Wire shared compiler into CAD font API

Cargo.lock

@@ -714,6 +714,7 @@ version = "0.21.0"
 dependencies = [
  "cadcraft-geom",
  "craft-dxf",
+ "craft-shx",
  "encoding_rs",
  "harfrust 0.14.0",
  "icu_segmenter",
@@ -1193,6 +1194,11 @@ dependencies = [
  "thiserror 2.0.21",
 ]
 
+[[package]]
+name = "craft-shx"
+version = "0.1.0"
+source = "git+https://github.com/storytold/craft-libs?rev=b3307f7814629961841b80ab907116252e41b34d#b3307f7814629961841b80ab907116252e41b34d"
+
 [[package]]
 name = "craft-ui"
 version = "0.1.0"

Cargo.toml

@@ -16,6 +16,7 @@ cadcraft-geom = { path = "crates/geom" }
 # DXF tags: the shared reader and writer (moved from crates/dxf; craft-libs#791).
 craft-dxf = { git = "https://github.com/storytold/craft-libs", rev = "006e4df225fca57e95ead0fb1f91920900798a99" }
 craft-dwg = { git = "https://github.com/storytold/craft-libs", rev = "7bb6c90076a0177d01cc4c482e7fd8dc9f31a8bf" }
+craft-shx = { git = "https://github.com/storytold/craft-libs", rev = "b3307f7814629961841b80ab907116252e41b34d" }
 cadcraft-color = { path = "crates/color" }
 cadcraft-doc = { path = "crates/doc" }
 cadcraft-constraints = { path = "crates/constraints" }

crates/fonts/Cargo.toml

@@ -11,6 +11,7 @@ workspace = true
 [dependencies]
 cadcraft-geom = { workspace = true }
 craft-dxf = { workspace = true }
+craft-shx = { workspace = true }
 skrifa = { workspace = true }
 harfrust = { workspace = true }
 unicode-bidi = { workspace = true }

crates/fonts/src/shx/compile.rs

@@ -1,313 +0,0 @@
-//! Shape source (`.shp`) to a compiled SHX file, as COMPILE does.
-//!
-//! A source is a list of definitions: a header line `*number,defbytes,NAME` followed by its
-//! specification bytes (on as many lines as needed, ending with 0). Numbers are decimal, or
-//! hexadecimal after a leading `0` (`012`, `08cfb`); parentheses only group; `;` starts a
-//! comment. A big font starts with `*BIGFONT nchars,nranges,first,last,…` and a Unicode font
-//! with `*UNIFONT,6,name` followed by `above,below,modes,encoding,type,0`. Shape 0 is a text
-//! font's record (`above,below,modes,0`).
-//!
-//! Operands are encoded by what they are: a subshape number takes two bytes in a Unicode font
-//! (and after `7,0` in a big font), displacements and bulges are two's complement, and an arc's
-//! direction byte (`-043`) keeps its sign in the high bit. `defbytes` is not checked: the
-//! program's own length is written.
-
-use super::ShxError;
-use super::parse::{BIGFONT, SHAPES_10, UNIFONT};
-
-/// Largest source compiled.
-const MAX_SOURCE: usize = 8 << 20;
-
-#[derive(Clone, Copy, PartialEq)]
-enum Kind {
-    Shapes,
-    Big,
-    Uni,
-}
-
-struct Shape {
-    number: u16,
-    name: String,
-    program: Vec<u8>,
-}
-
-/// A number token: value (sign included).
-fn number(tok: &str, line: usize) -> Result<i64, ShxError> {
-    let t: String = tok.chars().filter(|c| !matches!(c, '(' | ')') && !c.is_whitespace()).collect();
-    let (neg, digits) = match t.strip_prefix('-') {
-        Some(d) => (true, d),
-        None => (false, t.strip_prefix('+').unwrap_or(&t)),
-    };
-    let err = || ShxError::Source(line, format!("not a number: {tok:?}"));
-    let v = if digits.len() > 1 && digits.starts_with('0') {
-        i64::from_str_radix(digits.get(1..).unwrap_or_default(), 16).map_err(|_| err())?
-    } else {
-        digits.parse::<i64>().map_err(|_| err())?
-    };
-    if v > 0xFFFF {
-        return Err(err());
-    }
-    Ok(if neg { -v } else { v })
-}
-
-/// The comma-separated numbers of a line (comment removed, blank fields skipped).
-fn numbers(text: &str, line: usize) -> Result<Vec<i64>, ShxError> {
-    text.split(',').map(str::trim).filter(|t| !t.is_empty() && *t != "(" && *t != ")").map(|t| number(t, line)).collect()
-}
-
-/// The spec-byte encoder: walks the tokens as the reader walks the bytes.
-struct Enc<'a> {
-    toks: &'a [i64],
-    i: usize,
-    out: Vec<u8>,
-    kind: Kind,
-    line: usize,
-}
-
-impl Enc<'_> {
-    fn next(&mut self) -> Result<i64, ShxError> {
-        let v = self.toks.get(self.i).copied().ok_or_else(|| ShxError::Source(self.line, "the shape ends inside a command".into()))?;
-        self.i += 1;
-        Ok(v)
-    }
-    fn byte(&mut self) -> Result<(), ShxError> {
-        let v = self.next()?;
-        let b = u8::try_from(v).map_err(|_| ShxError::Source(self.line, format!("{v} is not a byte")))?;
-        self.out.push(b);
-        Ok(())
-    }
-    /// Two's complement −128..127.
-    fn signed(&mut self) -> Result<i64, ShxError> {
-        let v = self.next()?;
-        let b = i8::try_from(v).map_err(|_| ShxError::Source(self.line, format!("{v} is not −128..127")))?;
-        self.out.extend(b.to_le_bytes());
-        Ok(v)
-    }
-    /// Sign in the high bit (an arc's direction byte).
-    fn sign_magnitude(&mut self) -> Result<(), ShxError> {
-        let v = self.next()?;
-        let m = u8::try_from(v.unsigned_abs())
-            .ok()
-            .filter(|m| *m < 0x80)
-            .ok_or_else(|| ShxError::Source(self.line, format!("{v} is not an octant byte")))?;
-        self.out.push(if v < 0 { m | 0x80 } else { m });
-        Ok(())
-    }
-    fn word(&mut self) -> Result<(), ShxError> {
-        let v = self.next()?;
-        let w = u16::try_from(v).map_err(|_| ShxError::Source(self.line, format!("{v} is not a shape number")))?;
-        self.out.extend(w.to_be_bytes());
-        Ok(())
-    }
-
-    fn program(mut self) -> Result<Vec<u8>, ShxError> {
-        while self.i < self.toks.len() {
-            let code = self.next()?;
-            let c = u8::try_from(code).map_err(|_| ShxError::Source(self.line, format!("{code} is not a code")))?;
-            self.out.push(c);
-            match c {
-                0 => break,
-                3 | 4 => self.byte()?,
-                7 => match self.kind {
-                    Kind::Uni => self.word()?,
-                    Kind::Big => {
-                        let first = self.toks.get(self.i).copied().unwrap_or(0);
-                        if first == 0 {
-                            self.byte()?;
-                            self.word()?;
-                            for _ in 0..4 {
-                                self.byte()?;
-                            }
-                        } else {
-                            self.byte()?;
-                        }
-                    }
-                    Kind::Shapes => self.byte()?,
-                },
-                8 => {
-                    self.signed()?;
-                    self.signed()?;
-                }
-                9 => loop {
-                    let (x, y) = (self.signed()?, self.signed()?);
-                    if x == 0 && y == 0 {
-                        break;
-                    }
-                },
-                10 => {
-                    self.byte()?;
-                    self.sign_magnitude()?;
-                }
-                11 => {
-                    for _ in 0..4 {
-                        self.byte()?;
-                    }
-                    self.sign_magnitude()?;
-                }
-                12 => {
-                    for _ in 0..3 {
-                        self.signed()?;
-                    }
-                }
-                13 => loop {
-                    let (x, y) = (self.signed()?, self.signed()?);
-                    if x == 0 && y == 0 {
-                        break;
-                    }
-                    self.signed()?;
-                },
-                _ => {}
-            }
-        }
-        if self.out.last() != Some(&0) {
-            self.out.push(0);
-        }
-        Ok(self.out)
-    }
-}
-
-/// Compile shape source into an SHX file (a shape file or text font, a big font, or a Unicode
-/// font, as its first definition says).
-pub fn compile(source: &str) -> Result<Vec<u8>, ShxError> {
-    if source.len() > MAX_SOURCE {
-        return Err(ShxError::TooLarge);
-    }
-    let mut kind = Kind::Shapes;
-    let mut ranges: Vec<(u16, u16)> = Vec::new();
-    let mut uni_info: Option<(String, Vec<u8>)> = None;
-    // Definitions: header (number, name, line) and the numbers that follow it.
-    let mut defs: Vec<(i64, String, usize, Vec<i64>)> = Vec::new();
-    let mut uni_header_pending = false;
-    for (no, raw) in source.lines().enumerate() {
-        let line = no + 1;
-        let text = raw.split(';').next().unwrap_or_default().trim();
-        if text.is_empty() {
-            continue;
-        }
-        if let Some(head) = text.strip_prefix('*') {
-            let upper = head.trim_start().to_ascii_uppercase();
-            if let Some(rest) = upper.strip_prefix("BIGFONT") {
-                kind = Kind::Big;
-                let v = numbers(rest, line)?;
-                let n = usize::try_from(v.get(1).copied().unwrap_or(0)).unwrap_or(0);
-                for k in 0..n {
-                    let lo = v.get(2 + 2 * k).copied().unwrap_or(0);
-                    let hi = v.get(3 + 2 * k).copied().unwrap_or(lo);
-                    let to = |x: i64| u16::try_from(x).map_err(|_| ShxError::Source(line, "bad escape range".into()));
-                    ranges.push((to(lo)?, to(hi)?));
-                }
-                continue;
-            }
-            if upper.starts_with("UNIFONT") {
-                kind = Kind::Uni;
-                let name = head.splitn(3, ',').nth(2).unwrap_or_default().trim().to_string();
-                uni_info = Some((name, Vec::new()));
-                uni_header_pending = true;
-                continue;
-            }
-            uni_header_pending = false;
-            let mut parts = head.splitn(3, ',');
-            let num = number(parts.next().unwrap_or_default().trim(), line)?;
-            let _defbytes = parts.next();
-            let name = parts.next().unwrap_or_default().trim().to_string();
-            defs.push((num, name, line, Vec::new()));
-            continue;
-        }
-        let v = numbers(text, line)?;
-        if uni_header_pending {
-            if let Some((_, info)) = uni_info.as_mut() {
-                for x in v {
-                    info.push(u8::try_from(x).map_err(|_| ShxError::Source(line, "bad font record".into()))?);
-                }
-            }
-            continue;
-        }
-        match defs.last_mut() {
-            Some(d) => d.3.extend(v),
-            None => return Err(ShxError::Source(line, "specification bytes before any *number,defbytes,NAME line".into())),
-        }
-    }
-    let mut shapes: Vec<Shape> = Vec::new();
-    for (num, name, line, toks) in defs {
-        let number = u16::try_from(num).map_err(|_| ShxError::Source(line, format!("shape number {num} out of range")))?;
-        let program = if number == 0 {
-            // The font record: plain bytes.
-            toks.iter().map(|x| u8::try_from(*x).map_err(|_| ShxError::Source(line, "bad font record".into()))).collect::<Result<Vec<u8>, _>>()?
-        } else {
-            Enc { toks: &toks, i: 0, out: Vec::new(), kind, line }.program()?
-        };
-        if shapes.iter().any(|s| s.number == number) {
-            return Err(ShxError::Source(line, format!("shape {number} is defined twice")));
-        }
-        shapes.push(Shape { number, name, program });
-    }
-    if shapes.is_empty() {
-        return Err(ShxError::Empty);
-    }
-    shapes.sort_by_key(|s| s.number);
-    let record = |s: &Shape| -> Result<Vec<u8>, ShxError> {
-        let mut r: Vec<u8> = s.name.bytes().filter(|b| *b != 0).collect();
-        r.push(0);
-        r.extend(&s.program);
-        if r.len() > usize::from(u16::MAX) { Err(ShxError::TooLarge) } else { Ok(r) }
-    };
-    let count = u16::try_from(shapes.len()).map_err(|_| ShxError::TooLarge)?;
-    let len16 = |r: &[u8]| u16::try_from(r.len()).unwrap_or(u16::MAX);
-    let mut out = Vec::new();
-    match kind {
-        Kind::Shapes => {
-            out.extend(SHAPES_10);
-            out.extend(shapes.first().map_or(0, |s| s.number).to_le_bytes());
-            out.extend(shapes.last().map_or(0, |s| s.number).to_le_bytes());
-            out.extend(count.to_le_bytes());
-            let recs: Vec<Vec<u8>> = shapes.iter().map(record).collect::<Result<_, _>>()?;
-            for (s, r) in shapes.iter().zip(&recs) {
-                out.extend(s.number.to_le_bytes());
-                out.extend(len16(r).to_le_bytes());
-            }
-            for r in &recs {
-                out.extend(r);
-            }
-            out.extend(b"EOF");
-        }
-        Kind::Big => {
-            out.extend(BIGFONT);
-            let nranges = u16::try_from(ranges.len()).map_err(|_| ShxError::TooLarge)?;
-            out.extend(count.to_le_bytes());
-            out.extend(count.to_le_bytes());
-            out.extend(nranges.to_le_bytes());
-            for (lo, hi) in &ranges {
-                out.extend(lo.to_le_bytes());
-                out.extend(hi.to_le_bytes());
-            }
-            let recs: Vec<Vec<u8>> = shapes.iter().map(record).collect::<Result<_, _>>()?;
-            let mut off = out.len() + 8 * recs.len();
-            for (s, r) in shapes.iter().zip(&recs) {
-                out.extend(s.number.to_le_bytes());
-                out.extend(len16(r).to_le_bytes());
-                out.extend(u32::try_from(off).map_err(|_| ShxError::TooLarge)?.to_le_bytes());
-                off += r.len();
-            }
-            for r in &recs {
-                out.extend(r);
-            }
-        }
-        Kind::Uni => {
-            out.extend(UNIFONT);
-            let (name, info) = uni_info.unwrap_or_default();
-            out.extend((u32::from(count) + 1).to_le_bytes());
-            let mut rec: Vec<u8> = name.bytes().filter(|b| *b != 0).collect();
-            rec.push(0);
-            rec.extend(&info);
-            out.extend(len16(&rec).to_le_bytes());
-            out.extend(&rec);
-            for s in &shapes {
-                let r = record(s)?;
-                out.extend(s.number.to_le_bytes());
-                out.extend(len16(&r).to_le_bytes());
-                out.extend(r);
-            }
-        }
-    }
-    Ok(out)
-}

crates/fonts/src/shx/mod.rs

@@ -26,7 +26,6 @@
 //!   above, below, modes, encoding, embedding, 0) and then each shape as (number, length,
 //!   record).
 
-mod compile;
 mod parse;
 mod program;
 mod table;
@@ -39,7 +38,7 @@ use std::sync::{Arc, PoisonError, RwLock};
 
 use cadcraft_geom::Vec2;
 
-pub use compile::compile;
+pub use craft_shx::{ShxError, compile};
 pub use table::{
     FontProvider, add_drawing_dir, clear_registered, drawing_dirs, find, font_map, generation, installed, register, search_path, set_font_dirs,
     set_font_map, set_provider, set_search_path,
@@ -47,35 +46,6 @@ pub use table::{
 pub use text::ShxText;
 pub(crate) use text::{shape, width};
 
-/// Why a font file can't be read or a shape source can't be compiled.
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub enum ShxError {
-    /// Not an SHX file (unknown signature).
-    NotShx,
-    /// The file ends inside its header or index.
-    Truncated,
-    /// The file is larger, or has more of something, than CADCraft reads.
-    TooLarge,
-    /// The file is well-formed but holds no shape.
-    Empty,
-    /// Shape source error: line and message.
-    Source(usize, String),
-}
-
-impl std::fmt::Display for ShxError {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            ShxError::NotShx => f.write_str("not an SHX shape or font file"),
-            ShxError::Truncated => f.write_str("the SHX file is truncated"),
-            ShxError::TooLarge => f.write_str("the SHX file is too large"),
-            ShxError::Empty => f.write_str("the SHX file has no shapes"),
-            ShxError::Source(line, msg) => write!(f, "line {line}: {msg}"),
-        }
-    }
-}
-
-impl std::error::Error for ShxError {}
-
 /// The kind of SHX file.
 #[derive(Clone, Copy, Debug, PartialEq, Eq)]
 pub enum ShxKind {