// Copyright Eric Wing
// This plugin is the bridge to OS X's ImageIO framework
// which provides access to all of Apple's supported image types.
// This plugin plus the QTKit plugin obsoletes the old QuickTime plugin.
// This requires 10.4+. (The old QuickTime plugin will not support 64-bit.)


// Needs testing, especially in:
// 8-bits per pixel (256 color vs GL_ALPHA, and what about GL_LUMINANCE)?
// 16-bits per pixel (is GL_LUMINANCE_ALPHA a safe assumption?)
// Non-power-of-two textures (especially odd sizes)
// istream code path
// ostream code path
// write image, especially GL_LUMINANCE and GL_ALPHA paths and image formats other than PNG/JPEG

// Enhancements needed:
// Way to provide image type hint to ImageIO calls (via CFDictionary),
// probably especially important for istream which lacks extension information.
// Is there information we can use in the OSG options parameter?

// For ImageIO framework and also LaunchServices framework (for UTIs)
#include <ApplicationServices/ApplicationServices.h>
// For the vImage framework (part of the Accerlate framework)
#include <Accelerate/Accelerate.h>

// Used because CGDataProviderCreate became deprecated in 10.5
#include <AvailabilityMacros.h>

#include <osg/GL>
#include <osg/Notify>
#include <osg/Image>

#include <osgDB/Registry>
#include <osgDB/FileNameUtils>
#include <osgDB/FileUtils>

#include <sstream> // for istream
#include <iostream> // for ios::


/**************************************************************
 ***** Begin Callback functions for istream block reading *****
 **************************************************************/
 
// This callback reads some bytes from an istream and copies it
// to a Quartz buffer (supplied by Apple framework).
size_t MyProviderGetBytesCallback(void* istream_userdata, void* quartz_buffer, size_t the_count)
{
	std::istream* the_istream = (std::istream*)istream_userdata;
	the_istream->read((char*)quartz_buffer, the_count);
	return the_istream->gcount(); // return the actual number of bytes read
}

// This callback is triggered when the data provider is released
// so you can clean up any resources.
void MyProviderReleaseInfoCallback(void* istream_userdata)
{
	// What should I put here? Do I need to close the istream?
	// The png and tga don't seem to.
//	std::istream* the_istream = (std::istream*)istream_userdata;
}

void MyProviderRewindCallback(void* istream_userdata)
{
	std::istream* the_istream = (std::istream*)istream_userdata;
	the_istream->seekg(0, std::ios::beg);
}

#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
off_t MyProviderSkipForwardBytesCallback(void* istream_userdata, off_t the_count)
{
	std::istream* the_istream = (std::istream*)istream_userdata;
    off_t start_position = the_istream->tellg();
	the_istream->seekg(the_count, std::ios::cur);
    off_t end_position = the_istream->tellg();
    return (end_position - start_position);
}
#else // CGDataProviderCreate was deprecated in 10.5
void MyProviderSkipBytesCallback(void* istream_userdata, size_t the_count)
{
	std::istream* the_istream = (std::istream*)istream_userdata;
	the_istream->seekg(the_count, std::ios::cur);
}
#endif

/**************************************************************
***** End Callback functions for istream block reading ********
**************************************************************/


/**************************************************************
***** Begin Callback functions for ostream block writing ******
**************************************************************/
size_t MyConsumerPutBytesCallback(void* ostream_userdata, const void* quartz_buffer, size_t the_count)
{
	std::ostream* the_ostream = (std::ostream*)ostream_userdata;
	the_ostream->write((char*)quartz_buffer, the_count);
	// Don't know how to get number of bytes actually written, so
	// just returning the_count.
	return the_count;
}

void MyConsumerReleaseInfoCallback(void* ostream_userdata)
{
	std::ostream* the_ostream = (std::ostream*)ostream_userdata;
	the_ostream->flush();
}
/**************************************************************
***** End Callback functions for ostream block writing ********
**************************************************************/


/**************************************************************
***** Begin Support functions for reading (stream and file) ***
**************************************************************/

/* Create a CGImageSourceRef from raw data */
CGImageRef CreateCGImageFromDataStream(std::istream& fin)
{
    CGImageRef image_ref = NULL;
    CGImageSourceRef source_ref;
	/* The easy way would be to use CGImageSourceCreateWithData,
	 * but this presumes you have a known fixed-length buffer of data.
	 * The istream makes this harder to know, so we use the ProviderCallbacks APIs
	CFDataRef the_cf_data = CFDataCreateWithBytesNoCopy(
		kCFAllocatorDefault,
		(const UInt8*)the_data,
		CFIndex length,
		kCFAllocatorNull // do not free data buffer, must do it yourself
	);
    source_ref = CGImageSourceCreateWithData(the_cf_data, NULL);
*/

#if MAC_OS_X_VERSION_MAX_ALLOWED >= 1050 // CGDataProviderCreateSequential was introduced in 10.5; CGDataProviderCreate is deprecated
	CGDataProviderSequentialCallbacks provider_callbacks =
	{
        0,
		MyProviderGetBytesCallback,
		MyProviderSkipForwardBytesCallback,
		MyProviderRewindCallback,
		MyProviderReleaseInfoCallback
	};
	
	CGDataProviderRef data_provider = CGDataProviderCreateSequential(&fin, &provider_callbacks);


#else // CGDataProviderCreate was deprecated in 10.5

	CGDataProviderCallbacks provider_callbacks =
	{
		MyProviderGetBytesCallback,
		MyProviderSkipBytesCallback,
		MyProviderRewindCallback,
		MyProviderReleaseInfoCallback
	};
	
	CGDataProviderRef data_provider = CGDataProviderCreate(&fin, &provider_callbacks);
#endif
	// If we had a way of hinting at what the data type is, we could
	// pass this hint in the second parameter.
	source_ref = CGImageSourceCreateWithDataProvider(data_provider, NULL);

	CGDataProviderRelease(data_provider);


    if(!source_ref)
	{
		return NULL;
	}

	image_ref = CGImageSourceCreateImageAtIndex(source_ref, 0, NULL);
	
	/* Don't need the SourceRef any more (error or not) */
	CFRelease(source_ref);

	return image_ref;
}


/* Create a CGImageSourceRef from a file. */
/* Remember to CFRelease the created image when done. */
CGImageRef CreateCGImageFromFile(const char* the_path)
{
    CFURLRef the_url = NULL;
    CGImageRef image_ref = NULL;
    CGImageSourceRef source_ref = NULL;
	CFStringRef cf_string = NULL;

	/* Create a CFString from a C string */
	cf_string = CFStringCreateWithCString(
		NULL,
		the_path,
		kCFStringEncodingUTF8
	);
	if(!cf_string)
	{
		osg::notify(osg::WARN) << "CreateCGImageFromFile :: could not create CCFSTring" << std::endl;
        return NULL;
	}
 
	/* Create a CFURL from a CFString */
    the_url = CFURLCreateWithFileSystemPath(
		NULL, 
		cf_string,
		kCFURLPOSIXPathStyle,
		false
	);

	/* Don't need the CFString any more (error or not) */
	CFRelease(cf_string);
	
	if(!the_url)
	{
		osg::notify(osg::WARN) << "CreateCGImageFromFile :: could not create CFUrl" << std::endl;
        return NULL;
	}

	
    source_ref = CGImageSourceCreateWithURL(the_url, NULL);
	/* Don't need the URL any more (error or not) */
	CFRelease(the_url);

    if(!source_ref)
	{
		osg::notify(osg::WARN) << "CreateCGImageFromFile :: could not create ImageSource" << std::endl;
        return NULL;
    }

	// Get the first item in the image source (some image formats may
	// contain multiple items).
	image_ref = CGImageSourceCreateImageAtIndex(source_ref, 0, NULL);
	if (!image_ref) {
        osg::notify(osg::WARN) << "CreateCGImageFromFile :: could not get Image" << std::endl;
    }
    
	/* Don't need the SourceRef any more (error or not) */
	CFRelease(source_ref);

	return image_ref;
}

/* Once we have our image (CGImageRef), we need to get it into an osg::Image */
osg::Image* CreateOSGImageFromCGImage(CGImageRef image_ref)
{
	/* This code is adapted from Apple's Documentation found here:
	 * http://developer.apple.com/documentation/GraphicsImaging/Conceptual/OpenGL-MacProgGuide/index.html
	 * Listing 9-4††Using a Quartz image as a texture source.
	 * Unfortunately, this guide doesn't show what to do about
	 * non-RGBA image formats so I'm making the rest up
	 * (and it's probably all wrong).
	 */

	size_t the_width = CGImageGetWidth(image_ref);
	size_t the_height = CGImageGetHeight(image_ref);
	CGRect the_rect = {{0, 0}, {the_width, the_height}};

	size_t bits_per_pixel = CGImageGetBitsPerPixel(image_ref);
	size_t bytes_per_row = CGImageGetBytesPerRow(image_ref);
//	size_t bits_per_component = CGImageGetBitsPerComponent(image_ref);
	size_t bits_per_component = 8;
	
	CGImageAlphaInfo alpha_info = CGImageGetAlphaInfo(image_ref);
	
	GLint internal_format;
	GLenum pixel_format;
	GLenum data_type;
	
	void* image_data = calloc(the_width * 4, the_height);

	CGColorSpaceRef color_space;
	CGBitmapInfo bitmap_info = CGImageGetBitmapInfo(image_ref);

	switch(bits_per_pixel)
	{
		// Drat, if 8-bit, how do you distinguish
		// between a 256 color GIF, a LUMINANCE map
		// or an ALPHA map?
		case 8:
		{
			// I probably did the formats all wrong for this case,
			// especially the ALPHA case.
			if(kCGImageAlphaNone == alpha_info)
			{
				/*
				 internal_format = GL_LUMINANCE;
				 pixel_format = GL_LUMINANCE;
				 */
				internal_format = GL_RGBA8;
				pixel_format = GL_BGRA_EXT;
				data_type = GL_UNSIGNED_INT_8_8_8_8_REV;
				
				bytes_per_row = the_width*4;
//				color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
				color_space = CGColorSpaceCreateDeviceRGB();
//				bitmap_info = kCGImageAlphaPremultipliedFirst;
#if __BIG_ENDIAN__
				bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */
#else
				bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */
#endif 
			}
			else
			{
				internal_format = GL_ALPHA;
				pixel_format = GL_ALPHA;
				data_type = GL_UNSIGNED_BYTE;
				//			bytes_per_row = the_width;
//				color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericGray);
				color_space = CGColorSpaceCreateDeviceGray();
			}

			break;
		}
		case 16:
		{
			// FIXME: Is this really a reasonable assumption: GL_LUMINANCE_ALPHA?
			internal_format = GL_LUMINANCE_ALPHA;
			pixel_format = GL_LUMINANCE_ALPHA;
			data_type = GL_UNSIGNED_BYTE;
//			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericGray);
			color_space = CGColorSpaceCreateDeviceGray();
			break;
		}
		case 24:
		{
			internal_format = GL_RGBA8;
			pixel_format = GL_BGRA_EXT;
			data_type = GL_UNSIGNED_INT_8_8_8_8_REV;
			bytes_per_row = the_width*4;
//			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
			color_space = CGColorSpaceCreateDeviceRGB();
//			bitmap_info = kCGImageAlphaNone;
#if __BIG_ENDIAN__
			bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */
#else
			bitmap_info = kCGImageAlphaNoneSkipFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */
#endif       
			break;
		}
		case 32:
		{
			
			internal_format = GL_RGBA8;
			pixel_format = GL_BGRA_EXT;
			data_type = GL_UNSIGNED_INT_8_8_8_8_REV;
			
			bytes_per_row = the_width*4;
//			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
			color_space = CGColorSpaceCreateDeviceRGB();
//			bitmap_info = kCGImageAlphaPremultipliedFirst;
#if __BIG_ENDIAN__
			bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */
#else
			bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */
#endif 
			break;
		}
		default:
		{
			// osg::notify(osg::WARN) << "Unknown file type in " << fileName.c_str() << " with " << origDepth << std::endl;
            return NULL;
            break;
		}

	}
	
	// Sets up a context to be drawn to with image_data as the area to be drawn to
	CGContextRef bitmap_context = CGBitmapContextCreate(
		image_data,
		the_width,
		the_height,
		bits_per_component,
		bytes_per_row,
		color_space,
		bitmap_info
	);
	
	// Draws the image into the context's image_data
	CGContextDrawImage(bitmap_context, the_rect, image_ref);

	CGContextRelease(bitmap_context);

	osg::Image* osg_image = new osg::Image;
	
	osg_image->setImage(
		the_width,
		the_height,
		1,
		internal_format,
		pixel_format,
		data_type,
		(unsigned char*)image_data,
		osg::Image::USE_MALLOC_FREE // Assumption: osg_image takes ownership of image_data and will free
	);

	osg_image->flipVertical();
	return osg_image;



}
/**************************************************************
***** End Support functions for reading (stream and file) *****
**************************************************************/


/**************************************************************
***** Begin Support functions for writing (stream and file)****
**************************************************************/

/* Create a CGImageRef from osg::Image.
 * Code adapted from
 * http://developer.apple.com/samplecode/OpenGLScreenSnapshot/listing2.html
 */
CGImageRef CreateCGImageFromOSGData(const osg::Image& osg_image)
{
	size_t image_width = osg_image.s();
	size_t image_height = osg_image.t();
	/* From Apple's header for CGBitmapContextCreate()
	 * Each row of the bitmap consists of `bytesPerRow' bytes, which must be at
	 * least `(width * bitsPerComponent * number of components + 7)/8' bytes.
	 */
	size_t target_bytes_per_row;
	 
	CGColorSpaceRef color_space;
	CGBitmapInfo bitmap_info;
	/* From what I can figure out so far...
	 * We need to create a CGContext connected to the data we want to save
	 * and then call CGBitmapContextCreateImage() on that context to get
	 * a CGImageRef.
	 * However, OS X only allows 4-component image formats (e.g. RGBA) and not
	 * just RGB for the RGB-based CGContext. So for a 24-bit image coming in,
	 * we need to expand the data to 32-bit.
	 * The easiest and fastest way to do that is through the vImage framework
	 * which is part of the Accelerate framework.
	 * Also, the osg::Image data coming in is inverted from what we want, so
	 * we need to invert the image too. Since the osg::Image is const,
	 * we don't want to touch the data, so again we turn to the vImage framework
	 * and invert the data.
	 */
	vImage_Buffer vimage_buffer_in = 
	{
		(void*)osg_image.data(), // need to override const, but we don't modify the data so it's safe
		image_height,
		image_width,
		osg_image.getRowSizeInBytes()
	};

	void* out_image_data;
	vImage_Buffer vimage_buffer_out =
	{
		NULL, // will fill-in in switch
		image_height,
		image_width,
		0 // will fill-in in switch
	};	
	vImage_Error vimage_error_flag;

	// FIXME: Do I want to use format, type, or internalFormat?
	switch(osg_image.getPixelFormat())
	{
		case GL_LUMINANCE:
		{
			bitmap_info = kCGImageAlphaNone;
			target_bytes_per_row = (image_width * 8 + 7)/8;
			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericGray);
			if(NULL == color_space)
			{
				return NULL;
			}
			
			//	out_image_data = calloc(target_bytes_per_row, image_height);
			out_image_data = malloc(target_bytes_per_row * image_height);			
			if(NULL == out_image_data)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, malloc failed" << std::endl;
				CGColorSpaceRelease(color_space);
				return NULL;
			}

			vimage_buffer_out.data = out_image_data;
			vimage_buffer_out.rowBytes = target_bytes_per_row;

			// Now invert the image
			vimage_error_flag = vImageVerticalReflect_Planar8(
				&vimage_buffer_in, // since the osg_image is const...
				&vimage_buffer_out, // don't reuse the buffer
				kvImageNoFlags
			);
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData for GL_LUMINANCE, vImageVerticalReflect_Planar8 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				CGColorSpaceRelease(color_space);
				return NULL;
			}			


			break;
		}
		case GL_ALPHA:
		{
			bitmap_info = kCGImageAlphaOnly;
			target_bytes_per_row = (image_width * 8 + 7)/8;
			// According to:
			// http://developer.apple.com/qa/qa2001/qa1037.html
			// colorSpace=NULL is for alpha only
			color_space = NULL;
			
			//	out_image_data = calloc(target_bytes_per_row, image_height);
			out_image_data = malloc(target_bytes_per_row * image_height);			
			if(NULL == out_image_data)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, malloc failed" << std::endl;
				return NULL;
			}

			vimage_buffer_out.data = out_image_data;
			vimage_buffer_out.rowBytes = target_bytes_per_row;

			// Now invert the image
			vimage_error_flag = vImageVerticalReflect_Planar8(
				&vimage_buffer_in, // since the osg_image is const...
				&vimage_buffer_out, // don't reuse the buffer
				kvImageNoFlags
			);
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData for GL_ALPHA, vImageVerticalReflect_Planar8 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				return NULL;
			}			


			break;
		}
/*
		case GL_LUMINANCE_ALPHA:
		{
			// I don't know if we can support this.
			// The qa1037 doesn't show both gray+alpha.
			break;
		}
*/
		case GL_RGB:
		{
			bitmap_info = kCGImageAlphaNoneSkipFirst;
			target_bytes_per_row = (image_width * 8 * 4 + 7)/8;
			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
			if(NULL == color_space)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, CGColorSpaceCreateWithName failed" << std::endl;
				return NULL;
			}
			
			//	out_image_data = calloc(target_bytes_per_row, image_height);
			out_image_data = malloc(target_bytes_per_row * image_height);			
			if(NULL == out_image_data)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, malloc failed" << std::endl;
				CGColorSpaceRelease(color_space);
				return NULL;
			}

			// Use vImage to get an RGB buffer into ARGB.
			vimage_buffer_out.data = out_image_data;
			vimage_buffer_out.rowBytes = target_bytes_per_row;
			vimage_error_flag = vImageConvert_RGB888toARGB8888(
				&vimage_buffer_in,
				NULL, // we don't have a buffer containing alpha values
				255, // The alpha value we want given to all pixels since we don't have a buffer
				&vimage_buffer_out,
				0, // premultiply?
				kvImageNoFlags // Only responds to kvImageDoNotTile, but I think we want tiling/threading
			);
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, vImageConvert_RGB888toARGB8888 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				CGColorSpaceRelease(color_space);
				return NULL;
			}
			// Now invert the image
			vimage_error_flag = vImageVerticalReflect_ARGB8888(
				&vimage_buffer_out,
				&vimage_buffer_out, // reuse the same buffer
				kvImageNoFlags
			);
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, vImageAffineWarp_ARGB8888 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				CGColorSpaceRelease(color_space);
				return NULL;
			}			
			
			break;
		}
		case GL_RGBA:
		{
			bitmap_info = kCGImageAlphaPremultipliedLast;
			target_bytes_per_row = osg_image.getRowSizeInBytes();
			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
			if(NULL == color_space)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, CGColorSpaceCreateWithName failed" << std::endl;
				return NULL;
			}
			//	out_image_data = calloc(target_bytes_per_row, image_height);
			out_image_data = malloc(target_bytes_per_row * image_height);			
			if(NULL == out_image_data)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, malloc failed" << std::endl;
				CGColorSpaceRelease(color_space);
				return NULL;
			}
			vimage_buffer_out.data = out_image_data;
			vimage_buffer_out.rowBytes = target_bytes_per_row;
			// Invert the image
			vimage_error_flag = vImageVerticalReflect_ARGB8888(
				&vimage_buffer_in, // since the osg_image is const...
				&vimage_buffer_out, // don't reuse the buffer
				kvImageNoFlags
			);
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, vImageAffineWarp_ARGB8888 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				CGColorSpaceRelease(color_space);
				return NULL;
			}			
			break;
		}
		case GL_BGRA:
		{
			if(GL_UNSIGNED_INT_8_8_8_8_REV == osg_image.getDataType())
			{
#if __BIG_ENDIAN__
				bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Big; /* XRGB Big Endian */
#else
				bitmap_info = kCGImageAlphaPremultipliedFirst | kCGBitmapByteOrder32Little; /* XRGB Little Endian */
#endif 
			}
			else
			{
				// FIXME: Don't know how to handle this case
				bitmap_info = kCGImageAlphaPremultipliedLast;
			}

			target_bytes_per_row = osg_image.getRowSizeInBytes();
			color_space = CGColorSpaceCreateWithName(kCGColorSpaceGenericRGB);
			if(NULL == color_space)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, CGColorSpaceCreateWithName failed" << std::endl;
				return NULL;
			}
			//	out_image_data = calloc(target_bytes_per_row, image_height);
			out_image_data = malloc(target_bytes_per_row * image_height);			
			if(NULL == out_image_data)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, malloc failed" << std::endl;
				CGColorSpaceRelease(color_space);
				return NULL;
			}
			vimage_buffer_out.data = out_image_data;
			vimage_buffer_out.rowBytes = target_bytes_per_row;
			// Invert the image
			vimage_error_flag = vImageVerticalReflect_ARGB8888(
															   &vimage_buffer_in, // since the osg_image is const...
															   &vimage_buffer_out, // don't reuse the buffer
															   kvImageNoFlags
															   );
			if(vimage_error_flag != kvImageNoError)
			{
				osg::notify(osg::WARN) << "In CreateCGImageFromOSGData, vImageAffineWarp_ARGB8888 failed with vImage Error Code: " << vimage_error_flag << std::endl;
				free(out_image_data);
				CGColorSpaceRelease(color_space);
				return NULL;
			}			
			break;
		}
		// FIXME: Handle other cases.
		// Use vImagePermuteChannels_ARGB8888 to swizzle bytes
		default:
		{
			osg::notify(osg::WARN) << "In CreateCGImageFromOSGData: Sorry support for this format is not implemented." << std::endl;
			return NULL;
			break;
		}
	}

	CGContextRef bitmap_context = CGBitmapContextCreate(
		vimage_buffer_out.data,
		vimage_buffer_out.width,
		vimage_buffer_out.height,
		8,
		vimage_buffer_out.rowBytes,
		color_space,
		bitmap_info
	);
	/* Done with color space */
	CGColorSpaceRelease(color_space);

	if(NULL == bitmap_context)
	{
		free(out_image_data);
		return NULL;
	}
	

	/* Make an image out of our bitmap; does a cheap vm_copy of the bitmap */
	CGImageRef image_ref = CGBitmapContextCreateImage(bitmap_context);

	/* Done with data */
	free(out_image_data);

	/* Done with bitmap_context */
	CGContextRelease(bitmap_context);

	return image_ref;
}


/* Create a CGImageDestinationRef from a file. */
/* Remember to CFRelease when done. */
CGImageDestinationRef CreateCGImageDestinationFromFile(const char* the_path,  const osgDB::ReaderWriter::Options* the_options)
{
    CFURLRef the_url = NULL;
	CFStringRef cf_string = NULL;
	CFStringRef uti_type = NULL;
    CGImageDestinationRef dest_ref = NULL;
	bool found_png_option = false;
	bool found_jpeg_option = false;
	float compression_quality = 1.0f;

	/* Create a CFString from a C string */
	cf_string = CFStringCreateWithCString(
		NULL,
		the_path,
		kCFStringEncodingUTF8
	);
	if(!cf_string)
	{
		return NULL;
	}
	
	/* Create a CFURL from a CFString */
    the_url = CFURLCreateWithFileSystemPath(
		NULL, 
		cf_string,
		kCFURLPOSIXPathStyle,
		false
	);
	
	/* Don't need the CFString any more (error or not) */
	CFRelease(cf_string);
	
	if(!the_url)
	{
		return NULL;
	}
	
	if(the_options)
	{
		std::istringstream iss(the_options->getOptionString());
		std::string opt;
		while (iss >> opt)
		{
			// Not handled: The user could do something stupid and specify both PNG and JPEG options.
			
			if(opt=="PNG_COMPRESSION")
			{
				found_png_option = true;
				// I don't see an option to set PNG compression levels in the API so this info is unused.
				int level;
				iss >> level;
								
			}
			else if(opt=="JPEG_QUALITY")
			{
				found_jpeg_option = true;
				// Chances are that people are specifying values in libjpeg ranges and not ImageIO ranges.
				// ImageIO is normalized between 0.0 to 1.0 where 1.0 is lossless and 0 is max compression.
				// I am uncertain what libjpeg's range is. I'm guessing 0-100.
				int quality;
				iss >> quality;
				compression_quality = (float)quality/100.0f;
			}
		}
	}
	

	CFStringRef path_extension = CFURLCopyPathExtension(the_url);
	if(NULL == path_extension)
	{
		if(found_jpeg_option)
		{
			uti_type = UTTypeCreatePreferredIdentifierForTag(
				 kUTTagClassFilenameExtension,
				 CFSTR("jpg"),
				 kUTTypeImage // "public.image"
			);
		}
		else
		{
			uti_type = UTTypeCreatePreferredIdentifierForTag(
				 kUTTagClassFilenameExtension,
				 CFSTR("png"),
				 kUTTypeImage // "public.image"
			);
		}
	}
	else
	{
		uti_type = UTTypeCreatePreferredIdentifierForTag(
			kUTTagClassFilenameExtension,
			path_extension,
			kUTTypeImage // "public.image"
		);
		CFRelease(path_extension);
	}

													  
	dest_ref =  CGImageDestinationCreateWithURL(
		the_url, 
		uti_type, 
		1, // image file will contain only one image
		NULL
	);

	
	CFRelease(uti_type);
	CFRelease(the_url);


	// Not handled: The user could do something stupid and specify both PNG and JPEG options.
	if(found_jpeg_option)
	{
		// Do a bunch of work to setup a CFDictionary containing the jpeg compression properties.
		CFStringRef the_keys[1];
		CFNumberRef the_values[1];
		CFDictionaryRef the_dict;
				
		the_keys[0] = kCGImageDestinationLossyCompressionQuality;
		the_values[0] = CFNumberCreate(
			NULL,
			kCFNumberFloat32Type,
			&compression_quality
		);
		
		the_dict = CFDictionaryCreate(NULL, (const void**)&the_keys, (const void**)&the_values, 1, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
		CFRelease(the_values[0]);

		// Now that we have the dict, actually set the property.
		CGImageDestinationSetProperties(dest_ref, the_dict);
		
		CFRelease(the_dict);
	}

	return dest_ref;
}


/* Create a CGImageDestinationRef from a file. */
/* Remember to CFRelease when done. */
CGImageDestinationRef CreateCGImageDestinationFromDataStream(std::ostream& fout,  const osgDB::ReaderWriter::Options* the_options)
{
	CFStringRef uti_type = NULL;
    CGImageDestinationRef dest_ref = NULL;
	bool found_png_option = false;
	bool found_jpeg_option = false;
	float compression_quality = 1.0f;
	
	CGDataConsumerCallbacks consumer_callbacks =
	{
		MyConsumerPutBytesCallback,
		MyConsumerReleaseInfoCallback
	};
	
	CGDataConsumerRef data_consumer = CGDataConsumerCreate(&fout, &consumer_callbacks);

	if(the_options)
	{
		std::istringstream iss(the_options->getOptionString());
		std::string opt;
		while (iss >> opt)
		{
			// Not handled: The user could do something stupid and specify both PNG and JPEG options.
			
			if(opt=="PNG_COMPRESSION")
			{
				found_png_option = true;
				// I don't see an option to set PNG compression levels in the API so this info is unused.
				int level;
				iss >> level;
				
			}
			else if(opt=="JPEG_QUALITY")
			{
				found_jpeg_option = true;
				// Chances are that people are specifying values in libjpeg ranges and not ImageIO ranges.
				// ImageIO is normalized between 0.0 to 1.0 where 1.0 is lossless and 0 is max compression.
				// I am uncertain what libjpeg's range is. I'm guessing 0-100.
				int quality;
				iss >> quality;
				compression_quality = (float)quality/100.0f;
			}
		}
	}
	

	if(found_jpeg_option)
	{
		uti_type = UTTypeCreatePreferredIdentifierForTag(
			kUTTagClassFilenameExtension,
			CFSTR("jpg"),
			kUTTypeImage // "public.image"
		);
	}
	else // default to png
	{
		uti_type = UTTypeCreatePreferredIdentifierForTag(
			kUTTagClassFilenameExtension,
			CFSTR("png"),
			kUTTypeImage // "public.image"
		);
	}
	

	// If we had a way of hinting at what the data type is, we could
	// pass this hint in the second parameter.
	dest_ref = CGImageDestinationCreateWithDataConsumer(
		data_consumer,
		uti_type,
		1, // image file will contain only one image
		NULL
	);
	
	CGDataConsumerRelease(data_consumer);
	CFRelease(uti_type);
	
	
	// Not handled: The user could do something stupid and specify both PNG and JPEG options.
	if(found_jpeg_option)
	{
		// Do a bunch of work to setup a CFDictionary containing the jpeg compression properties.
		CFStringRef the_keys[1];
		CFNumberRef the_values[1];
		CFDictionaryRef the_dict;
		
		the_keys[0] = kCGImageDestinationLossyCompressionQuality;
		the_values[0] = CFNumberCreate(
									   NULL,
									   kCFNumberFloat32Type,
									   &compression_quality
									   );
		
		the_dict = CFDictionaryCreate(NULL, (const void**)&the_keys, (const void**)&the_values, 1, &kCFCopyStringDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
		CFRelease(the_values[0]);
		
		// Now that we have the dict, actually set the property.
		CGImageDestinationSetProperties(dest_ref, the_dict);
		
		CFRelease(the_dict);
	}
	
	return dest_ref;
}
/**************************************************************
***** End Support functions for writing (stream and file) *****
**************************************************************/



class ReaderWriterImageIO : public osgDB::ReaderWriter

{
public:
    ReaderWriterImageIO::ReaderWriterImageIO()
    {

         supportsExtension("jpg",   "jpg image file"); 
         supportsExtension("jpeg",  "jpeg image file");
         supportsExtension("jpe",   "jpe image file");
         supportsExtension("jp2",   "jp2 image file");
         supportsExtension("tiff",  "tiff image file"); 
         supportsExtension("tif",   "tif image file");               
         supportsExtension("gif",   "gif image file");
         supportsExtension("png",   "png image file");
         supportsExtension("pict",  "pict image file");
         supportsExtension("pct",   "pct image file");
         supportsExtension("pic",   "pic image file");
         supportsExtension("bmp",   "bmp image file");
         supportsExtension("BMPf",  "BMPf image file");
         supportsExtension("ico",   "ico image file");
         supportsExtension("icns",  "icns image file");
         supportsExtension("tga",   "tga image file");
         supportsExtension("targa", "targa image file");
         supportsExtension("psd",   "psd image file");
		 
         supportsExtension("pdf",   "pdf image file");
         supportsExtension("eps",   "eps image file");
         supportsExtension("epi",   "epi image file");
         supportsExtension("epsf",  "epsf image file");
         supportsExtension("epsi",  "epsi image file");
         supportsExtension("ps",    "postscript image file");
		 
         supportsExtension("dng",   "dng image file");
         supportsExtension("cr2",   "cr2 image file");
         supportsExtension("crw",   "crw image file");
         supportsExtension("fpx",   "fpx image file");
         supportsExtension("fpxi",  "fpxi image file");
         supportsExtension("raf",   "raf image file");
         supportsExtension("dcr",   "dcr image file");
         supportsExtension("ptng",  "ptng image file");
         supportsExtension("pnt",   "pnt image file");
         supportsExtension("mac",   "mac image file");
         supportsExtension("mrw",   "mrw image file");
         supportsExtension("nef",   "nef image file");
         supportsExtension("orf",   "orf image file");
         supportsExtension("exr",   "exr image file");
         supportsExtension("qti",   "qti image file");
         supportsExtension("qtif",  "qtif image file");
         supportsExtension("hdr",   "hdr image file");
         supportsExtension("sgi",   "sgi image file");
         supportsExtension("srf",   "srf image file");
         supportsExtension("cur",   "cur image file");
         supportsExtension("xbm",   "xbm image file");

         supportsExtension("raw",   "raw image file");
    }

	virtual const char* className() const { return "Mac OS X ImageIO based Image Reader/Writer"; }


   virtual bool acceptsExtension(const std::string& extension) const
   {
	   // ImageIO speaks in UTIs.
	   // http://developer.apple.com/graphicsimaging/workingwithimageio.html
	   // The Cocoa drawing guide lists these and says to use the
	   // imageFileTypes class method of NSImage to get a complete
	   // list of extensions. But remember ImageIO may support more formats
	   // than Cocoa.
	   // http://developer.apple.com/documentation/Cocoa/Conceptual/CocoaDrawingGuide/Images/chapter_7_section_3.html
	   // Apple's UTI guide:
	   // http://developer.apple.com/documentation/Carbon/Conceptual/understanding_utis/utilist/chapter_4_section_1.html
      return
         osgDB::equalCaseInsensitive(extension,"jpg") || 
         osgDB::equalCaseInsensitive(extension,"jpeg") ||
         osgDB::equalCaseInsensitive(extension,"jpe") ||
         osgDB::equalCaseInsensitive(extension,"jp2") ||
         osgDB::equalCaseInsensitive(extension,"tiff") || 
         osgDB::equalCaseInsensitive(extension,"tif") ||               
         osgDB::equalCaseInsensitive(extension,"gif") ||
         osgDB::equalCaseInsensitive(extension,"png") ||
         osgDB::equalCaseInsensitive(extension,"pict") ||
         osgDB::equalCaseInsensitive(extension,"pct") ||
         osgDB::equalCaseInsensitive(extension,"pic") ||
         osgDB::equalCaseInsensitive(extension,"bmp") ||
         osgDB::equalCaseInsensitive(extension,"BMPf") ||
         osgDB::equalCaseInsensitive(extension,"ico") ||
         osgDB::equalCaseInsensitive(extension,"icns") ||
         osgDB::equalCaseInsensitive(extension,"tga") ||
         osgDB::equalCaseInsensitive(extension,"targa") ||
         osgDB::equalCaseInsensitive(extension,"psd") ||
		 
         osgDB::equalCaseInsensitive(extension,"pdf") ||
         osgDB::equalCaseInsensitive(extension,"eps") ||
         osgDB::equalCaseInsensitive(extension,"epi") ||
         osgDB::equalCaseInsensitive(extension,"epsf") ||
         osgDB::equalCaseInsensitive(extension,"epsi") ||
         osgDB::equalCaseInsensitive(extension,"ps") ||
		 
         osgDB::equalCaseInsensitive(extension,"dng") ||
         osgDB::equalCaseInsensitive(extension,"cr2") ||
         osgDB::equalCaseInsensitive(extension,"crw") ||
         osgDB::equalCaseInsensitive(extension,"fpx") ||
         osgDB::equalCaseInsensitive(extension,"fpxi") ||
         osgDB::equalCaseInsensitive(extension,"raf") ||
         osgDB::equalCaseInsensitive(extension,"dcr") ||
         osgDB::equalCaseInsensitive(extension,"ptng") ||
         osgDB::equalCaseInsensitive(extension,"pnt") ||
         osgDB::equalCaseInsensitive(extension,"mac") ||
         osgDB::equalCaseInsensitive(extension,"mrw") ||
         osgDB::equalCaseInsensitive(extension,"nef") ||
         osgDB::equalCaseInsensitive(extension,"orf") ||
         osgDB::equalCaseInsensitive(extension,"exr") ||
         osgDB::equalCaseInsensitive(extension,"qti") ||
         osgDB::equalCaseInsensitive(extension,"qtif") ||
         osgDB::equalCaseInsensitive(extension,"hdr") ||
         osgDB::equalCaseInsensitive(extension,"sgi") ||
         osgDB::equalCaseInsensitive(extension,"srf") ||
         osgDB::equalCaseInsensitive(extension,"cur") ||
         osgDB::equalCaseInsensitive(extension,"xbm") ||

         osgDB::equalCaseInsensitive(extension,"raw");
   }


	
	ReadResult readImageStream(std::istream& fin) const
	{
		// Call ImageIO to load the image.
		CGImageRef cg_image_ref = CreateCGImageFromDataStream(fin);
		if (NULL == cg_image_ref) return ReadResult::FILE_NOT_FOUND;

		// Create an osg::Image from the CGImageRef.
		osg::Image* osg_image = CreateOSGImageFromCGImage(cg_image_ref);
	
		CFRelease(cg_image_ref);
		return osg_image;
	}

	virtual ReadResult readImage(std::istream& fin, const osgDB::ReaderWriter::Options* the_options = NULL) const
	{
		ReadResult read_result = readImageStream(fin);
		return read_result;
	}
	
	ReadResult readImageFile(const std::string& file_name) const
	{
		osg::notify(osg::INFO) << "imageio readImageFile: " << file_name << std::endl;
        
        // Call ImageIO to load the image.
		CGImageRef cg_image_ref = CreateCGImageFromFile(file_name.c_str());
		if (NULL == cg_image_ref) return ReadResult::FILE_NOT_FOUND;

		// Create an osg::Image from the CGImageRef.
		osg::Image* osg_image = CreateOSGImageFromCGImage(cg_image_ref);
	
		CFRelease(cg_image_ref);

		return osg_image;
	}

	virtual ReadResult readImage(const std::string& file_name, const osgDB::ReaderWriter::Options* the_options) const
	{
		std::string ext = osgDB::getLowerCaseFileExtension(file_name);
		if (!acceptsExtension(ext)) return ReadResult::FILE_NOT_HANDLED;

		std::string full_file_name = osgDB::findDataFile( file_name, the_options );
		if (full_file_name.empty()) return ReadResult::FILE_NOT_FOUND;

#if 1
		ReadResult read_result = readImageFile(full_file_name);
#else
		// Only here to help test istream backend. The file version is better because 
		// the filenname.extension could potentially be used by ImageIO to hint what the format type is.
		std::ifstream istream(full_file_name.c_str(), std::ios::in | std::ios::binary);
		if(!istream) return ReadResult::FILE_NOT_HANDLED;
		ReadResult read_result = readImage(istream);
#endif

		if(read_result.validImage())
		{
			read_result.getImage()->setFileName(full_file_name);
		}
		return read_result;
	}


	WriteResult writeImageStream(const osg::Image& osg_image, std::ostream& fout, const osgDB::ReaderWriter::Options* the_options) const
	{
		WriteResult ret_val = WriteResult::ERROR_IN_WRITING_FILE;

		CGImageDestinationRef cg_dest_ref = CreateCGImageDestinationFromDataStream(fout, the_options);
		if (NULL == cg_dest_ref) return WriteResult::ERROR_IN_WRITING_FILE;
		
		CGImageRef cg_image_ref = CreateCGImageFromOSGData(osg_image);
		if(NULL == cg_image_ref)
		{
			CFRelease(cg_dest_ref);
			return WriteResult::ERROR_IN_WRITING_FILE;
		}
		
		CGImageDestinationAddImage(cg_dest_ref, cg_image_ref, NULL);
		if(CGImageDestinationFinalize(cg_dest_ref))
		{
			ret_val = WriteResult::FILE_SAVED;
		}
		else
		{
			ret_val = WriteResult::ERROR_IN_WRITING_FILE;
		}
		
		CFRelease(cg_image_ref);
		CFRelease(cg_dest_ref);
		
		return WriteResult::FILE_SAVED;	
	}
		
	virtual WriteResult writeImage(const osg::Image& osg_image, std::ostream& fout, const osgDB::ReaderWriter::Options* the_options) const
	{
		WriteResult write_result = writeImageStream(osg_image, fout, the_options);
		return write_result;
	}

	WriteResult writeImageFile(const osg::Image& osg_image, const std::string& full_file_name, const osgDB::ReaderWriter::Options* the_options) const
	{
		WriteResult ret_val = WriteResult::ERROR_IN_WRITING_FILE;
		// Call ImageIO to load the image.
		CGImageDestinationRef cg_dest_ref = CreateCGImageDestinationFromFile(full_file_name.c_str(), the_options);
		if (NULL == cg_dest_ref) return WriteResult::ERROR_IN_WRITING_FILE;

		CGImageRef cg_image_ref = CreateCGImageFromOSGData(osg_image);
		if(NULL == cg_image_ref)
		{
			CFRelease(cg_dest_ref);
			return WriteResult::ERROR_IN_WRITING_FILE;
		}

		CGImageDestinationAddImage(cg_dest_ref, cg_image_ref, NULL);
		if(CGImageDestinationFinalize(cg_dest_ref))
		{
			ret_val = WriteResult::FILE_SAVED;
		}
		else
		{
			ret_val = WriteResult::ERROR_IN_WRITING_FILE;
		}
		
		CFRelease(cg_image_ref);
		CFRelease(cg_dest_ref);
		
		return WriteResult::FILE_SAVED;
	}

	virtual WriteResult writeImage(const osg::Image& osg_image, const std::string& file_name, const osgDB::ReaderWriter::Options* the_options) const
	{
		std::string ext = osgDB::getFileExtension(file_name);
		if (!acceptsExtension(ext)) return WriteResult::FILE_NOT_HANDLED;

#if 1
		// FIXME: Something may need to provide a proper writable location for the files.
		std::string full_file_name;
		full_file_name = file_name;
		return writeImageFile(osg_image, full_file_name, the_options);
#else
		// Only here to help test ostream backend. The file version is better because 
		// the filenname.extension could potentially be used by ImageIO to hint what the format type is.
		std::ofstream fout(file_name.c_str(), std::ios::out | std::ios::binary);
		if(!fout) return WriteResult::ERROR_IN_WRITING_FILE;
		return writeImage(osg_image, fout, the_options);
#endif		
	}

};

// now register with Registry to instantiate the above
// reader/writer.

osgDB::RegisterReaderWriterProxy<ReaderWriterImageIO> g_readerWriter_ImageIO_Proxy;