Updated docs

Author: tschaub

readme.md

@@ -15,6 +15,7 @@ Given any GeoJSON data, generate a `BitBox` with the provided options.
 Supported options:
 
  * `resolution` - The size (width and height) of a "cell" in the same units as the input data.
+ * `origin` - By default, `[0, 0]` is considered the origin.
 
 ### `bitgeo.or(datas, options)`
 
@@ -32,14 +33,14 @@ var bitbox = bitgeo(data, options);
 
 A bitbox is a (conceptually) rasterized representation of vector data containing information about where data is present and absent.
 
-#### `bitbox.getArea()`
-
-Returns the area of the bitbox where data is present (this will be an integer multiple of `resolution * resolution`).
-
 #### `bitbox.get(i, j)`
 
 Test if data is present at the provided location.  The `i` and `j` values are offsets from the origin in terms of the bitbox resolution.  For example, if a bitbox is created with `resolution: 10`, then `bitbox.get(1, 2)` would return `true` if there is data between `[10, 20]` and `[20, 30]` (with upper bounds being exclusive).
 
+#### `bitbox.forEach(callback)`
+
+Calls the provided callback for each `true` bit in the bitbox.  The callback will be called with `i` and `j` as arguments.  If the callback returns `false`, iteration will stop.
+
 #### `bitbox.contains(minI, minJ, maxI, maxJ)`
 
 Determine if all, some, or none of a range of bits are `true`.  Returns `bitgeo.ALL` if all of the bits in the provided range are `true`, `bitgeo.SOME` if some bits are `true` and some are `false`, and `bitgeo.NONE` if all of the bits in the range are `false`.  Ranges are inclusive (both min and max values are tested).
@@ -51,3 +52,7 @@ Return a bitbox that is the union of two bitboxes (`bitbox` and `other`).
 #### `bitbox.and(other)`
 
 Return a bitbox that is the intersection of two bitboxes (`bitbox` and `other`).
+
+#### `bitbox.getArea()`
+
+Returns the area of the bitbox where data is present (this will be an integer multiple of `resolution * resolution`).