Since font sizes in SolveSpace are specified in terms of cap height,
we need U+0041 to determine cap height. Some fonts lack it; in
that case, we assume that cap height is the same as the size we've
requested. This avoids a crash, at the cost of completely wrong
(although consistent) metrics; I do not really know of a better way.
This commit updates a *lot* of rather questionable path handling
logic to be robust. Specifically:
* All path operations go through Platform::Path.
* All ad-hoc path handling functions are removed, together with
PATH_SEP. This removes code that was in platform-independent
parts, but had platform-dependent behavior.
* Group::linkFileRel is removed; only an absolute path is stored
in Group::linkFile. However, only Group::linkFileRel is saved,
with the relative path calculated on the fly, from the filename
passed into SaveToFile. This eliminates dependence on global
state, and makes it unnecessary to have separare code paths
for saved and not yet saved files.
* In a departure from previous practice, functions with
platform-independent code but platform-dependent behavior
are all grouped under platform/. This makes it easy to grep
for functions with platform-dependent behavior.
* Similarly, new (GUI-independent) code for all platforms is added
in the same platform.cpp file, guarded with #ifs. It turns out
that implementations for different platforms had a lot of shared
code that tended to go out of sync.
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.
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.
This includes explanation and context for non-obvious cases and
shortens debug cycles when just-in-time debugging is not available
(like on Linux) by immediately printing description of the assert
as well as symbolized backtrace.
config.h now includes the git hash and so, as long as it's included
in solvespace.h, any change of git HEAD will trigger a complete
recompilation, which makes bisecting especially annoying.
While we're at it, remove HAVE_STDINT_H from it, since we require
C++11 and all MSVC versions that include C++11 also include stdint.h.
Most of these were just converting char* into std::string back and
forth; some more used ReadUTF8, which was converted to use nicer
STL-style iterators over UTF-8 text.
The remaining ones are:
* arguments to Expr::From, which we'll change when refactoring
the expression lexer;
* arguments to varargs functions, which we'll change when adding
localization (that requires custom printf-style functions to
allow for changing argument order);
* arguments where only string literals are ever passed, which
are OK;
* in platform-specific code, which is OK.
Benefits:
* Much simpler code.
* Handles the entire TTF spec, not just a small subset that
only really worked well on Windows fonts.
* Handles all character sets as well as accented characters.
* Much faster parsing, since Freetype lazily loads and
caches glyphs.
* Support for basically every kind of font that was invented,
not just TTF.
Note that OpenType features, e.g. ligatures, are not yet supported.
This means that Arabic and Devanagari scripts, among others, will
not be rendered in their proper form.
RTL scripts are not supported either, neither in TTF nor in
the text window. Adding RTL support is comparatively easy, but
given that Arabic would not be legibly rendered anyway, this is not
done so far.
It works. Mostly. Sort of. Only on Windows fonts. Sometimes it
randomly refuses to render glyphs (try `х`, that's not a latin ex).
I'm not really sure why, the logic seems right.
Why do we have a homegrown TTF parser anyway? It's kind of awful.
It breaks on any slightly unusual input. It plows through UTF-16BE
font names like a nuclear-powered steamroller. It outright ignores
composite glyphs (is that why it's broken this time?). The kerning
is seizure-inducing. It ignores any characters outside BMP by design.
Maybe we should just replace it with freetype.
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.
After this commit, SolveSpace can robustly handle non-ASCII filenames
on every OS. Additionally, on Windows, filenames longer than 260
characeters can be used, and files on network shares can be opened
directly, without mounting them as a network drive.
After this commit, SolveSpace deals with paths as follows:
* Paths are generally treated as opaque platform-specific strings.
This helps on Linux, because paths on Linux don't have any
specific encoding and it helps to avoid any operations on them.
* The UI in some places wants to get a basename. In this case,
the newly introduced PATH_SEP is used. This allows to treat
backslash as a regular character, which it is on Linux and OS X.
* The only place where any nontrivial operations on paths are
performed is the g->impFile/impFileRel logic.
Specifically, when saved, g->impFile always contains an absolute
path with separators of the current platform, and g->impFileRel
always contains a relative path with UNIX separators. This allows
to treat backslash as a regular character.
Old files will contain g->impFileRel with Windows separators;
these are detected by looking for a drive letter in g->impFile
and in that case mapping Windows separators to UNIX ones.
There is no need to treat UNIX separators (forward slashes) in
any special way on Windows because there is no way on Windows,
not even via UNC paths, to create or address a directory entry
with a forward slash in its name.
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.
The main benefit is that std::swap will ensure that the type
of arguments is copy-constructible and move-constructible.
It is more concise as well.
When min and max are defined as macros, they will conflict
with STL header files included by other C++ libraries;
in this case STL will #undef any other definition.
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.
