A category for Sparrow 1.X that allows a SPDisplayObject to be dynamically converted to a UIImage.

SPDisplayObject+Image.h

//
//  SPDisplayObject+Image.h
//  Sparrow
//
//  Created by Shilo White on 11/9/11.
//  Copyright (c) 2011 Shilocity Productions. All rights reserved.
//

#import "SPDisplayObject.h"

@interface SPDisplayObject (Image)
@property (nonatomic, readonly) UIImage *UIImage;
@property (nonatomic, readonly) UIImage *fullSizeUIImage;
- (UIImage *)UIImageWithBackgroundColor:(uint)backgroundColor;
- (UIImage *)UIImageWithBackgroundColor:(uint)backgroundColor fullSize:(BOOL)fullSize;
@end

SPDisplayObject+Image.m

//
//  SPDisplayObject+Image.m
//  Sparrow
//
//  Created by Shilo White on 11/9/11.
//  Copyright (c) 2011 Shilocity Productions. All rights reserved.
//

#import "SPDisplayObject+Image.h"
#import "SPView.h"
#import "SPRenderSupport.h"

@interface SPView (RenderSupport)
@property (nonatomic, readonly) SPRenderSupport *renderSupport;
@end

@implementation SPView (RenderSupport)
- (SPRenderSupport *)renderSupport {
    return mRenderSupport;
}
@end

@implementation SPDisplayObject (Image)
- (UIImage *)UIImage {
    return [self UIImageWithBackgroundColor:0x0];
}

- (UIImage *)fullSizeUIImage {
    return [self UIImageWithBackgroundColor:0x0 fullSize:YES];
}

- (UIImage *)UIImageWithBackgroundColor:(uint)backgroundColor {
    return [self UIImageWithBackgroundColor:backgroundColor fullSize:NO];
}

- (UIImage *)UIImageWithBackgroundColor:(uint)backgroundColor fullSize:(BOOL)fullSize {
    SPStage *stage = [SPStage mainStage];
    SPView *nativeView = stage.nativeView;
    int contentScaleFactor = [nativeView contentScaleFactor];
    int width = self.width*contentScaleFactor;
    int height = self.height*contentScaleFactor;
    int bufferLength = width*height*4;
    unsigned char buffer[bufferLength];
    
    [SPRenderSupport clearWithColor:backgroundColor alpha:1.0f];
    [self render:nativeView.renderSupport];
    glReadPixels(0, (stage.height*contentScaleFactor)-height, width, height, GL_RGBA, GL_UNSIGNED_BYTE, &buffer);
    
    CGDataProviderRef dataProviderRef = CGDataProviderCreateWithData(NULL, &buffer, bufferLength, NULL);
    CGImageRef imageRef = CGImageCreate(width, height, 8, 32, width*4, CGColorSpaceCreateDeviceRGB(), kCGBitmapByteOrderDefault, dataProviderRef, NULL, true, kCGRenderingIntentDefault);
    
    if (!fullSize) {
        width /= contentScaleFactor;
        height /= contentScaleFactor;
    }
    
    uint32_t *pixels = (uint32_t *)malloc(bufferLength);
    CGContextRef context = CGBitmapContextCreate(pixels, width, height, 8, width*4, CGImageGetColorSpace(imageRef), kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Big);
    
    CGContextTranslateCTM(context, 0, height);
    CGContextScaleCTM(context, 1.0, -1.0);
    CGContextDrawImage(context, CGRectMake(0, 0, width, height), imageRef);
    CGImageRelease(imageRef);
    
    imageRef = CGBitmapContextCreateImage(context);
    UIImage *image = [UIImage imageWithCGImage:imageRef];
    
    CGContextRelease(context);
    free(pixels);
    CGImageRelease(imageRef);
    CGDataProviderRelease(dataProviderRef);
    
    return image;
}
@end