Text quality in metafile created at runtime assigned to ppImage

rbuser

RB18, D7.

I'm trying to generate a metafile at run-time, and then assign it to a
ppImage to be printed in a group header.

The following code works, but the text is pretty ugly. It appears as
non-antialiased scaled text (lots of "pixelation" in the chars).

Any suggestions on how I can get better text quality?

TIA.


const
TRAY_WIDTH = 9600;
TRAY_DEPTH = 3400;
xOffset = 40;
yOffset = -50;

HeaderBandBeforePRint:

var
MetaFile: TMetafile;
MFCanvas: TMetafileCanvas;
maxwidth: Integer;
maxHt: Integer;
aPic: TPicture;
begin
MetaFile := TMetafile.Create;
try
maxwidth := ppImageVLM.spWidth;
maxHt := Trunc((maxwidth / TRAY_WIDTH ) * TRAY_DEPTH);


aPic:=TPicture.Create;
aPic.Bitmap.Width := ppImageVLM.spWidth;
aPic.Bitmap.Height := maxHt;
aPic.Bitmap.Canvas.Font.Name := 'Tahoma';

MetaFile.Width := TRAY_WIDTH;
MetaFile.Height:= TRAY_DEPTH;

MFCanvas := TMetafileCanvas.Create(MetaFile,
aPic.Bitmap.Canvas.Handle);

try
MFCanvas.Brush.Color := clYellow;
MFCanvas.FloodFill(0,0,clYellow,fsBorder);
MFCanvas.Brush.Color := clSkyBlue;
MFCanvas.Font.Name := 'Tahoma';
MFCanvas.Font.Size := 100;
MFCanvas.Rectangle(0, 0, TRAY_WIDTH, TRAY_DEPTH);
MFCanvas.TextOut(100,100, 'TESTME');
finally
MFCanvas.Free;
end;



aPic.Bitmap.Canvas.StretchDraw(Rect(0, 0, maxwidth, maxHt), MetaFile);

ppImageVLM.Picture.Assign(aPic);

finally
MetaFile.Free;
aPic.free;
end;



Cheers,
EdB

nicocizik

Hi Ed,

The reason you are getting a low quality image is likely due to the fact
that you are converting the metafile to a bitmap. Is there a reason you
are doing this?

If you would like the metafile to display inside a TppImage, simply
assign it to the TppImage.Picture.Graphic (or Metafile) property. For
instance...

...

MetaFile := TMetafile.Create;
MFCanvas := TMetafileCanvas.Create(MetaFile, THandle(GetDC(0)));

//Draw to canvas

MFCanvas.Free;

ppImageVLM.Picture.Metafile := Metafile

...

The preferred way to draw directly to the report canvas however is to
use the TppPaintBox. This way you can avoid the metafile altogether and
draw directly to its canvas instead. See the following article on how
it can be used.

http://www.digital-metaphors.com/rbWiki/RCL/Fundamentals/How_To...Use_the_PaintBox_Component

--

rbuser

Thanks for follow-up Nico

I'm looking to use metafile so I can let it scale for me...

I'm modeling about 50 shelving units - each is 96x34 inches - expressed
in 100th of an inch.

Each shelf has any combination of bins - from the full size of the
shelf to a non-homogeneous set of NxM bins.

I can set up the metafile with width x height of 9600x3400, then just
draw each bin as a rect based on the bottom-left to top-right of the
bin size (with bin size in inches x 100).

On-screen this works great in a PaintBox on a form (on resize of the
form, the paintbox gets invalidated and redraws to scale).


Using the metafile in the report, I share most of the code and the
report output looks efeectively the same as screen only - except for
the text output.

NOTE: When I modify the code to use your changes below, I get a blank
image on the report.

EdB

nicocizik

Hi Ed,

Below is the code I used to test your case. I also sent an example to
your email.

Be sure your TppImage has the Stretch property set to True.

procedure TForm1.Button1Click(Sender: TObject);
const
TRAY_WIDTH = 9600;
TRAY_DEPTH = 3400;
var
MetaFile: TMetafile;
MFCanvas: TMetafileCanvas;
lDC: THandle;
begin

MetaFile := TMetafile.Create;

try
MetaFile.Width := TRAY_WIDTH;
MetaFile.Height:= TRAY_DEPTH;

lDC := GetDC(0);
MFCanvas := TMetafileCanvas.Create(MetaFile, lDC);

try
MFCanvas.Brush.Color := clYellow;
MFCanvas.FloodFill(0,0,clYellow,fsBorder);
MFCanvas.Brush.Color := clSkyBlue;
MFCanvas.Font.Name := 'Tahoma';
MFCanvas.Font.Size := 100;
MFCanvas.Rectangle(0, 0, TRAY_WIDTH, TRAY_DEPTH);
MFCanvas.TextOut(100,100, 'TESTME');

finally
MFCanvas.Free;
end;

ppImage1.Picture.Graphic := MetaFile;

ppReport1.Print;

finally
MetaFile.Free;
end;

end;

--

rbuser

Hi Nico,

I received the email just as I was pulling to the customer site.

Worked perfectly - many, MANY thanks.

You'd think that after the dozen years or so that I've used RB I'd be
used to great support for a great product - but you folks are /always/
raising the bar - I can't compliment DM enough.

Thanks.

EdB