RelativeCCSender.hpp

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#pragma once
 
#include <Control_Surface/Control_Surface_Class.hpp>
 
#include <Arduino.h> // for constrain
 
BEGIN_CS_NAMESPACE
 
enum relativeCCmode {
    TWOS_COMPLEMENT,
    BINARY_OFFSET,
    SIGN_MAGNITUDE,
    REAPER_RELATIVE_1 = TWOS_COMPLEMENT,
    REAPER_RELATIVE_2 = BINARY_OFFSET,
    REAPER_RELATIVE_3 = SIGN_MAGNITUDE,
    TRACKTION_RELATIVE = TWOS_COMPLEMENT,
    MACKIE_CONTROL_RELATIVE = SIGN_MAGNITUDE,
};
 
class RelativeCCSender {
  public:
    static uint8_t toTwosComplement7bit(int8_t value) { return value & 0x7F; }
    static uint8_t toBinaryOffset7bit(int8_t value) { return value + 64; }
    static uint8_t toSignedMagnitude7bit(int8_t value) {
        uint8_t mask = value >> 7;
        uint8_t abs = (value + mask) ^ mask;
        uint8_t sign = mask & 0b01000000;
        return (abs & 0b00111111) | sign;
    }
    static uint8_t mapRelativeCC(int8_t value) {
        switch (mode) {
            case TWOS_COMPLEMENT: return toTwosComplement7bit(value);
            case BINARY_OFFSET: return toBinaryOffset7bit(value);
            case SIGN_MAGNITUDE: return toSignedMagnitude7bit(value);
            default: return 0; // Keeps the compiler happy
        }
    }
 
    static void send(long delta, MIDICNChannelAddress address) {
        while (delta != 0) {
            // Constrain relative movement to +/-15 for
            // Mackie Control Universal compatibility
            long thisDelta = constrain(delta, -15, 15);
            uint8_t msgVal = mapRelativeCC(thisDelta);
            // send a Control Change MIDI event
            Control_Surface.MIDI().sendCC(address, msgVal);
            delta -= thisDelta;
        }
    }
 
    static void setMode(relativeCCmode mode) { RelativeCCSender::mode = mode; }
 
  private:
    static relativeCCmode mode;
};
 
END_CS_NAMESPACE