	29680, 28955, 28225, 27492, 26754, 26012, 25266, 24516,
+	23762, 23005, 22244, 21480, 20713, 19942, 19169, 18392,
+	17613, 16831, 16046, 15259, 14469, 13678, 12884, 12088,
+	11291, 10492, 9691, 8888, 8085, 7280, 6473, 5666,
+	4858, 4050, 3240, 2431, 1620, 810, 0
 };
 
 //Generate a table index and table shift value using input value from a selected rate
@@ -465,7 +496,7 @@ Bits Operator::TemplateVolume(  ) {
 			return vol;
 		}
 		//In sustain phase, but not sustaining, do regular release
-                /* fall through */
+				/* fall through */
 	case RELEASE:
 		vol += RateForward( releaseAdd );;
 		if ( GCC_UNLIKELY(vol >= ENV_MAX) ) {
@@ -1294,21 +1325,40 @@ void Chip::GenerateBlock3_Mix( Bitu total, Bit32s* output  ) {
 	}
 }
 
-void Chip::Setup( Bit32u rate ) {
+struct CacheEntry {
+	Bit32u rate;
+	Bit32u freqMul[16];
+	Bit32u linearRates[76];
+	Bit32u attackRates[76];
+};
+static std::vector<CacheEntry> cache;
+static Mutex cacheMutex;
+
+static const CacheEntry *CacheLookupRateDependent( Bit32u rate )
+{
+	for ( size_t i = 0, n = cache.size(); i < n; ++i ) {
+		if (cache[i].rate == rate)
+			return &cache[i];
+	}
+	return NULL;
+}
+
+static const CacheEntry &ComputeRateDependent( Bit32u rate )
+{
+	{
+		MutexHolder lock( cacheMutex );
+		if (const CacheEntry *entry = CacheLookupRateDependent( rate ))
+			return *entry;
+	}
+
 	double original = OPLRATE;
-//	double original = rate;
 	double scale = original / (double)rate;
 
-	//Noise counter is run at the same precision as general waves
-	noiseAdd = (Bit32u)( 0.5 + scale * ( 1 << LFO_SH ) );
-	noiseCounter = 0;
-	noiseValue = 1;	//Make sure it triggers the noise xor the first time
-	//The low frequency oscillation counter
-	//Every time his overflows vibrato and tremoloindex are increased
-	lfoAdd = (Bit32u)( 0.5 + scale * ( 1 << LFO_SH ) );
-	lfoCounter = 0;
-	vibratoIndex = 0;
-	tremoloIndex = 0;
+	CacheEntry entry;
+	entry.rate = rate;
+	Bit32u *freqMul = entry.freqMul;
+	Bit32u *linearRates = entry.linearRates;
+	Bit32u *attackRates = entry.attackRates;
 
 	//With higher octave this gets shifted up
 	//-1 since the freqCreateTable = *2
@@ -1330,6 +1380,7 @@ void Chip::Setup( Bit32u rate ) {
 		EnvelopeSelect( i, index, shift );
 		linearRates[i] = (Bit32u)( scale * (EnvelopeIncreaseTable[ index ] << ( RATE_SH + ENV_EXTRA - shift - 3 )));
 	}
+
 //	Bit32s attackDiffs[62];
 	//Generate the best matching attack rate
 	for ( Bit8u i = 0; i < 62; i++ ) {
@@ -1382,6 +1433,36 @@ void Chip::Setup( Bit32u rate ) {
 		//This should provide instant volume maximizing
 		attackRates[i] = 8 << RATE_SH;
 	}
+
+	MutexHolder lock( cacheMutex );
+	if (const CacheEntry *entry = CacheLookupRateDependent( rate ))
+		return *entry;
+
+	cache.push_back(entry);
+	return cache.back();
+}
+
+void Chip::Setup( Bit32u rate ) {
+	double original = OPLRATE;
+//	double original = rate;
+	double scale = original / (double)rate;
+
+	//Noise counter is run at the same precision as general waves
+	noiseAdd = (Bit32u)( 0.5 + scale * ( 1 << LFO_SH ) );
+	noiseCounter = 0;
+	noiseValue = 1;	//Make sure it triggers the noise xor the first time
+	//The low frequency oscillation counter
+	//Every time his overflows vibrato and tremoloindex are increased
+	lfoAdd = (Bit32u)( 0.5 + scale * ( 1 << LFO_SH ) );
+	lfoCounter = 0;
+	vibratoIndex = 0;
+	tremoloIndex = 0;
+
+	const CacheEntry &entry = ComputeRateDependent( rate );
+	freqMul = entry.freqMul;
+	linearRates = entry.linearRates;
+	attackRates = entry.attackRates;
+
 	//Setup the channels with the correct four op flags
 	//Channels are accessed through a table so they appear linear here
 	chan[ 0].fourMask = 0x00 | ( 1 << 0 );
diff --git a/src/chips/dosbox/dbopl.h b/src/chips/dosbox/dbopl.h
index 429735f..89d2019 100644
--- a/src/chips/dosbox/dbopl.h
+++ b/src/chips/dosbox/dbopl.h
@@ -227,11 +227,11 @@ struct Chip {
 	Bit32u noiseValue;
 
 	//Frequency scales for the different multiplications
-	Bit32u freqMul[16];
+	const Bit32u *freqMul/*[16]*/;
 	//Rates for decay and release for rate of this chip
-	Bit32u linearRates[76];
+	const Bit32u *linearRates/*[76]*/;
 	//Best match attack rates for the rate of this chip
-	Bit32u attackRates[76];
+	const Bit32u *attackRates/*[76]*/;
 
 	//18 channels with 2 operators each
 	Channel chan[18];