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CONTRIBUTING.md

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+CONTRIBUTING
+============
+## Submitting changes
+Please send a GitHub Pull Request with a clear list of what you've done (read more about [pull requests](http://help.github.com/pull-requests/)). 
+
+## Features
+If you have an idea for new features just [open an issue](https://github.com/vurtun/zahnrad/issues) with your suggestion.
+  * Find and correct spelling mistakes
+  * Add (insert your favorite platform or render backend here) demo implementation
+  * Add clipboard user callbacks back into all demos
+  * Add additional widgets [some possible widgets](http://doc.qt.io/qt-5/widget-classes.html#the-widget-classes)
+  * Extend xlib demo to support image drawing with arbitrary image width and height
+  * Change cursor in `zr_widget_edit_box` and `zr_widget_edit_field` to thin standard cursor version used in editors
+  * Rewrite the chart API to support a better range of charts (maybe take notes from Javascript chart frameworks) 
+  * Create an API to allow scaling between groups (maybe extend and convert the demo example)
+  * Add Tab support (maybe use `zr_group` and add a header)  
+  * Come up with a better way to provide and create widget and window styles
+  * Add support for multiple pointers for touch input devices (probably requires to rewrite mouse handling in `struct zr_input`)
+  * Extend context to not only support overlapping windows but tiled windows as well
+
+## Bugs
+  * Text pixel width is bugged at the moment if you edit text with enabled font baking and vertex buffer API.
+  * Text handling is still a little bit chanky and probably needs to be further tested and polished
+
+## Coding conventions
+  * Only use a C89 (ANSI C) compiler or rather style
+  * For indent use four spaces
+  * Do not typedef structs, unions and enums
+  * Variable, object and function names should always be lowercase and use underscores instead of camel case
+  * Whitespace after for, while, if, do, switch
+  * Always use parentheses if using the sizeof operator (e.g: sizeof(struct zr_context) and not sizeof struct zr_context)
+  * Beginning braces on the new line for functions and on the same line otherwise.
+  * Only use fixed size types (zr_uint, zr_size, ...) if you really need to and use basic types otherwise
+  * Do not include any header files in either zahnrad.h or zahnrad.c
+  * Do not add any dependencies
+  * Do not use any compiler specific extensions
+