texture param and loadTexture()

pages/Javascript-API.md

@@ -67,6 +67,9 @@ Loads the specified scene by url and rebuilds the geometry. If no arguments are
 
 `base_path` is an optional argument specifying an alternate base URL for resolving relative paths in the scene file. It is primarily useful for development and debugging.
 
+#### `loadTextures()`
+Reloads and rebinds all [textures](textures.md) in the scene.
+
 #### `rebuild()`
 Rebuilds the current scene from scratch.
 

pages/textures.md

@@ -57,7 +57,7 @@ styles:
                 fox: [0, 32, 32, 32]
 ```
 
-Whether defined in the `textures` element or inline, at a minimum, a URL must be passed:
+Whether defined in the `textures` element or inline, at a minimum, a `URL` or `element` must be passed:
 
 ```yaml
 textures:
@@ -76,7 +76,7 @@ If provided for a _lines_ style, the texture is repeated across the line, with t
 ## texture parameters
 
 ####`url`
-Required _string_. Defines the path to an image file. No default.
+Optional _string_, though either `url` or [`element`](#element) is required ([JS-only](https://github.com/tangrams/tangram). This element is required for [ES](https://github.com/tangrams/tangram-es)). Specifies the path to a texture source file. No default.
 
 URLs can be absolute or relative.
 
@@ -90,6 +90,33 @@ URLs can be absolute or relative.
         url: http://ghostimages.com/ghost.png
 ```
 
+#### `element`
+[[JS-only](https://github.com/tangrams/tangram)] Optional _string_, though either [`url`](#url) or `element` is required. Specifies a CSS element selector string. No default.
+
+This parameter allows an HTML element to be used as the source of the texture, as identified by a CSS selector string.
+
+For example, this canvas element:
+
+`<canvas class='awesome-texture'>`
+
+Can be referenced as:
+
+```yaml
+textures:
+   awesome-texture:
+      element: .awesome-texture
+```
+
+You can also reference an element by `id`, but the use of `#` in CSS means the YAML must be quoted so it's not interpreted as a YAML comment:
+
+`<canvas id='texture-id'>`
+
+```yaml
+textures:
+   awesome-texture:
+      element: '#texture-id' # no comment!
+```
+
 #### `filtering`
 Optional _string_, one of `linear`, `nearest`, or `mipmap`. Defaults to `linear`.