OpenTK
======

The Open Toolkit is an advanced, low-level C# library that wraps OpenGL, OpenGL ES and OpenAL. It is suitable for games, scientific applications and any other project that requires 3d graphics, audio or compute functionality.

Project website: http://www.opentk.com/

Official git repository: https://github.com/opentk/opentk


Features
========

- Create cutting-edge graphics with OpenGL 4.4 and OpenGL ES 3.0
- Spice up your GUI with 3d graphics
- Improve your code flow with strong types and inline documentation
- Write once run everywhere

OpenTK is available for Windows, Linux, Mac OS X, *BSD, SteamOS, Android and iOS. It can be used standalone or integrated into a GUI (Windows.Forms, WPF, GTK+, Qt, VTK, ...)

[Download binaries](http://www.opentk.com) or [NuGet packages](http://www.nuget.org/packages/OpenTK/)


Instructions
============

The simplest way to use OpenTK in your project is to install the [NuGet package](http://www.nuget.org/packages/OpenTK/).

Alternatively, download the [OpenTK binaries](http://www.opentk.com) and:

1. Copy OpenTK.dll and OpenTK.dll.config to your project directory
2. Use "Add reference" to add OpenTK.dll as a project reference
3. Use "Add files" to add OpenTK.dll.config to your project, and enable the "Copy to Output Directory" option.

If you wish to build OpenTK from source, simply double-click OpenTK.sln and build through your IDE. Alternatively, open a command prompt and type:

```
msbuild /p:Configuration=Release OpenTK.sln  # Windows
xbuild  /p:Configuration=Release OpenTK.sln  # Linux and Mac OS X
```

News
====

OpenTK 1.1.3 was released on 20 June 2014.

This release resolves a number of identified issues and synchronizes the OpenGL and OpenGL ES bindings with the June 2014 Khronos specifications.

**Changelog:**

1. Fixed a potential crash in bindings accepting a string array.
2. Fixed a marshalling issue where bindings might return an incorrect boolean value on some architectures.
3. Fixed a regression where mouse scrolling coordinates on Linux where flipped. Mouse scrolling now uses identical coordinate systems on Windows, Linux and Mac OS X: (+x, +y) = (right, up).
4. Fixed a potential deadlock when exiting the X11/XInput2 subsystem.
5. Fixed an issue where single-to-half floating point conversions would return incorrect results for specific numbers.
6. Added an API compatibility test - backwards-incompatible changes will now cause a compilation failure in the continuous integration server.
7. New platform: XQuartz (X11 over Mac OS X).
8. New platform: XWayland (X11 over Wayland).
9. New OpenGL and OpenGL ES extensions:
  - EXT_geometry_point_size
  - EXT_primitive_bounding_box
  - EXT_texture_array
  - EXT_tessellation_point_size

OpenTK 1.1.3 is backwards compatible with 1.1.2. Users of previous versions are strongly encouraged to upgrade.


Known issues
============

The SDL2 backend has a number of limitations compared to the native platform backends. In particular, SDL2 does not support:
   - `OpenTK.GLControl`. OpenTK will automatically use a native platform backend instead.
   - `DisplayDevice.ChangeResolution()` without a fullscreen `INativeWindow`.
   - changing `INativeWindow.WindowBorder` once a window is created.
   - high-resolution mouse input. Additionally, it is limited to a single keyboard and mouse device.


Contributing
============

1. Install git and a C# IDE (see requirements section below)
2. Fork the _develop_ branch of https://github.com/opentk/opentk
3. Commit your changes in small, incremental steps with clear descriptions
4. When ready, issue a Pull Request (PR) against the _develop_ branch of https://github.com/opentk/opentk

For details on coding style and best practices, refer to https://github.com/opentk/opentk/wiki/Contributing

Some areas we could really use your help:
- Tutorials for OpenGL 3.x and 4.x. [Inspiration here](https://github.com/Groovounet/ogl-samples)
- New platforms:
  - Native Client (NaCL)
  - Blackberry
  - Raspberry PI
  - Wayland
  - Mir
  - WinRT (via ANGLE)
  - Linux KMS (EGL without X11)
- New features:
  - Multitouch
  - Improved joystick support (HID backend for Windows, Linux)

Further ideas for improvement are always welcome!


Requirements
============

- Windows (XP/Vista/7/8), Linux, Mac OS X, *BSD, SteamOS, Android or iOS
- For graphics, OpenGL drivers or a suitable emulator, such as [ANGLE](https://github.com/opentk/opentk/tree/Dependencies/Readme.txt)
- For audio, OpenAL drivers or [OpenAL Soft](https://github.com/opentk/opentk/tree/Dependencies/Readme.txt)
- To develop desktop applications: Visual Studio, Xamarin Studio, MonoDevelop or SharpDevelop
- To develop Android applications: Xamarin Studio or the Xamarin Extensions for Visual Studio
- To develop iOS applications: Xamarin Studio and XCode


Documentation
=============

Your favorite IDE will display inline documentation for all OpenTK APIs. Additional information can be found in the [OpenTK Manual](http://www.opentk.com/doc) and in the [opentk/Documentation/](https://github.com/opentk/opentk/tree/develop/Documentation) folder.

Technical documentation about the implementation of OpenTK can be found in the [Technical Wiki](https://github.com/opentk/opentk/wiki).


Need Help?
==========

Post your questions at the [OpenTK forums](http://www.opentk.com/forum).

Report bugs at https://github.com/opentk/opentk/issues


License
=======

The Open Toolkit is distributed under the permissive MIT/X11 license and is absolutely free.

http://www.opentk.com/project/license


API compatibility
=================

OpenTK 1.1.3 is backwards compatible with 1.1.2.

OpenTK 1.1.2 is backwards compatible with 1.1.1.

OpenTK 1.1.1 is backwards compatible with 1.1.0.

OpenTK 1.1.0 is not backwards compatible with 1.0. Most projects will be able to upgrade without any modifications. Projects using the following signatures will have to implement the suggested changes:

Namespace OpenTK.Graphics.OpenGL
Change signature:
- GL.MultiDrawArrays (`out` -> `ref`)
- GL.Amd.DeletePerfMonitors (`out` -> `ref`)

Change signature (may cause crash): 
- GL.Apple.ObjectPurgeable (returns `AppleObjectPurgeable` instead of `IntPtr`)
- GL.Ext.SeparableFilter2D
- GL.Ibm.EdgeFlagPointerList (`bool[]` -> `bool*[]`)
- GL.NV.TransformFeedbackVaryings (`string[]` -> `int[]`)

Change return type:
- GL.WaitSync (returns `WaitSyncFlags` instead of `ArbSync`)


Namespace OpenTK.Graphics.ES11
Change return type:
- GL.GetError (`ErrorCode` instead of `All`)

Change `ref` parameters to `out`:
- GL.GenBuffers
- GL.GenTextures
- GL.GetBoolean
- GL.GetBufferParameter
- GL.GetClipPlane
- GL.GetClipPlanex
- GL.GetFixed
- GL.GetFloat
- GL.GetInteger
- GL.GetLight
- GL.GetLightx
- GL.GetMaterial
- GL.GetMaterialx
- GL.GetTexEnv
- GL.GetTexEnvx
- GL.GetTexParameter
- GL.GetTexParameterx
- GL.Oes.GenFramebuffers
- GL.Oes.GetClipPlane
- GL.Oes.GetClipPlanex
- GL.Oes.GetFixed
- GL.Oes.GetFramebufferAttachmentParameter
- GL.Oes.GetLightx
- GL.Oes.GetMaterialx
- GL.Oes.GetRenderbufferParameter
- GL.Oes.GetTexEnvx
- GL.Oes.GetTexGen
- GL.Oes.GetTexGenx
- GL.Oes.GetTexParameterx
- GL.Oes.QueryMatrixx
- GL.NV.GenFences
- GL.NV.GetFence

Change namespace:
- GL.ClipPlanefIMG -> GL.Img.ClipPlane
- GL.DisableDriverControlQCOM -> GL.Qcom.DisableDriverControl


Namespace OpenTK.Graphics.ES20.GL
Change signature (may cause crash):
- GL.NV.GetFence now takes three parameters instead of two

Change `ref` parameters to `out`:
- GL.GetActiveAttrib
- GL.GetActiveUniform
- GL.GetAttachedShaders
- GL.GetProgramInfoLog
- GL.GetShaderInfoLog
- GL.GetShaderSource
- GL.Amd.GetPerfMonitorCounterData
- GL.Amd.GetPerfMonitorCounters
- GL.Amd.GetPerfMonitorCounterString
- GL.Amd.GetPerfMonitorGroup
- GL.Amd.GetPerfMonitorGroupString
- GL.Amd.SelectPerfMonitorCounters

Change namespace:
- GL.DisableDriverControlQCOM -> GL.Qcom.DisableDriverControl
- GL.GetDriverControlsQCOM -> GL.Qcom.GetDriverControls
- GL.GetDriverControlStringQCOM -> GL.Qcom.GetDriverControlString