From a7109124434a19875d8d825a39c400e263b39538 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Frank=20B=C3=B6sing?= <f.boesing@gmx.de>
Date: Mon, 27 Feb 2017 19:24:16 +0100
Subject: [PATCH] Allow to modify the samplerate

---
 reSID.cpp    | 18 ++++++++++++------
 reSID.h      |  3 +++
 reSID/wave.h |  2 +-
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/reSID.cpp b/reSID.cpp
index 5d8f468..79ee813 100644
--- a/reSID.cpp
+++ b/reSID.cpp
@@ -27,17 +27,23 @@
 #include "reSID.h"
 #include <AudioStream.h>
 
-#define SAMPLERATE 44118
-#define CLOCKFREQ (22.5 * SAMPLERATE) //nearest int to 985248
+
+#define SAMPLERATE AUDIO_SAMPLE_RATE_EXACT
+#define CLOCKFREQ 985248
 
 void AudioPlaySID::begin(void)
 {
 	sidptr = &sid;
 	this->reset();
-	sid.set_sampling_parameters(CLOCKFREQ, SAMPLE_FAST, SAMPLERATE); 
+	setSampleParameters(CLOCKFREQ, SAMPLERATE);
 	playing = true;
 }
 
+void AudioPlaySID::setSampleParameters(unsigned clockfreq, unsigned samplerate) {
+	sid.set_sampling_parameters(clockfreq, SAMPLE_FAST, samplerate); 
+	csdelta = round((float)clockfreq / ((float)samplerate / AUDIO_BLOCK_SAMPLES));
+}
+
 void AudioPlaySID::reset(void)
 {
 	sid.reset();
@@ -59,9 +65,9 @@ void AudioPlaySID::update(void) {
 	// allocate the audio blocks to transmit
 	block = allocate();
 	if (block == NULL) return;
-	
-	//I'm not 100% if this is correct:
-	cycle_count delta_t = CLOCKFREQ / (SAMPLERATE / AUDIO_BLOCK_SAMPLES);
+		
+	//cycle_count delta_t = CLOCKFREQ / (SAMPLERATE / AUDIO_BLOCK_SAMPLES);
+	cycle_count delta_t = csdelta;
 	
 	sidptr->clock(delta_t, (short int*)block->data, AUDIO_BLOCK_SAMPLES);
 
diff --git a/reSID.h b/reSID.h
index b9c0e05..56eda49 100644
--- a/reSID.h
+++ b/reSID.h
@@ -36,11 +36,14 @@ class AudioPlaySID : public AudioStream
 public:
 	AudioPlaySID(void) : AudioStream(0, NULL) { begin(); }
 	void begin(void);
+	void setSampleParameters(unsigned clockfreq, unsigned samplerate);
 	inline void setreg(int ofs, int val) { sid.write(ofs, val); }
+	inline uint8_t getreg(int ofs) { return sid.read(ofs); }
 	void reset(void);
 	void stop(void);
 	inline bool isPlaying(void) { return playing; }	
 private:
+	cycle_count csdelta;
 	volatile bool playing;
 	virtual void update(void);	
 	SID sid;
diff --git a/reSID/wave.h b/reSID/wave.h
index 0a26126..376960d 100644
--- a/reSID/wave.h
+++ b/reSID/wave.h
@@ -267,7 +267,7 @@ reg12 WaveformGenerator::output___T()
 {
   reg24 msb = (ring_mod ? accumulator ^ sync_source->accumulator : accumulator)
     & 0x800000;
-  return ((msb ? ~accumulator : accumulator) >> 11) & 0xfff;
+  return ((msb ? ~accumulator : accumulator) >> 11) & 0xffe;
 }
 
 // Sawtooth: