Generate Hydra Fastfetch emblem and verify packaged ASCII art

dev/render-logo.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python3
+"""Convert the generated Hydra silhouette to Fastfetch ASCII using Pillow.
+
+Run from the repository root with Python + Pillow (development only):
+    python3 dev/render-logo.py
+"""
+
+import argparse
+from pathlib import Path
+
+from PIL import Image
+
+
+ROOT = Path(__file__).resolve().parents[1]
+RAMP = ' .:-=+*#%@'  # '$' is reserved for Fastfetch color placeholders.
+CAPTION = 'H Y D R A  O S'
+
+
+def render(source, columns):
+    # This is a single-color mark: opacity, not luminance, defines its shape.
+    # Threshold near-transparent generation noise before reducing the image.
+    with Image.open(source) as image:
+        mask = image.convert('RGBA').getchannel('A').point(
+            lambda value: 255 if value > 160 else 0)
+    bounds = mask.getbbox()
+    if bounds is None:
+        raise ValueError('The source image has no visible silhouette')
+    mask = mask.crop(bounds)
+    # A terminal character is approximately twice as tall as it is wide.
+    rows = max(1, round(mask.height / mask.width * columns * 0.5))
+    pixels = mask.resize((columns, rows), Image.Resampling.LANCZOS)
+    lines = []
+    for y in range(rows):
+        line = ''
+        for x in range(columns):
+            coverage = pixels.getpixel((x, y)) / 255
+            level = min(9, max(0, round((coverage - 0.09) / 0.82 * 9)))
+            line += RAMP[level]
+        lines.append(line.rstrip())
+    return '$1' + '\n'.join(lines) + '\n\n$2' + CAPTION.center(columns).rstrip() + '\n'
+
+
+def main():
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--source', type=Path,
+                        default=ROOT / 'assets/branding/hydra-mark.png')
+    parser.add_argument('--output', type=Path,
+                        default=ROOT / 'image/rootfs/usr/share/hydra/fastfetch.txt')
+    parser.add_argument('--columns', type=int, default=44)
+    args = parser.parse_args()
+    if not len(CAPTION) <= args.columns <= 100:
+        parser.error('columns must be between 13 and 100')
+    args.output.write_text(render(args.source, args.columns), encoding='ascii')
+    print(args.output)
+
+
+if __name__ == '__main__':
+    main()