Very long canvas - print fail

[athely]

Hi,

I have a problem when i want to print (in pdf throught PDFCreator in attachement) a chart with a very big height.
I use TeeCreateMetafile after having resize chart canvas with requested big height.
Then I use Printer.Canvas.StretchDraw to draw on pdf canvas.
In attached example, we can see that problem occurs on page 34.

Problem is that serie plot seems to be blocked at a certain Y, like if there is a limitation.
I use Delphi 2009 and TeeChart 8.08.

Thanks for your help

Anthony

[Yeray]

Hello Anthony,

It seems to work fine with TeeChart v2017.22, RAD XE and PdfCreator v2.5.2:

TestTChartLongCanvas__2017-11-15_15h20.zip

(225.98 KiB) Downloaded 1684 times

Could you please try it with the latest version?

[odaumas]

Hello everyone.
Back to this problem.
Printing fails again using version V2020.29.200113 and PDFCreator 2.4.1 neither with PDFCreator 4.0.4.
Any idea ?

Thanks for your help.

[Yeray]

Hello,

It isn't failing for me with RAD Rio 10.3.3, TeeChart Pro v2020.29 and PDFCreator 4.0.4:

TestTChartLongCanvas__2020-05-18_09h30.zip

(224.19 KiB) Downloaded 1565 times

[odaumas]

Thanks for your reply Yeray.
Some thing's weird.
When I launch your attachment with Acrobat reader 2020.009.20063 .
The printing looks failed.

[odaumas]

Sorry, screen shot forgotten .

[Yeray]

Hello,

I could reproduce that and it seems like a problem with the metafile generation.

[odaumas]

Hello Yeray,

So, how can i fix it ?
Is this an internal TChart problem ?
If so, can we expect a patch ?

Thank you for your help.

[Marc]

Hello,

This appears to be a size limit for a Windows Metafile of 32767 pixels.

Ref.
https://stackoverflow.com/questions/342 ... -metafiles

If the test is run at 33 pages a metafile of 1036x31317 pixels is created. It appears that one page more tips the file over the size limit.

Regards,
Marc Meumann

[odaumas]

Hello Marc,
Thank you for your investigation. It's interesting.

However we had already seen that it worked properly.

So, back to the 2018-24 version, we can see that it works well.
Then, I couldn't install 2018-25 version, cause the recompilation does not work,
then, after installation of the 2018-26 version, we can see that the problem of the canvas reappears.

Regards.

[Marc]

Hello,

If you export to metafile in both cases there may be a clue to the different behaviour.

Regards,
Marc

[odaumas]

Hi Marc,
Here are the two metafiles created with v24 and v30.
No difference was found.
Then I checked StretchDraw procedure in each v24 and v30, saw no difference.

What a mystery

[Marc]

Hello,

The metafiles don't seem to have saved correctly in the zip you posted, but we'll take another look at this to see if we can shed any light. With the current version of TeeChart the plot cuts the last data points in the metafile at exactly 32,767 pixels, the known limit for a metafile. The canvas continues to plot gridlines to the required size limit though (33,000+ pixels), that raises suspicions that some other factor is involved. I don't see any obvious cause, the TeeChart code relating to metafile generation hasn't changed for a very long time, but we will go through it again.

Regards,
Marc

[Marc]

Hi,

Found it. There is a maximum pixel limitation setting in TeeChart, used to control out-of-bound axis calculations, that we'll need to review. It's currently set to $7FFF (decimal 32767).

Whilst we check what to do, if you have the sourcecode version you can modify it as an interim workaround:

ie.
TeEngine.pas

In the initialization section at the end of the unit:

TeeMaxPixelPos:=$7FFF;

change to: (for example)

TeeMaxPixelPos:=34000;

We'll probably need to change this to an accessible variable so that it can adjust to unusual circumstances such as the case here in hand.

Sorry for the delay in finding this.

Regards,
Marc

[Yeray]

Hello,

I've moved the TeeMaxPixelPos variable to interface section so from the next version you'd be able to set it as follows:

Code: Select all

  VCLTee.TeEngine.TeeMaxPixelPos:=34000;