This patch reorders px4_defines.h to make it more readable (I think)
but more importantly, cleans up the #include <math.h>/<cmath>
and [std::]isfinite stuff.
My main goal was to completely get rid of including math.h/cmath,
because that doesn't really belong in a header that is supposed to
define macro's and is included in almost every source file (if not
all).
I'm not sure what it did before ;) (pun intended), but now it does
the following:
PX4_ISFINITE is only used in C++ code (that was already the case,
but hereby is official; for C code just use 'isfinite()') and is
defined to be std::isfinite, except on __PX4_QURT because that uses
the HEXAGON toolset which (erroneously) defines isfinite as macro.
I would have liked to remove PX4_ISFINITE completely from the code
and just use std::isfinite whereever that is needed, but that would
have required changing the libecl submodule, and at the moment I'm
getting tired of changing submodules... so maybe something for the
future.
Also, all includes of <math.h> or <cmath> have been removed except
for __PX4_NUTTX. Like the HEXAGON toolset NuttX currently defines
isfinite as macro for C++. So, we could have solved this in the
same was as __P4_QURT; but since we can fix NuttX ourselves I chose
to add a kludge to px4_defines.h instead that fixes this problem,
until the time that NuttX can be fixed (again postponing changing
a submodule). The kludge still demands including <cmath>, thus.
After removal of the math header file, it needed to be included
in source files that actually need it, of course.
Finally, I had a look at the math macro's (like M_PI, M_PI_F,
M_DEG_TO_RAD etc). These are sometimes (erroneously) defined in
certain math.h header files (like both, hexagon and nuttx).
This is incorrect: neither the C nor the C++ standard defines
math constants (neither as macro nor otherwise). The "problem"
here was that px4_defines.h defined some of the M_*_F float
constants in terms of the M_* double constant, which are
sometimes not defined either thus. So, I cleaned this up by
defining the M_*_F math constants as float literals in px4_defines.h,
except when they are defined in math.h for that platform.
This means that math.h has to be always included when using those
constants, but well; not much difference there as those files
usually also need/use the macro NAN (which *is* a standard macro
defined by math.h).
Finally finally, DEFAULT_PARAM_FILE was removed as it isn't
used anymore.
All in all I think the resulting px4_defines.h is nice, giving me
much less the feeling of a nearly unmaintainable and over time
slowly growing collection of kludges and hacks.
It makes more sense to set the optimization flags on a platform basis
instead of individually for each module. This allows for different
optimization options for SITL, NuttX, Snapdragon, etc.
Reason: the value is easier to read & handle (for example plotting). In
most places the value is needed, not the integral.
Note that this breaks the replay format for sdlog2 replay
- voting is now at a central place instead of duplicated within the
estimators
-> this also means that estimators that did not do voting so far,
now have voting, like ekf2
- estimators requiring more than that can still subscribe to the raw
sensors
- allows sensors_combined to be 3 times smaller
- reduces logger, memcpy (cache) & RAM overhead
- all modules requiring only 1 or 2 sensor values now automatically get
the voted result
- this also adds voting to baro
Decreases the message size from 780 to 280 bytes.
In particular, all modules using sensor_combined must use the integral now.
The sensor value can easily be reconstructed by dividing with dt.
Voters now need to be moved into sensors module, because error count and
priority is removed from the topic.
Any module that requires additional data from a sensor can subscribe to
the raw sensor topics.
At two places, values are set to zero instead of subscribing to the raw
sensors (with the assumption that no one reads them):
- mavlink mavlink_highres_imu_t::abs_pressure
- sdlog2: sensor temperatures
GCC output:
implicit conversion from ‘float’ to ‘double’ to match other operand of
binary expression [-Werror=double-promotion]
It seems gcc 6.1.1 uses the float variant of fabs, whereas older gcc's
use the double version. This makes it compile for both.
Carlo Wood