Before this commit, pt-on-line constraints are buggy. To reproduce,
extrude a circle, then add a datum point and constrain it to the
axis of the circle, then move it. The cylinder will collapse.
To quote Jonathan:
> On investigation, I (a) confirm that the problem is
> the unconstrained extrusion depth going to zero, and (b) retract
> my earlier statement blaming extrude and other similar non-entity
> parameter treatment for this problem; you can easily reproduce it
> with a point in 3d constrained to lie on any line whose length
> is free.
>
> PT_ON_LINE is written using VectorsParallel, for no obvious reason.
> Rewriting that constraint to work on two projected distances (using
> any two basis vectors perpendicular to the line) should fix that
> problem, since replacing the "point on line in 3d" constraint with
> two "point on line in 2d" constraints works. That still has
> the hairy ball problem of choosing the basis vectors, which you
> can't do with a continuous function; you'd need Vector::Normal()
> or equivalent.
>
> You could write three equations and make the constraint itself
> introduce one new parameter for t. I don't know how well that
> would work numerically, but it would avoid the hairy ball problem,
> perhaps elegant at the cost of speed.
Indeed, this commit implements the latter solution: it introduces
an additional free parameter. The point being coincident with
the start of the line corresponds to the parameter being zero, and
point being coincident with the end corresponds to one).
In effect, instead of constraining two of three degrees of freedom
(for which the equations do not exist because of the hairy ball
theorem), it constrains three and adds one more.
These points can be used for constraining the width of the text
(or to the width of the text).
The main parts of the commit are:
* TtfFont is restructured to be able to return the aspect ratio
for a given string.
* This aspect ratio is written to the savefile, such that even if
the font is missing, the sketch would still be solved correctly.
* The two additional points are constrained via perpendicularly
to the two main points (which form a v vector).
The compatibility features are as follows:
* When the font is missing in old files, 1:1 aspect ratio is used,
which works for the replacement symbol anyhow.
* When the two additional points are missing in old files, their
would-be positions are calculated and they are moved there,
avoiding 'jumping' of underconstrained sketches.
SolveSpace 2.0 used the height of 'A' (i.e. cap height) to determine
the reference height.
SolveSpace 2.1 completely broke that during transition to Freetype,
and used something more or less random, by using FT_Set_Char_Size
with units_per_EM.
SolveSpace 2.2 attempted to fix that, but also used something more
or less random, by using FT_Request_Size with "unit" values.
Turns out that Freetype actually doesn't have a concept of cap height
at all. It is possible to extract it from the TT_OS2 table that is
present in some TrueType fonts, but it is not present in Microsoft
fonts (the msttcorefonts ones), and for those Linux fonts in which
it is present it doesn't appear very reliable.
So instead, use the height of 'A' instead, like version 2.0 did.
This has the advantage that it is quite bulletproof, and also matches
exactly what the old files are measured against.
One downside is that fonts without an 'A' glyph would not render.
We can deal with that when it becomes a problem.
This is a bit slow, but more importantly creates a race condition
where e.g. a failing "normal" test will be overwritten by
a succeeding "normal_migrate_from_v20".
This shouldn't ever be a problem since saving dumps the entire
internal state, or is supposed to, at least.
Before this commit, a translate group based on another translate
group would always use the "union" boolean operation, which does not
work at all if one wants an array with a difference operation, and
results in degraded performance if one wants an array with
an assemble operation.
This significantly improves performance e.g. in case of a sketch
containing a multitude of wooden panels, as the meshes can be
merely transformed instead of being joined.
The check was actually half-broken from the beginning and
until df83ee4; the thick red line was rendered properly but
the error text was rendered with width 0, which by chance worked
on some GL implementations. That commit has fixed the underlying
bug but left the text line width at 0 to avoid test breakage.
This commit fixes the bug, turns off the check completely, and
updates the tests to account for breakage.
Unfortunately there is no portable way to open an Unicode path with
std::fstream. On *nix, it is enough to call the const char*
constructor. On MSVC, it is enough to call a nonstandard
const wchar_t* constructor. However, on MinGW, there is no way at all
to construct an std::fstream with a wide path, not even using
undocumented APIs. (There used to be a const wchar_t* overload added
back in libstdc++ 4.7, but it got removed for a reason that I was not
able to find out.)
In 2.0, the distance between the points in the TTF request specified
cap height. In 2.1, that was accidentally changed to some arbitrary
value near cap height instead, due to a 72pt factor mess-up.
This commit restores the old behavior.
We're using gcov+lcov, since these tools appear to be the only
usable ones that use the SC/CC metric; and measuring just the line
coverage would be practically criminal negligence.
gcov only works with GCC and Clang, and MSVC's own coverage
measurement tools are not up to the task; so MSVC is out of luck.
This commit alters the build system substantially; it adds another
platform, `headless`, that provides stubs in place of all GUI
functions, and provides a library `solvespace_headless` alongside
the main executable. To cut down build times, only the few files
that have #if defined(HEADLESS) are built twice for the executable
and the library; the rest is grouped into a new `solvespace_cad`
library. It is not usable on its own and just serves for grouping.
This commit also gates the tests behind a -DENABLE_TESTS=ON CMake
option, ON by default (but suggested as OFF in the README so that
people don't ever have to install cairo to build the executable.)
The tests introduced in this commit are (so far) rudimentary,
although functional, and they serve as a stepping point towards
introducing coverage analysis.
EvilSpirit
whitequark