MixerGroup.cpp

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/**
 * @file mixer_group.cpp
 *
 * Mixer collection.
 */

#include "MixerGroup.hpp"

#include "HelicopterMixer/HelicopterMixer.hpp"
#include "MultirotorMixer/MultirotorMixer.hpp"
#include "NullMixer/NullMixer.hpp"
#include "SimpleMixer/SimpleMixer.hpp"

#define debug(fmt, args...) do { } while(0)
//#define debug(fmt, args...)   do { printf("[mixer] " fmt "\n", ##args); } while(0)
//#include <debug.h>
//#define debug(fmt, args...)   syslog(fmt "\n", ##args)

unsigned
MixerGroup::mix(float *outputs, unsigned space)
{
    unsigned index = 0;

    for (auto mixer : _mixers) {
        index += mixer->mix(outputs + index, space - index);

        if (index >= space) {
            break;
        }
    }

    return index;
}

/*
 * set_trims() has no effect except for the SimpleMixer implementation for which set_trim()
 * always returns the value one.
 * The only other existing implementation is MultirotorMixer, which ignores the trim value
 * and returns _rotor_count.
 */
unsigned
MixerGroup::set_trims(int16_t *values, unsigned n)
{
    unsigned index = 0;

    for (auto mixer : _mixers) {
        // convert from integer to float
        // to be safe, clamp offset to range of [-500, 500] usec
        float offset = math::constrain((float)values[index] / 10000, -1.0f, 1.0f);

        debug("set trim: %d, offset: %5.3f", values[index], (double)offset);
        index += mixer->set_trim(offset);

        if (index >= n) {
            break;
        }
    }

    return index;
}

/*
 * get_trims() has no effect except for the SimpleMixer implementation for which get_trim()
 * always returns the value one and sets the trim value.
 * The only other existing implementation is MultirotorMixer, which ignores the trim value
 * and returns _rotor_count.
 */
unsigned
MixerGroup::get_trims(int16_t *values)
{
    unsigned index_mixer = 0;
    unsigned index = 0;

    for (auto mixer : _mixers) {
        float trim = 0;
        index_mixer += mixer->get_trim(&trim);

        // MultirotorMixer returns the number of motors so we
        // loop through index_mixer and set the same trim value for all motors
        while (index < index_mixer) {
            values[index] = trim * 10000;
            index++;
        }
    }

    return index;
}

void
MixerGroup::set_thrust_factor(float val)
{
    for (auto mixer : _mixers) {
        mixer->set_thrust_factor(val);
    }
}

void
MixerGroup::set_airmode(Mixer::Airmode airmode)
{
    for (auto mixer : _mixers) {
        mixer->set_airmode(airmode);
    }
}

unsigned
MixerGroup::get_multirotor_count()
{
    for (auto mixer : _mixers) {
        unsigned rotor_count = mixer->get_multirotor_count();

        if (rotor_count > 0) {
            return rotor_count;
        }
    }

    return 0;
}

uint16_t
MixerGroup::get_saturation_status()
{
    uint16_t sat = 0;

    for (auto mixer : _mixers) {
        sat |= mixer->get_saturation_status();
    }

    return sat;
}

void
MixerGroup::groups_required(uint32_t &groups)
{
    for (auto mixer : _mixers) {
        mixer->groups_required(groups);
    }
}

int
MixerGroup::load_from_buf(Mixer::ControlCallback control_cb, uintptr_t cb_handle, const char *buf, unsigned &buflen)
{
    int ret = -1;
    const char *end = buf + buflen;

    /*
     * Loop until either we have emptied the buffer, or we have failed to
     * allocate something when we expected to.
     */
    while (buflen > 0) {
        Mixer *m = nullptr;
        const char *p = end - buflen;
        unsigned resid = buflen;

        /*
         * Use the next character as a hint to decide which mixer class to construct.
         */
        switch (*p) {
        case 'Z':
            m = NullMixer::from_text(p, resid);
            break;

        case 'M':
            m = SimpleMixer::from_text(control_cb, cb_handle, p, resid);
            break;

        case 'R':
            m = MultirotorMixer::from_text(control_cb, cb_handle, p, resid);
            break;

        case 'H':
            m = HelicopterMixer::from_text(control_cb, cb_handle, p, resid);
            break;

        default:
            /* it's probably junk or whitespace, skip a byte and retry */
            buflen--;
            continue;
        }

        /*
         * If we constructed something, add it to the group.
         */
        if (m != nullptr) {
            add_mixer(m);

            /* we constructed something */
            ret = 0;

            /* only adjust buflen if parsing was successful */
            buflen = resid;
            debug("SUCCESS - buflen: %d", buflen);

        } else {

            /*
             * There is data in the buffer that we expected to parse, but it didn't,
             * so give up for now.
             */
            break;
        }
    }

    /* nothing more in the buffer for us now */
    return ret;
}

void MixerGroup::set_max_delta_out_once(float delta_out_max)
{
    for (auto mixer : _mixers) {
        mixer->set_max_delta_out_once(delta_out_max);
    }
}