The current messages accurately reflect what happens to the system
of equations that represents the sketch, but can be quite confusing
to users that only think in terms of the constraints.
We use "unsolvable" and not "impossible" because while most of
the cases that result in this error message will indeed stem from
mutually exclusive sets of constraints, it is still possible that
there is some solution that our solver is unable to find using
numeric methods.
This removes the arbitrary 64 byte restriction (which effectively
limits us to as little as 16 Unicode characters with CJK encodings),
makes classes smaller, and is easier to use.
As a consequence of making the length of all ex-NameStr fields
unbounded, all functions that returned a buffer derived from those
were changed to return std::string. Then, functions that are
contextually similar to the ones described above were changed
to return std::string. Then, functions that now happened to mostly
take an std::string argument converted to a C string were changed
to accept std::string.
This has produced a bit of churn, but is probably for the better.
Now it is possible to give non-ASCII names to groups
as well as see non-ASCII filenames of imported files.
In the future this makes localization possible.
This works for LTR languages, such as European and CJK,
but not RTL such as Arabic. Does Arabic even exist in
monospaced form? I have no idea.
What do we gain from this? Several things.
* First, usage of PATH_MAX (the POSIX constant) is eliminated.
PATH_MAX is actually a lie; Linux and OS X (and probably other BSDs
too) do not have an actual path length limit. Linux claims 4096,
OS X claims 1024, but it is trivial to construct paths that are
longer.
* Second, while Windows does enforce a limit of MAX_PATH (the Win32
constant) for its ASCII functions, the Unicode variants, when
used with UNC paths, do not have this restriction.
The capability to use UNC paths is useful by itself, as it allows
to access files on network shares directly.
* Third, representing paths as std::string will make it easier to
interoperate with *W WinAPI functions later.
This will allow us to use non-POD classes inside these objects
in future and is otherwise functionally equivalent, as well
as more concise.
Note that there are some subtleties with handling of
brace-initialization. Specifically:
On aggregates (e.g. simple C-style structures) using an empty
brace-initializer zero-initializes the aggregate, i.e. it makes
all members zero.
On non-aggregates an empty brace-initializer calls the default
constructor. And if the constructor doesn't explicitly initialize
the members (which the auto-generated constructor doesn't) then
the members will be constructed but otherwise uninitialized.
So, what is an aggregate class? To quote the C++ standard
(C++03 8.5.1 §1):
An aggregate is an array or a class (clause 9) with no
user-declared constructors (12.1), no private or protected
non-static data members (clause 11), no base classes (clause 10),
and no virtual functions (10.3).
In SolveSpace, we only have to handle the case of base classes;
Constraint and Entity have those. Thus, they had to gain a default
constructor that does nothing but initializes the members to zero.
Some extra code is necessary to determine that the back faces
should not be drawn in red for transparent solids. It is expected
that the user will first ensure that the shell is watertight
and then set the opacity; back faces are still drawn if
the opacity is exactly 1.
The savefile format is changed backwards-compatibly by stashing
the alpha value in uppermost byte of 4-byte hex color value
in Surface and Triangle clauses. The existing files have 00
in the high byte, so RgbColor::FromPackedInt treats that
as "opaque".
In principle, GTK3 is the way forward, and GTK2 is officially
deprecated, though still maintained. In practice however, GTK3
is often unbearably buggy; e.g. on my system, combo boxes
don't ever roll up in GTK3 windows. So I have added support
for both.
This required a few minor changes to the core, namely:
* GTK wants to know beforehand whether a menu item is a check
menu item or a regular one.
* GTK doesn't give us an easy way to execute something after
any event is processed, so an explicit idle timer is added.
This is a no-op on Win32.
* A few function signatures were const'ed, since GTK expects
immutable strings when converting to Glib::ustring.
The SolveSpace top-level directory was getting a bit cluttered, so
following the example of numerous other free-software projects, we move the
main application source into a subdirectory and adjust the build systems
accordingly.
Also, got rid of the obj/ directory in favor of creating it on the fly in
Makefile.msvc.