/*

 Copyright (C) 2016 Apple Inc. All Rights Reserved.

 See LICENSE.txt for this sample’s licensing information

 Abstract:

 The RosyWriter CPU-based effect renderer

 */

#import "RosyWriterCPURenderer.h"

@implementation RosyWriterCPURenderer

#pragma mark RosyWriterRenderer

- (BOOL)operatesInPlace

{

    return YES;

}

- (FourCharCode)inputPixelFormat

{

    return kCVPixelFormatType_32BGRA;

}

- (void)prepareForInputWithFormatDescription:(CMFormatDescriptionRef)inputFormatDescription outputRetainedBufferCountHint:(size_t)outputRetainedBufferCountHint

{

    // nothing to do, we are stateless

}

- (void)reset

{

    // nothing to do, we are stateless

}

- (CVPixelBufferRef)copyRenderedPixelBuffer:(CVPixelBufferRef)pixelBuffer

{   

    const int kBytesPerPixel = 4;

    CVPixelBufferLockBaseAddress( pixelBuffer, 0 );

    int bufferWidth = (int)CVPixelBufferGetWidth( pixelBuffer );

    int bufferHeight = (int)CVPixelBufferGetHeight( pixelBuffer );

    size_t bytesPerRow = CVPixelBufferGetBytesPerRow( pixelBuffer );

    uint8_t *baseAddress = CVPixelBufferGetBaseAddress( pixelBuffer );

    for ( int row = 0; row < bufferHeight; row++ )

    {

        uint8_t *pixel = baseAddress + row * bytesPerRow;

        for ( int column = 0; column < bufferWidth; column++ )

        {

            pixel[1] = 0; // De-green (second pixel in BGRA is green)

            pixel += kBytesPerPixel;

        }

    }

    CVPixelBufferUnlockBaseAddress( pixelBuffer, 0 );

    return (CVPixelBufferRef)CFRetain( pixelBuffer );

}

@end