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CARenderer Class Reference

Overview

CARenderer allows an application to render a layer tree into a CGL context. For real-time output you should use an instance of NSView to host the layer-tree.

Tasks

Rendered Layer

•   layer  property

Renderer Geometry

•   bounds  property

Create a New Renderer

• + rendererWithCGLContext:options:

Render a Frame

• – beginFrameAtTime:timeStamp:
• – updateBounds
• – addUpdateRect:
• – render
• – nextFrameTime
• – endFrame

Properties

For more about Objective-C properties, see “Properties” in The Objective-C 2.0 Programming Language.

bounds

The bounds of the receiver.

@property CGRect bounds

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

layer

The root layer of the layer-tree the receiver should render.

@property(retain) CALayer *layer

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

Class Methods

rendererWithCGLContext:options:

Creates and returns a CARenderer instance with the render target specified by the Core OpenGL context.

+ (CARenderer *)rendererWithCGLContext:(void *)ctx options:(NSDictionary *)dict

Parameters

ctx

A Core OpenGL render context that is used as the render target.

dict

A dictionary of optional parameters.

Return Value

A new instance of CARenderer that will use ctx as the render target.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

Instance Methods

addUpdateRect:

Adds the rectangle to the update region of the current frame.

- (void)addUpdateRect:(CGRect)aRect

Parameters

aRect

A rectangle defining the region to be added to the update region.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

beginFrameAtTime:timeStamp:

Begin rendering a frame at the specified time.

- (void)beginFrameAtTime:(CFTimeInterval)timeInterval timeStamp:(CVTimeStamp *)timeStamp

Parameters

timeInterval

The layer time.

timeStamp

The display timestamp associated with timeInterval. Can be null.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

endFrame

Release any data associated with the current frame.

- (void)endFrame

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

nextFrameTime

Returns the time at which the next update should happen.

- (CFTimeInterval)nextFrameTime

Return Value

The time at which the next update should happen.

Discussion

If infinite, no update needs to be scheduled yet. If nextFrameTime is the current frame time, a continuous animation is running and an update should be scheduled after an appropriate delay.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

render

Render the update region of the current frame to the target context.

- (void)render

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

updateBounds

Returns the bounds of the update region that contains all pixels that will be rendered by the current frame.

- (CGRect)updateBounds

Return Value

The bounds of the update region..

Discussion

Initially updateBounds will include all differences between the current frame and the previously rendered frame.

Availability

• Available in Mac OS X v10.5 and later.

Declared In

CARenderer.h

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