At least one dive computer in the Suunto Vyper family, the Vytec DS, is
capable of recording gas mix switches, and therefore supports more than
one mix. When going through the dive profile caching process, also look
for gas changes and record how many mixes were used in the dive. Mix 1
is always the main tank and it’s O2 value can be found in the dive
header, but the other tank O2 values are not available ahead of time. By
reviewing the dive profile ahead of time, the entire list of mixes can
be returned to the application at the beginning of the dive as per
usual.
The code to calculate parameters like maximum depth and divetime is
duplicated in multiple places. Move this code to a single place, and
cache the data in the parser instead.
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.
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.
The Suunto Vyper, Spyder and Eon store a surface event after the last
depth sample. Adding an artificial zero depth sample avoids the problem
of having an incomplete sample without a depth measurement.
Because these devices also store the tank pressure and/or the
temperature at the begin/end of the dive, these measurements are
associated with the new surface samples.
