cocos2d-iphone screenshots

CCScreenshot.h

#import "cocos2d.h"

@interface CCScreenshot: NSObject

+ (NSString *)screenshotPathForFile:(NSString *)file;
+ (CCRenderTexture *)screenshotWithStartNode:(CCNode*)startNode filename:(NSString*)filename;

@end

CCScreenshot.m

#import "CCScreenshot.h"

@implementation CCScreenshot

+ (NSString *)screenshotPathForFile:(NSString *)file {
  NSArray* paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
  NSString* documentsDirectory = [paths objectAtIndex:0];
  NSString* screenshotPath = [documentsDirectory stringByAppendingPathComponent:file];
  return screenshotPath;
}

+ (CCRenderTexture *)screenshotWithStartNode:(CCNode*)startNode filename:(NSString*)filename {
  [CCDirector sharedDirector].nextDeltaTimeZero = YES;

  CGSize winSize = [CCDirector sharedDirector].winSize;
  CCRenderTexture* rtx = [CCRenderTexture renderTextureWithWidth:winSize.width height:winSize.height];

  [rtx begin];
  [startNode visit];
  [rtx end];

  [rtx saveBuffer:[self screenshotPathForFile:filename] format:kCCImageFormatPNG];
  return rtx;
}

@end

http://ios.biomsoft.com/2011/12/13/how-to-use-ccrendertexture-for-motion-blur-screenshots-and-drawing-sketches/#more-908