This commit makes common external packages always be included through
find_package to eliminate differences in variables set, wraps
find_package for vendored libraries on Windows to factor out common
code, and removes miscellaneous useless code elsewhere in dependency
handling.
This also fixes a problem where pkg-config would pick up `build`
libraries instead of `host` when cross-compiling.
It was never really needed, since both Linux and OS X, where
GlOffscreen is used, guarantee that the API we need is present,
on all OS versions we're interested in.
Also, reorganize GlOffscreen consistently with the rest of our
codebase, and don't use RAII for OpenGL resource management because
of its requirement for an active context.
We now build and distribute Windows executables for every release,
so mention that. Conversely, the Debian packages are basically
unusable, so drop them for now.
This has the following benefits:
* Less geometry to generate; we can do both in one pass;
* Less geometry to draw;
* Eliminate overdraw of outlines on top of emphasized edges;
* In future, being able to seamlessly stitch stippled lines.
The contour edges are now also drawn before emphasized edges;
this makes intersections of contour and emphasized edges look better
as the thinner emphasized edge doesn't clobber the depth buffer.
This has several desirable consequences:
* It is now possible to port SolveSpace to a later version of
OpenGL, such as OpenGLES 2, so that it runs on platforms that
only have that OpenGL version;
* The majority of geometry is now rendered without references to
the camera in C++ code, so a renderer can now submit it to
the video card once and re-rasterize with a different projection
matrix every time the projection is changed, avoiding expensive
reuploads;
* The DOGD (draw or get distance) interface is now
a straightforward Canvas implementation;
* There are no more direct references to SS.GW.(projection)
in sketch rendering code, which allows rendering to multiple
viewports;
* There are no more unnecessary framebuffer flips on CPU on Cocoa
and GTK;
* The platform-dependent GL code is now confined to rendergl1.cpp.
* The Microsoft and Apple headers required by it that are prone to
identifier conflicts are no longer included globally;
* The rendergl1.cpp implementation can now be omitted from
compilation to run SolveSpace headless or with a different
OpenGL version.
Note these implementation details of Canvas:
* GetCamera currently always returns a reference to the field
`Camera camera;`. This is so that a future renderer that caches
geometry in the video memory can define it as asserting, which
would provide assurance against code that could accidentally
put something projection-dependent in the cache;
* Line and triangle rendering is specified through a level of
indirection, hStroke and hFill. This is so that a future renderer
that batches geometry could cheaply group identical styles.
* DrawPixmap and DrawVectorText accept a (o,u,v) and not a matrix.
This is so that a future renderer into an output format that
uses 2d transforms (e.g. SVG) could easily derive those.
Some additional internal changes were required to enable this:
* Pixmap is now always passed as std::shared_ptr<{const ,}Pixmap>.
This is so that the renderer could cache uploaded textures
between API calls, which requires it to capture a (weak)
reference.
* The PlatformPathEqual function was properly extracted into
platform-specific code. This is so that the <windows.h> header
could be included only where needed (in platform/w32* as well
as rendergl1.cpp).
* The SBsp{2,3}::DebugDraw functions were removed. They can be
rewritten using the Canvas API if they are ever needed.
While no visual changes were originally intended, some minor fixes
happened anyway:
* The "emphasis" yellow line from top-left corner is now correctly
rendered much wider.
* The marquee rectangle is now pixel grid aligned.
* The hidden entities now do not clobber the depth buffer, removing
some minor artifacts.
* The workplane "tab" now scales with the font used to render
the workplane name.
* The workplane name font is now taken from the normals style.
* Workplane and constraint line stipple is insignificantly
different. This is so that it can reuse the existing stipple
codepaths; rendering of workplanes and constraints predates
those.
Some debug functionality was added:
* In graphics window, an fps counter that becomes red when
rendering under 60fps is drawn.
If SolveSpace crashes after the open, or hangs and is forcibly
killed, data would be lost. (I lost my data.) Instead, remove
autosave only in two cases: right after a successful save, or right
after a save is declined. This should be completely safe.
Also, use a more appealing isometric projection if none specified,
instead of orthographic.
Also, use the scale, offset and projection from the viewport at
the time of export.
It's broken. It expects a valid OpenGL context during generation
that immediately pushes changes to the screen. This is never true
on non-Windows as offscreen rendering is used, and also incompatible
with OpenGL core profile.
Further, right now it displays junk on Windows as well due to some
issue with the bitmap font texture loading.
We will restore it later, in a saner form.
