On 2016-04-09 09:09, Ondrej Pokorny wrote:
> P.WriteText(25, 0, 'Sample Text'); // DOESN'T WORK !!!
Indeed. As I mentioned, the Write*Text() names are a bit inaccurate and
will be improved. At the moment WriteText() is meant for the Standard
PDF Fonts, and WriteUTF8Text() for any TTF fonts used.
> P.WriteUTF8Text(25, 20, 'Sample Text');
>
> xFontCache := TFPFontCacheList.Create;
> try
> xFont := TFPFontCacheItem.Create('fonts\FreeSans.ttf');
> xFontCache.Add(xFont);
> xWidth := xFont.TextWidth('Sample Text', cFontSize) * 25.4 / 72; //
> 25.4 / 72 = conversion PDFTomm (?)
I believe here is your mistake. Your system is probably 96 DPI, not 72.
If you use gTTFontCache.DPI it would have given you the correct result.
At the moment the FontCache object defaults to the most common desktop
DPI, which is 96, but in your actual application you can query it with
whatever GUI you have and set the value yourself.
Here is verbosely commented code that draws a rectangle around the Page
Title text. Screenshot of the output is attached.
==========================
{ draw a rectangle around the Page Title text }
lPt1.X := 25; // units in MM
lPt1.Y := 20; // units in MM
lFntPtSize := 23;
{ a rough calculation but not 100% accurate for a specific font. }
// lTextHeightInMM := ((gTTFontCache.PointSizeInPixels(lFntPtSize) *
25.4) / 72) / 2;
lFC := gTTFontCache.Find('FreeSans', False, False);
if not Assigned(lFC) then
raise Exception.Create('FreeSans font not found');
lFntInfo := lFC.GetFontData;
{ result is in pixels }
lHeight := lFntInfo.CapHeight * lFntPtSize * gTTFontCache.DPI / (72 *
lFntInfo.Head.UnitsPerEm);
{ convert pixels to mm as our PDFPage.UnitOfMeasure is set to mm. }
lTextHeightInMM := (lHeight * 25.4) / 72;
lWidth := lFC.TextWidth('Sample Text', lFntPtSize);
{ convert the Font Units to Millimeters }
lTextWidthInMM := (lWidth * 25.4) / gTTFontCache.DPI;
{ result is in pixels }
lHeight := Abs(lFntInfo.Descender) * lFntPtSize * gTTFontCache.DPI /
(72 * lFntInfo.Head.UnitsPerEm);
{ convert pixels to mm as you PDFPage.UnitOfMeasure is set to mm. }
lDescenderHeightInMM := (lHeight * 25.4) / 72;
{ adjust the Y coordinate for the font Descender, because
WriteUTF8Text draws on the baseline. }
lPt1.Y := lPt1.Y + lDescenderHeightInMM;
P.SetColor(clRed, true);
P.DrawRect(lPt1.X, lPt1.Y, lTextWidthInMM, lTextHeightInMM, 1, false,
true);
lFntInfo.Free;
==========================
Regards,
- Graeme -
--
fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal
http://fpgui.sourceforge.net/
My public PGP key: http://tinyurl.com/graeme-pgp
--
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