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Thread: TextOut: printed text displaced on paper, correct when printing to PDF

  1. #1

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    TextOut: printed text displaced on paper, correct when printing to PDF

    Hi! I am printing some text using the API function TextOut. The following code snippet shows how I am converting my coordinates to pixels:

    'The TextOut function expects the x and y coordinates in pixels
    CurrentX = CurrentX / Printer.ScaleWidth * Printer.width / Printer.TwipsPerPixelX
    CurrentY = CurrentY / Printer.ScaleHeight * Printer.Height / Printer.TwipsPerPixelY

    hfontOld = SelectObject(hdc, hfont) 'No reference to Printer object beyond this line!

    TextOut hdc, CurrentX, CurrentY, Txt, Len(Txt) 'Printer.print cannot be used with API-defined fonts


    Now when I select "PDF Creator" in the printer dialog, the printing results are as expected, but when I use a real printer, the text gets displaced. The larger CurrentX or CurrentY, the larger the displacement, so there seems to be a wrong factor (about 2.5% off). A friend of mine tested my code on his computer with his printer - same result!

    I have no explanation why real printers and PDF printers behave differently!

    VB6, Win 7

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    PowerPoster Zvoni's Avatar
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Every reference i found had to do with the SetTextAlign-Function
    Last edited by Zvoni; Tomorrow at 31:69 PM.
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  3. #3

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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Thank you Zvoni. Unfortunately in my case the displacement is not constant. It is proportional to the distance from the upper left corner, so the factor is wrong somehow.

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    PowerPoster Zvoni's Avatar
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    OK.
    let's do it this way:

    Debug your code and read all values before printing.
    CurrentX, CurrentY, Printer.ScaleWidth etc. and everything else.
    Read them for your PDF-Printer, and then read them for the "real" printer.
    Maybe some clues are hidden in there
    Last edited by Zvoni; Tomorrow at 31:69 PM.
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Quote Originally Posted by Zvoni View Post
    Debug your code and read all values before printing.
    CurrentX, CurrentY, Printer.ScaleWidth etc. and everything else.
    Read them for your PDF-Printer, and then read them for the "real" printer.
    Maybe some clues are hidden in there
    Actually that's what I did before I decided to post in this forum. I compared all relevant properties - no difference! At least no significant difference that would explain the effect.

  6. #6
    PowerPoster Zvoni's Avatar
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Then the only explanation i'd have is, that the "real" printer displaces the position due to border-issues (which logically a PDF-Printer shouldn't have)
    since CurrentX and CurrentY are logical coordinates.
    Maybe the real printer needs some 0.5 inches of border, and the position doesn't start at top left (0,0) but at somewhere more "inside"
    Last edited by Zvoni; Tomorrow at 31:69 PM.
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Perhaps your printer device context is not set to use the MM_TEXT map mode (See GetMapMode) ?

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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    @Zvoni: Wouldn't that lead to a constant displacement? Anyway, in the printer properties dialog I tried to set the printing borders to zero. No change.

    @Merrion: It is set to MM_TEXT, unfortunately. Nice idea though!

  9. #9
    PowerPoster Zvoni's Avatar
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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Just a thought: The PDF and the real printer use the same paper-"size"?
    e.g. PDF is set to A4, while the real printer is set to letter
    Last edited by Zvoni; Tomorrow at 31:69 PM.
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  10. #10

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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Same size (A4). But thanks for not giving up!

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    Re: TextOut: printed text displaced on paper, correct when printing to PDF

    Quote Originally Posted by stefanP View Post
    Hi! I am printing some text using the API function TextOut. The following code snippet shows how I am converting my coordinates to pixels:

    'The TextOut function expects the x and y coordinates in pixels
    CurrentX = CurrentX / Printer.ScaleWidth * Printer.width / Printer.TwipsPerPixelX
    CurrentY = CurrentY / Printer.ScaleHeight * Printer.Height / Printer.TwipsPerPixelY

    hfontOld = SelectObject(hdc, hfont) 'No reference to Printer object beyond this line!

    TextOut hdc, CurrentX, CurrentY, Txt, Len(Txt) 'Printer.print cannot be used with API-defined fonts


    Now when I select "PDF Creator" in the printer dialog, the printing results are as expected, but when I use a real printer, the text gets displaced. The larger CurrentX or CurrentY, the larger the displacement, so there seems to be a wrong factor (about 2.5% off). A friend of mine tested my code on his computer with his printer - same result!

    I have no explanation why real printers and PDF printers behave differently!

    VB6, Win 7
    Your above x,y calculation looks - well - "adventurous"...

    Seeing you work with GDI-Functions - may I ask, why you didn't switch the Printer into vbPixels-Scalemode?
    (then giving the Coords to your GDI-Functions directly as Pixels - without any conversion needed).

    Also take into account - that on "physical" printers, the value of Printer.ScaleLeft needs to be considered.
    On PDF-Printers (which have no physical restriction with regards to their Printable-Area) this value is usually Zero -
    whilst on physical Printers it is almost always larger than Zero.

    Olaf

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