A command-line tool that generates word cloud PNG images from text input. Built in Rust with a custom layout algorithm — only external crates are used for PNG generation (image/imageproc) and font rendering (ab_glyph).

Inspired by Max Woolf's description of building a Rust word cloud generator: https://minimaxir.com/2026/02/ai-agent-coding/

See walkthrough.md for a walkthrough of the Rust code, and animated-word-cloud for an animated demo.

• Reads from file or stdin — pass a filename or pipe text in
• Auto-incrementing output names — generates wordcloud.png, wordcloud-2.png, etc. to avoid overwriting
• Configurable dimensions — --width and --height flags
• Multiple color schemes — vibrant (default), warm, cool, mono, earth, neon
• Custom background color — any hex color via --background
• Tunable parameters — min/max font size, max words, minimum word length

1. Text processing: Tokenizes input, filters stop words (English common words, contractions, web/URL fragments), removes short words and numbers
2. Frequency counting: Ranks words by occurrence count
3. Font scaling: Maps word frequency to font size using logarithmic scaling for better visual distribution
4. Spiral layout: Places words along an Archimedean spiral from center outward, with random angular offsets per word
5. Collision detection: Uses a grid-based spatial index for fast overlap checking (much faster than brute-force for 200+ words)

# From a file
wordcloud input.txt

# From stdin
cat mytext.txt | wordcloud

# With options
wordcloud input.txt -o output.png --width 1600 --height 1000 --colors warm --background 000000

# Customize word selection
wordcloud input.txt --max-words 100 --min-font-size 16 --max-font-size 120 --min-word-len 4

Arguments:
  [INPUT]  Input text file (reads from stdin if not provided)

Options:
  -o, --output <OUTPUT>                Output PNG filename (auto-generates wordcloud.png, wordcloud-2.png, etc.)
      --width <WIDTH>                  Image width in pixels [default: 1200]
      --height <HEIGHT>                Image height in pixels [default: 800]
      --max-words <MAX_WORDS>          Maximum number of words to display [default: 200]
      --min-font-size <MIN_FONT_SIZE>  Minimum font size in pixels [default: 12]
      --max-font-size <MAX_FONT_SIZE>  Maximum font size in pixels [default: 90]
      --colors <COLORS>                Color scheme: vibrant, warm, cool, mono, earth, neon [default: vibrant]
      --background <BACKGROUND>        Background color as hex [default: 1a1a2e]
      --min-word-len <MIN_WORD_LEN>    Minimum word length to include [default: 3]

Generated from Simon Willison's blog content for February 2026 (simonwillison.net/dashboard/all-content-in-a-month.json?month=2026-02):

Top words from the dataset: "code" (158), "claude" (134), "showboat" (123), "github" (123), "simonwillison" (78), "rodney" (76), "coding" (66), "model" (64), "agent" (63), "sqlite" (62).

cargo build --release

Requires a system font — looks for DejaVu Sans Bold or Liberation Sans Bold.

• No word cloud crate used — the layout algorithm, word counting, stop word filtering, and spatial indexing are all implemented from scratch
• Archimedean spiral placement with per-word random angular offset for natural-looking layouts
• Grid-based spatial index (40px cells) for O(1) average-case collision checking
• Logarithmic font scaling to prevent top words from dominating the visual
• Places 190+ words in a 1200x800 canvas with the default settings