58 lines
1.5 KiB
Markdown
58 lines
1.5 KiB
Markdown
# hachure-fill
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[Demo](https://hachure-fill.pages.dev/)
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This package calculates the hachure lined to fill a polygon. The **angle** of the lines and the **gap** between lines can be configured.
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The algorithm works on convex, concave, simple, complex polygons, and polygons with holes.
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## Install
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From npm
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```
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npm install --save hachure-fill
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```
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The package is distributed as an ES6 module.
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## Usage
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### hachureFill(points: Point[], angle: number, gap: number): Line[];
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The function takes in a polygon, which is represented as an array of points (each point being a an array of 2 numbers `[x, y]`).
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The **angle** sets the angle of the hachure lines in degrees.
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The **gap** arguments sets the distance between each hachure line.
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The function returns an array of lines. Each line is an array of two points.
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```javascript
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import { hachureFill } from 'hachure-fill';
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// Polygon vertices
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const vertices = [
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[10, 10],
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[200, 10],
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[100, 100],
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[300, 100],
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[60, 200]
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];
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// Lines filling the polygon
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// at an angle of 45 degrees.
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// Lines are 10px apart.
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const lines = hachureFill(vertices, 45, 10);
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// Draw lines...
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```
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### hachureFill(points: Point[][], angle: number, gap: number): Line[];
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When dealing with Polygon with holes, you can provide an array of polygons. The outer polygon, and polygones represented each of the holes.
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The polygons need not be nested, but if they are, even-odd rules apply to fill the shape.
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