There are two different ways to specify the volume of a tank. In the
metric system, the tank volume is specified as the water capacity, while
in the imperial system the tank volume is specified as the air capacity
at the surface (1 ATM) when the tank is filled at its working pressure.
To avoid mistakes, the tank volume is now always returned as the metric
volume. For imperial tanks, the tank volume is converted to the metric
representation.
The difference between CUFT@PSI and CUFT@BAR is only for the Cobalt user
interface, to allow the user to enter the tank volume independent of the
units configured in the main preferences. Internally the working
pressure is always stored in psi.
The primary tank, which is the tank connected to the hose and thus the
tank pressure sensor, it not necessary the first tank. The correct tank
index can be found by searching the array for a gas mix with a sensor id
equal to one.
The gasmix value in the sample data is the id of the gasmix. Depending
how the user manipulated the gasmix settings, this id is not necessary
identical to the index into the gasmix array. The array index can be
found by searching the array for a mix with the correct id.
Currently, each backend has it's own function to verify whether the
object vtable pointer is the expected one. All these functions can be
removed in favor of a single isintance function in the base class,
which takes the expected vtable pointer as a parameter.
Functions which are called through the vtable, don't need to verify the
vtable pointer, and those checks are removed.
The term "backend" can be confusing because it can refer to both the
virtual function table and the device/parser backends. The use of the
term "vtable" avoids this.
The Cobalt tracks only the NDL time in the samples. There are however
two indications when the dive changes into a decompression dive, but
they don't always occur at the same time and may or may not appear in
the same sample. The first indication is that the NDL time goes to zero
and the other is the first occurrence of the "deco schedule computed"
bit (0x02) in the violation byte of the sample.
As soon as the NDL time goes to zero, an attempt is made to generate a
deco schedule. Depending upon the algorithm used, a schedule may or may
not have any stops, even though the NDL time is zero. If the schedule
does generate deco stops, the deco schedule computed bit is set in the
violation byte of the sample. This bit is set each time a non-zero
schedule is computed. But because this bit is immediately cleared after
the sample has been stored, and only set again at the completion of the
next schedule computation, not every sample will have this bit set.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
These are based on the documentation we have and have been tested and
verified against actual dive data (with the exception of the pO2 and
ascent speed violations).
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
I forgot to update the device and parser initialization functions to
store the context pointer into the objects. As a result, the internal
context pointers were always NULL.
The public api is changed to require a context object for all
operations. Because other library objects store the context pointer
internally, only the constructor functions need an explicit context
object as a parameter.
Adding the "dc_" namespace prefix (which is of course an abbreviation
for libdivecomputer) should avoid conflicts with other libraries. For
the time being, only the high-level device and parser layers are
changed.
The public header files are moved to a new subdirectory, to separate
the definition of the public interface from the actual implementation.
Using an identical directory layout as the final installation has the
advantage that the example code can be build outside the project tree
without any modifications to the #include statements.
