Add a bunch of API documentation

Minor changes to ordering of default arguments

Readme.md

@@ -11,11 +11,45 @@ It was inspired by [btmills/geopattern](https://github.com/btmills/geopattern) a
 
 v0.2.0 represents a ground-up rewrite of the original, eliminating the dependency on d3.js and adding the ability to render to PNG or canvas. **v0.1.x users should note that the API has changed and v0.2.0 is not backwards-compatible**.
 
-# Getting Started
+# Getting Trianglify
+
+You can grab Trianglify with your preferred package manager:
+
+```
+npm install trianglify
+bower install trianglify
+```
+
+Include it in your HTML via CDNJS:
+
+```html
+<script src="https://cdnjs.cloudflare.com/ajax/libs/trianglify/0.2.0/trianglify.min.js"></script>
+```
+
+Or clone the repo:
+
+```
+git clone https://github.com/qrohlf/trianglify.git
+```
+
+
+# Quickstart
+
+```html
+<script src="https://cdnjs.cloudflare.com/ajax/libs/trianglify/0.2.0/trianglify.min.js"></script>
+<script>
+	var pattern = Trianglify({
+		width: window.innerWidth, 
+		height: window.innerHeight
+	});
+	document.body.appendChild(pattern.canvas())
+</script>
+```
 
 See https://qrohlf.com/trianglify for a overview on getting started and a demonstration of some configuration options.
 
-# API Documentation
+
+# API
 
 Trianglify exposes a single function into the global namespace, called `Trianglify`. This takes a single options object as an argument and returns a pattern object.
 
@@ -28,7 +62,7 @@ The pattern object contains data about the generated pattern's options and geome
 
 ### pattern.opts
 
-The options used to generate the pattern
+Object containing the options used to generate the pattern.
 
 ### pattern.polys
 
@@ -54,6 +88,65 @@ Rendering function for canvas. When called with no arguments returns a HTMLCanva
 
 Rendering function for PNG. Returns a data URI with the PNG data in base64 encoding. See [examples/save-as-png.js](examples/save-as-png.js) for an example of decoding this into a file.
 
-# Options Documentation
 
-# License
+# Options
+
+Trianglify is configured by an options object passed in as the only argument. The following option keys are supported:
+
+### width
+
+Integer, defaults to `600`. Specify the width in pixels of the pattern to generate. 
+
+### height
+
+Integer, defaults to `400`. Specify the height in pixels of the pattern to generate.
+
+### cell_size
+
+Integer, defaults to `75`. Specify the size of the mesh used to generate triangles. Larger values will result in coarser patterns, smaller values will result in finer patterns. Note that very small values may dramatically increase the runtime of Trianglify.
+
+### variance
+
+Decimal value between 0 and 1 (inclusive), defaults to 0.75. Specify the amount of randomness used when generating triangles. 
+
+### seed
+
+Number or string, defaults to `null`. Seeds the random number generator to create repeatable patterns. When set to null, the random number will be seeded with random values from the environment. An example usage would be passing in blog post titles as the seed to generate unique trianglify patterns for every post on a blog that won't change when the page reloads.
+
+### x_colors
+
+String or array of CSS-formatted colors, default is `'random'`. Specify the color gradient used on the x axis.
+
+Valid string values are 'random' or the name of a [colorbrewer palette](http://bl.ocks.org/mbostock/5577023) (i.e. 'YlGnBu' or 'RdBu'). When set to 'random', a gradient will be randomly selected from the colorbrewer library.
+
+Valid array values should specify the color stops in any CSS format (i.e. `['#000000', '#4CAFE8', '#FFFFFF']`).
+
+### y_colors
+
+String or array of CSS-formatted colors, default is `'match_x'`. When set to 'match_x' the same gradient will be used on both axes. Otherwise, accepts the same options as x_colors.
+
+### color_space
+
+String, defaults to `'lab'`. Set the color space used for generating gradients. Supported values are rgb, hsv, hsl, hsi, lab and hcl. See this [blog post](https://vis4.net/blog/posts/avoid-equidistant-hsv-colors/) for some background on why this matters.
+
+### color_function
+
+Specify a custom function for coloring triangles, defaults to `null`. Accepts a function to override the standard gradient coloring that takes the x,y coordinates of a triangle's centroid as arguments and returns a CSS-formatted color string representing the color that triangle should have.
+
+Here is an example color function that uses the HSL color format to generate a rainbow pattern:
+
+```javascript
+var colorFunc = function(x, y) {
+	return 'hsl('+Math.floor(Math.abs(x*y)*360)+',80%,60%)';
+};
+
+var pattern = Trianglify({color_function: colorFunc})
+```
+
+### stroke_width
+
+Number, defaults to `1.51`. Specify the width of the stroke on triangle shapes in the pattern. The default value is the ideal value for eliminating antialiasing artifacts when rendering patterns to a canvas.
+
+# License
+
+Trianglify is GPLv3 licensed. Please [contact me](mailto:qr@qrohlf.com) if you are interested in purchasing Trianglify under an alternative license.