This migrates all remaining uses of cImport (and addTranslateC for good
measure) to using translate-c for C translation, ensuring that we are
ready for when cImport is removed from the language, and also that all
sources of C translation are using the same snapshot of the external
package (when can then be updated when we need to fix something).
A couple of notes:
* A few options have been added to support the new translations, namely
the ability to link libraries (passed through to linkLibrary on the
Translator side) and whether or not to initialize default values
(looks like cImport did this without a way to control it, but
translate-c does not do it by default).
* Using the new library linking option actually simplifies the process
of translating a number of the C packages as we have been shipping the
necessary headers for these packages already with the applicable
libraries. For some of the more complex translation processes though,
we still include the appropriate directories directly.
GtkGLArea had numerous downsides that forced us to invent unsightly hacks
in our renderer to work around them, most chiefly the fact that it holds
its own GdkGLContext on the main thread (GL contexts are not at all
thread-safe), forcing us to keep our GL calls on the main thread.
It also does not interact well with triple-buffering and initialization
is forced to be this sort of deferred song-and-dance since we need to
wait for the GLArea to initialize its GL context before we can initialize
the renderer, the core surface, and then most things in the GTK surface.
We instead invent our own custom widget named RenderSurface that takes
simple DMABUFs and displays them. The task of obtaining a GL context
falls to manual EGL bindings, since we also need EGL to export OpenGL
textures into DMABUFs. We keep the EGL context solely on the render
thread meaning that the main thread never concerns itself with rendering
except when being notified that the renderer has pushed a new frame.
What makes this extra significant is that now the entire GTK apprt no
longer depends on OpenGL in any way, shape or form. As long as it is
being fed DMABUFs, it can render from whichever graphics API you want.
This means we can add more backends based on OpenGL ES or more likely
Vulkan rather painlessly in the future.
**AI disclosure**: I came up with the idea and let Pi implement most of
the nitty-gritty details around EGL, as well as replumbing the renderer
and cleaning up all the GTK-specific workarounds there. I then carefully
vetted every line of code and spent roughly as much time reviewing as
coding. Most of the documentation and all commit messages are in my
own words.
The GLSL to MSL conversion process uses a passed-in sampler state for
the `iChannel0` parameter and we weren't providing it. This magically
worked on Apple Silicon for unknown reasons but failed on Intel GPUs.
In normal, hand-written MSL, we'd explicitly create the sampler state as
a normal variable (we do this in `shaders.metal` already!), but the
Shadertoy conversion stuff doesn't do this, probably because the exact
sampler parameters can't be safely known.
This fixes a Metal validation error when using custom shaders:
```
-[MTLDebugRenderCommandEncoder validateCommonDrawErrors:]:5970: failed
assertion `Draw Errors Validation Fragment Function(main0): missing Sampler
binding at index 0 for iChannel0Smplr[0].
```
This sets up for a couple improvments (see TODO comments) and also sets
the glyph atlas textures to nearest neighbor sampling since we can do
that now that we never scale glyphs.
BPTC is required to be available OpenGL >= 4.2 and our minimum is 4.3 so
this is safe in terms of support. I tested briefly in a VM and didn't
encounter any problems so this should just be a complete win.
(Note: texture data is already automatically compressed on Metal)
This commit is very large, representing about a month of work with many
interdependent changes that don't separate cleanly in to atomic commits.
The main change here is unifying the renderer logic to a single generic
renderer, implemented on top of an abstraction layer over OpenGL/Metal.
I'll write a more complete summary of the changes in the description of
the PR.
NEEDS REVIEW
continuation of #5037resolves#4729
renders all shaders to the default buffer and then copies it to the
designated custom shader texture.
this is a draft pr because:
- it introduces a new shader "pipeline" which doesnt fit in with how the
system was designed to work (which is only rendering to the fbo)
- im not sure if this is the best way to achieve shaders being able to
sample their output while also drawing to the screen. the cusom fbo
(previous implementation) was useful in that it modularized the custom
shader stage in rendering
---------
Co-authored-by: Mitchell Hashimoto <m@mitchellh.com>
There are scenarios where this configuration looks bad. This commit
introduces some heuristics to prevent it. Here are the heuristics:
* Extension is always enabled on alt screen.
* Extension is disabled if a row contains any default bg color. The
thinking is that in this scenario, using the default bg color looks
just fine.
* Extension is disabled if a row is marked as a prompt (using semantic
prompt sequences). The thinking here is that prompts often contain
perfect fit glyphs such as Powerline glyphs and those look bad when
extended.
This introduces some CPU cost to the extension feature but it should be
minimal and respects dirty tracking. This is unfortunate but the feature
makes many terminal scenarios look much better and the performance cost
is minimal so I believe it is worth it.
Further heuristics are likely warranted but this should be a good
starting set.
