Rework the mixer architecture based on discussions about arbitrary geometry mixing and plugins.

Now the mixer is a C++ library that can be fairly easily bolted into an output driver to provide mixing services.

Teach the FMU driver how to use it as an example.  More testing is still required.

1 files changed, 0 insertions, 236 deletions

diff --git a/apps/systemlib/mixer.h b/apps/systemlib/mixer.h
deleted file mode 100644
index 3a9e31bb1..000000000
--- a/apps/systemlib/mixer.h
+++ /dev/null
@@ -1,236 +0,0 @@
-/****************************************************************************
- *
- *   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.
- *
- ****************************************************************************/
-
-#ifndef _SYSTEMLIB_MIXER_H
-#define _SYSTEMLIB_MIXER_H
-
-/**
- * @file mixer.h
- *
- * Generic control value mixing library.
- *
- * This library implements a generic mixer function that can be used
- * by any driver or subsytem that wants to combine several control signals
- * into a single output.
- *
- * Terminology
- * ===========
- *
- * control value
- *	A mixer input value, typically provided by some controlling
- *	component of the system.
- *
- * control group
- * 	A collection of controls provided by a single controlling component.
- *
- * actuator
- *	The mixer output value.
- *
- * Mixing basics
- * =============
- *
- * An actuator derives its value from the combination of one or more
- * control values. Each of the control values is scaled according to
- * the actuator's configuration and then combined to produce the
- * actuator value, which may then be further scaled to suit the specific
- * output type.
- *
- * Internally, all scaling is performed using floating point values.
- * Inputs and outputs are clamped to the range -1.0 to 1.0.
- *
- * control    control   control
- *    |          |         |
- *    v          v         v
- *  scale      scale     scale
- *    |          |         |
- *    |          v         |
- *    +-------> mix <------+
- *               |
- *             scale
- *               |
- *               v
- *              out
- *
- * Scaling
- * -------
- *
- * Each scaler allows the input value to be scaled independently for
- * inputs greater/less than zero. An offset can be applied to the output,
- * as well as lower and upper boundary constraints.
- * Negative scaling factors cause the output to be inverted (negative input
- * produces positive output).
- *
- * Scaler pseudocode:
- *
- * if (input < 0)
- *     output = (input * NEGATIVE_SCALE) + OFFSET
- * else
- *     output = (input * POSITIVE_SCALE) + OFFSET
- *
- * if (output < LOWER_LIMIT)
- *     output = LOWER_LIMIT
- * if (output > UPPER_LIMIT)
- *     output = UPPER_LIMIT
- *
- *
- * Mixing
- * ------
- *
- * Mixing is performed by summing the scaled control values.
- *
- *
- * Controls
- * --------
- *
- * Each mixer is presented with an array of controls from which it
- * selects the set that will be mixed for each actuator.
- *
- * The precise assignment of controls may vary depending on the
- * application, but the following assignments should be used
- * when appropriate.
- *
- * control | standard meaning
- * --------+-----------------------
- *     0   | roll
- *     1   | pitch
- *     2   | yaw
- *     3   | primary thrust
- */
-
-struct scaler_s {
-	float		negative_scale;	/**< scale for inputs < 0 */
-	float		positive_scale;	/**< scale for inputs > 0 */
-	float		offset;		/**< bias applied to output */
-	float		lower_limit;	/**< minimum output value */
-	float		upper_limit;	/**< maximum output value */
-	uint8_t		control_group;	/**< control group this scaler reads from */
-	uint8_t		control_index;	/**< control index within the group */
-};
-
-struct mixer_s {
-	unsigned	control_count;	/**< number of control scalers */
-	struct scaler_s	output_scaler;	/**< scaler applied to mixer output */
-	struct scaler_s	control_scaler[0]; /**< array of control scalers */
-};
-
-/**
- * Handy macro for determining the allocation size of a mixer.
- */
-#define MIXER_SIZE(_num_scalers)	(sizeof(struct mixer_s) + ((_num_scalers) * sizeof(struct scaler_s)))
-
-__BEGIN_DECLS
-
-/**
- * Perform a mixer calculation.
- *
- * Note that the controls array, and the arrays it indexes, are assumed
- * to be sufficiently large for any control index in the mixer.
- *
- * @param mixer			Mixer configuration.
- * @param controls		Array of pointers to control group values.
- * @return			The mixed output.
- */
-__EXPORT float	mixer_mix(struct mixer_s *mixer, float **controls);
-
-/**
- * Check a mixer configuration for sanity.
- *
- * @param mixer			The mixer configuration to be checked.
- * @param group_count		The highest-numbered control group that
- *				should be considered legal.
- * @param control_count		The highest control index that should be
- *				considered legal.
- * @return			Zero if the mixer configuration is sane,
- *				nonzero otherwise.
- */
-__EXPORT int	mixer_check(struct mixer_s *mixer, unsigned group_count, unsigned control_count);
-
-/**
- * Evaluate the control inputs to a mixer and update the bitmask of
- * required control groups.
- *
- * This function allows an actuator driver to selectively fetch just
- * the control groups required to support a particular mixer or set of
- * mixers.
- *
- * @param mixer			The mixer being evaluated.
- * @param groups		Pointer to a bitmask to be updated with set bits
- *				corresponding to the control groups used by the
- *				mixer.
- */
-__EXPORT void	mixer_requires(struct mixer_s *mixer, uint32_t *groups);
-
-/**
- * Read a mixer definition from a file.
- *
- * A mixer definition is a text representation of the configuration of a
- * mixer.  The definition consists of a single-line header indicating the
- * number of scalers and then one line defining each scaler.  The first
- * scaler in the file is always the output scaler, followed by the input
- * scalers.
- *
- * M: <scaler count>
- * S: <control group> <control index> <negative_scale*> <positive_scale*> <offset*> <lower_limit*> <upper_limit*>
- * S: ...
- *
- * The <control ...> values for the output scaler are ignored by the mixer.
- *
- * Values marked * are integers representing floating point values; values are
- * scaled by 10000 on load/save.
- *
- * Multiple mixer definitions may be stored in a single file; it is assumed that
- * the reader will know how many to expect and read accordingly.
- *
- * A mixer entry with a scaler count of zero indicates a disabled mixer. This
- * will return NULL for the mixer when processed by this function, and will be
- * generated by passing NULL as the mixer to mixer_save.
- *
- * @param fd			The file to read the definitions from.
- * @param mixer			Mixer is returned here.
- * @return			1 if a mixer was read, zero on EOF or negative on error.
- */
-__EXPORT int	mixer_load(int fd, struct mixer_s **mixer);
-
-/**
- * Save a mixer definition to a file.
- *
- * @param fd			The file to write the definitions to.
- * @param mixer			The mixer definition to save.
- * @return			Zero on success, negative on error.
- */
-__EXPORT int	mixer_save(int fd, struct mixer_s *mixers);
-
-
-__END_DECLS
-
-#endif /* _SYSTEMLIB_MIXER_H */