EWOL: Bases                                {#page_bases}
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Overview:
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EWOL is an OpenGL library for creating graphical user interfaces.
It works on many UNIX-like platforms, Windows, and OS X and some mobile platforms Android, iOs(soon).
EWOL is released under the APACHE-2 license, which allows for very flexible licensing of client applications.
EWOL has a C++ architecture that allows for maximum flexibility.

The main idea of EWOL is to create a complete abstraction of the platforms.
This generate some restriction that you will see an overwiew in the under section.

User requires:
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To use ewol you need to know only C++ language. It could be usefull to know:
- **Python** for all build tool.
- **git** and **repo** for all version management.
- **OpenGL-ES2** if you want to create custum advenced widget.

If you just want to have an interface of the openGl just refer to the [lib[gale|Gale library]].

Ewol does not manage the Audio but it is full integrated in [lib[audio-river|River library]].


Architecture:
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One of the important point to know in this framwork is some of absurd things came from the multiple architecture type.

I will Explain the main points:
- IOs does [b]NOT[/b] simply support the shared object sub lib, this force ewol to be APACHE-2, and depend on some sub-library with small license restriction.
- Android have a JAVA main, then the application main will not be used with this platform
- Android event (keyboard, mouse, touch-screen and ...) will arrive in asynchron mode ==> need to be resynchronyse in one thread
- Only one graphyc framework is availlable on all platform. This is OpenGL (nned check for windows phone)
- Main interesting point is packaging of the application data:
  * Linux store it in /usr/share/applName/*
  * MacOs store it in applName.app/subFolder/*
  * Android store it in the .pkg that is a renamed .zip that the name is dynamic
  * Windows (TODO : Never done a pakage)
    This will generate a complex result of data access...
- Sub lib Change on all the platform, the I will use the idea of Apple, that incluse in a package all needed libs. This could be a problem for small platform, but this framwork need to have a OpenGL-ES2 instance then the memory problem, is not really a problem.