T25: release builds: scripts/windows-zip.ps1 zips elyterminal.exe, the icon inside as resource 1 (build.rs, embed-resource), a GUI program carrying its C runtime, git started without a console; scripts/linux-tar.sh builds on Debian 12, glibc 2.35 for this build, with a desktop entry and the icon; every window names itself com.zacharyzhang.elyterminal; rust-toolchain.toml pins 1.95.0, and CI installs it without rustup default

examples/icons.rs

@@ -1,33 +1,71 @@
-//! Renders an SVG into a macOS iconset: `icons SVG FOLDER`.
+//! Renders the icon: `icons iconset SVG FOLDER` or `icons ico SVG FILE`.
 
 use std::path::Path;
 
-use anyhow::Context as _;
+use anyhow::{Context as _, bail};
 use resvg::{tiny_skia, usvg};
 
 fn main() -> anyhow::Result<()> {
     let mut args = std::env::args().skip(1);
+    let form = args.next().context("icons: name a form, iconset or ico")?;
     let svg = args.next().context("icons: name an SVG to render")?;
-    let out = args
-        .next()
-        .context("icons: name an iconset folder to write")?;
+    let out = args.next().context("icons: name where to write")?;
     let data = std::fs::read(&svg).with_context(|| format!("icons: cannot read {svg}"))?;
     let tree = usvg::Tree::from_data(&data, &usvg::Options::default())
         .with_context(|| format!("icons: {svg} is not an SVG"))?;
-    std::fs::create_dir_all(&out).with_context(|| format!("icons: cannot make {out}"))?;
-    for points in [16, 32, 128, 256, 512] {
-        for (scale, suffix) in [(1, ""), (2, "@2x")] {
-            let side = points * scale;
-            let mut pixmap = tiny_skia::Pixmap::new(side, side).context("icons: no pixmap")?;
-            let fit = side as f32 / tree.size().width();
-            let transform = tiny_skia::Transform::from_scale(fit, fit);
-            resvg::render(&tree, transform, &mut pixmap.as_mut());
-            let png = Path::new(&out).join(format!("icon_{points}x{points}{suffix}.png"));
-            pixmap
-                .save_png(&png)
-                .with_context(|| format!("icons: cannot write {}", png.display()))?;
-        }
+    match form.as_str() {
+        "iconset" => iconset(&tree, &out)?,
+        "ico" => ico(&tree, &out)?,
+        other => bail!("icons: no form {other}; iconset or ico"),
     }
     println!("icons: {svg} drawn into {out}");
     Ok(())
 }
+
+/// A macOS iconset: each size at 1x and 2x.
+fn iconset(tree: &usvg::Tree, out: &str) -> anyhow::Result<()> {
+    std::fs::create_dir_all(out).with_context(|| format!("icons: cannot make {out}"))?;
+    for points in [16, 32, 128, 256, 512] {
+        for (scale, suffix) in [(1, ""), (2, "@2x")] {
+            let png = Path::new(out).join(format!("icon_{points}x{points}{suffix}.png"));
+            std::fs::write(&png, draw(tree, points * scale)?)
+                .with_context(|| format!("icons: cannot write {}", png.display()))?;
+        }
+    }
+    Ok(())
+}
+
+/// A Windows icon: one PNG per size, as Windows reads since Vista.
+fn ico(tree: &usvg::Tree, out: &str) -> anyhow::Result<()> {
+    let sides = [16, 24, 32, 48, 64, 128, 256];
+    let images = sides
+        .iter()
+        .map(|&side| draw(tree, side))
+        .collect::<anyhow::Result<Vec<_>>>()?;
+    let mut file = vec![0, 0, 1, 0];
+    file.extend((images.len() as u16).to_le_bytes());
+    let mut offset = 6 + 16 * images.len();
+    for (side, png) in sides.iter().zip(&images) {
+        // The format writes 256 as 0.
+        let edge = (side % 256) as u8;
+        file.extend([edge, edge, 0, 0]);
+        file.extend(1u16.to_le_bytes());
+        file.extend(32u16.to_le_bytes());
+        file.extend((png.len() as u32).to_le_bytes());
+        file.extend((offset as u32).to_le_bytes());
+        offset += png.len();
+    }
+    for png in &images {
+        file.extend(png);
+    }
+    std::fs::write(out, file).with_context(|| format!("icons: cannot write {out}"))
+}
+
+/// The SVG drawn into a square PNG `side` pixels wide.
+fn draw(tree: &usvg::Tree, side: u32) -> anyhow::Result<Vec<u8>> {
+    let mut pixmap = tiny_skia::Pixmap::new(side, side).context("icons: no pixmap")?;
+    let fit = side as f32 / tree.size().width();
+    let transform = tiny_skia::Transform::from_scale(fit, fit);
+    resvg::render(tree, transform, &mut pixmap.as_mut());
+    pixmap.encode_png().context("icons: cannot encode a PNG")
+}