Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium

x
  • Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 1115
  • Last Modified:

Print Canvas and Screen Canvas

I'm working on a project where I send text to a canvas and do all the wrapping of the text manually.  But the difference between the Printer?s canvas and the screen canvas make it very difficult to do anti aliasing.  Does any one have any suggestions.  Or algorithms  to calculate the difference in text appearance on a printer canvas compared to a screen canvas.  I know this questions has a lot of holes if you have any questions please ask.  

My goal is to give the user a print preview that is accurate.  

Thanks

Mike
0
mchagberg
Asked:
mchagberg
1 Solution
 
comptebidon81Commented:
Did you try to play with the property PrintScale. Maybe setting it to PrintToFit could Help. I haven't try, but I think it will make a difference.
0
 
lsaeCommented:
listening...
0
 
mchagbergAuthor Commented:
I'm sorry Comptebidon81 I don't know how to make printTofit apply to printing in the way I'm doing it.  I'm drawing every item on the print canvas one at a time.

text images to whole thing.  I put the text on in the order it is in a listbox.  And Images go on in the preview window.  When I add images I brake the string up into smaller strings to wrap around the image.

It's quite a process.  But I run the same procedure twice. Once when the user previews and once when they print.

Not to mention all the times they add and image or new item to the list.

my problem is that I want the preview to look the same as the print but because of difference in the screen canvas and Printer canvas it is not very accurate
0
Concerto's Cloud Advisory Services

Want to avoid the missteps to gaining all the benefits of the cloud? Learn more about the different assessment options from our Cloud Advisory team.

 
DragonSlayerCommented:
Just a thought, perhaps you could run your procedure once (for Preview) then save it to disk as an Image, and finally, print the image?


DragonSlayer.
0
 
ziolkoCommented:
Look at: GetDeviceCaps() or one of my previouse Q:
ww.experts-exchange.com/jsp/qManageQuestion.jsp?ta=delphi&qid=10309960
ziolko.
0
 
lacobCommented:
If I uderstood:
Screen canvas use resolution 96 or 120 ppi and printer use 300, 600 or more there is base difference
when you san use the same FontSize on printer like on Screen you can use this algorithm: PrinterFont.Size:=Round((GetDeviceCaps(Form1.Canvas.Handle,LOGPIXELSY) /72) *PrinterResolution).

If you can use PrintPreview in your SW and you can use the same result on screen like on printer there is also little harder way to do it. When you are drawing on Canvas(or DeviceContext) with the same resolution like in printer and show it on screen with zoom (smaller). Use winodows functions SetMapMode(Form1.Canvas.Handle,MM_ISOTROPIC)
, SetWindowExtEx(Form1.Canvas.Handle,XBase,YBase,oldWindowExtent) and SetViewportExtEx(Form1.Canvas.Handle,XResolution,YResolution,OldViewportExtent). There is Zoom=Resolution/Base.


It is good if you can print data drawed by user wherever on Canvas.
Don't remember to set old Mapping mode at last of drawing.
0
 
geobulCommented:
Listening...
0
 
TomazBCommented:
Listening...
0
 
mchagbergAuthor Commented:
DragonSlayer.
my boss doesn't want a rastered image.

lacob

I'm going to give it a shot give me a couple of days
0
 
mchagbergAuthor Commented:
lacob

I still havent had a chance to work on this any more

but I'll give you the points any way if you can help me with some thing else.

I need the API call to inverse text and turn it upside down.

thanks

Mike
0
 
lacobCommented:
Mike
if you can inverse color of text (if I understood)
use Canvas.Pen.mode:=pmNotXor and your active pen and brush color will be xored with color where you want draw
if you want rorate text before drawing (applied only on TT or vector fonts) use
FontH:HFONT;
LogFont:TLogFont;
FFont:TFont;

FFont:=TFont.Create;
LogFont.lfHeight:=...
LogFont.lfEscapement:=Angle*10 //angle in degrees
                               //using in WinNT orherwise
                               //can be zero
LogFont.lfOrientation:=Angle*10 //angle in degrees
FFont.Assing(Canvas.Font);
FontH:=CreateFontIndirect(LogFont);
Canvas.FontHandle:=FontH;
Canvas.TextOut or some drawing operations
Canvas.Font.Assing(FFont);
DeleteObject(FontH);
FFont.Free;

or you can draw text in Bitmap and rotate bitmap
but you can find (now I dont know) any algorithm to rotate position of BitmapPixels to another Bitmap
0
 
mchagbergAuthor Commented:
Thanks
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now