Render, SVG: vello_cpu and usvg without their text features: one skrifa, read-fonts and harfrust fewer in the engine

The default `text` features of vello_cpu (glyph runs, through glifo) and
usvg (fontdb, harfrust 0.12, skrifa 0.44 and its read-fonts 0.41) build
another copy of the font stack into the engine, next to the workspace's
skrifa 0.47 and harfrust 0.13. Neither is used: the renderer draws the
glyph outlines vectorcraft-text gives it, and SVG import reads <text>
from the XML itself and never gives usvg a font (usvg leaves out text it
has no font for).

- vello_cpu: its default features but `text` (std, png, u8_pipeline),
  plus f32_pipeline as before.
- usvg: `svgz` only, for gzipped SVG images inside an SVG; `text`,
  `system-fonts`, `memmap-fonts` and `writer` are off. text_layout.rs uses
  usvg as a reference viewer with a font, so crates/svg turns `text` on as
  a dev-dependency feature, as crates/pdf does for krilla's `simple-text`.
- A test pins `svgz`: SVGZ images, linked or as a data URL, import as
  vector art.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Cargo.lock

@@ -1383,24 +1383,13 @@ dependencies = [
  "bytemuck",
 ]
 
-[[package]]
-name = "fontconfig-parser"
-version = "0.5.8"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbc773e24e02d4ddd8395fd30dc147524273a83e54e0f312d986ea30de5f5646"
-dependencies = [
- "roxmltree 0.20.0",
-]
-
 [[package]]
 name = "fontdb"
 version = "0.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2660c5e9157bf76d2db1294e4a9feba604ef610819a3b591088d0d8392a3290f"
 dependencies = [
- "fontconfig-parser",
  "log",
- "memmap2",
  "slotmap",
  "tinyvec",
 ]

Cargo.toml

@@ -59,9 +59,14 @@ wasmi = { version = "2.0.0", default-features = false, features = ["std", "valid
 wat = "1.228"
 
 # rendering / formats
-vello_cpu = { version = "0.2", features = ["f32_pipeline"] }
+# Without `text` (glyph runs, through glifo and a second skrifa): the renderer draws the outlines
+# vectorcraft-text gives it. The other default features stay.
+vello_cpu = { version = "0.2", default-features = false, features = ["std", "png", "u8_pipeline", "f32_pipeline"] }
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "webp", "gif", "tiff", "bmp"] }
-usvg = "0.48"
+# Without `text` and the system fonts (fontdb, harfrust and skrifa, at other versions than ours):
+# SVG import reads `<text>` from the XML itself and never gives usvg a font. A test of the SVG
+# crate turns `text` on.
+usvg = { version = "0.48", default-features = false, features = ["svgz"] }
 # Without `simple-text` (its text shaping, the only user of rustybuzz and ttf-parser, which are
 # unmaintained, #1730): the PDF writer places glyphs itself. A test of the PDF crate turns it on.
 krilla = { version = "0.8", default-features = false, features = ["raster-images"] }

crates/svg/Cargo.toml

@@ -33,6 +33,8 @@ skrifa = { workspace = true }
 # A variable font built in code (no font file is committed).
 vectorcraft-text = { workspace = true, features = ["test-fonts"] }
 resvg = { version = "0.45", default-features = false }
+# usvg as a reference viewer that lays text out in a font (text_layout.rs).
+usvg = { workspace = true, features = ["text"] }
 vectorcraft-testkit = { workspace = true }
 proptest = { workspace = true }
 image = { workspace = true }

crates/svg/tests/import_details.rs

@@ -126,6 +126,27 @@ fn svg_images_import_as_vector_art() {
     assert!((boxes[1].x0 - 100.0).abs() < 1e-6 && (boxes[1].height() - 20.0).abs() < 1e-6, "{boxes:?}");
 }
 
+/// usvg unpacks gzipped SVG images itself (its `svgz` feature, which the workspace keeps).
+#[test]
+fn svgz_images_import_as_vector_art() {
+    let dir = folder("svgzimage");
+    let inner =
+        r##"<svg xmlns="http://www.w3.org/2000/svg" width="20" height="10" viewBox="0 0 20 10"><rect width="10" height="10" fill="#f00"/></svg>"##;
+    let gz = vectorcraft_svg::compress(inner);
+    std::fs::write(dir.join("img").join("logo.svgz"), &gz).unwrap();
+    let data = format!("data:image/svg+xml;base64,{}", vectorcraft_svg::base64_encode(&gz));
+    let body =
+        format!(r#"<image href="img/logo.svgz" x="10" y="10" width="40" height="20"/><image href="{data}" x="100" y="10" width="40" height="20"/>"#);
+    let (d, w) = open_in(&dir, &body);
+    assert!(w.is_empty(), "{w:?}");
+    assert!(images(&d).is_empty());
+    let mut boxes: Vec<Rect> = art(&d).iter().filter(|n| n.path_data().is_some()).filter_map(|n| n.geometric_bounds()).collect();
+    boxes.sort_by(|a, b| a.x0.total_cmp(&b.x0));
+    assert_eq!(boxes.len(), 2, "{:?}", art(&d));
+    assert!((boxes[0].x0 - 10.0).abs() < 1e-6 && (boxes[0].width() - 20.0).abs() < 1e-6, "{boxes:?}");
+    assert!((boxes[1].x0 - 100.0).abs() < 1e-6 && (boxes[1].height() - 20.0).abs() < 1e-6, "{boxes:?}");
+}
+
 #[test]
 fn nested_clips_intersect() {
     let body = r##"<defs><clipPath id="inner"><rect x="60" y="0" width="200" height="200"/></clipPath>