Add MIDI interface classes

lib/audiodev/MIDIDecoder.cpp

@@ -0,0 +1,181 @@
+#include "boo/audiodev/MIDIDecoder.hpp"
+#include "MIDICommon.hpp"
+#include <memory>
+
+namespace boo
+{
+
+static inline uint8_t clamp7(uint8_t val) {return std::max(0, std::min(127, int(val)));}
+
+bool MIDIDecoder::ReadController::readByte(uint8_t& a)
+{
+    return m_in.receive(&a, 1) != 0;
+}
+
+bool MIDIDecoder::ReadController::read2Bytes(uint8_t& a, uint8_t& b)
+{
+    uint8_t buf[2];
+    int len = m_in.receive(buf, 2);
+    a = buf[0];
+    b = buf[1];
+    return len > 1;
+}
+
+bool MIDIDecoder::ReadController::readBuffer(void* buf, size_t len)
+{
+    return m_in.receive(buf, len) == len;
+}
+
+uint32_t MIDIDecoder::_readContinuedValue(uint8_t a)
+{
+    uint32_t ret = a & 0x7f;
+
+    if (a & 0x80)
+    {
+        ret <<= 7;
+        bool good = m_readControl.readByte(a);
+        if (!good)
+            return ret;
+        ret |= a & 0x7f;
+
+        if (a & 0x80)
+        {
+            ret <<= 7;
+            good = m_readControl.readByte(a);
+            if (!good)
+                return ret;
+            ret |= a & 0x7f;
+        }
+    }
+
+    return ret;
+}
+
+bool MIDIDecoder::receiveBytes()
+{
+    uint8_t a, b;
+    bool good = m_readControl.read2Bytes(a, b);
+    if (!good)
+        return false;
+
+    if (a & 0x80)
+        m_status = a;
+    else
+        b = a;
+
+    uint8_t chan = m_status & 0xf;
+    switch (Status(m_status & 0xf0))
+    {
+    case Status::NoteOff:
+    {
+        good = m_readControl.read2Bytes(a, b);
+        if (!good)
+            return false;
+        m_out.noteOff(chan, clamp7(a), clamp7(b));
+        break;
+    }
+    case Status::NoteOn:
+    {
+        good = m_readControl.read2Bytes(a, b);
+        if (!good)
+            return false;
+        m_out.noteOn(chan, clamp7(a), clamp7(b));
+        break;
+    }
+    case Status::NotePressure:
+    {
+        good = m_readControl.read2Bytes(a, b);
+        if (!good)
+            return false;
+        m_out.notePressure(chan, clamp7(a), clamp7(b));
+        break;
+    }
+    case Status::ControlChange:
+    {
+        good = m_readControl.read2Bytes(a, b);
+        if (!good)
+            return false;
+        m_out.controlChange(chan, clamp7(a), clamp7(b));
+        break;
+    }
+    case Status::ProgramChange:
+    {
+        m_out.programChange(chan, clamp7(b));
+        break;
+    }
+    case Status::ChannelPressure:
+    {
+        m_out.channelPressure(chan, clamp7(b));
+        break;
+    }
+    case Status::PitchBend:
+    {
+        good = m_readControl.read2Bytes(a, b);
+        if (!good)
+            return false;
+        m_out.pitchBend(chan, clamp7(b) * 128 + clamp7(a));
+        break;
+    }
+    case Status::SysEx:
+    {
+        switch (Status(m_status & 0xff))
+        {
+        case Status::SysEx:
+        {
+            uint32_t len = _readContinuedValue(a);
+            std::unique_ptr<uint8_t[]> buf(new uint8_t[len]);
+            if (!m_readControl.readBuffer(buf.get(), len))
+                return false;
+            m_out.sysex(buf.get(), len);
+            break;
+        }
+        case Status::TimecodeQuarterFrame:
+        {
+            good = m_readControl.read2Bytes(a, b);
+            if (!good)
+                return false;
+            m_out.timeCodeQuarterFrame(a >> 4 & 0x7, a & 0xf);
+            break;
+        }
+        case Status::SongPositionPointer:
+        {
+            good = m_readControl.read2Bytes(a, b);
+            if (!good)
+                return false;
+            m_out.songPositionPointer(clamp7(b) * 128 + clamp7(a));
+            break;
+        }
+        case Status::SongSelect:
+        {
+            m_out.songSelect(clamp7(b));
+            break;
+        }
+        case Status::TuneRequest:
+            m_out.tuneRequest();
+            break;
+        case Status::Start:
+            m_out.startSeq();
+            break;
+        case Status::Continue:
+            m_out.continueSeq();
+            break;
+        case Status::Stop:
+            m_out.stopSeq();
+            break;
+        case Status::Reset:
+            m_out.reset();
+            break;
+        case Status::SysExTerm:
+        case Status::TimingClock:
+        case Status::ActiveSensing:
+        default: break;
+        }
+        break;
+    }
+    default: break;
+    }
+
+    return true;
+}
+
+}