The spine-c runtime provides basic functionality to load and manipulate Spine skeletal animation data using ANSI C. It does not perform rendering but can be extended to enable Spine animations for other C-based projects, including C++ or Objective-C projects.

1. Download the Spine Runtimes source using git or by downloading it as a zip.
2. Open the spine-c.sln Visual C++ 2010 Express project file. For other IDEs, you will need to create a new project and import the source.

Alternatively, the contents of the spine-c/src and spine-c/include directories can be copied into your project. Be sure your header search is configured to find the contents of the spine-c/include directory. Note that the includes use spine/Xxx.h, so the spine directory cannot be omitted when copying the files.

If SPINE_SHORT_NAMES is defined, the sp prefix for all structs and functions is optional. Only use this if the spine-c names won't cause a conflict.

Loading data

Extending spine-c requires implementing three methods:

• _spAtlasPage_createTexture Loads a texture and stores it and its size in the void* rendererObject, width and height fields of an spAtlasPage struct.
• _spAtlasPage_disposeTexture Disposes of a texture loaded with _spAtlasPage_createTexture.
• _spUtil_readFile Reads a file. If this doesn't need to be customized, _readFile is provided which reads a file using fopen.

With these implemented, the spine-c API can then be used to load Spine animation data. Rendering is done by enumerating the slots for a skeleton and rendering the attachment for each slot. Each attachment has a rendererObject field that is set when the attachment is loaded.

For example, AtlasAttachmentLoader is typically used to load attachments when using a Spine texture atlas. When AtlasAttachmentLoader loads a RegionAttachment, the attachment's void* rendererObject is set to an AtlasRegion. Rendering code can then obtain the AtlasRegion from the attachment, get the AtlasPage it belongs to, and get the page's void* rendererObject. This is the renderer specific texture object set by _spAtlasPage_createTexture. Attachment loading can be customized if not using AtlasAttachmentLoader or to provider different renderer specific data.

spine-sfml serves as a simple example of extending spine-c.

spine-c uses an OOP style of programming where each "class" is made up of a struct and a number of functions prefixed with the struct name. More detals about how this works are available in extension.h. This mechanism allows you to provide your own implementations for spAttachmentLoader, spAttachment and spTimeline, if necessary.

• spine-cocos2d-iphone
• spine-cocos2dx
• spine-sfml
• spine-torque2d