This commit does three things:
* Recognizes that BeginFrame()/EndFrame() are badly named, since
BeginFrame() sets up framebuffer, and EndFrame() flushes a frame,
and they do not have to be called in pairs; and so renames them
to NewFrame()/FlushFrame().
* Reduces the amount of frame flushes in GraphicsWindow::Paint()
to two, which is the minimum since we use two different cameras
for geometry and UI;
* Changes the FPS measurement code to only take into account
the time spent rendering our main geometry, and not the UI
rendering or window system interaction time.
Before this commit, tooltips in the text window are drawn under
the red "X" indicating a disabled button. After this commit, they
are moved on top of that.
This commit also alters the OpenGL renderers' SetCamera() method
to clear the depth buffer, as that would interfere with drawing
the UI; the toolbar would get occluded by geometry.
OpenGL 2 and newer do not have the glPolygonMode(..., GL_LINES) API,
so produce the wireframe on our side. It's somewhat slow, and draws
every line three times, but it is cached when the OpenGL 2 renderer
is used, and this should do for a debugging feature.
gcc 6 displays these when compiling in release mode; all of these
warnings except the rankOk one were benign because there would have
been an error about the incomplete switch statement.
The rankOk warning highlighted a real problem: bailing early to
didnt_converge would have branched on an uninitialized variable.
Abstract the exact details of the OpenGL renderer in the render.h
header; this allows us to use GL-specific types in the renderer
class and functions without including OpenGL (and Windows, where
applicable) headers in every source file.
OpenGL 1.1 permits implementations to reject non-power-of-2 sized
textures. In practice this only affects the default Windows OpenGL
implementation, i.e. with no vendor drivers installed. This is still
important in case the application runs in a VM.
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.
