Generate Puzzle

Generate jigsaw puzzles using the jigsawR package's unified API.

When to Use

• Creating puzzle SVG files for a specific type and configuration
• Testing puzzle generation with different parameters
• Generating sample output for documentation or demos
• Creating ggplot2 puzzle visualizations with geom_puzzle_*()

Inputs

• Required: Puzzle type ("rectangular", "hexagonal", "concentric", "voronoi", "random", "snic")
• Required: Grid dimensions (type-dependent: c(cols, rows) or c(rings))
• Optional: Size in mm (default varies by type)
• Optional: Seed for reproducibility (default: 42)
• Optional: Offset (0 = interlocked, >0 = separated pieces)
• Optional: Layout ("grid" or "repel" for rectangular)
• Optional: Fusion groups (PILES notation string)

Procedure

Step 1: Read Config Constraints

R_EXE="/mnt/c/Program Files/R/R-4.5.0/bin/Rscript.exe"
"$R_EXE" -e "cat(yaml::yaml.load_file('inst/config.yml')[['{TYPE}']]$grid$max)"

Or read inst/config.yml directly to check valid ranges for the chosen type.

Got: The min/max values for grid, size, tabsize, and other parameters are known for the chosen puzzle type.

If fail: If config.yml is missing or the type key doesn't exist, check that you are in the jigsawR project root and the package has been built at least once.

Step 2: Determine Type and Parameters

Map the user's request to valid generate_puzzle() arguments:

Got: User request mapped to valid generate_puzzle() arguments with correct type, grid dimensions, and size values within the ranges from config.yml.

If fail: If unsure which parameter format to use, refer to the table above. Rectangular and voronoi types use c(cols, rows) for grid; hexagonal and concentric use c(rings).

Step 3: Create R Script

Write a script file (preferred over -e for complex commands):

library(jigsawR)

result <- generate_puzzle(
  type = "rectangular",
  seed = 42,
  grid = c(3, 4),
  size = c(400, 300),
  offset = 0,
  layout = "grid"
)

cat("Pieces:", length(result$pieces), "\n")
cat("SVG length:", nchar(result$svg_content), "\n")
cat("Files:", paste(result$files, collapse = ", "), "\n")

Save to a temporary script file.

Got: An R script file saved to a temporary location containing library(jigsawR), a generate_puzzle() call with all parameters, and diagnostic output lines.

If fail: If the script has syntax errors, verify that all string arguments are quoted and numeric vectors use c(). Avoid complex shell escaping by always using script files.

Step 4: Execute via WSL R

R_EXE="/mnt/c/Program Files/R/R-4.5.0/bin/Rscript.exe"
"$R_EXE" /path/to/script.R

Got: Script completes without errors. SVG file(s) written to output/.

If fail: Check that renv is restored (renv::restore()). Verify package is loaded (devtools::load_all()). Do NOT use --vanilla flag (renv needs .Rprofile).

Step 5: Verify Output

• SVG file exists in output/ directory
• SVG content starts with <?xml or <svg
• Piece count matches expected: cols * rows (rectangular), ring formula (hex/concentric)
• For ggplot2 approach, verify the plot object renders without error

Got: SVG file exists in output/, content starts with <?xml or <svg, and piece count matches the grid specification (cols * rows for rectangular, ring formula for hex/concentric).

If fail: If SVG file is missing, check the output/ directory exists. If piece count is wrong, verify grid dimensions match the puzzle type's expected formula. For ggplot2 output, check that the plot renders without error by wrapping in tryCatch().

Step 6: Save Output

Generated files are saved to output/ by default. The result object contains:

• $svg_content — raw SVG string
• $pieces — list of piece data
• $canvas_size — dimensions
• $files — paths to written files

Got: The result object contains $svg_content, $pieces, $canvas_size, and $files fields. Files listed in $files exist on disk.

If fail: If $files is empty, the puzzle may have generated in-memory only. Explicitly save with writeLines(result$svg_content, "output/puzzle.svg").

Validation

• Script executes without errors
• SVG file is well-formed XML
• Piece count matches grid specification
• Same seed produces identical output (reproducibility)
• Parameters are within config.yml constraints

Pitfalls

• Using --vanilla flag: Breaks renv activation. Never use it.
• Complex -e commands: Use script files instead; shell escaping causes Exit code 5.
• Grid vs size confusion: Grid is piece count, size is physical dimensions in mm.
• Offset semantics: 0 = assembled puzzle, positive = exploded/separated pieces.
• SNIC without package: snic type requires the snic package installed.

Related Skills

• add-puzzle-type — scaffold a new puzzle type end-to-end
• validate-piles-notation — validate fusion group strings before passing to generate_puzzle()
• run-puzzle-tests — run the test suite after generation changes
• write-testthat-tests — add tests for new generation scenarios