Random Geometric Hatching Patchwork Generator

Description

Partition a caller-supplied rectangular outline into grid patches and clip selected angle/spacing hatches to every patch boundary.

Procedural artwork expresses a visual idea through coordinates, repeated motifs, colors, or explicit placement constraints. A coordinate plan can be checked and reproduced before rendering, while physical material behavior and fabrication require separate information.

Partition a caller-supplied rectangular outline into grid patches and clip selected angle/spacing hatches to every patch boundary.

When to use this tool

Use this generator to create reproducible geometric hatching patchwork cases from the supplied model or bank. Inspect the returned evidence before using cases in a test or exercise.

How to use the tool and how it works

Supply outline, rows, columns, angles, spacings in the field shapes below. Set seed when you need an explicit replay.
Run the tool and correct any input error. For generated controls, distinguish a successful fixture containing an invalid case from failure to generate the fixture.
Read patches, bounds. Use the conventions below. Keep answer-bearing fields separate when presenting an exercise.

Split the supplied outline rectangle into rows and columns. For every patch, sample an angle in turns and a spacing, then clip its parallel hatch lines to that patch. Return patch rectangles and segments with overall outline bounds.^[1]

Input field	Meaning and units	Accepted input
outline	Outline	Required. Object; no unknown keys.
outline.x	X	Required. Finite number.
outline.y	Y	Required. Finite number.
outline.width	Width	Required. Finite number; strictly above 0.
outline.height	Height	Required. Finite number; strictly above 0.
rows	Rows	Required. Safe integer; minimum 1; maximum 8.
columns	Columns	Required. Safe integer; minimum 1; maximum 8.
angles	Angles	Required. Array of Finite number.; minimum items 1; maximum items 16.
spacings	Spacings	Required. Array of Finite number; strictly above 0.; minimum items 1; maximum items 16.
seed	Optional numeric seed; takes precedence over context randomness. Without either, use the fixed tool.io default seed.	Optional. Safe integer.

Output field	Interpretation	Returned shape
patches	Patches	Required. Array of Object; no unknown keys.; minimum items 1; maximum items 32.
patches[].rect	Rect	Required. Object; no unknown keys.
patches[].rect.x	X	Required. Finite number.
patches[].rect.y	Y	Required. Finite number.
patches[].rect.width	Width	Required. Finite number; strictly above 0.
patches[].rect.height	Height	Required. Finite number; strictly above 0.
patches[].angle	Angle	Required. Finite number.
patches[].spacing	Spacing	Required. Finite number; strictly above 0.
patches[].lines	Lines	Required. Array of Object; no unknown keys.; minimum items 0; maximum items 128.
patches[].lines[].from	From	Required. Array of Finite number.; minimum items 2; maximum items 2.
patches[].lines[].to	To	Required. Array of Finite number.; minimum items 2; maximum items 2.
bounds	Bounds	Required. Object; no unknown keys.
bounds.minX	Min X	Required. Finite number.
bounds.minY	Min Y	Required. Finite number.
bounds.maxX	Max X	Required. Finite number.
bounds.maxY	Max Y	Required. Finite number.
bounds.width	Width	Required. Finite number.
bounds.height	Height	Required. Finite number.
randomness	Replay source and normalized 32-bit seed, or null seed for an advancing context source.	Required. Object; no unknown keys.
randomness.seed	Optional safe-integer replay seed; normalization and precedence are explained below.	Required. Safe integer. or Null.
randomness.source	Source	Required. Text; one of "context", "seed".

An explicit safe-integer seed takes precedence over injected context randomness and is normalized to an unsigned 32-bit integer. With no seed and no context source, replay uses the fixed tool.io default seed. A context source must return finite values from zero inclusive to one exclusive; its advancing state must be retained separately. randomness records the source and normalized seed, or null for context. These generators are not cryptographic random sources.

json

{
  "input": {
    "outline": {
      "x": 0,
      "y": 0,
      "width": 4,
      "height": 2
    },
    "rows": 1,
    "columns": 2,
    "angles": [
      0
    ],
    "spacings": [
      1
    ],
    "seed": 42
  },
  "output": {
    "patches": [
      {
        "rect": {
          "x": 0,
          "y": 0,
          "width": 2,
          "height": 2
        },
        "angle": 0,
        "spacing": 1,
        "lines": [
          {
            "from": [
              0,
              0
            ],
            "to": [
              2,
              0
            ]
          },
          {
            "from": [
              0,
              1
            ],
            "to": [
              2,
              1
            ]
          },
          {
            "from": [
              0,
              2
            ],
            "to": [
              2,
              2
            ]
          }
        ]
      },
      {
        "rect": {
          "x": 2,
          "y": 0,
          "width": 2,
          "height": 2
        },
        "angle": 0,
        "spacing": 1,
        "lines": [
          {
            "from": [
              2,
              0
            ],
            "to": [
              4,
              0
            ]
          },
          {
            "from": [
              2,
              1
            ],
            "to": [
              4,
              1
            ]
          },
          {
            "from": [
              2,
              2
            ],
            "to": [
              4,
              2
            ]
          }
        ]
      }
    ],
    "bounds": {
      "minX": 0,
      "minY": 0,
      "maxX": 4,
      "maxY": 2,
      "width": 4,
      "height": 2
    },
    "randomness": {
      "seed": 42,
      "source": "seed"
    }
  }
}

Limitations and assumptions

The total candidate line count is bounded before line construction. Angles and spacings are literal drawing parameters; the tool does not optimize optical effects or check physical fabrication.
A replay requires the same complete input and implementation. The stated sampling convention applies within its eligible space. A finite draw does not exhaust all possible outputs; repeats remain possible unless a distinct-selection rule is explicit.
The field tables state structural bounds; cross-field constraints and bounded search or output budgets also apply. Unknown keys are rejected where the object contract disallows them. Input errors are distinct from null fields and deliberate invalid controls in a successful output.

Alternative or Complementary methods

For a supplied example, inspect the returned construction or delegated check directly. To evaluate a consumer, also test cases chosen for its own boundaries; a generated finite corpus does not establish exhaustive coverage.

References

Tool behavior and example: Random Geometric Hatching Patchwork Generator — tool.io

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