This fixes a strange problem where GTK 2 (but not GTK 3) with NVidia
drivers would not have a depth buffer, but only during exporting
PNGs, despite the fact that normal rendering path and PNG rendering
path come through the same offscreen rendering code.
This avoids a pitfall where a point and a line are selected that are
not in the current workplane, but since the view is parallel to
the workplane, that's not visible, and incorrect measurement results.
The states are:
* Draw all lines (on top of shaded mesh).
* Draw occluded (by shaded mesh) lines as stippled.
* Do not draw occluded (by shaded mesh) lines.
As usual, the export output follows the screen output.
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.
Without -fno-exceptions, the branch coverage information is
practically useless, as every call becomes a branch.
The functionality of Expr is retained as-is, although SjLj error
handling is a maintenance nightmare. However, the entire parser
probably should be eventually replaced, so for now it is not
a great concern.
SurfaceRenderer is a new renderer implementing the Canvas interface
running entirely on the CPU; it projects strokes and triangles
in the exact same way as OpenGL would, and it can be used for
rendering into raster or vector 2d surfaces.