VideoView.m

//
//  VideoView.m
//  MacVideoWall
//
//  Created by David Rönnqvist on 9/28/13.
//  This is the source code behind the Mac Video Wall that I was trying to port to iOS in [this Stack Overflow question](http://stackoverflow.com/questions/19065816/ios-alternative-to-qtmovielayer-that-has-non-nil-contents)
//

#import "VideoView.h"

#import <QuartzCore/QuartzCore.h>
#import <QTKit/QTKit.h>

@interface VideoView ()

@property (strong) CALayer *sourceLayer;

@end

@implementation VideoView

- (void)awakeFromNib {
    // Initialization code here.
    
    // The view needs layers
    [self setWantsLayer:YES];
    self.layer.backgroundColor = [NSColor colorWithCalibratedWhite:0.15 alpha:1.0].CGColor;

    // Give the view's layer a perspective transform for it's children
    CATransform3D perspective = CATransform3DIdentity;
    perspective.m34 = 1./800.;
    self.layer.sublayerTransform = perspective;
    
    
    // Load the movie
    NSError *error = nil;
    NSURL *videoURL = [[NSBundle mainBundle] URLForResource:@"video" withExtension:@"m4v"];
    NSLog(@"can %@ play this", [QTMovie canInitWithURL:videoURL]?@"absolutely":@"not");
    
    QTMovie *movie = [QTMovie movieWithURL:videoURL error:&error];
    if (error) {
        NSLog(@"ERROR! %@", [error localizedDescription]);
    }
    
    // Create a movie layer
    QTMovieLayer *movieLayer = [QTMovieLayer layerWithMovie:movie];
    self.sourceLayer = movieLayer;
    movieLayer.frame = CGRectInset(self.bounds, 50, 50);
    [self.layer addSublayer:movieLayer];
    
    // Start playing the movie
    [movie play];
    
    
    // Layout more layers inside this layer
    CGRect    layerRects = CGRectInset(self.bounds, 15, 15);
    NSInteger num        = 10;
    CGFloat   margin     = 0.;
    
    // Width & height of the layers
    CGFloat width  = CGRectGetWidth(layerRects)/num-margin;
    CGFloat height = CGRectGetHeight(layerRects)/num-margin;
    
    CGFloat floatNum = num;

    self.sourceLayer.frame = (CGRect){layerRects.origin, CGSizeMake(width, height)};
    self.sourceLayer.contentsRect = CGRectMake(0, 0, 1/floatNum, 1/floatNum);
    
    // These are just the animations that tilt the all the layers
    CABasicAnimation *flipY = [CABasicAnimation animationWithKeyPath:@"transform.rotation.y"];
    flipY.fromValue    = @(-M_PI/5.);
    flipY.toValue      = @(+M_PI/5.);
    flipY.duration     = 2.0;
    flipY.autoreverses = YES;
    flipY.repeatCount  = INFINITY;
    
    CABasicAnimation *flipX = [CABasicAnimation animationWithKeyPath:@"transform.rotation.x"];
    flipX.fromValue    = @(-M_PI/3.);
    flipX.toValue      = @(+M_PI/3.);
    flipX.duration     = 3.5;
    flipX.autoreverses = YES;
    flipX.repeatCount  = INFINITY;
    
    // Tilt the source layer
    [self.sourceLayer addAnimation:flipY forKey:nil];
    [self.sourceLayer addAnimation:flipX forKey:nil];
    
    // Loop over the rows and coumns to create a grid of layers
    for (NSInteger col=0; col<num; col++) {
        for (NSInteger row=0; row<num; row++) {
            if (row+col == 0) continue;
            
            // Create a new layer
            CALayer *copiedLayer = [CALayer layer];
            // Give it the same contents as the movie layer
            copiedLayer.contents = self.sourceLayer.contents;
            copiedLayer.frame = CGRectMake(CGRectGetMinX(layerRects)+row*width  +row*margin,
                                           CGRectGetMinY(layerRects)+col*height +col*margin,
                                           width, height);
            
            // Display only part of that conent in this layer
            copiedLayer.contentsRect = CGRectMake(row/floatNum, col/floatNum, 1/floatNum, 1/floatNum);
            [self.layer addSublayer:copiedLayer];
        
            // Add the tilting animation
            [copiedLayer addAnimation:flipY forKey:nil];
            [copiedLayer addAnimation:flipX forKey:nil];
        }
    }
}

@end