C / C++ / MFC

Re: Win-Sockets / Unicode

23-Dec-06 6:52

In addition to Gary Wheeler's response..

This line

memcpy(pPointerToBuffer,MyString,wcslen(MyString)*sizeof(TCHAR))

IMO could be confusing. wcslen() is for wchar_t types only, but TCHAR is generic and its type
depends on whether UNICODE is defined or not. For code that could potentially be compiled with
OR without UNICODE then I'd recommend using all generics:

// All generics
memcpy(pPointerToBuffer,MyString,_tcslen(MyString)*sizeof(TCHAR))

For code that will always be UNICODE compiled, use:

// All wchar_t
memcpy(pPointerToBuffer,MyString,wcslen(MyString)*sizeof(wchar_t))

Whatever is best for your situation - the point is consistency (makes it easier to prevent or
track down bugs later Smile | :)

).

As stated by Mr Wheeler, both ends will need to know the character type. That can be exchanged in
initial handshake between peers or it could be assumed (always the same). Both are fine - it's
a matter of what you need.

Along the same lines, you mentioned you have int or DWORD values you send as well. If you know
the CPU on both ends will always store "int"s in little-endian format then you can just send
them as a byte stream (byte count = sizeof(int)). If there's a chance the peers will use
different byte ordering then you'll want to convert them to network byte order (or whatever
scheme you choose to use) so that both ends will always be able to put an int back together
in the proper order.

All that aside, your code is fine for Unicode strings Smile | :)

FreeCastle28-Dec-06 3:57

FreeCastle

28-Dec-06 3:57

Hey, thanks a lot. Now it's all clear to me. (sry for late reply)

Handling images

hint_5422-Dec-06 9:04

hint_54

22-Dec-06 9:04

Greetings

I'm building a website that has an automate engine to display pictures. There is a menu that lets you choose the event. The directories are organized like this:

- root
-- Weddings
--- WBlaBla1
---- Pic1
---- Pic2
---- PicN
--- WBlaBla2
---- Pic1
---- Pic2
---- PicN
--- SomeOtherTypeOfEventWithTheSameStructureHasPreviously
-- SomethingElse

The purpose is to sell the pictures, so it will have a cart shop. The problem is that I have the pictures in very high resolution, and I want to prevent the users from accessing the pictures in this format (i.e. 1807x1772). I know that PHP can handle this (i.e. display thumbnails) but the thing is that, with time, the events will be more and more, and this consumes space in the server, and the space is rented, offcourse.

So I had the idea of writting a C++ application that converts ALL the pictures in a directory to a low resolution version AND with a water mark, that way the sysadmin could convert the pictures before uploading them to the server. What I would like to ask is how to do this in C++, I mean, not search the pictures nor that sort of things, but how to lower the resolution and add the water mark to them. The pictures are all in JPG format.

Best regards

hint_54

Mark Salsbery22-Dec-06 12:08

22-Dec-06 12:08

Th easiest way I know of (on Windows) is to use GDI+ to load and save the images. A simple
stretchblt to a smaller, proportioned size is all that's necessary...load, resize, and save.

hint_5422-Dec-06 12:32

hint_54

22-Dec-06 12:32

I'll take a look Wink | ;)

thx

hint_54

Mark Salsbery22-Dec-06 12:47

22-Dec-06 12:47

Here ya go...a holiday present Smile | :)

(I ripped the GetEncoderClsid() right out of the GDI+ docs

int GetEncoderClsid(const WCHAR* format, CLSID* pClsid)
{
	UINT  num = 0;          // number of image encoders
	UINT  size = 0;         // size of the image encoder array in bytes
 
	ImageCodecInfo* pImageCodecInfo = NULL;
 
	GetImageEncodersSize(&num, &size);
	if(size == 0)
		return -1;  // Failure
 
	pImageCodecInfo = (ImageCodecInfo*)(malloc(size));
	if(pImageCodecInfo == NULL)
		return -1;  // Failure
 
	GetImageEncoders(num, size, pImageCodecInfo);
 
	for(UINT j = 0; j < num; ++j)
	{
		if( wcscmp(pImageCodecInfo[j].MimeType, format) == 0 )
		{
			*pClsid = pImageCodecInfo[j].Clsid;
			free(pImageCodecInfo);
			return j;  // Success
		}    
	}
 
	free(pImageCodecInfo);
	return -1;  // Failure
}
 
...
 
	// Resize an 640x480 image to 320x240
	// (I already know this source image is 640x480 - In real life use
	//   SrcBitmap.GetWidth() and SrcBitmap.GetHeight() to get an image's dimensions
 
	Gdiplus::Bitmap SrcBitmap(L"D:\\Source\\Images\\sony-cybershot.jpg", FALSE);
	Gdiplus::Bitmap DstBitmap(320,240,SrcBitmap.GetPixelFormat()); 
	Graphics DstGraphics(&DstBitmap);
	DstGraphics.DrawImage(&SrcBitmap, 0, 0, 320, 240);
	CLSID jpgClsid;
	GetEncoderClsid(L"image/jpeg", &jpgClsid);
	DstBitmap.Save(L"D:\\Source\\Images\\sony-cybershot_test.jpg", &jpgClsid, NULL);

include file search sequence

hint_5422-Dec-06 12:55

hint_54

22-Dec-06 12:55

Djii

thx !!

hint_54

WBurgMo22-Dec-06 7:21

WBurgMo

22-Dec-06 7:21

I downloaded the Apache Portable Runtime for windows. It included a
VC6 solution and project definitions. I loaded the soultion with Visual Studio 2005 and it successfully converted the solution and project to
the new format. I can compile the code with the converted solution.

I decided to create a new solution from scratch. But when I compile my
solution it finds the wrong include file. In my configuration I specify
an include search string of:
".\include; .\include\arch; .\include\arch\win32; .\include\arch\unix"

The include in question, "apr_arch_file_io.h", exists in the "win32" and
"unix" directories. but the compiler loads the one in the "unix" directory.

I do not understand why the converted solution works and mine does not.
If I remove the include from the "unix" directory then my solution
compiles cleanly.

Any thoughts as to what configuration option I have to set to my solution to work. I have looked at the converted project defintions but
nothing obvious stands out.

Thanks for any help

James Johnson

Re: include file search sequence

John R. Shaw23-Dec-06 12:27

John R. Shaw

23-Dec-06 12:27

One thought only: look at the preprocessor directives for the converted project and in the code. When cross platform code is involved you normally insert ‘#ifdef’ statements in the code to specify which platform you are compiling for.

INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra

Is there a way to tell how much memory you're using?

BarryOg22-Dec-06 5:48

BarryOg

22-Dec-06 5:48

I'm writing a directx program to display some primatives and I'm just wondering is there a way to query windows on how much memory you're using.

Re: Is there a way to tell how much memory you're using?

Mark Salsbery22-Dec-06 6:03

C++ Windows CE code to XP

22-Dec-06 6:03

Windows has GlobalMemoryStatus() and GlobalMemoryStatusEx(). About as useful as the task
manager Smile | :)

There's some useful stuff in The CRT Debug Heap[^]

I'm sure there's others....these just come to mind immediately.

KellyR22-Dec-06 2:54

KellyR

22-Dec-06 2:54

Hi, could someone point me in the direction of tutorials or articles about how to port C++ code from Windows CE to Windows XP? Also any pointers or tips on things to be careful with or watch out for while doing this would be greatly appreciated.

Thanks!

Re: C++ Windows CE code to XP

John R. Shaw23-Dec-06 12:42

John R. Shaw

23-Dec-06 12:42

I know nothing about CE programming other than it is a subset of Windows and therefore it should require almost no changes, if any, to port it. The complications would normally occur if you were trying to go the other way. If you can not run it on the desktop Windows platform, then you should look at the main entry routine (function/method), because that is where the problem would most likely lay.

INTP
"Program testing can be used to show the presence of bugs, but never to show their absence."Edsger Dijkstra

Resource compression

Jörgen Sigvardsson22-Dec-06 2:06

Jörgen Sigvardsson

22-Dec-06 2:06

I was wondering if anyone knows of a fairly transparent way to compress resource data (icons mainly). I've googled, but so far I haven't found anything.

--
Verletzen zerfetzen zersetzen zerstören
Doch es darf nicht mir gehören
Ich muss zerstören

David Crow22-Dec-06 5:01

David Crow

22-Dec-06 5:01

Is this even possible? If you compressed the icons, how would the system know to first uncompress them before using them? I guess you could compress the icons, and then store them as RT_RCDATA. When you need them, just reverse the process.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Jörgen Sigvardsson22-Dec-06 5:07

Jörgen Sigvardsson

22-Dec-06 5:07

I was thinking about some kind of scheme which could decompress the resource sections, and then replace the compressed data with the uncompressed data.

I found something that will do it for me, but differently: UPX[^]. Works quite well!

If you take a look at the compressed PE with a resource explorer, you'll see that it has compressed the data, which it'll replace during inflation of the "real" exe (except for the version section, first icon entry, and type libraries). I managed to shrink my exe to less than a third of its original size (icon resources - Sigh | :sigh:

). Didn't detect any significantly higher load time.

--
Verletzen zerfetzen zersetzen zerstören
Doch es darf nicht mir gehören
Ich muss zerstören

Michael Dunn22-Dec-06 8:31

Michael Dunn

22-Dec-06 8:31

I've had good luck UPX too, but one thing to watch out for is using it on a DLL that will be loaded by some method other than LoadLibrary(), such as res://. If it will be loaded like that, you can't compress the resources or else Bad Things will happen.

--Mike--
Visual C++ MVP Cool | :cool:

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Jörgen Sigvardsson22-Dec-06 8:49

Jörgen Sigvardsson

22-Dec-06 8:49

That's because it loads the DLL without calling DllMain(), right? Thanks for the heads up on that one. I have a DLL which I'm using with res://!

--
From the Makers of Futurama