Added documentation on feature tags.

learning/workflow/export/feature_tags.rst

@@ -0,0 +1,108 @@
+.. _doc_feature_tags:
+
+Feature Tags
+============
+
+Introduction
+------------
+
+Godot has a special system to tag availability of features. Each *feature* is represented
+as a string, and it can refer to many of the following:
+
+* Platform name.
+* Platform bits (64/32).
+* Platform type (dekstop/mobile).
+* Supported texture compression in platform.
+* Whether a build is debug or release.
+* Many more things.
+
+Features can be queried in run-time to the singleton API by calling:
+
+::
+
+	OS.has_feature(name)
+
+
+Default features
+----------------
+
+Here is a list of most feature tags in Godot. Keep in mind they are *case sensitive*:
+
++-----------------+--------------------------------------------------------+
+| **Feature Tag** | **Description**                                        |
++=================+========================================================+
+| **Android**     | Running on Android                                     |
++-----------------+--------------------------------------------------------+
+| **JavaScript**  | Running on Javascript (HTML5)                          |
++-----------------+--------------------------------------------------------+
+| **OSX**         | Running on OSX                                         |
++-----------------+--------------------------------------------------------+
+| **iOS**         | Running on iOS                                         |
++-----------------+--------------------------------------------------------+
+| **UWP**         | Running on UWB                                         |
++-----------------+--------------------------------------------------------+
+| **Windows**     | Running on Windows                                     |
++-----------------+--------------------------------------------------------+
+| **X11**         | Running on X11                                         |
++-----------------+--------------------------------------------------------+
+| **debug**       | Running on debug build                                 |
++-----------------+--------------------------------------------------------+
+| **release**     | Running on release build                               |
++-----------------+--------------------------------------------------------+
+| **32**          | Running on 32 bits build                               |
++-----------------+--------------------------------------------------------+
+| **64**          | Running on 64 bits build                               |
++-----------------+--------------------------------------------------------+
+| **mobile**      | Host OS is a mobile platform                           |
++-----------------+--------------------------------------------------------+
+| **pc**          | Host OS is a PC                                        |
++-----------------+--------------------------------------------------------+
+| **web**         | Hot OS is a web browser                                |
++-----------------+--------------------------------------------------------+
+| **etc**         | Textures using ETC compression are supported           |
++-----------------+--------------------------------------------------------+
+| **etc2**        | Textures using ETC2 compression are supported          |
++-----------------+--------------------------------------------------------+
+| **s3tc**        | Textures using S3TC (DXT/BC) compression are supported |
++-----------------+--------------------------------------------------------+
+| **pvrtc**       | Textures using PVRTC compression are supported         |
++-----------------+--------------------------------------------------------+
+
+Custom features
+---------------
+
+It is possible to add custom features to a build, just use the relevant
+field in the *export preset** used to generate it:
+
+.. image:: /img/feature_tags1.png
+
+Overriding project settings
+---------------------------
+
+Features can be used to override specific configuration values in the *Project Settings*.
+This allows to better customize any configuration when doing a build.
+
+In the following example, a different icon is added for the demo build of the game (which was
+customized in a special export preset which, in turn, includes only demo levels).
+
+.. image:: /img/feature_tags2.png
+
+After overriding, a new field is added for this specific configuration:
+
+.. image:: /img/feature_tags3.png
+
+Default overrides
+-----------------
+
+There are already a lot of settings that come with overrides by default, they can be found
+in many sections of the project settings.
+
+.. image:: /img/feature_tags4.png
+
+Customizing Build
+------------------
+
+Feature tags can be used to customize a build process too, by writing a custom **ExportPlugin**.
+They also are used to specify which shared library is loaded and exported in **GDNative**.
+
+

learning/workflow/export/index.rst

@@ -5,7 +5,9 @@ Export
    :maxdepth: 1
    :name: toc-learn-workflow-export
 
+ 
    exporting_projects
+   feature_tags
    exporting_for_pc
    exporting_for_ios
    exporting_for_uwp