diff --git a/site/public/documentation/core.md b/site/public/documentation/core.md index 1f31f3d..405e716 100644 --- a/site/public/documentation/core.md +++ b/site/public/documentation/core.md @@ -21,6 +21,8 @@ Once you've [downloaded Planetary.js](https://github.com/BinaryMuse/planetary.js ``` +If you use the default `topojson` plugin (most people will), you'll also need to make sure `world-110m.json` (or some other TopoJSON data file) is available on your server. This file is also available from [the download page](https://github.com/BinaryMuse/planetary.js/releases). See the [TopoJSON Plugin](/documentation/builtin_topojson.html) documentation for more information. + Core API -------- diff --git a/site/public/documentation/index.md b/site/public/documentation/index.md index 40c2363..09d6191 100644 --- a/site/public/documentation/index.md +++ b/site/public/documentation/index.md @@ -9,3 +9,43 @@ The documentation is split up into several sections: * [Planet API](/documentation/planet.html) describes the API associated with a planet instance, including modifying its properties and accessing a special canvas context that allows you to draw on the globe. * [Plugins](/documentation/plugins.html) describes the plugin architecture of Planetary.js and shows how you can easily build your own plugins to modify the behavior of Planetary.js * [Built-In Plugins](/documentation/builtin.html) describes each of the built-in plugins in turn, including their public API and how to use them in a project. + +Quick Start +----------- + +If you want to get up-and-running quickly, or like to experiment and figure things out, you can use this HTML and JavaScript to get a quick, simple globe working quickly. + +Note that you'll need to run this page from a web server of some kind so that Planetary.js can load the TopoJSON data via Ajax (Ajax requests don't work when viewing a page directly from the filesystem). + +
+
HTML
+ +```html + + + + + + + + + + + +``` + +
JavaScript
+ +```javascript +var planet = planetaryjs.planet(); +// You can remove this statement if `world-110m.json` +// is in the same path as the HTML page: +planet.loadPlugin(planetaryjs.plugins.earth({ + topojson: { file: 'http/path/to/world-110m.json' } +})); +// Make the planet fit well in its canvas +planet.projection.scale(250).translate([250, 250]); +var canvas = document.getElementById('globe'); +planet.draw(canvas); +``` +
diff --git a/site/public/documentation/plugins.md b/site/public/documentation/plugins.md index ade7666..901bd8a 100644 --- a/site/public/documentation/plugins.md +++ b/site/public/documentation/plugins.md @@ -11,7 +11,7 @@ Plugins are loaded either globally by `planetaryjs.loadPlugin` or for a specific Anatomy of a Plugin ------------------- -A plugin is simply a JavaScript function that takes a planet instance as a parameter and performs some predefined operation. **The best plugins do one tiny thing.** If you want a plugin to do a lot of things at once, you should build a plugin that wraps other, smaller plugins; in fact, this is exactly how the `earth` plugin is built. See the [Earth](/documentation/builtin_earth.html) documentation for more details. +A plugin is simply a JavaScript function that takes a planet instance as a parameter and performs some predefined operation. **The best plugins do one tiny thing.** If you want a plugin to do a lot of things at once, you should build a plugin that wraps other, smaller plugins; in fact, this is exactly how the `earth` plugin is built. See the [Earth Plugin](/documentation/builtin_earth.html) documentation for more details. Most of the time, a plugin will implement its behavior by registering callbacks into the planet's lifecycle hooks. For example, the following simple plugin increments the planet's projection's rotation by one degree every tick (this would make for a very fast spinning globe, but demonstrates the idea nicely enough): @@ -55,3 +55,123 @@ var autorotate = function(degreesPerTick) { planet.loadPlugin(autorotate(5)); ``` + +Setting Yourself Up +------------------- + +If you need to do some work before your plugin is ready to be used, you can add a hook to a planet's `onInit` hook to do the necessary setup. + +
+
JavaScript
+ +```javascript +var somePlugin = function(planet) { + planet.onInit(function() { + doSomeSetupWork(); + }); +}; +``` +
+ +If you need to do some asynchronous setup--such as fetching data with an Ajax request--before your plugin is ready, you can accept an argument to your `onInit` function. When you're done setting up, call this function and Planetary.js will continue to initialize the planet. **If you accept the parameter but don't call it, the initialization process will stop** (and your planet will not work). + +
+
JavaScript
+ +```javascript +var somePlugin = function(planet) { + planet.onInit(function(done) { + doSomeAsynchronousSetupWork(function() { + done(); + }); + }); +}; +``` +
+ +Drawing on the Canvas +--------------------- + +Many plugins will want to draw onto the globe's canvas; you can do so by registering a function to a planet's `onDraw` hook. + +
+
JavaScript
+ +```javascript +var somePlugin = function(planet) { + planet.onDraw(function() { + planet.withSavedContext(function(context) { + context.beginPath(); + planet.path.context(context)({type: 'Sphere'}); + context.fillStyle = 'black'; + context.fill(); + }); + }); +}; +``` +
+ +The planet exposes properties and methods, such as `context`, `path`, and `withSavedContext` to assist with drawing to the canvas. The [Planet API](/documentation/planet.html) documentation goes into more detail on individual properties. + +### Drawing Geo Paths + +As explained in the `planet.path` documentation on the [Planet API](/documentation/planet.html) page, `planet.path` is a [`d3.geo.path`](https://github.com/mbostock/d3/wiki/Geo-Paths) object that can be used to draw geographical geometry onto the canvas. The path will take care of transforming the coordinates to be projected onto the orthographic view of the globe. + +As a demonstration of this technique, the following is a plugin that will take the land data from a TopoJSON data source (stored on `planet.plugins.topojson.world`), convert it to a GeoJSON feature, and draw it on the planet. This code is similar to (but slightly simplified from) how the [Land plugin](/documentation/builtin_land.html) works. + +
+
JavaScript
+ +```javascript +var drawLand = function(planet) { + planet.onDraw(function() { + planet.withSavedContext(function(context) { + var world = planet.plugins.topojson.world; + var land = topojson.feature(world, world.objects.land); + + context.beginPath(); + planet.path.context(context)(land); + context.fillStyle = 'white'; + context.fill(); + }); + }); +}; +``` +
+ +Exposing Data and Methods +------------------------- + +Obviously, you can use private internal variables to keep track of any data your plugin needs to operate. However, if you want to expose a public API to users of your plugin, you should avoid attaching them directly to the planet and instead attach them to the planet's `plugins` namespace. You should use a name specific to your plugin, and this name should be well documented in your plugin's documentation. + +
+
JavaScript
+ +```javascript +var autorotate = function(degreesPerTick) { + return function(planet) { + var paused = false; + + planet.plugins.autorotate = { + pause: function() { paused = true; }, + resume: function() { paused = false; } + }; + + planet.onDraw(function() { + if (paused) return; + + var rotation = planet.projection.rotate(); + rotation[0] += degreesPerTick; + if (rotation[0] >= 180) rotation[0] -= 360; + planet.projection.rotate(rotation); + }); + }; +}; + +planet.loadPlugin(autorotate(5)); +planet.draw(canvas); +setTimeout(function() { + planet.plugins.autorotate.pause(); +}, 5000); +``` +