49b95d8466
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.
Packages
This folder contains packages written for and used by Ghostty that could potentially be useful for other projects. These are in-tree with Ghostty because I don't want to maintain them as separate projects (i.e. get dedicated issues, PRs, etc.). If you want to use them, you can copy and paste them into your project.
License
This license only applies to the contents of the pkg folder within
the Ghostty project. This license does not apply to the rest of the
Ghostty project.
Copyright © 2024 Mitchell Hashimoto, Ghostty contributors
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.