First commit.

Signed-off-by: Chen Xiao <abigwc@gmail.com>

client/node_modules/hachure-fill/README.md

@@ -0,0 +1,57 @@
+# hachure-fill
+
+[Demo](https://hachure-fill.pages.dev/)
+
+This package calculates the hachure lined to fill a polygon. The **angle** of the lines and the **gap** between lines can be configured.
+
+The algorithm works on convex, concave, simple, complex polygons, and polygons with holes. 
+
+![preview of a polygon](https://user-images.githubusercontent.com/833927/242424090-90e60c00-c87b-4033-ae63-c0f38fa5d291.png)
+
+
+## Install
+
+From npm
+
+```
+npm install --save hachure-fill
+```
+
+The package is distributed as an ES6 module. 
+
+## Usage
+
+### hachureFill(points: Point[], angle: number, gap: number): Line[];
+
+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]`). 
+
+The **angle** sets the angle of the hachure lines in degrees. 
+
+The  **gap** arguments sets the distance between each hachure line. 
+
+The function returns an array of lines. Each line is an array of two points. 
+
+```javascript
+import { hachureFill } from 'hachure-fill';
+
+// Polygon vertices
+const vertices = [
+  [10, 10],
+  [200, 10],
+  [100, 100],
+  [300, 100],
+  [60, 200]
+];
+
+// Lines filling the polygon 
+// at an angle of 45 degrees. 
+// Lines are 10px apart.
+const lines = hachureFill(vertices, 45, 10);
+
+// Draw lines...
+```
+
+### hachureFill(points: Point[][], angle: number, gap: number): Line[];
+
+When dealing with Polygon with holes, you can provide an array of polygons. The outer polygon, and polygones represented each of the holes. 
+The polygons need not be nested, but if they are, even-odd rules apply to fill the shape.