From: Jeremy W. <jez...@ho...> - 2003-12-23 13:49:47
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Hi, A couple of months ago I was planning on doing exactly that - I never got round to doing it, but it is something that I may have to do in the next couple of months. I use GD to draw my charts, and plot them onto the DC with Win32::GUI::DIBitmap. There are several different approaches, and I was going to go for the lazy route:) I was planning on doing something like this: On the mouse move, a copy of the original chart would be created. The lines would then be drawn on the copy, the new image would then be drawn on to the DC. The copying/painting to the DC are handled by Win32::GUI::DIBitmap. This method isnt exactly efficient, but would be fast enough for smooth crosshairs as the mouse pointer moves around. There is a much more efficient approach, but would involve a little more work:) Feel free to email me off list if you have any questions. >From: Jonathan Southwick <jon...@al...> >To: Win32-GUI <per...@li...> >Subject: [perl-win32-gui-users] need help with Graphic >Date: Mon, 22 Dec 2003 11:37:15 -0500 > > >I have a Graphic object that I am plotting data on. While the cursor is on >this object I have a cross-hairs cursor. What I would like to do is extend >lines from the cursor position to the edges of the graph (the perimeter) >but not have them overwrite what is plotted there and as I move the cursor >around the lines move accordingly. > >It would be the same effect as using a selection tool in any common paint >program. > >I know how to track the current mouse position and i know the values for >the boundaries of the graph; I just don't know how to produce the effect I >am wanting. > >Has anyone ever accomplished this? Does anyone know HOW to do it? Any >help would be greatly appreciated. > >Jonathan >======================== >Jonathan Southwick >jon...@al... >Technical & Network Services >Allegheny College >Meadville, PA 16335 >(814) 332-2755 > > > >------------------------------------------------------- >This SF.net email is sponsored by: IBM Linux Tutorials. >Become an expert in LINUX or just sharpen your skills. Sign up for IBM's >Free Linux Tutorials. Learn everything from the bash shell to sys admin. >Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&op=click >_______________________________________________ >Perl-Win32-GUI-Users mailing list >Per...@li... >https://lists.sourceforge.net/lists/listinfo/perl-win32-gui-users _________________________________________________________________ Send a funky Messenger Christmas card http://www.msn.co.uk/christmascard |