Filter4Cam 實作: 6. 測試 Camera Overlay 與 Filter Rectangle

since: 2012/03/07
update: 2012/03/07
reference: iOS Camera Overlay Example Using AVCaptureSession | musicalgeometry

A. 說明
     1. 直接以目前的專案來初步測試: "相機鋪蓋" 與 "濾鏡矩形" 的效果.
     2. 不調整 UI, 而以程式的方式來測試.
     3. 不考量設備方向的改變.

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B. 開啓 ViewController.h 檔案, 修改如下:
....
@interface ViewController : GLKViewController <AVCaptureVideoDataOutputSampleBufferDelegate>
{
....
    //@add for test
    UILabel *scanningLabel;
    UIImageView *overlayImageView;
    UIButton *overlayButton;
}
....
//@add for test
@property (nonatomic, strong)UILabel *scanningLabel;
@property (nonatomic, strong)UIImageView *overlayImageView;
@property (nonatomic, strong)UIButton *overlayButton;
....
//@add for test
- (void)helperTest;
- (CIImage *)filterTest:(CIImage *)sourceImage;
- (void)scanButtonPressedTest;
- (void)hideLabelTest:(UILabel *)label;
- (void)cameraOverlayTest;

@end

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C. 開啓 ViewController.m 檔案, 修改如下:
....
@implementation ViewController
....
//@add for test
@synthesize scanningLabel = _scanningLabel;
@synthesize overlayImageView = _overlayImageView;
@synthesize overlayButton = _overlayButton;
....
#pragma mark Test
....
//@test for initialize scanningLabel
- (UILabel *)scanningLabel
{
    if (_scanningLabel == nil) {
        _scanningLabel = [[UILabel alloc] initWithFrame:CGRectMake(100, 50, 120, 30)];
    }
   
    return _scanningLabel;
}

//@test for initialize overlayImageView
- (UIImageView *)overlayImageView
{  
    if (_overlayImageView == nil) {
        _overlayImageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"overlaygraphic.png"]];
    }
   
    return _overlayImageView;
}

//@test for initialize overlayButton
- (UIButton *)overlayButton
{
    if (_overlayButton == nil) {
        _overlayButton = [UIButton buttonWithType:UIButtonTypeCustom];
    }
   
    return _overlayButton;
}

//@test for scanButtonPressed
- (void)scanButtonPressedTest {
    [self.scanningLabel setHidden:NO];
    [self performSelector:@selector(hideLabelTest:) withObject:self.scanningLabel afterDelay:2];
}

//@test for hideLabel
- (void)hideLabelTest:(UILabel *)label {
    [label setHidden:YES];
}
....
//@test for cameraOverlay
- (void)cameraOverlayTest
{   
    //@overlayImageView
    [self.overlayImageView setFrame:CGRectMake(30, 100, 260, 200)];
    [self.view addSubview:self.overlayImageView];
   
    //@overlayButton
    [self.overlayButton setImage:[UIImage imageNamed:@"scanbutton.png"] forState:UIControlStateNormal];
    [self.overlayButton setFrame:CGRectMake(130, 320, 60, 30)];
    [self.overlayButton addTarget:self action:@selector(scanButtonPressedTest) forControlEvents:UIControlEventTouchUpInside];
    [self.view addSubview:self.overlayButton];
   
    //@scanningLabel
    [self.scanningLabel setBackgroundColor:[UIColor clearColor]];
    [self.scanningLabel setFont:[UIFont fontWithName:@"Courier" size: 18.0]];
    [self.scanningLabel setTextColor:[UIColor redColor]];
    [self.scanningLabel setText:@"Scanning..."];
    [self.scanningLabel setHidden:YES];
    [self.view addSubview:self.scanningLabel];
}
....
- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    //@add:helper Test
    [self helperTest];
   
    //@add: establish Render
    [self establishRender];
    //[self setupGL];

    //@add: establishCamera
    [self establishCamera:kCameraBack];
   
    //@add test for cameraOverlay
    [self cameraOverlayTest];
   
    //@add: startRunning
    [self startRunningSession];
}
....
-(void)captureOutput:(AVCaptureOutput *)captureOutput didOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer fromConnection:(AVCaptureConnection *)connection {

    // 將取得的 sampleBuffer 轉成 CVPixelBuffer
    CVPixelBufferRef pixelBuffer = (CVPixelBufferRef)CMSampleBufferGetImageBuffer(sampleBuffer);
   
    // 接著, 將 CVPixelBuffer 利用 Core Image 的初始化方法再轉成 CIImage.
    CIImage *ciImage = [CIImage imageWithCVPixelBuffer:pixelBuffer];
       
    //@add:濾鏡測試
    //ciImage = [self filterTest:ciImage];
   
    //@add:方向轉變的調整
    ciImage = [Filter4CamHelper orientationTransform:ciImage];
 
    // 然後使用 CIContext 物件將其內容畫到 render buffer
    [self.coreImageContext drawImage:ciImage atPoint:CGPointZero fromRect:[ciImage extent]];
   
    //@add test for filter Rectangle
    //@add:濾鏡測試
    ciImage = [self filterTest:ciImage];
    [self.coreImageContext drawImage:ciImage inRect:CGRectMake(30, 180, 260, 200) fromRect:[ciImage extent]];
   
    // 最後, 在螢幕上呈現出來.
    [self.glContext presentRenderbuffer:GL_RENDERBUFFER];
}

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D. 編譯並執行