C / C++ / MFC

1-Jun-05 6:54

I am trying to use a CStatic control to allow custom drawing.

Here is the setup. There is a sound library called Bass that has add-ons that allow things such as in my case using Sonique visuals.
To use it you have to amongst other things call the following:

BOOL BASSVISDEF(BASS_SONIQUEVIS_Render)(HVIS handle, DWORD channel, HDC canvas);

I may be going at this all wrong but I am trying to pass this function an HDC to a CStatic control.

CStatic VisWindow; // control variable

<br />
HDC hdc = HDC(VisWindow.GetDC());<br />
BASS_SONIQUEVIS_Render( vischan, chan, hdc);<br />
VisWindow.ReleaseDC((CDC*)hdc);

This is the only way I can get it to compile. Any sugguestions?

David Crow1-Jun-05 7:02

David Crow

1-Jun-05 7:02

smesser wrote:
This is the only way I can get it to compile. Any sugguestions?

Any suggestions for what? Did you get it to compile or not?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Steve Messer1-Jun-05 7:10

1-Jun-05 7:10

Yes, it compiles but there is another problem.

The C++ interface to the dll I am trying to use is broken at the moment so I can only compile and not link and run.

It just seems I jumped too many hoops for this to work correctly.

The delphi implementation ( provided by author of dll) is really simple.

BASS_SONIQUE_Render( vischan, chan, PaintBox1.Canvas.Handle );

I was thinking that my approach was overly difficult.

David Crow1-Jun-05 7:30

David Crow

1-Jun-05 7:30

smesser wrote:
...I can only compile and not link and run.

So what's the linker error?

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

Steve Messer1-Jun-05 7:38

1-Jun-05 7:38

seem the .lib file that the dll author is not C++ compliant.

First the header file for the dll contains these functions:

void BASSVISDEF(BASS_SONIQUEVIS_CreateFakeSoniqueWnd);
void BASSVISDEF(BASS_SONIQUEVIS_DestroyFakeSoniqueWnd);

They Yield the following error and warnings:

c:\BassVisMFC\BassVisMFC\BassVis.h(49): warning C4229: anachronism used : modifiers on data are ignored
c:\BassVisMFC\BassVisMFC\BassVis.h(49): error C2182: 'BASS_SONIQUEVIS_CreateFakeSoniqueWnd' : illegal use of type 'void'
c:\BassVisMFC\BassVisMFC\BassVis.h(50): warning C4229: anachronism used : modifiers on data are ignored
c:\BassVisMFC\BassVisMFC\BassVis.h(50): error C2182: 'BASS_SONIQUEVIS_DestroyFakeSoniqueWnd' : illegal use of type 'void'

If I comment out from the header those offending lines since I don't seem to need them anyways I then get this linking error.

bass_vis.lib : warning LNK4003: invalid library format; library ignored

Ryan Binns1-Jun-05 18:25

Ryan Binns

1-Jun-05 18:25

smesser wrote:
HDC hdc = HDC(VisWindow.GetDC());
BASS_SONIQUEVIS_Render(vischan, chan, hdc);
VisWindow.ReleaseDC((CDC*)hdc);

That's not going to work. You need to use:

CDC *pDC = VisWindow.GetDC();
BASS_SONIQUEVIS_Render(vischan, chan, pDC->getSafeHdc());
VisWindow.ReleaseDC(pDC);

HDC and CDC* are not the same type - you can't typecast between them.

Ryan

"Punctuality is only a virtue for those who aren't smart enough to think of good excuses for being late" John Nichol "Point Of Impact"

Steve Messer13-Jun-05 20:38

working with binary files in C++

13-Jun-05 20:38

Finally got a version of the dll from the author and your suggestion works perfectly.

Thanks

knapak1-Jun-05 5:55

1-Jun-05 5:55

Hi guys

I apologize for reposting this question but probably I didn't reach enough people last night and only got one response that didn't help me much (sorry Chris but thank you).

I'm still strugling with the problem of reading a huge file in the most efficient way. I was suggested last week to "read the file into memory as one big chunk". I think that the advice refered to reading the data in binary format instead of text. Cool... so first I have to translate my text files into binary and then read them... Problem is that all examples that I've found refer to either read a single number or things such as a struct with phone directory...

How about reading a 2 dimensional array of doubles as text, save it as binary and then load it into another array after reading the binary file???

examples???

Thanks a million.

David Crow1-Jun-05 7:07

David Crow

1-Jun-05 7:07

A file is neither binary nor text as it resides on disk. It all depends on how the file is processed that determines whether it is binary or text. You can open the file and read all of it into memory with something like:

HANDLE hFile = CreateFile("myfile", GENERIC_READ, ...);
LPBYTE lpBuffer = new BYTE[10240];
DWORD dwRead;
ReadFile(hFile, lpBuffer, sizeof(BYTE) * 10240, &dwRead, NULL);
CloseHandle(hFile);

Now you can do whatever you want with lpBuffer. You might also benefit from a memory-mapped file.

"Ideas are a dime a dozen. People who put them into action are priceless." - Unknown

knapak1-Jun-05 8:21

1-Jun-05 8:21

Hi
Sorry if this sounds stupid, please bear with me since I'm a self instructed amateur.

If files are neither text or binary, what's the point of using something like:

To write a binary file

int MyNumber = 10;<br />
ofstream FileOut(FileName,ios::binary);<br />
FileOut.write((char*) &MyNumber, sizeof MyNumber);<br />
fout.close();

and to read

ifstream FileIn(FileName, ios::binary)<br />
FileIn.read((char*) &MyNumber,sizeof MyNumber);<br />
FileIn.close();<br />

Thanks a million you for your help

S. Senthil Kumar1-Jun-05 8:33

S. Senthil Kumar

1-Jun-05 8:33

ios::binary is used to tell the ifstream and ofstream classes to treat the data as binary. If you don't specify ios::binary and try to read a binary file and if the binary file happens to have a non-text byte value, it'll stop there or throw an exception.

You can open any file in binary mode though, because ifstream and ofstream will not try to interpret them as text characters.

Regards
Senthil
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knapak1-Jun-05 9:23

1-Jun-05 9:23

OK... so I wrote the following code and it writes and reads the file with a map. It compiles, runs and gives the requested output, but apparently there's a runtime problem since after execution a window pops indicating that there was a problem (one of those windows to send information to the creator of the program)... I can't see what's wrong but I know where the problem is since I commented different sections of the code and narrowed it down to the marked fragment below.

Here's the code:

int main()<br />
{<br />
	typedef map<int, double> IMAP;<br />
<br />
	IMAP Grid, NewGrid;<br />
<br />
	int IntValue1, rows = 3;<br />
	double DouValue2;<br />
<br />
	for(int i=0; i < rows; i++)<br />
	{<br />
		IntValue1 = i + 1;<br />
		DouValue2 = i * 2;<br />
		Grid.insert(IMAP::value_type(IntValue1, DouValue2));<br />
	}<br />
<br />
	IMAP::const_iterator IteratorG = Grid.begin();<br />
<br />
	cout << "Original Map" << endl;<br />
	while (IteratorG != Grid.end() )<br />
	{<br />
		cout << IteratorG->first << " " << IteratorG->second << endl;<br />
		IteratorG ++;<br />
	}<br />
<br />
	ofstream FileOut("C:/MyBinary.bin" , ios::binary);<br />
	FileOut.write((char*) &Grid, sizeof Grid);<br />
	FileOut.close();<br />

THE ERROR IS FROM HERE

ifstream FileIn("C:/MyBinary.bin", ios::binary);<br />
FileIn.read((char*) &NewGrid,sizeof NewGrid);<br />
FileIn.close();<br />

TO HERE

	IMAP::const_iterator NewIteratorG = NewGrid.begin();<br />
<br />
	cout << " " << endl;<br />
	cout << "New Map" << endl;<br />
	while (NewIteratorG != NewGrid.end() )<br />
	{<br />
		cout << NewIteratorG->first << " " << NewIteratorG->second << endl;<br />
		NewIteratorG ++;<br />
	}<br />
	return 0;<br />
}<br />

Thanks a million!

S. Senthil Kumar2-Jun-05 1:15

S. Senthil Kumar

2-Jun-05 1:15

Writing out a std::map is not a good idea. It internally uses pointers and dynamically allocated memory, so writing the map will only write out the pointers and not their values. For eg

class Test
{
public:
   int *p;
};

int main()
{
   Test test;
   test.p = new int();
   *(test.p) = 100;
}

Writing out test to a file will write out p, which is just a address (and which will change for every program run). Because you're reading it back in the same program, you're alteast able to read back the values. Try reading the file after shutting down the program that wrote to it, you'll find that iteration itself crashes.

I'd suggest writing out the values to file, manually and then reading them back, (again manually).

Regards
Senthil
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knapak2-Jun-05 11:48