/****************************************************************************
*
* Copyright (C) 2012 PX4 Development Team. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name PX4 nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/**
* @file mixer.cpp
*
* Programmable multi-channel mixer library.
*/
#include <nuttx/config.h>
#include <sys/types.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <fcntl.h>
#include <poll.h>
#include <errno.h>
#include <stdio.h>
#include <math.h>
#include <unistd.h>
#include <ctype.h>
#include <systemlib/err.h>
#include "mixer.h"
Mixer::Mixer(ControlCallback control_cb, uintptr_t cb_handle) :
_next(nullptr),
_control_cb(control_cb),
_cb_handle(cb_handle)
{
}
float
Mixer::get_control(uint8_t group, uint8_t index)
{
float value;
_control_cb(_cb_handle, group, index, value);
return value;
}
float
Mixer::scale(const mixer_scaler_s &scaler, float input)
{
float output;
if (input < 0.0f) {
output = (input * scaler.negative_scale) + scaler.offset;
} else {
output = (input * scaler.positive_scale) + scaler.offset;
}
if (output > scaler.max_output) {
output = scaler.max_output;
} else if (output < scaler.min_output) {
output = scaler.min_output;
}
return output;
}
int
Mixer::scale_check(struct mixer_scaler_s &scaler)
{
if (scaler.offset > 1.001f)
return 1;
if (scaler.offset < -1.001f)
return 2;
if (scaler.min_output > scaler.max_output)
return 3;
if (scaler.min_output < -1.001f)
return 4;
if (scaler.max_output > 1.001f)
return 5;
return 0;
}
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;
}
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;
}
/****************************************************************************/
NullMixer::NullMixer() :
Mixer(nullptr, 0)
{
}
unsigned
NullMixer::mix(float *outputs, unsigned space)
{
if (space > 0) {
*outputs = 0.0f;
return 1;
}
return 0;
}
void
NullMixer::groups_required(uint32_t &groups)
{
}
NullMixer *
NullMixer::from_text(const char *buf, unsigned &buflen)
{
NullMixer *nm = nullptr;
/* enforce that the mixer ends with space or 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] == ' ' || buf[i] == '\n' || buf[i] == '\r') {
/* found a line ending or space, so no split symbols / numbers. good. */
break;
} else {
return nm;
}
}
if ((buflen >= 2) && (buf[0] == 'Z') && (buf[1] == ':')) {
nm = new NullMixer;
buflen -= 2;
}
return nm;
}