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# QCPlugInContext

The `QCPlugInContext` protocol defines methods that you use only from within the execution method ([`execute(_:atTime:withArguments:)`](/documentation/Quartz/QCPlugIn/execute(_:atTime:withArguments:))) of a `QCPlugIn` object.

```
protocol QCPlugInContext
```

## Topics

### Getting the OpenGL Context

[`-  CGLContextObj`](/documentation/Quartz/QCPlugInContext/cglContextObj())

Returns the destination CGL context to use for OpenGL rendering from within the execution method.

### Logging Messages

[`-  logMessage:`](/documentation/Quartz/QCPlugInContext/logMessage:)

Writes a message to the Quartz Composer log.

### Getting Execution Context Information

[`-  userInfo`](/documentation/Quartz/QCPlugInContext/userInfo())

Returns a mutable dictionary that contains information that can be shared between all instances of the `QCPlugIn` subclass, running in the same Quartz Composer context.

[`-  bounds`](/documentation/Quartz/QCPlugInContext/bounds())

Returns the bounds of the rendering context.

[`-  colorSpace`](/documentation/Quartz/QCPlugInContext/colorSpace())

Returns the color space used by the rendering context.

### Getting an Image Provider

[`-  outputImageProviderFromBufferWithPixelFormat:pixelsWide:pixelsHigh:baseAddress:bytesPerRow:releaseCallback:releaseContext:colorSpace:shouldColorMatch:`](/documentation/Quartz/QCPlugInContext/outputImageProviderFromBuffer(withPixelFormat:pixelsWide:pixelsHigh:baseAddress:bytesPerRow:releaseCallback:releaseContext:colorSpace:shouldColorMatch:))

Returns an image provider from a single memory buffer.

[`-  outputImageProviderFromTextureWithPixelFormat:pixelsWide:pixelsHigh:name:flipped:releaseCallback:releaseContext:colorSpace:shouldColorMatch:`](/documentation/Quartz/QCPlugInContext/outputImageProviderFromTexture(withPixelFormat:pixelsWide:pixelsHigh:name:flipped:releaseCallback:releaseContext:colorSpace:shouldColorMatch:))

Returns an image provider from an OpenGL texture.


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