This project is part of the @thi.ng/umbrella monorepo.
2D grid and shape iterators w/ multiple orderings.
Provides the altogether 25 following orderings to generate grid coordinates, including iterators for shape rasterization, drawing, clipping, filling, processing in general:
Also see the filtered version
columnEnds2d(),
which only includes the end points of each column.
Also see the filtered version
diagonalEnds2d(),
which only includes the end points of the diagonals.
Supports custom strides... example uses step = 4
Supports custom strides... example uses step = 4
Supports custom PRNG implementations via IRandom interface defined in
@thi.ng/random
Also see the filtered version
rowEnds2d(),
which only includes the end points of each row.
Some functions have been ported from Christopher Kulla's Java-based Sunflow renderer.
For more basic 2D/3D grid iteration, also see range2d() & range3d()
in
@thi.ng/transducers.
The floodFill() iterator can be used to iterate arbitrary 2D grids using an
user-provided predicate function. The function recursively explores (in a
row-major manner) the space in the [0,0]..(width,height) interval, starting at
given x,y and continues as long given predicate function returns a truthy
value. Any eligible 90-degree connected regions will be found and iterated
recursively. The predicate function is used to select eligible grid cells
(e.g. "pixels" of sorts).
// source "image"
const img = [
"█", " ", " ", " ", "█",
"█", " ", "█", " ", " ",
" ", " ", "█", " ", "█",
" ", "█", "█", " ", " ",
" ", " ", " ", "█", "█",
];
// flood fill iterator from point (1,0)
// only accept " " as source pixel value
// image size is 5x5
const region = floodFill((x, y) => img[x + y * 5] === " ", 1, 0, 5, 5);
// label filled pixels using increasing ASCII values
let ascii = 65; // "A"
for(let [x,y] of region) img[x + y * 5] = String.fromCharCode(ascii++);
// result image showing fill order
img
// [
// "█", "A", "B", "C", "█",
// "█", "I", "█", "D", "E",
// "K", "J", "█", "F", "█",
// "L", "█", "█", "G", "H",
// "M", "N", "O", "█", "█"
// ]Additionally, the following shape iterators are available, all also with optional clipping:
STABLE - used in production
Search or submit any issues for this package
- @thi.ng/morton - Z-order curve / Morton encoding, decoding & range extraction for arbitrary dimensions
- @thi.ng/rasterize - 2D shape drawing & rasterization
- @thi.ng/transducers - Lightweight transducer implementations for ES6 / TypeScript
yarn add @thi.ng/grid-iteratorsES module import:
<script type="module" src="https://cdn.skypack.dev/@thi.ng/grid-iterators"></script>For Node.js REPL:
# with flag only for < v16
node --experimental-repl-await
> const gridIterators = await import("@thi.ng/grid-iterators");
Package sizes (gzipped, pre-treeshake): ESM: 2.22 KB
- @thi.ng/api
- @thi.ng/arrays
- @thi.ng/binary
- @thi.ng/bitfield
- @thi.ng/morton
- @thi.ng/random
- @thi.ng/transducers
Several demos in this repo's /examples directory are using this package.
A selection:
| Screenshot | Description | Live demo | Source |
|---|---|---|---|
 |
Visualization of different grid iterator strategies | Demo | Source |
import * as gi from "@thi.ng/grid-iterators";
[...gi.zigzagRows2d(4, 4)]
// [
// [ 0, 0 ], [ 1, 0 ], [ 2, 0 ], [ 3, 0 ],
// [ 3, 1 ], [ 2, 1 ], [ 1, 1 ], [ 0, 1 ],
// [ 0, 2 ], [ 1, 2 ], [ 2, 2 ], [ 3, 2 ],
// [ 3, 3 ], [ 2, 3 ], [ 1, 3 ], [ 0, 3 ]
// ]Karsten Schmidt
If this project contributes to an academic publication, please cite it as:
@misc{thing-grid-iterators,
title = "@thi.ng/grid-iterators",
author = "Karsten Schmidt",
note = "https://thi.ng/grid-iterators",
year = 2019
}© 2019 - 2021 Karsten Schmidt // Apache Software License 2.0