feat: add optional background blur via image crate

Gaussian blur applied at texture load time when `background-blur` is
set in the [appearance] section of moongreet.toml. Blur runs once,
result is shared across monitors.
This commit is contained in:
nevaforget 2026-03-28 14:53:16 +01:00
parent 14d6476e5a
commit 293bba32a6
6 changed files with 197 additions and 10 deletions

131
Cargo.lock generated
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@ -2,6 +2,12 @@
# It is not intended for manual editing.
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@ -20,6 +26,18 @@ version = "2.11.0"
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@ -59,6 +77,15 @@ version = "1.0.4"
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]
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@ -81,6 +108,15 @@ version = "2.3.0"
source = "registry+https://github.com/rust-lang/crates.io-index"
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@ -91,6 +127,16 @@ dependencies = [
"rustc_version",
]
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dependencies = [
"crc32fast",
"miniz_oxide",
]
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name = "foldhash"
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@ -504,6 +550,21 @@ version = "2.3.0"
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[[package]]
name = "image"
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dependencies = [
"bytemuck",
"byteorder-lite",
"moxcms",
"num-traits",
"png",
"zune-core",
"zune-jpeg",
]
[[package]]
name = "indexmap"
version = "2.13.0"
@ -567,6 +628,16 @@ dependencies = [
"autocfg",
]
[[package]]
name = "miniz_oxide"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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dependencies = [
"adler2",
"simd-adler32",
]
[[package]]
name = "moongreet"
version = "0.4.1"
@ -578,6 +649,7 @@ dependencies = [
"glib-build-tools",
"gtk4",
"gtk4-layer-shell",
"image",
"log",
"serde",
"serde_json",
@ -586,6 +658,25 @@ dependencies = [
"toml 0.8.23",
]
[[package]]
name = "moxcms"
version = "0.8.1"
source = "registry+https://github.com/rust-lang/crates.io-index"
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"num-traits",
"pxfm",
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dependencies = [
"autocfg",
]
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@ -628,6 +719,19 @@ version = "0.3.32"
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"crc32fast",
"fdeflate",
"flate2",
"miniz_oxide",
]
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name = "prettyplease"
version = "0.2.37"
@ -656,6 +760,12 @@ dependencies = [
"unicode-ident",
]
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name = "pxfm"
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source = "registry+https://github.com/rust-lang/crates.io-index"
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@ -760,6 +870,12 @@ dependencies = [
"serde_core",
]
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@ -1128,3 +1244,18 @@ name = "zmij"
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dependencies = [
"zune-core",
]

View File

@ -15,6 +15,7 @@ gio = "0.22"
toml = "0.8"
serde = { version = "1", features = ["derive"] }
serde_json = "1"
image = { version = "0.25", default-features = false, features = ["jpeg", "png"] }
log = "0.4"
systemd-journal-logger = "2.2"

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@ -1,5 +1,12 @@
# Decisions
## 2026-03-28 Optional background blur via `image` crate
- **Who**: Selene, Dom
- **Why**: Blurred wallpaper as greeter background is a common UX pattern for login screens
- **Tradeoffs**: Adds `image` crate dependency (~15 transitive crates); CPU-side Gaussian blur at load time adds startup latency proportional to image size and sigma. Acceptable because blur runs once and the texture is shared across monitors.
- **How**: `load_background_texture(bg_path, blur_radius)` loads texture, optionally applies `imageops::blur()`, returns blurred `gdk::Texture`. Config option `background-blur: Option<f32>` in `[appearance]` TOML section.
## 2026-03-28 Audit fixes for shared wallpaper texture (v0.4.1)
- **Who**: Selene, Dominik
- **Why**: Quality, performance, and security audits flagged issues in `load_background_texture()`, debug logging, and greetd error handling

View File

@ -22,6 +22,8 @@ struct TomlConfig {
#[derive(Debug, Clone, Default, Deserialize)]
struct Appearance {
background: Option<String>,
#[serde(rename = "background-blur")]
background_blur: Option<f32>,
#[serde(rename = "gtk-theme")]
gtk_theme: Option<String>,
}
@ -30,6 +32,7 @@ struct Appearance {
#[derive(Debug, Clone, Default)]
pub struct Config {
pub background_path: Option<String>,
pub background_blur: Option<f32>,
pub gtk_theme: Option<String>,
}
@ -56,6 +59,9 @@ pub fn load_config(config_paths: Option<&[PathBuf]>) -> Config {
Some(parent.join(&bg).to_string_lossy().to_string());
}
}
if appearance.background_blur.is_some() {
merged.background_blur = appearance.background_blur;
}
if appearance.gtk_theme.is_some() {
merged.gtk_theme = appearance.gtk_theme;
}
@ -72,7 +78,7 @@ pub fn load_config(config_paths: Option<&[PathBuf]>) -> Config {
}
}
log::debug!("Config result: background={:?}, gtk_theme={:?}", merged.background_path, merged.gtk_theme);
log::debug!("Config result: background={:?}, blur={:?}, gtk_theme={:?}", merged.background_path, merged.background_blur, merged.gtk_theme);
merged
}
@ -114,6 +120,7 @@ mod tests {
fn default_config_has_none_fields() {
let config = Config::default();
assert!(config.background_path.is_none());
assert!(config.background_blur.is_none());
assert!(config.gtk_theme.is_none());
}
@ -131,7 +138,7 @@ mod tests {
let conf = dir.path().join("moongreet.toml");
fs::write(
&conf,
"[appearance]\nbackground = \"/custom/wallpaper.jpg\"\ngtk-theme = \"catppuccin\"\n",
"[appearance]\nbackground = \"/custom/wallpaper.jpg\"\nbackground-blur = 20.0\ngtk-theme = \"catppuccin\"\n",
)
.unwrap();
let paths = vec![conf];
@ -140,9 +147,20 @@ mod tests {
config.background_path.as_deref(),
Some("/custom/wallpaper.jpg")
);
assert_eq!(config.background_blur, Some(20.0));
assert_eq!(config.gtk_theme.as_deref(), Some("catppuccin"));
}
#[test]
fn load_config_blur_optional() {
let dir = tempfile::tempdir().unwrap();
let conf = dir.path().join("moongreet.toml");
fs::write(&conf, "[appearance]\nbackground = \"/bg.jpg\"\n").unwrap();
let paths = vec![conf];
let config = load_config(Some(&paths));
assert!(config.background_blur.is_none());
}
#[test]
fn load_config_resolves_relative_background() {
let dir = tempfile::tempdir().unwrap();
@ -196,7 +214,7 @@ mod tests {
fs::write(&wallpaper, "fake").unwrap();
let config = Config {
background_path: Some(wallpaper.to_str().unwrap().to_string()),
gtk_theme: None,
..Config::default()
};
assert_eq!(
resolve_background_path_with(&config, Path::new("/nonexistent")),
@ -208,7 +226,7 @@ mod tests {
fn resolve_ignores_config_path_when_file_missing() {
let config = Config {
background_path: Some("/nonexistent/wallpaper.jpg".to_string()),
gtk_theme: None,
..Config::default()
};
let result = resolve_background_path_with(&config, Path::new("/nonexistent"));
assert!(result.to_str().unwrap().contains("moongreet"));

View File

@ -6,6 +6,7 @@ use gdk_pixbuf::Pixbuf;
use glib::clone;
use gtk4::prelude::*;
use gtk4::{self as gtk, gio};
use image::imageops;
use std::cell::RefCell;
use std::collections::HashMap;
use std::os::unix::net::UnixStream;
@ -96,9 +97,10 @@ fn is_valid_username(name: &str) -> bool {
}
/// Load the background image as a shared texture (decode once, reuse everywhere).
pub fn load_background_texture(bg_path: &Path) -> Option<gdk::Texture> {
/// When `blur_radius` is `Some(sigma)` with sigma > 0, a Gaussian blur is applied.
pub fn load_background_texture(bg_path: &Path, blur_radius: Option<f32>) -> Option<gdk::Texture> {
let path_str = bg_path.to_str()?;
if bg_path.starts_with("/dev/moonarch/moongreet") {
let texture = if bg_path.starts_with("/dev/moonarch/moongreet") {
match gio::resources_lookup_data(path_str, gio::ResourceLookupFlags::NONE) {
Ok(bytes) => match gdk::Texture::from_bytes(&bytes) {
Ok(texture) => Some(texture),
@ -132,9 +134,37 @@ pub fn load_background_texture(bg_path: &Path) -> Option<gdk::Texture> {
None
}
}
}?;
match blur_radius {
Some(sigma) if sigma > 0.0 => Some(apply_blur(&texture, sigma)),
_ => Some(texture),
}
}
/// Apply Gaussian blur to a texture and return a blurred texture.
fn apply_blur(texture: &gdk::Texture, sigma: f32) -> gdk::Texture {
let width = texture.width() as u32;
let height = texture.height() as u32;
let stride = width as usize * 4;
let mut pixel_data = vec![0u8; stride * height as usize];
texture.download(&mut pixel_data, stride);
let img = image::RgbaImage::from_raw(width, height, pixel_data)
.expect("pixel buffer size matches texture dimensions");
let blurred = imageops::blur(&image::DynamicImage::ImageRgba8(img), sigma);
let bytes = glib::Bytes::from(blurred.as_raw());
let mem_texture = gdk::MemoryTexture::new(
width as i32,
height as i32,
gdk::MemoryFormat::B8g8r8a8Premultiplied,
&bytes,
stride,
);
mem_texture.upcast()
}
/// Create a wallpaper-only window for secondary monitors.
pub fn create_wallpaper_window(
texture: &gdk::Texture,
@ -1628,7 +1658,7 @@ mod tests {
#[test]
fn load_background_texture_missing_file_returns_none() {
let result = load_background_texture(Path::new("/nonexistent/wallpaper.jpg"));
let result = load_background_texture(Path::new("/nonexistent/wallpaper.jpg"), None);
assert!(result.is_none());
}
@ -1639,7 +1669,7 @@ mod tests {
// Create a sparse file that exceeds MAX_WALLPAPER_FILE_SIZE
let f = std::fs::File::create(&path).unwrap();
f.set_len(MAX_WALLPAPER_FILE_SIZE + 1).unwrap();
let result = load_background_texture(&path);
let result = load_background_texture(&path, None);
assert!(result.is_none());
}
@ -1650,7 +1680,7 @@ mod tests {
// 0xFF is not valid UTF-8
let non_utf8 = OsStr::from_bytes(&[0xff, 0xfe, 0xfd]);
let path = Path::new(non_utf8);
let result = load_background_texture(path);
let result = load_background_texture(path, None);
assert!(result.is_none());
}
}

View File

@ -55,7 +55,7 @@ fn activate(app: &gtk::Application) {
log::debug!("Background path: {}", bg_path.display());
// Load background texture once — shared across all windows
let bg_texture = greeter::load_background_texture(&bg_path);
let bg_texture = greeter::load_background_texture(&bg_path, config.background_blur);
if bg_texture.is_none() {
log::error!("Failed to load background texture — greeter will start without wallpaper");
}