M1: IES LM-63 and EULUMDAT readers, symmetry expansion, emergency flux

CLAUDE.md

@@ -49,4 +49,6 @@ task id per commit (e.g. `M1.2: EULUMDAT reader`), commit only green states, ope
 ## Running
 - `cargo run -p luxpath-cli -- --help`
 - `cargo run -p luxpath-cli -- point 2.5 3` (direct illuminance demo)
+- `cargo run -p luxpath-cli -- photometry <file.ies|.ldt>` (what a photometric file says)
+- `cargo xtask fuzz [seconds]` (fuzz the photometric readers; 600 s is M1's exit criterion)
 - `cargo xtask parity` (feature progress by milestone)

Cargo.toml

@@ -24,6 +24,8 @@ serde_json = "1"
 toml = "0.9"
 # IFC (STEP) parsing; MPL-2.0, used unmodified as a dependency (AGENTS.md §1.2)
 ifc-lite-core = "20.4"
+# tests only
+proptest = { version = "1.11", default-features = false, features = ["std"] }
 
 [workspace.lints.rust]
 unsafe_code = "forbid"

README.md

@@ -24,6 +24,7 @@ GUI-only. luxpath aims to be:
 
 ```sh
 cargo run -p luxpath-cli -- point 2.5 3      # direct illuminance 3 m away from a source mounted at 2.5 m
+cargo run -p luxpath-cli -- photometry crates/photometry/tests/fixtures/downlight.ldt   # read an IES or LDT file
 cargo xtask ci                               # every quality gate
 cargo xtask parity                           # feature progress by milestone
 ```

ROADMAP.md

@@ -2,7 +2,7 @@
 
 **Stage: pre-alpha** · next: alpha (M1–M4 + M6 validation) · ~150–250 agent-assisted hours away
 
-> **Last updated:** 2026-10-16 · **Change:** project created (M0 scaffold)
+> **Last updated:** 2026-10-21 · **Change:** M1 (photometry readers) done
 
 luxpath's one-page summary. Details live in:
 
@@ -24,13 +24,14 @@ luxpath's one-page summary. Details live in:
 
 ## Next up
 
-1. **M1:** IES LM-63 and EULUMDAT readers, symmetry expansion, emergency-mode flux.
-2. **M2:** grids, sums over luminaires, tilt, vertical illuminance.
+1. **M2:** grids, sums over luminaires, tilt, vertical illuminance, photometry plausibility warnings (gap 13).
+2. **Real photometric files** from the owner's practice, kept in `plan/` (gap 12).
 3. **Open question:** buy EN 1838:2024 (around €100 from a national standards body) to verify the requirement values.
 
 ## Progress log
 
 | Date | Change |
 |---|---|
+| 2026-10-21 | M1: IES LM-63 (1986–2019) and EULUMDAT readers, symmetry expansion, tilt data, emergency flux, located errors, property tests, a 10-minute fuzz run (22.8 million inputs) without a panic; `luxpath photometry`. Existing crates evaluated first: none usable (docs/architecture.md). |
 | 2026-10-16 | M7 (early): `luxpath-ifc` and `luxpath inspect-ifc`; 9 public models inspected, findings in docs/research.md §7. |
 | 2026-10-16 | M0: workspace, layering and parity gates, C-γ intensity table, direct illuminance, demo CLI, docs. |

apps/luxpath-cli/src/main.rs

@@ -1,21 +1,23 @@
 //! `luxpath`: the command-line tool.
 //!
-//! Commands: `point` (direct illuminance under an isotropic source, a demonstration) and
-//! `inspect-ifc` (what an IFC model contains for an emergency-lighting check). `luxpath check
-//! scene.toml` is M3–M4.
+//! Commands: `point` (direct illuminance under an isotropic source, a demonstration),
+//! `photometry` (what a photometric file says, as luxpath reads it) and `inspect-ifc` (what an IFC
+//! model contains for an emergency-lighting check). `luxpath check scene.toml` is M3–M4.
 
 use std::process::ExitCode;
 
 use luxpath_calc::{Luminaire, direct_horizontal_illuminance};
 use luxpath_geom::Vec3;
-use luxpath_photometry::IntensityTable;
+use luxpath_photometry::{Format, IntensityTable, MAX_FILE_BYTES, Photometry, Symmetry};
 
 const USAGE: &str = "\
 luxpath — open emergency-lighting calculations
 
 USAGE:
     luxpath point <mounting height m> <horizontal offset m> [flux lm]
         Direct illuminance on the floor from an isotropic 1000 cd/klm source (demonstration).
+    luxpath photometry <file.ies|file.ldt>
+        What a photometric file says, as luxpath reads it: flux, symmetry, peak, light output ratio.
     luxpath inspect-ifc <model.ifc> [--json]
         What an IFC model contains for an emergency-lighting check, and what is missing.
     luxpath --version
@@ -44,6 +46,16 @@ fn main() -> ExitCode {
                 ExitCode::from(2)
             }
         },
+        Some("photometry") => match photometry(args.get(1..).unwrap_or_default()) {
+            Ok(text) => {
+                print!("{text}");
+                ExitCode::SUCCESS
+            }
+            Err(message) => {
+                eprintln!("error: {message}");
+                ExitCode::from(2)
+            }
+        },
         Some("inspect-ifc") => match inspect_ifc(args.get(1..).unwrap_or_default()) {
             Ok(text) => {
                 print!("{text}");
@@ -80,6 +92,67 @@ fn inspect_ifc(args: &[String]) -> Result<String, String> {
     }
 }
 
+fn photometry(args: &[String]) -> Result<String, String> {
+    let path = args.first().ok_or("missing the photometric file path")?;
+    let size = std::fs::metadata(path).map_err(|e| format!("{path}: {e}"))?.len();
+    if size > MAX_FILE_BYTES as u64 {
+        return Err(format!("{path}: {size} bytes is more than the {MAX_FILE_BYTES}-byte limit"));
+    }
+    let bytes = std::fs::read(path).map_err(|e| format!("{path}: {e}"))?;
+    let p = luxpath_photometry::read(&bytes).map_err(|e| format!("{path}: {e}"))?;
+    Ok(describe(&p))
+}
+
+fn describe(p: &Photometry) -> String {
+    let format = match p.format() {
+        Format::Ies(edition) => format!("IES {edition:?}").replace("Lm63_", "LM-63-"),
+        Format::Eulumdat => "EULUMDAT".to_string(),
+    };
+    let symmetry = match p.symmetry() {
+        Symmetry::None => "none (every C plane stored)",
+        Symmetry::Rotational => "rotational (one C plane)",
+        Symmetry::PlaneC0C180 => "about the C0–C180 plane",
+        Symmetry::PlaneC90C270 => "about the C90–C270 plane",
+        Symmetry::Quadrants => "quadrants (C0–C90 stored)",
+    };
+    let t = p.table();
+    let n_gamma = t.gamma_angles().len().max(1);
+    let (peak_at, peak) =
+        t.values().iter().enumerate().fold((0, 0.0), |best, (i, v)| if *v > best.1 { (i, *v) } else { best });
+    let peak_c = t.c_angles().get(peak_at / n_gamma).copied().unwrap_or(0.0);
+    let peak_gamma = t.gamma_angles().get(peak_at % n_gamma).copied().unwrap_or(0.0);
+    let gamma = |i: Option<&f64>| i.copied().unwrap_or(0.0);
+    let mut out = String::new();
+    let mut line = |label: &str, value: String| {
+        if !value.is_empty() {
+            out += &format!("{label:<18} {value}\n");
+        }
+    };
+    line("format", format);
+    line("manufacturer", p.manufacturer.clone());
+    line("luminaire", p.name.replace('\n', " "));
+    line("catalogue", p.catalogue.clone());
+    let kind = if p.is_absolute() { "luminaire flux, absolute photometry" } else { "lamp flux" };
+    line("rated flux", format!("{:.1} lm ({kind})", p.flux_lm()));
+    line("symmetry", symmetry.to_string());
+    line(
+        "table",
+        format!(
+            "{} C planes × {} γ angles (γ {}°–{}°)",
+            t.c_angles().len(),
+            t.gamma_angles().len(),
+            gamma(t.gamma_angles().first()),
+            gamma(t.gamma_angles().last())
+        ),
+    );
+    line("peak", format!("{peak:.1} cd/klm at C{peak_c}° γ{peak_gamma}°"));
+    line("light output", format!("{:.1} % of the rated flux", p.light_output_ratio() * 100.0));
+    if let Some(tilt) = p.tilt() {
+        line("tilt", format!("{} angles, lamp geometry {}", tilt.angles_deg().len(), tilt.lamp_geometry));
+    }
+    out
+}
+
 fn point(args: &[String]) -> Result<f64, String> {
     let number = |i: usize, name: &str| -> Result<Option<f64>, String> {
         args.get(i)

apps/luxpath-cli/tests/photometry.rs

@@ -0,0 +1,40 @@
+//! End to end: `luxpath photometry` on the committed synthetic fixtures and on a broken file.
+
+#![allow(clippy::unwrap_used)]
+
+use std::process::Command;
+
+fn luxpath(args: &[&str]) -> (i32, String, String) {
+    let out = Command::new(env!("CARGO_BIN_EXE_luxpath")).args(args).output().unwrap();
+    (
+        out.status.code().unwrap_or(-1),
+        String::from_utf8_lossy(&out.stdout).into(),
+        String::from_utf8_lossy(&out.stderr).into(),
+    )
+}
+
+const FIXTURES: &str = concat!(env!("CARGO_MANIFEST_DIR"), "/../../crates/photometry/tests/fixtures");
+
+#[test]
+fn describes_ies_and_eulumdat_files_alike() {
+    for (file, format) in [("downlight.ies", "IES LM-63-2002"), ("downlight.ldt", "EULUMDAT")] {
+        let (code, out, err) = luxpath(&["photometry", &format!("{FIXTURES}/{file}")]);
+        assert_eq!(code, 0, "{err}");
+        assert!(out.contains(format), "{out}");
+        assert!(out.contains("1000.0 lm (lamp flux)"), "{out}");
+        assert!(out.contains("rotational"), "{out}");
+        assert!(out.contains("300.0 cd/klm at C0° γ0°"), "{out}");
+    }
+}
+
+#[test]
+fn a_broken_file_is_an_error_with_its_line() {
+    let dir = std::env::temp_dir().join(format!("luxpath-cli-{}", std::process::id()));
+    std::fs::create_dir_all(&dir).unwrap();
+    let path = dir.join("broken.ies");
+    std::fs::write(&path, "IESNA:LM-63-2002\nTILT=NONE\n1 1000 1 2 1 1 2 0 0 0\n1 1 0\n0 90\n0\n100\n").unwrap();
+    let (code, _, err) = luxpath(&["photometry", path.to_str().unwrap()]);
+    assert_eq!(code, 2);
+    assert!(err.contains("line 7: the file ends before the candela values"), "{err}");
+    std::fs::remove_dir_all(&dir).ok();
+}

crates/photometry/Cargo.toml

@@ -10,5 +10,8 @@ repository.workspace = true
 [dependencies]
 luxpath-geom.workspace = true
 
+[dev-dependencies]
+proptest.workspace = true
+
 [lints]
 workspace = true