HelicopterMixer.hpp

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#pragma once

#include <mixer/Mixer/Mixer.hpp>

/** helicopter swash servo mixer */
struct mixer_heli_servo_s {
    float angle;
    float arm_length;
    float scale;
    float offset;
    float min_output;
    float max_output;
};

#define HELI_CURVES_NR_POINTS 5

/** helicopter swash plate mixer */
struct mixer_heli_s {
    uint8_t             control_count;  /**< number of inputs */
    float               throttle_curve[HELI_CURVES_NR_POINTS];
    float               pitch_curve[HELI_CURVES_NR_POINTS];
    mixer_heli_servo_s      servos[4];  /**< up to four inputs */
};

/**
 * Generic helicopter mixer for helicopters with swash plate.
 *
 * Collects four inputs (roll, pitch, yaw, thrust) and mixes them to servo commands
 * for swash plate tilting and throttle- and pitch curves.
 */
class HelicopterMixer : public Mixer
{
public:
    /**
     * Constructor.
     *
     * @param control_cb        Callback invoked to read inputs.
     * @param cb_handle     Passed to control_cb.
     * @param mixer_info        Pointer to heli mixer configuration
     */
    HelicopterMixer(ControlCallback control_cb, uintptr_t cb_handle, mixer_heli_s mixer_info);
    virtual ~HelicopterMixer() = default;

    // no copy, assignment, move, move assignment
    HelicopterMixer(const HelicopterMixer &) = delete;
    HelicopterMixer &operator=(const HelicopterMixer &) = delete;
    HelicopterMixer(HelicopterMixer &&) = delete;
    HelicopterMixer &operator=(HelicopterMixer &&) = delete;

    /**
     * Factory method.
     *
     * Given a pointer to a buffer containing a text description of the mixer,
     * returns a pointer to a new instance of the mixer.
     *
     * @param control_cb        The callback to invoke when fetching a
     *              control value.
     * @param cb_handle     Handle passed to the control callback.
     * @param buf           Buffer containing a text description of
     *              the mixer.
     * @param buflen        Length of the buffer in bytes, adjusted
     *              to reflect the bytes consumed.
     * @return          A new HelicopterMixer instance, or nullptr
     *              if the text format is bad.
     */
    static HelicopterMixer      *from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf,
            unsigned &buflen);

    unsigned            mix(float *outputs, unsigned space) override;

    void                groups_required(uint32_t &groups) override { groups |= (1 << 0); }

    unsigned            set_trim(float trim) override { return 4; }
    unsigned            get_trim(float *trim) override { return 4; }

private:
    mixer_heli_s            _mixer_info;
};