Now that it's done at the rasterization stage, we don't need to handle
it on the GPU. This also means that we can switch to nearest neighbor
interpolation in the Metal shader since we're guaranteed to be pixel
perfect. Accidentally, we were already nearest neighbor in the OpenGL
shaders because I used the Rectangle texture mode in the big renderer
rework, which doesn't support interpolation- anyway, that's no longer
problematic since we won't be scaling glyphs on the GPU anymore.
Adds support for background images via the `background-image` config.
Resolves#3645, supersedes PRs #4226 and #5233.
See docs of added config keys for usage details.
In this format it will be a lot easier to iterate on this since adding
and removing pipelines only has to be done in a single place.
This commit also separates out the main background color from individual
cell background color drawing, because sometimes kitty images need to be
between the main background and individual cell backgrounds (kitty image
z-index seems to be entirely broken at the moment, I intend to fix it in
future commits).
These should not be independent per-frame, that makes the time
calculations all sorts of jank.
Also moves the uniforms struct layout in to `shadertoy.zig` and cleans
up the handling in general somewhat.
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.
More mathematically sound approach, does a much better job of matching
the appearance of non-linear blending. Removed `experimental` from name
because it's not really an experiment anymore.
This commit is quite large because it's fairly interconnected and can't
be split up in a logical way. The main part of this commit is that alpha
blending is now always done in the Display P3 color space, and depending
on the configured `window-colorspace` colors will be converted from sRGB
or assumed to already be Display P3 colors. In addition, a config option
`text-blending` has been added which allows the user to configure linear
blending (AKA "gamma correction"). Linear alpha blending also applies to
images and makes custom shaders receive linear colors rather than sRGB.
In addition, an experimental option has been added which corrects linear
blending's tendency to make dark text look too thin and bright text look
too thick. Essentially it's a correction curve on the alpha channel that
depends on the luminance of the glyph being drawn.
Metal needed to be changed to account for wide chars having decorations
on the right half and OpenGL needed to account for multiple glyphs being
under the cursor at once (decorations and combining marks) as well as
wide chars.
This happened to work in releases somehow but Xcode debug builds would
catch this as an assertion. Our cell bg pipeline now uses the "full
screen vertex shader" which takes no parameters, so we don't need a
vertex descriptor.
- Significant changes to optimize memory usage.
- Adjusted formatting of the metal shader code to improve readability.
- Normalized naming conventions in shader code.
- Abstracted repetitive code for attribute descriptors to a helper
function.
With a minimum contrast set, the colored glyphs that Powerline uses
would sometimes be set to white or black while the surrounding background
colors remain unchanged, breaking up contiguous colors on segments of
the Powerline.
This no longer happens with this patch as Powerline glyphs are now
special-cased and exempt from the minimum contrast adjustment.
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.
This uses WCAG2 algorithms with a minimum ratio hardcoded of 3:1. This
is not shippable in its current state because we want the ratio to be
configurable and I'm not happy with the way data is being sent to the
shader.
