Mixer.cpp

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/**
 * @file mixer.cpp
 *
 * Programmable multi-channel mixer library.
 */

#include "Mixer.hpp"

#include <math.h>
#include <cstring>
#include <ctype.h>

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

float
Mixer::get_control(uint8_t group, uint8_t index)
{
    float value;

    _control_cb(_cb_handle, group, index, value);

    return value;
}

const char *
Mixer::findtag(const char *buf, unsigned &buflen, char tag)
{
    while (buflen >= 2) {
        if ((buf[0] == tag) && (buf[1] == ':')) {
            return buf;
        }

        buf++;
        buflen--;
    }

    return nullptr;
}

char
Mixer::findnexttag(const char *buf, unsigned buflen)
{
    while (buflen >= 2) {
        if (isupper(buf[0]) && buf[1] == ':') {
            return buf[0];
        }

        buf++;
        buflen--;
    }

    return 0;
}

const char *
Mixer::skipline(const char *buf, unsigned &buflen)
{
    const char *p;

    /* if we can find a CR or NL in the buffer, skip up to it */
    if ((p = (const char *)memchr(buf, '\r', buflen)) || (p = (const char *)memchr(buf, '\n', buflen))) {
        /* skip up to it AND one beyond - could be on the NUL symbol now */
        buflen -= (p - buf) + 1;
        return p + 1;
    }

    return nullptr;
}

bool
Mixer::string_well_formed(const char *buf, unsigned &buflen)
{
    /* enforce that the mixer ends with a new line */
    for (int i = buflen - 1; i >= 0; i--) {
        if (buf[i] == '\0') {
            continue;
        }

        /* require a space or newline at the end of the buffer, fail on printable chars */
        if (buf[i] == '\n' || buf[i] == '\r') {
            /* found a line ending, so no split symbols / numbers. good. */
            return true;
        }

    }

    debug("pre-parser rejected: No newline in buf");

    return false;
}