Use png crate directly instead of image

Reduce dependencies a bit.

Cargo.lock

@@ -573,12 +573,6 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cd7cc57abe963c6d3b9d8be5b06ba7c8957a930305ca90304f24ef040aa6f961"
 
-[[package]]
-name = "color_quant"
-version = "1.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d7b894f5411737b7867f4827955924d7c254fc9f4d91a6aad6b097804b1018b"
-
 [[package]]
 name = "colorchoice"
 version = "1.0.0"
@@ -1118,20 +1112,6 @@ dependencies = [
  "objc2",
 ]
 
-[[package]]
-name = "image"
-version = "0.24.7"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6f3dfdbdd72063086ff443e297b61695500514b1e41095b6fb9a5ab48a70a711"
-dependencies = [
- "bytemuck",
- "byteorder",
- "color_quant",
- "num-rational",
- "num-traits",
- "png",
-]
-
 [[package]]
 name = "indexmap"
 version = "2.0.2"
@@ -1552,7 +1532,6 @@ dependencies = [
  "bitflags 2.4.1",
  "clap",
  "directories",
- "image",
  "keyframe",
  "knuffel",
  "libc",
@@ -1560,6 +1539,7 @@ dependencies = [
  "logind-zbus",
  "miette",
  "pipewire",
+ "png",
  "portable-atomic",
  "profiling",
  "proptest",
@@ -1620,27 +1600,6 @@ dependencies = [
  "winapi",
 ]
 
-[[package]]
-name = "num-integer"
-version = "0.1.45"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "225d3389fb3509a24c93f5c29eb6bde2586b98d9f016636dff58d7c6f7569cd9"
-dependencies = [
- "autocfg",
- "num-traits",
-]
-
-[[package]]
-name = "num-rational"
-version = "0.4.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0638a1c9d0a3c0914158145bc76cff373a75a627e6ecbfb71cbe6f453a5a19b0"
-dependencies = [
- "autocfg",
- "num-integer",
- "num-traits",
-]
-
 [[package]]
 name = "num-traits"
 version = "0.2.17"

Cargo.toml

@@ -14,7 +14,6 @@ async-io = { version = "1.13.0", optional = true }
 bitflags = "2.4.1"
 clap = { version = "4.4.6", features = ["derive"] }
 directories = "5.0.1"
-image = { version = "0.24.7", default-features = false, features = ["png"] }
 keyframe = { version = "1.1.1", default-features = false }
 knuffel = "3.2.0"
 libc = "0.2.149"
@@ -22,6 +21,7 @@ logind-zbus = { version = "3.1.2", optional = true }
 log = { version = "0.4.20", features = ["max_level_trace", "release_max_level_debug"] }
 miette = "5.10.0"
 pipewire = { version = "0.7.2", optional = true }
+png = "0.17.10"
 portable-atomic = { version = "1.5.0", default-features = false, features = ["float"] }
 profiling = "1.0.11"
 sd-notify = "0.4.1"

src/niri.rs

@@ -9,7 +9,6 @@ use std::{env, mem, thread};
 
 use _server_decoration::server::org_kde_kwin_server_decoration_manager::Mode as KdeDecorationsMode;
 use anyhow::Context;
-use image::ImageFormat;
 use smithay::backend::allocator::Fourcc;
 use smithay::backend::renderer::element::solid::{SolidColorBuffer, SolidColorRenderElement};
 use smithay::backend::renderer::element::surface::{
@@ -85,7 +84,7 @@ use crate::frame_clock::FrameClock;
 use crate::handlers::configure_lock_surface;
 use crate::layout::{output_size, Layout, MonitorRenderElement};
 use crate::pw_utils::{Cast, PipeWire};
-use crate::utils::{center, get_monotonic_time, make_screenshot_path};
+use crate::utils::{center, get_monotonic_time, make_screenshot_path, write_png_rgba8};
 
 pub const CLEAR_COLOR: [f32; 4] = [0.2, 0.2, 0.2, 1.];
 pub const CLEAR_COLOR_LOCKED: [f32; 4] = [0.3, 0.1, 0.1, 1.];
@@ -1881,14 +1880,8 @@ impl Niri {
         thread::spawn(move || {
             let mut buf = vec![];
 
-            if let Err(err) = image::write_buffer_with_format(
-                &mut std::io::Cursor::new(&mut buf),
-                &pixels,
-                size.w as u32,
-                size.h as u32,
-                image::ColorType::Rgba8,
-                ImageFormat::Png,
-            ) {
+            let w = std::io::Cursor::new(&mut buf);
+            if let Err(err) = write_png_rgba8(w, size.w as u32, size.h as u32, &pixels) {
                 warn!("error encoding screenshot image: {err:?}");
                 return;
             }
@@ -1942,16 +1935,17 @@ impl Niri {
         debug!("saving screenshot to {path:?}");
 
         thread::spawn(move || {
-            let res = image::save_buffer(
-                &path,
-                &pixels,
-                size.w as u32,
-                size.h as u32,
-                image::ColorType::Rgba8,
-            );
+            let file = match std::fs::File::create(&path) {
+                Ok(file) => file,
+                Err(err) => {
+                    warn!("error creating file: {err:?}");
+                    return;
+                }
+            };
 
-            if let Err(err) = res {
-                warn!("error saving screenshot image: {err:?}");
+            let w = std::io::BufWriter::new(file);
+            if let Err(err) = write_png_rgba8(w, size.w as u32, size.h as u32, &pixels) {
+                warn!("error encoding screenshot image: {err:?}");
                 return;
             }
 

src/utils.rs

@@ -1,5 +1,5 @@
 use std::ffi::OsStr;
-use std::io;
+use std::io::{self, Write};
 use std::os::unix::process::CommandExt;
 use std::path::PathBuf;
 use std::process::{Command, Stdio};
@@ -89,3 +89,17 @@ pub fn spawn(command: impl AsRef<OsStr>, args: impl IntoIterator<Item = impl AsR
         }
     }
 }
+
+pub fn write_png_rgba8(
+    w: impl Write,
+    width: u32,
+    height: u32,
+    pixels: &[u8],
+) -> Result<(), png::EncodingError> {
+    let mut encoder = png::Encoder::new(w, width, height);
+    encoder.set_color(png::ColorType::Rgba);
+    encoder.set_depth(png::BitDepth::Eight);
+
+    let mut writer = encoder.write_header()?;
+    writer.write_image_data(pixels)
+}