# E440-Scale

SVG scale artwork and web generator for E440-style round-dial analog panel
meters. Scales are typeset in **Alte DIN 1451 Mittelschrift**.

## Repository layout

```
E440-Scale_template.svg   Inkscape working file (case body, tick marks, labels)
E440-Scale_paths.svg      Paths-only export — text converted to outlines
E440-Scale_text.svg       Live-text export — embedded font, editable labels
fonts/                     TTF fonts (required for Docker build)
web/                       Flask web generator
k8s/                       Kubernetes manifests
Dockerfile                 Container build
```

## SVG files

The canvas is **93.824249 × 57.215687 mm**. The coordinate origin is
offset: layer 1 carries `transform="translate(-60.717741,-107.14126)"`, so
absolute SVG coordinates begin around x=61, y=107.

The dial's case geometry — body outline, mounting ears, pivot point
(local `107.42845, 162.62819`), rim radius (`43.842751` mm), and angular
sweep (`±45.667°` from vertical) — is fixed across every generated scale.
Only the tick marks, numeric labels, unit label, and corner text vary.

| File | Purpose |
|---|---|
| `E440-Scale_template.svg` | Master Inkscape file. Edit this one. |
| `E440-Scale_paths.svg` | All text converted to outlines. Use for cutting plotters, laser engravers, or any workflow where fonts must not be embedded as live text. |
| `E440-Scale_text.svg` | Live `<text>` nodes with the font embedded as base64. Smaller file; requires an SVG viewer that supports embedded fonts. |

Open files in **Inkscape** (developed with v1.4.3). There is no build step
— edit the SVG directly or use the web generator.

## Web generator

A Flask app that generates arc-dial scale SVGs from a form. Supports two
output modes switchable in the UI:

- **Paths** — glyphs rendered as outlines via fontTools; opens cleanly in
  Inkscape, Illustrator, and cutting software
- **Text** — live `<text>` elements with the selected font embedded as
  base64

### Run locally

```bash
source .venv/bin/activate
cd web && python app.py      # http://localhost:5000
```

Fonts are loaded at startup from the `fonts/` directory in the repo root.

### Form parameters

| Field | Description |
|---|---|
| Unit | Symbol shown centered above the arc (e.g. `uA`, `V`, `%`). Supports inline markup — see below |
| Left label / Right label | Up to 2 lines each, placed in the bottom-left/bottom-right corners of the dial |
| Mapping | **Linear**, **√** (square root), **Log**, or **1/x** (reciprocal). Major ticks are always evenly spaced angularly; the mapping controls their values and how minor ticks are placed within each interval. |
| Min / Max | Numeric range of the scale |
| Major intervals | Number of major tick intervals |
| Minor per interval | Minor ticks between each pair of major ticks. When odd, the exact midpoint subdivision is drawn as a taller "medium" tick, matching the reference dial's 3-tier tick scheme |
| Labels | Number of numeric labels; Labels − 1 should divide evenly into Major intervals |
| Custom labels | Optional comma-separated labels that override the calculated numbers |
| Label size (mm) | Font size of the numeric labels, in millimetres (default `5.1126`) |

### Scale mappings

| Mapping | Major tick values | Minor tick placement | Constraints |
|---|---|---|---|
| Linear | Evenly spaced | Uniform | None |
| √ | Quadratic (0, 1, 4, 9 … × max) — compresses low values | Crowded toward the high end of each interval | Min ≥ 0 |
| Log | Geometric (min × r⁰, r¹, r² …) — each interval spans the same ratio | Crowded toward the high end of each interval | Min and Max > 0 |
| 1/x | Harmonic (values decrease left → right, e.g. ∞, 10, 5, 2, 1) — compresses high values | Uniform (in angle space, i.e. proportional to 1/v) | Min and Max > 0; Max may be ∞ |

### Unit markup

The Unit field accepts a lightweight shorthand (no LaTeX engine — everything
is drawn as glyph paths and auto-sized to fit above the arc):

| Markup | Result |
|---|---|
| `cm^2` | superscript (`^{...}` for multiple characters) |
| `H_2O` | subscript (`_{...}` for multiple characters) |
| `{1/2}` | stacked fraction with a horizontal rule; a bare `/` stays inline |

Constructs nest: `{m/s^2}` is a fraction with a superscript in the
denominator, `x^{1/2}` a superscripted fraction.

## Container

```bash
docker build -t e440-scale:latest .
docker run -p 5000:5000 e440-scale:latest
```

Fonts are loaded from `fonts/` in the repo root; they are bundled into the
image at build time.

The production image is at `git.baumann.gr/adebaumann/e440-generator`.

## Kubernetes

Manifests in `k8s/` deploy to the `works` namespace with a Traefik v2
IngressRoute at `works.baumann.gr/E440-generator`.

```bash
# Managed by ArgoCD — push to git to deploy
git push
```

Resources: namespace, deployment (1 replica, gunicorn), ClusterIP service,
Traefik IngressRoute + stripPrefix middleware.

## License

GPL-3.0 — see [LICENSE](LICENSE).