From 7cfe4dbcef738681b5445aa14b35fc1a6f8ff001 Mon Sep 17 00:00:00 2001
From: JP Cimalando <jpcima@users.noreply.github.com>
Date: Thu, 7 Jun 2018 07:21:29 +0200
Subject: chips: create a common method set for generation and resampling

---
 src/chips/opl_chip_base.h | 81 +++++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 74 insertions(+), 7 deletions(-)

(limited to 'src/chips/opl_chip_base.h')

diff --git a/src/chips/opl_chip_base.h b/src/chips/opl_chip_base.h
index fb9b9e9..5721a81 100644
--- a/src/chips/opl_chip_base.h
+++ b/src/chips/opl_chip_base.h
@@ -9,24 +9,91 @@
 #define override
 #endif
 
+#if defined(ADLMIDI_ENABLE_HQ_RESAMPLER)
+class VResampler;
+#endif
+
 class OPLChipBase
 {
 protected:
     uint32_t m_rate;
 public:
     OPLChipBase();
-    OPLChipBase(const OPLChipBase &c);
     virtual ~OPLChipBase();
 
-    virtual void setRate(uint32_t rate);
+    virtual void setRate(uint32_t rate) = 0;
     virtual void reset() = 0;
-    virtual void reset(uint32_t rate);
     virtual void writeReg(uint16_t addr, uint8_t data) = 0;
-    virtual int generate(int16_t *output, size_t frames) = 0;
-    virtual int generateAndMix(int16_t *output, size_t frames) = 0;
-    virtual int generate32(int32_t *output, size_t frames);
-    virtual int generateAndMix32(int32_t *output, size_t frames);
+
+    virtual void nativePreGenerate() = 0;
+    virtual void nativePostGenerate() = 0;
+    virtual void nativeGenerate(int16_t *frame) = 0;
+
+    virtual void generate(int16_t *output, size_t frames) = 0;
+    virtual void generateAndMix(int16_t *output, size_t frames) = 0;
+    virtual void generate32(int32_t *output, size_t frames) = 0;
+    virtual void generateAndMix32(int32_t *output, size_t frames) = 0;
+
     virtual const char* emulatorName() = 0;
+private:
+    OPLChipBase(const OPLChipBase &c);
+    OPLChipBase &operator=(const OPLChipBase &c);
+};
+
+// A base class providing F-bounded generic and efficient implementations,
+// supporting resampling of chip outputs
+template <class T>
+class OPLChipBaseT : public OPLChipBase
+{
+public:
+    OPLChipBaseT();
+    virtual ~OPLChipBaseT();
+
+    virtual void setRate(uint32_t rate) override;
+    virtual void reset() override;
+    void generate(int16_t *output, size_t frames) override;
+    void generateAndMix(int16_t *output, size_t frames) override;
+    void generate32(int32_t *output, size_t frames) override;
+    void generateAndMix32(int32_t *output, size_t frames) override;
+private:
+    void setupResampler(uint32_t rate);
+    void resetResampler();
+    void resampledGenerate(int32_t *output);
+#if defined(ADLMIDI_ENABLE_HQ_RESAMPLER)
+    VResampler *m_resampler;
+#else
+    int32_t m_oldsamples[2];
+    int32_t m_samples[2];
+    int32_t m_samplecnt;
+    int32_t m_rateratio;
+    enum { rsm_frac = 10 };
+#endif
+    // amplitude scale factors in and out of resampler, varying for chips;
+    // values are OK to "redefine", the static polymorphism will accept it.
+    enum { resamplerPreAmplify = 1, resamplerPostAttenuate = 1 };
+};
+
+// A base class which provides frame-by-frame interfaces on emulations which
+// don't have a routine for it. It produces outputs in fixed size buffers.
+// Fast register updates will suffer some latency because of buffering.
+template <class T, unsigned Buffer = 256>
+class OPLChipBaseBufferedT : public OPLChipBaseT<T>
+{
+public:
+    OPLChipBaseBufferedT()
+        : OPLChipBaseT<T>(), m_bufferIndex(0) {}
+    virtual ~OPLChipBaseBufferedT()
+        {}
+public:
+    void reset() override;
+    void nativeGenerate(int16_t *frame) override;
+protected:
+    virtual void nativeGenerateN(int16_t *output, size_t frames) = 0;
+private:
+    unsigned m_bufferIndex;
+    int16_t m_buffer[2 * Buffer];
 };
 
+#include "opl_chip_base.tcc"
+
 #endif // ONP_CHIP_BASE_H
-- 
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