Merge pull request #644 from dotCooCoo/feat/ase-import

Swatches: swatch exchange (.ase) files open as swatch libraries

crates/testkit/src/ase.rs

@@ -0,0 +1,61 @@
+//! Hand-written swatch exchange (`.ase`) files for swatch library tests: version 1.0, big-endian,
+//! with colors in each model and color type, and color groups.
+
+/// One block of a swatch exchange file.
+#[derive(Clone, Debug)]
+pub enum Block<'a> {
+    /// A color group starts (its name).
+    GroupStart(&'a str),
+    /// The open color group ends.
+    GroupEnd,
+    /// A color: its name, model (`b"RGB "`, `b"CMYK"`, `b"LAB "` or `b"Gray"`), components and
+    /// color type (0 global, 1 spot, 2 process).
+    Color(&'a str, &'a [u8; 4], &'a [f32], u16),
+}
+
+/// A name: a `u16` count of UTF-16 code units, the terminating zero included, then the units.
+fn name(out: &mut Vec<u8>, name: &str) {
+    let units: Vec<u16> = name.encode_utf16().chain([0]).collect();
+    out.extend(u16::try_from(units.len()).unwrap().to_be_bytes());
+    out.extend(units.iter().flat_map(|u| u.to_be_bytes()));
+}
+
+/// A swatch exchange file of `blocks`.
+pub fn ase(blocks: &[Block]) -> Vec<u8> {
+    let mut out = b"ASEF\0\x01\0\0".to_vec();
+    out.extend(u32::try_from(blocks.len()).unwrap().to_be_bytes());
+    for b in blocks {
+        let mut body = vec![];
+        let kind: u16 = match b {
+            Block::GroupStart(n) => {
+                name(&mut body, n);
+                0xC001
+            }
+            Block::GroupEnd => 0xC002,
+            Block::Color(n, model, values, kind) => {
+                name(&mut body, n);
+                body.extend(*model);
+                body.extend(values.iter().flat_map(|v| v.to_be_bytes()));
+                body.extend(kind.to_be_bytes());
+                0x0001
+            }
+        };
+        out.extend(kind.to_be_bytes());
+        out.extend(u32::try_from(body.len()).unwrap().to_be_bytes());
+        out.extend(body);
+    }
+    out
+}
+
+/// A library of four colors: "Sky" (global RGB) and "Ink" (spot CMYK), then the group "Neutrals"
+/// of the process colors "Mist" (Gray, 25% ink) and "Clay" (Lab 50, 20, −30).
+pub fn sample() -> Vec<u8> {
+    ase(&[
+        Block::Color("Sky", b"RGB ", &[0.0, 0.5, 1.0], 0),
+        Block::Color("Ink", b"CMYK", &[1.0, 0.5, 0.0, 0.2], 1),
+        Block::GroupStart("Neutrals"),
+        Block::Color("Mist", b"Gray", &[0.75], 2),
+        Block::Color("Clay", b"LAB ", &[0.5, 20.0, -30.0], 2),
+        Block::GroupEnd,
+    ])
+}

crates/testkit/src/lib.rs

@@ -10,6 +10,7 @@
 //! - [`raster`]: rendering helpers and image comparison with a perceptual tolerance.
 //! - [`geom`]: geometry assertions (approximate equality, curve sampling, Hausdorff distance).
 //! - [`pdf`]: hand-written PDF files (page boxes, colour spaces, encryption) for import tests.
+//! - [`ase`]: hand-written swatch exchange (`.ase`) files for swatch library tests.
 //!
 //! This crate may only be used as a dev-dependency (enforced by `cargo xtask layers`).
 // Test support only (a dev-dependency of every crate that uses it): a failed setup or assertion
@@ -18,6 +19,7 @@
 #![allow(clippy::unwrap_used, clippy::expect_used, clippy::panic)]
 #![forbid(unsafe_code)]
 
+pub mod ase;
 pub mod fixtures;
 pub mod geom;
 pub mod invariants;