This will allow us in future to accept `const T &` anywhere it's
necessary to reduce the amount of copying.
This commit is quite conservative: it does not attempt very hard to
refactor code that performs incidental mutation. In particular
dogd and caches are not marked with the `mutable` keyword.
dogd will be eliminated later, opening up more opportunities to
add const qualifiers.
This commit also doesn't introduce any uses of the newly added const
qualifers. This will be done later.
A new button is added, "Show/hide outline of solid model".
When the outline is hidden, it is rendered using the "solid edge"
style. When the outline is shown, it is rendered using the "outline"
style.
In SolveSpace's true WYSIWYG tradition, the 2d view export follows
the rendered view exactly.
Moreover, shell edges are not rendered anymore, since there is not
much need in them anymore and not drawing them lessens the overlap
between various kinds of lines, which already includes entities,
solid edges and outlines.
Before this change, the two buttons "Show/hide shaded model" (S) and
"Show/hide hidden lines" (H) resulted in drawing the following
elements in the following styles:
Button | Non-occluded | Non-occluded | Occluded | Occluded
state | solid edges | entities | solid edges | entities
--------+--------------+--------------+-------------+--------------
!S !H | | | solid-edge | entity style
--------+ | +-------------+--------------
S !H | | | invisible
--------+ solid-edge | entity style +-------------+--------------
!S H | | | |
--------+ | | solid-edge | entity style
S H | | | |
--------+--------------+--------------+-------------+--------------
After this change, they are drawn as follows:
Button | Non-occluded | Non-occluded | Occluded | Occluded
state | solid edges | entities | solid edges | entities
--------+--------------+--------------+-------------+--------------
!S !H | | | solid-edge | entity style
--------+ | +-------------+--------------
S !H | | | invisible
--------+ solid-edge | entity style +-------------+--------------
!S H | | | |
--------+ | | hidden-edge | stippled¹
S H | | | |
--------+--------------+--------------+-------------+--------------
¹ entity style, but the stipple parameters taken from hidden-edge
In SolveSpace's true WYSIWYG tradition, the 2d view export follows
the rendered view exactly.
Also, it is now possible to edit the stipple parameters of built-in
styles, so that by changing the hidden-edge style to non-stippled
it is possible to regain the old behavior.
Before this commit, "emphasized edges" were displayed as well as
exported. An "emphasized edge" is an edge between triangles that
come from different faces. They are helpful in the rendered
display because they hint at the locations of faces, but not
in the 2d export since they just clutter the drawing.
After this commit, "emphasized edges" are displayed but "sharp
edges" are exported. A "sharp edge" is an edge between triangles
where the two matching vertexes have different normals, indicating
a discontiguity in the surface. "Sharp edges" are also displayed
while post-viewing the exported geometry.
According to the C++ standard, "this" is never NULL, so checks
of the form "if(!this)" can be legally optimized out. This
breaks SolveSpace on GCC 6, and probably on other compilers and
configurations.
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".
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.