page rendering is quite slow.

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   Hi,

I am trying version 7.21, and I noticed that DARenderPageToDC(...) is quite slow. I call DARenderPageToDC(...) in OnDraw event, so that repainting has a delay, which is quite annoying.

I called these functions:

DAOpenFile(...), 
DAFindPage(...)
DARenderPageToDC(...)

and no other function is called. The Quick Pdf Library Demo seems to be fast.

So I'd like to ask what is the best way to render a page?

Thx
michael

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giantjupiter Members Profile Find Members Posts Beginner Joined: 13 Sep 10 Status: Offline Points: 4	Post Options Post Reply Quote giantjupiter Report Post Thanks(0) Quote Reply Topic: page rendering is quite slow. Posted: 13 Sep 10 at 4:47PM
	Hi, I am trying version 7.21, and I noticed that DARenderPageToDC(...) is quite slow. I call DARenderPageToDC(...) in OnDraw event, so that repainting has a delay, which is quite annoying. I called these functions: DAOpenFile(...), DAFindPage(...) DARenderPageToDC(...) and no other function is called. The Quick Pdf Library Demo seems to be fast. So I'd like to ask what is the best way to render a page? Thx michael

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3529	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 13 Sep 10 at 7:37PM
	Hi Michael! Is it slow with all pdf-documents or only few (very special)? What about ... LoadFromFile... SelectPage... RenderPageToDC... Is it faster? Cheers and welcome here, Ingo Edited by Ingo - 13 Sep 10 at 7:37PM

giantjupiter Members Profile Find Members Posts Beginner Joined: 13 Sep 10 Status: Offline Points: 4	Post Options Post Reply Quote giantjupiter Report Post Thanks(0) Quote Reply Posted: 13 Sep 10 at 11:44PM
	Hi, Ingo, It is much obvious when there is an large image in the page, and it seems only RenderPageToDC() is slow and other functions are ok. The pause of rendering text is short but still noticable. Should I render it to a bitmap first, then every time repaint the bitmap. I am also trying mupdf, but it don't have this problem. By the way, I am trying them with wxWidgets, and I put RenderPageToDC() and mupdf's winblit() in the inherited function of wxWindow::OnDraw(), which is invoked to repaint the DC. Thx, Michael Edited by giantjupiter - 13 Sep 10 at 11:52PM

pavsej Members Profile Find Members Posts Beginner Joined: 22 Sep 10 Status: Offline Points: 2	Post Options Post Reply Quote pavsej Report Post Thanks(0) Quote Reply Posted: 22 Sep 10 at 8:59AM
	I have the same Problem with one large image on a PDF page. I kind of solved it by changing PrinterResolution. For preveiw I use lower Resolution, for real printing job I use higher Resolution. In my case rendering of one PDF page with one image takes (RenderPageToDC): 2.3 sec - 300 DPI 6.5 sec - 600 DPI Anyway, any performace improvement would be welcome.

Ingo Members Profile Find Members Posts Moderator Group Joined: 29 Oct 05 Status: Offline Points: 3529	Post Options Post Reply Quote Ingo Report Post Thanks(0) Quote Reply Posted: 22 Sep 10 at 2:27PM
	Hi! And 900 dpi perhaps 15 sec... But 72 dpi (the standard) immediately. It depends on what you wanna do ... like always ;-) The dev-team has already done a lot in case of speed but if you want a lot then ... ;-) Cheers, Ingo