#!/usr/bin/env python3
"""Render the Prime butterfly SVG to ASCII via half-block encoding.
Usage:
uv run scripts/render-logo.py [--width 60] [--threshold 96] [--svg path]
Outputs the rendered art to stdout.
Requires `cairo` on the system (brew install cairo). Uses cairosvg + pillow,
both pulled via uv's --with on each invocation so there's no committed venv.
"""
# /// script
# requires-python = ">=3.10"
# dependencies = ["cairosvg", "pillow"]
# ///
from __future__ import annotations
import argparse
import io
import os
import sys
from pathlib import Path
def render(svg_path: Path, width: int, threshold: int, style: str) -> str:
# Late imports so --help works without the deps installed.
import cairosvg
from PIL import Image
if style == "dots":
# 1 pixel = 1 character cell. Compensate for terminal cells being ~2x taller than wide
# so the rendered shape keeps the original proportions.
# Use ▪ (BLACK SMALL SQUARE) so adjacent cells read as a tightly packed dot matrix —
# mid-dot · is too small and reads as "spaced out" against the cell.
png_bytes = cairosvg.svg2png(url=str(svg_path), output_width=width * 2)
img = Image.open(io.BytesIO(png_bytes)).convert("RGBA")
bg = Image.new("RGBA", img.size, (0, 0, 0, 255))
bg.paste(img, (0, 0), img)
img = bg.convert("L")
target_h = max(1, img.size[1] // 4)
img = img.resize((width, target_h), Image.LANCZOS)
px = img.load()
rows: list[str] = []
for y in range(target_h):
row = "".join("▪" if px[x, y] > threshold else " " for x in range(width))
rows.append(row.rstrip())
else:
png_bytes = cairosvg.svg2png(url=str(svg_path), output_width=width)
img = Image.open(io.BytesIO(png_bytes)).convert("RGBA")
bg = Image.new("RGBA", img.size, (0, 0, 0, 255))
bg.paste(img, (0, 0), img)
img = bg.convert("L")
w, h = img.size
if h % 2:
padded = Image.new("L", (w, h + 1), 0)
padded.paste(img, (0, 0))
img = padded
h += 1
px = img.load()
table = {(False, False): " ", (True, False): "▀", (False, True): "▄", (True, True): "█"}
rows = []
for y in range(0, h, 2):
rows.append(
"".join(
table[(px[x, y] > threshold, px[x, y + 1] > threshold)] for x in range(w)
).rstrip()
)
while rows and not rows[0].strip():
rows.pop(0)
while rows and not rows[-1].strip():
rows.pop()
if rows:
left = min(len(r) - len(r.lstrip(" ")) for r in rows if r.strip())
rows = [r[left:] for r in rows]
return "\n".join(rows)
def main() -> int:
repo_root = Path(__file__).resolve().parent.parent
default_svg = repo_root / "assets" / "brand" / "prime-butterfly.svg"
parser = argparse.ArgumentParser(description=__doc__)
parser.add_argument("--width", type=int, default=60, help="output columns (default: 60)")
parser.add_argument(
"--threshold",
type=int,
default=96,
help="luminance cutoff 0-255; raise for thinner strokes (default: 96)",
)
parser.add_argument(
"--svg", type=Path, default=default_svg, help=f"input SVG (default: {default_svg})"
)
parser.add_argument(
"--style",
choices=("blocks", "dots"),
default="blocks",
help="blocks = half-block ▀▄█; dots = mid-dot · matrix (default: blocks)",
)
args = parser.parse_args()
if not args.svg.exists():
print(f"svg not found: {args.svg}", file=sys.stderr)
return 1
# Set DYLD_FALLBACK_LIBRARY_PATH for homebrew cairo on Apple Silicon.
if sys.platform == "darwin" and "DYLD_FALLBACK_LIBRARY_PATH" not in os.environ:
os.environ["DYLD_FALLBACK_LIBRARY_PATH"] = "/opt/homebrew/lib:/usr/local/lib"
print(render(args.svg, args.width, args.threshold, args.style))
return 0
if __name__ == "__main__":
raise SystemExit(main())