1 files changed, 72 insertions, 3 deletions
diff --git a/README.md b/README.md
index bf42e08..364a339 100644
--- a/README.md
+++ b/README.md
@@ -3,14 +3,83 @@
 Pan/zoom library for SVG elements. Hold and drag to pan. Use the mouse wheel to
 zoom. See `src/app.js` for a usage example.
 
-## View demo
+## Usage
+
+### Requirements
+
+All the content to be panned/zoomed must be in one root element.
+
+`image.svg`
+
+``` xml
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<svg viewBox="..." version="1.1" xmlns="http://www.w3.org/2000/svg">
+    <g id="main">
+        <!-- SVG elements to be panned/zoomed... -->
+    </g>
+</svg>
+```
+
+`index.html`
+
+``` html
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta charset="utf-8"/>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0"/>
+  </head>
+  <body>
+    <object type="image/svg+xml" data="image.svg"></object>
+    <script src="index.js"></script>
+  </body>
+</html>
+```
+
+### Standard
+
+`index.js`
+
+``` js
+import { pan, zoom } from 'pan-zoom';
+
+const optionalZoomFactor = 0.1,
+  object = document.querySelector('object');
+
+window.addEventListener('load', function () {
+  const svg = object.contentDocument.querySelector('svg'),
+    targetEl = svg.querySelector('#main');
+
+  svg.addEventListener('wheel', zoom(targetEl, optionalZoomFactor), { passive: false });
+  svg.addEventListener('pointerdown', pan(targetEl), { passive: false });
+});
+```
+
+### With restore
+
+The same as standard except the pan/zoom returns to what it was after a page
+refresh.
+
+`index.js`
+
+``` js
+import { withRestore as panzoom } from 'pan-zoom';
+const object = document.querySelector('object');
+
+window.addEventListener('load', function () {
+  const svg = object.contentDocument.querySelector('svg');
+  panzoom.start(svg, '#main');
+});
+```
+
+## Start the demo
 
 1. Install the development server packages.
 
-        docker run --rm -w /app -v $PWD:/app -u $(id -u):$(id -u) node npm install
+        $ docker run --rm -w /app -v $PWD:/app -u $(id -u):$(id -u) node npm install
 
 2. Start the server.
 
-        docker run --rm --init -it -w /app -v $PWD:/app -p 8080:8080 node node dev-server.js
+        $ docker run --rm --init -it -w /app -v $PWD:/app -p 8080:8080 node node dev-server.js
 
 3. Visit `localhost:8080` to view.