/*

File: FrameReader.h

Abstract: Declares the interface for the FrameReader class which

allows to grab frames from an OpenGL context.

The FrameReader is initialized with an OpenGL context to read from and

the dimensions of the frames to grab. In case the "asynchronousFetching"

parameter is set to true, the FrameReader will use asynchronous texture

fetching to grab the frames from the OpenGL context: this improves

performances, but at the expense of a one-frame latency (first call to

-readFrame will return NULL). Frame grabbing is performed by calling

-readFrame which returns a CVPixelBuffer containing the frame pixels

(which have been vertically flipped to compensate for OpenGL bottom-left

referential origin).

Version: 1.0

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*/

#import <Cocoa/Cocoa.h>

#import <QuartzCore/QuartzCore.h>

@interface FrameReader : NSObject

{

    NSOpenGLContext*            _glContext;

    unsigned                    _width,

                                _height;

    CVPixelBufferPoolRef        _bufferPool;

    unsigned                    _bufferRowBytes;

    void*                       _frameBuffer;

    void*                       _frameBuffers[2];

    unsigned long               _textureNames[2]; //GLuint

    unsigned                    _currentTextureIndex;

    BOOL                        _skipFirstBuffer;

}

- (id) initWithOpenGLContext:(NSOpenGLContext*)context pixelsWide:(unsigned)width pixelsHigh:(unsigned)height asynchronousFetching:(BOOL)asynchronous;

- (CVPixelBufferRef) readFrame;

@end