/**
?@file?mem_image.cpp
?@author?Kevin?Lynx
?@brief?to?load/save?images?from/to?memory?based?on?GDI+
*/
#include?“mem_image.h“
#include?

static?int?GetEncoderClsid（?const?WCHAR?*format?CLSID?*pClsid?）
{
	UINT?num?=?0?size?=?0;
	Gdiplus::ImageCodecInfo?*pImageCodecInfo?=?NULL;?
	Gdiplus::GetImageEncodersSize（?&num?&size?）;
	if（?size?==?0?）
	{
		return?-1;
	}
	pImageCodecInfo?=?（Gdiplus::ImageCodecInfo*）?malloc（?size?）;
	Gdiplus::GetImageEncoders（?num?size?pImageCodecInfo?）;
	for（?UINT?i?=?0;?i?	{
		if（?wcscmp（?pImageCodecInfo[i].MimeType?format?）?==?0?）
		{
			*pClsid?=?pImageCodecInfo[i].Clsid;
			free（?pImageCodecInfo?）;
			return?i;
		}
	}
	free（?pImageCodecInfo?）;
	return?-1;
}

static?bool?mem_to_global（?const?void?*buf?size_t?size?HGLOBAL?global?）
{
	void?*dest?=?::GlobalLock（?global?）;
	if（?dest?==?NULL?）
	{
		return?false;
	}
	memcpy（?dest?buf?size?）;
	::GlobalUnlock（?global?）;
	return?true;
}

static?bool?stream_to_mem（?IStream?*stream?void?**outbuf?size_t?*size?）
{
	ULARGE_INTEGER?ulnSize;
	LARGE_INTEGER?lnOffset;
	lnOffset.QuadPart?=?0;
	/*?get?the?stream?size?*/
	if（?stream->Seek（?lnOffset?STREAM_SEEK_END?&ulnSize?）?!=?S_OK?）
	{
		return?false;
	}
	if（?stream->Seek（?lnOffset?STREAM_SEEK_SET?NULL?）?!=?S_OK?）
	{
		return?false;
	}

	/*?read?it?*/
	*outbuf?=?malloc（?（size_t）ulnSize.QuadPart?）;
	*size?=?（size_t）?ulnSize.QuadPart;
	ULONG?bytesRead;
	if（?stream->Read（?*outbuf?（ULONG）ulnSize.QuadPart?&bytesRead?）?!=?S_OK?）
	{
		free（?*outbuf?）;
		return?false;
	}

	return?true;
}

Gdiplus::Image?*mi_from_memory（?const?void?*buf?size_t?size?）
{
	IStream?*stream?=?NULL;
	HGLOBAL?global?=?::GlobalAlloc（?GMEM_MOVEABLE?size?）;
	if（?global?==?NULL?）
	{
		return?NULL;
	}
	/*?copy?the?buf?content?to?the?HGLOBAL?*/
	if（?!mem_to_global（?buf?size?global?）?）
	{
		::GlobalFree（?global?）;
		return?NULL;
	}
	/*?get?the?IStream?from?the?global?object?*/
	if（?::CreateStreamOnHGlobal（?global?TRUE?&stream?）?!=?S_OK?）
	{
		::GlobalFree（?global?）;
		return?NULL;
	}
	/*?create?the?image?from?the?stream?*/
	Gdiplus::Image?*image?=?Gdiplus::Image::FromStream（?stream?）;

	stream->Release（）;
	/*?i?suppose?when?the?reference?count?for?stream?is?0?it?will?
	GlobalFree?automatically.?The?Image?maintain?the?object?also.*/	
	return?image;
}

void?*mi_to_memory（?Gdiplus::Image?*image?void?**outbuf?size_t?*size?）
{
	IStream?*stream?=?NULL;
	if（?::CreateStreamOnHGlobal（?NULL?TRUE?&stream?）?!=?S_OK?）
	{
		return?NULL;
	}
	/*?get?the?jpg?encoder?*/
	::CLSID?jpgClsid;
	GetEncoderClsid（?L“image/jpeg“?&jpgClsid?）;

	/*?save?the?image?to?stream?*/
	Gdiplus::Status?save_s?=?image->Save（?stream?&jpgClsid?）;
	if（?save_s?!=?Gdiplus::Ok?）
	{
		stream->Release（）;
		return?NULL;
	}

	/*?read?the?stream?to?buffer?*/
	if（?!stream_to_mem（?stream?outbuf?size?）?）
	{
		stream->Release（）;
		return?NULL;
	}
	return

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????目錄???????????0??2017-10-09?14:12??Screen_Shot\
?????目錄???????????0??2017-10-09?14:12??Screen_Shot\Debug\
?????目錄???????????0??2017-10-09?14:12??Screen_Shot\ScreenShot\
?????文件?????????897??2017-09-26?22:08??Screen_Shot\ScreenShot.sln
?????文件???????18432??2017-10-09?14:12??Screen_Shot\ScreenShot.suo
?????文件????????3014??2009-05-28?19:47??Screen_Shot\ScreenShot\mem_image.cpp
?????文件?????????645??2009-05-28?19:47??Screen_Shot\ScreenShot\mem_image.h
?????文件????????2366??2017-09-26?22:08??Screen_Shot\ScreenShot\ReadMe.txt
?????文件????????1980??2017-09-26?22:13??Screen_Shot\ScreenShot\resource.h
?????文件???????52660??2017-10-09?13:52??Screen_Shot\ScreenShot\ScreenShot.aps
?????文件????????7186??2017-10-09?14:12??Screen_Shot\ScreenShot\ScreenShot.cpp
?????文件??????????39??2017-09-26?22:08??Screen_Shot\ScreenShot\ScreenShot.h
?????文件???????23558??2009-08-31?02:31??Screen_Shot\ScreenShot\ScreenShot.ico
?????文件????????7496??2017-10-09?13:52??Screen_Shot\ScreenShot\ScreenShot.rc
?????文件????????4607??2017-10-09?11:56??Screen_Shot\ScreenShot\ScreenShot.vcxproj
?????文件????????1804??2017-10-09?11:56??Screen_Shot\ScreenShot\ScreenShot.vcxproj.filters
?????文件?????????143??2017-09-26?22:08??Screen_Shot\ScreenShot\ScreenShot.vcxproj.user
?????文件???????23558??2009-08-31?02:31??Screen_Shot\ScreenShot\small.ico
?????文件?????????215??2017-09-26?22:08??Screen_Shot\ScreenShot\stdafx.cpp
?????文件?????????420??2017-09-26?22:08??Screen_Shot\ScreenShot\stdafx.h
?????文件?????????236??2017-09-26?22:08??Screen_Shot\ScreenShot\targetver.h