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stevewaffles/makeAnimatedGif.m

Forked from mayoff/makeAnimatedGif.m
Created May 27, 2014 04:30
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  1. @mayoff mayoff created this gist Feb 16, 2013.
    56 changes: 56 additions & 0 deletions makeAnimatedGif.m
    View file
    Original file line number Diff line number Diff line change
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    #import <UIKit/UIKit.h>
    #import <ImageIO/ImageIO.h>
    #import <MobileCoreServices/MobileCoreServices.h>

    static UIImage *frameImage(CGSize size, CGFloat radians) {
    UIGraphicsBeginImageContextWithOptions(size, YES, 1); {
    [[UIColor whiteColor] setFill];
    UIRectFill(CGRectInfinite);
    CGContextRef gc = UIGraphicsGetCurrentContext();
    CGContextTranslateCTM(gc, size.width / 2, size.height / 2);
    CGContextRotateCTM(gc, radians);
    CGContextTranslateCTM(gc, size.width / 4, 0);
    [[UIColor redColor] setFill];
    CGFloat w = size.width / 10;
    CGContextFillEllipseInRect(gc, CGRectMake(-w / 2, -w / 2, w, w));
    }
    UIImage *image = UIGraphicsGetImageFromCurrentImageContext();
    UIGraphicsEndImageContext();
    return image;
    }

    static void makeAnimatedGif(void) {
    static NSUInteger kFrameCount = 16;

    NSDictionary *fileProperties = @{
    (__bridge id)kCGImagePropertyGIFDictionary: @{
    (__bridge id)kCGImagePropertyGIFLoopCount: @0, // 0 means loop forever
    }
    };

    NSDictionary *frameProperties = @{
    (__bridge id)kCGImagePropertyGIFDictionary: @{
    (__bridge id)kCGImagePropertyGIFDelayTime: @0.02f, // a float (not double!) in seconds, rounded to centiseconds in the GIF data
    }
    };

    NSURL *documentsDirectoryURL = [[NSFileManager defaultManager] URLForDirectory:NSDocumentDirectory inDomain:NSUserDomainMask appropriateForURL:nil create:YES error:nil];
    NSURL *fileURL = [documentsDirectoryURL URLByAppendingPathComponent:@"animated.gif"];

    CGImageDestinationRef destination = CGImageDestinationCreateWithURL((__bridge CFURLRef)fileURL, kUTTypeGIF, kFrameCount, NULL);
    CGImageDestinationSetProperties(destination, (__bridge CFDictionaryRef)fileProperties);

    for (NSUInteger i = 0; i < kFrameCount; i++) {
    @autoreleasepool {
    UIImage *image = frameImage(CGSizeMake(300, 300), M_PI * 2 * i / kFrameCount);
    CGImageDestinationAddImage(destination, image.CGImage, (__bridge CFDictionaryRef)frameProperties);
    }
    }

    if (!CGImageDestinationFinalize(destination)) {
    NSLog(@"failed to finalize image destination");
    }
    CFRelease(destination);

    NSLog(@"url=%@", fileURL);
    }