Help me please using CDC::SetMapMode(int nMapMode)

Question

4.00/5 (1 vote)

See more:

I have changed the maping mode as the code below is shown: to work with (1 logical unit = 1 millimeter)

void CGLVImpressionView::OnPrepareDC(CDC* pDC, CPrintInfo* pInfo)
{
    CView::OnPrepareDC(pDC, pInfo);
    // TODO: Add your specialized code here and/or call the base class
    pDC->SetMapMode(MM_ISOTROPIC);
    // Working with (1 logical unit = 1 mm) for both width & height of the device context.
    pDC->SetWindowExt(1, 1);
    pDC->SetViewportExt(pDC->GetDeviceCaps(HORZRES) / pDC->GetDeviceCaps(HORZSIZE),
                        pDC->GetDeviceCaps(VERTRES) / pDC->GetDeviceCaps(VERTSIZE));
    pDC->SetBkMode(TRANSPARENT);
    //CView::OnPrepareDC(pDC, pInfo);
}

and when I create a font like this:

void CGLVImpressionView::OnBeginPrinting(CDC* pDC, CPrintInfo* /*pInfo*/) 
{
	// TODO: Add your specialized code here and/or call the base class
	m_fnTimes12.CreatePointFont(120, _T("Times New Roman"), pDC);
	m_fnTimes14.CreatePointFont(140, _T("Times New Roman"), pDC);

        //CView::OnBeginPrinting(pDC, pInfo);
}

It will be drawn with a huge size :(
What am I doing wrong ?
Help me please.

This image may be useful:
http://img546.imageshack.us/img546/7144/dpiw.jpg

Posted 16-Mar-11 16:58pm

Mr. Tomay

Updated 17-Mar-11 9:53am

v7

Add a Solution

6 solutions

Solution 3

The mapping mode will probably affect the font size. Try to reset the mapping mode to normal just before drawing the text, then set it back to whatever you want.

Or you may just reduce your font size as a quick workaround...

Posted 17-Mar-11 2:17am

Olivier Levrey

Updated 17-Mar-11 2:18am

v2

Comments

Mr. Tomay 17-Mar-11 13:40pm

Not a bad idea, but it's not good for programming for your first idea.
For font sizes, it will not be exact (Just Estimated) for your second idea.

Olivier Levrey 18-Mar-11 4:27am

I am not an expert in printing programming, I just tried to find a solution to your problem. If nobody else offers a solution, I am affraid you will have to cope with my "not good for programming" one...

Solution 4

I think your calculation may be incorrect. Looking at my printer I get the following values
HORZRES : 2892
HORZSIZE : 204

VERTRES : 4125
VERTSIZE : 291

Giving a ViewPort Extent of 14 x 14 so your characters will be scaled up by 14 times in each direction when rendered. You may find it easier just to leave the mapping at MM_TEXT which will correctly scale from Window to ViewPort when printing text.

Posted 17-Mar-11 5:59am

Richard MacCutchan

Comments

Mr. Tomay 17-Mar-11 14:30pm

14 here means 14 pixels per 1 millimeter
check this

Richard MacCutchan 17-Mar-11 14:41pm

Try changing those values to a smaller number and see what happens. Also, as I said before, why not just stick with MM_TEXT?

Mr. Tomay 17-Mar-11 14:53pm

I am not using MM_TEXT because I want to work with 1 millimeter as a logical unit to print an A4 paper, so my calculation will be exact.
All GDI drawing went as expected, except font drawings

Richard MacCutchan 18-Mar-11 10:10am

Well, you can either take my advice, and switch to MM_TEXT when writing characters, or change your font creation. Instead of using
CreatePointFont() use CreateFont() which allows you to specify the font size in logical units rather than points.

And perhaps you would care to revise your 1-vote of my (valid and true) explanation of your problem.

Olivier Levrey 18-Mar-11 11:00am

I agree. Have my 5. Op is distributing 1 to everybody...

Richard MacCutchan 18-Mar-11 12:48pm

Thanks, I don't mind being down-voted when I'm wrong, but I think it is not a fair grade when it's just because the questioner does not like the answer.

Mr. Tomay 18-Mar-11 19:03pm

For the votes, I don't think that it has more importance than the problem it self, and it's not true that I don't like the answer, I just kept it as last recourse, and the same thing for Oliver.

Mr. Tomay 18-Mar-11 19:20pm

I found the origin of the problem: It was that I have changed the maping mode after doing calculations of the (point = 1/72 inch), because OnBeginPrinting is never called after OnPrepareDC.
and thanks for anyone who tried to help.

Solution 1

Use 12 and 14 instead of 120 and 140 in createpointfont. May be this'll solve your problem

Posted 17-Mar-11 1:55am

manu_000

Comments

Olivier Levrey 17-Mar-11 8:20am

This is an obvious and easy workaround. My 5.

Mr. Tomay 17-Mar-11 13:31pm

CreatePointFont() creates a font in tenths of a point
check this

Solution 2

You're specifying a 120 and 140-point font height. No matter what mapping mode you use, the fonts are going to be huge.

Posted 17-Mar-11 1:58am

#realJSOP

Comments

Olivier Levrey 17-Mar-11 8:15am

The size parameter of the CreatePointFont is in tenths of a point. Passing 120 will result as a 12-point font.

Mr. Tomay 17-Mar-11 13:34pm

Oliver is right

Solution 5

try this code in your onpreparedc

MIDL

int dpi=pDC->GetDeviceCaps(LOGPIXELSX);
int dpmm=dpi/25; //dots per mm

pDC->SetMapMode(MM_ISOTROPIC);
pDC->SetWindowExt(1, 1);
pDC->SetViewportExt(dpmm,dpmm);

Posted 17-Mar-11 21:26pm

Rajesh Katalkar

Comments

Mr. Tomay 18-Mar-11 18:46pm

your calculations is exactly the same as mine, I've just did it in other way

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

mbue · Accepted Answer · 2011-03-19T02:54:00

Solution 6

Your initialisation is wrong. The order of functions called:
1.) OnPreparePrinting
2.) OnBeginPrinting
3.) OnPrepareDC
4.) OnDraw
yous should create the fonts in OnPrepareDC function.
Regards.

[edit] your fonts are ceated for MM_TEXT but drawn with MM_ISOTROPIC.

Posted 19-Mar-11 2:54am

mbue

Updated 19-Mar-11 2:59am

v2

Comments

Mr. Tomay 20-Mar-11 6:11am

Yes you are right, the order of printing functions is:
1.) OnPreparePrinting()
2.) OnBeginPrinting()
3.) OnPrepareDC()
4.) OnDraw() / OnPrint()
5.) OnEndPrinting()

But I just found the origin of my problem 1 day before your answer. Thanks anyway ;). I corrected this using this code:


void CGLVImpressionView::OnBeginPrinting(CDC* pDC, CPrintInfo* /*pInfo*/) 
{
	// TODO: Add your specialized code here and/or call the base class
        pDC->SetMapMode(MM_ISOTROPIC);
        // Working with (1 logical unit = 1 mm) for both width & height of the device context.
        pDC->SetWindowExt(pDC->GetDeviceCaps(HORZSIZE), pDC->GetDeviceCaps(VERTSIZE));
        pDC->SetViewportExt(pDC->GetDeviceCaps(HORZRES), pDC->GetDeviceCaps(VERTRES));

	m_fnTimes12.CreatePointFont(120, _T("Times New Roman"), pDC);
	m_fnTimes14.CreatePointFont(140, _T("Times New Roman"), pDC);

        //CView::OnBeginPrinting(pDC, pInfo);
}


void CGLVImpressionView::OnPrepareDC(CDC* pDC, CPrintInfo* pInfo)
{
    CView::OnPrepareDC(pDC, pInfo);
    // TODO: Add your specialized code here and/or call the base class
    pDC->SetMapMode(MM_ISOTROPIC);
    // Working with (1 logical unit = 1 mm) for both width & height of the device context.
    pDC->SetWindowExt(pDC->GetDeviceCaps(HORZSIZE), pDC->GetDeviceCaps(VERTSIZE));
    pDC->SetViewportExt(pDC->GetDeviceCaps(HORZRES), pDC->GetDeviceCaps(VERTRES));

    pDC->SetBkMode(TRANSPARENT);

    //CView::OnPrepareDC(pDC, pInfo);
}