iOS GPUImage之GPUImageFilterGroup组合滤镜（5）

示例：使用GPUImageFilterGroup为GPUImagePicture添加组合滤镜

代码：

//
//  ViewController.m
//  GPUImageTest
//
//  Created by 黄健 on 16/7/1.
//  Copyright © 2016年 黄健. All rights reserved.
//

#import "ViewController.h"

#import "GPUImage.h"

@interface ViewController ()
{
UIImage *_inputImage;
UIImage *_outputImage;
}
@property (weak, nonatomic) IBOutlet UIImageView *iconImageView;

@property (nonatomic,strong) GPUImagePicture        *picture;
@property (nonatomic,strong) GPUImageView           *imageView;
@property (nonatomic,strong) GPUImageFilterGroup    *filterGroup;

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];

// 图片输入源
_inputImage = [UIImage imageNamed:@"icon"];

// 初始化 picture
_picture    = [[GPUImagePicture alloc] initWithImage:_inputImage smoothlyScaleOutput:YES];

// 初始化 imageView
_imageView  = [[GPUImageView alloc] initWithFrame:self.iconImageView.bounds];
[self.iconImageView addSubview:_imageView];

// 初始化 filterGroup
_filterGroup = [[GPUImageFilterGroup alloc] init];
[_picture addTarget:_filterGroup];

// 添加 filter
/**
原理：
1. filterGroup(addFilter) 滤镜组添加每个滤镜
2. 按添加顺序（可自行调整）前一个filter(addTarget) 添加后一个filter
3. filterGroup.initialFilters = @[第一个filter]];
4. filterGroup.terminalFilter = 最后一个filter;

*/
GPUImageRGBFilter *filter1         = [[GPUImageRGBFilter alloc] init];
GPUImageToonFilter *filter2        = [[GPUImageToonFilter alloc] init];
GPUImageColorInvertFilter *filter3 = [[GPUImageColorInvertFilter alloc] init];
GPUImageSepiaFilter       *filter4 = [[GPUImageSepiaFilter alloc] init];
[self addGPUImageFilter:filter1];
[self addGPUImageFilter:filter2];
[self addGPUImageFilter:filter3];
[self addGPUImageFilter:filter4];

// 处理图片
[_picture processImage];
[_filterGroup useNextFrameForImageCapture];

self.iconImageView.image = [_filterGroup imageFromCurrentFramebuffer];

}

- (void)addGPUImageFilter:(GPUImageOutput<GPUImageInput> *)filter
{
[_filterGroup addFilter:filter];

GPUImageOutput<GPUImageInput> *newTerminalFilter = filter;

NSInteger count = _filterGroup.filterCount;

if (count == 1)
{
_filterGroup.initialFilters = @[newTerminalFilter];
_filterGroup.terminalFilter = newTerminalFilter;

} else
{
GPUImageOutput<GPUImageInput> *terminalFilter    = _filterGroup.terminalFilter;
NSArray *initialFilters                          = _filterGroup.initialFilters;

[terminalFilter addTarget:newTerminalFilter];

_filterGroup.initialFilters = @[initialFilters[0]];
_filterGroup.terminalFilter = newTerminalFilter;
}
}

@end

示例：使用GPUImageFilterGroup为GPUImageVideoCamera添加四种组合滤镜

//
//  ViewController.m
//  GPUImageTest
//
//  Created by 黄健 on 16/7/1.
//  Copyright © 2016年 黄健. All rights reserved.
//

#import "ViewController.h"

#import "GPUImage.h"

@interface ViewController ()

@property (nonatomic,strong) GPUImageVideoCamera    *videoCamera;
@property (nonatomic,strong) GPUImageView           *filterImageView;
@property (nonatomic,strong) GPUImageFilterGroup    *filterGroup;

@end

@implementation ViewController

- (void)viewDidLoad
{
[super viewDidLoad];

// 初始化 videoCamera
_videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPresetHigh cameraPosition:AVCaptureDevicePositionBack];
_videoCamera.outputImageOrientation              = UIInterfaceOrientationPortrait;
_videoCamera.horizontallyMirrorFrontFacingCamera = NO;
_videoCamera.horizontallyMirrorRearFacingCamera  = NO;

// 初始化 filterGroup
_filterGroup = [[GPUImageFilterGroup alloc] init];
[_videoCamera addTarget:_filterGroup];

// 添加 filter
/**
原理：
1. filterGroup(addFilter) 滤镜组添加每个滤镜
2. 按添加顺序（可自行调整）前一个filter(addTarget) 添加后一个filter
3. filterGroup.initialFilters = @[第一个filter]];
4. filterGroup.terminalFilter = 最后一个filter;

*/
GPUImageRGBFilter *filter1         = [[GPUImageRGBFilter alloc] init];
GPUImageToonFilter *filter2        = [[GPUImageToonFilter alloc] init];
GPUImageSepiaFilter *filter3       = [[GPUImageSepiaFilter alloc] init];
GPUImageColorInvertFilter *filter4 = [[GPUImageColorInvertFilter alloc] init];
[self addGPUImageFilter:filter1];
[self addGPUImageFilter:filter2];
[self addGPUImageFilter:filter3];
[self addGPUImageFilter:filter4];

// 初始化 imageView
_filterImageView  = [[GPUImageView alloc] initWithFrame:self.view.bounds];
[self.view addSubview:_filterImageView];
[_filterGroup addTarget:_filterImageView];

[_videoCamera startCameraCapture];

}

- (void)addGPUImageFilter:(GPUImageOutput<GPUImageInput> *)filter
{
[_filterGroup addFilter:filter];

GPUImageOutput<GPUImageInput> *newTerminalFilter = filter;

NSInteger count = _filterGroup.filterCount;

if (count == 1)
{
_filterGroup.initialFilters = @[newTerminalFilter];
_filterGroup.terminalFilter = newTerminalFilter;

} else
{
GPUImageOutput<GPUImageInput> *terminalFilter    = _filterGroup.terminalFilter;
NSArray *initialFilters                          = _filterGroup.initialFilters;

[terminalFilter addTarget:newTerminalFilter];

_filterGroup.initialFilters = @[initialFilters[0]];
_filterGroup.terminalFilter = newTerminalFilter;
}
}

@end