On Nov 19, 2009, at 4:37 PM, Chinh Nguyen wrote: > The conversion to screen coordinates is causing stair stepping in connected > lines and other oddities when exporting to PDF. As a temporary solution > until the code is rewritten, I've created a subclass of my view that's sized > at the large coordinate space's dimensions specifically for rendering the > image to PDF. However, I can't seem to resize the PDF data down to the more > manageable screen view's dimensions when saving to disk. I've tried creating > an NSPDFImageRep from the PDF data and resizing it but it has no effect on > the saved to disk image (I guess setSize: does not affect the original data). > What I end up with is a PDF file with large dimensions that overwhelms > whatever application I'm placing it into. > > What I ended up doing is creating an NSView subclass that simply draws the > PDF at the size I want and returns the PDF data from that. This works but is > there a better way of resizing the dimensions of PDF data or is the size the > size that it's generated at and there's no changing it?
A PDF file has a number of rectangles that affect how and where it draws. I would recommend looking at CGPDFContext. It gives you the ability to specify the size of the PDF you are generating. You would basically use a combination of changing the size of the PDF and using a coordinate transformation to scale the PDF content to the size that you want. > Also, I allow the user to export the image as a bitmap and even override the > dimensions. I create an NSImage from the PDF data, resize the NSImage, then > save the TIFF representation to the bitmap format I want. This works in > Leopard but no longer works in Snow Leopard. I read the tech note about > changes to NSImage and caching but I had no luck with the different caching > methods. I ended up creating an NSImage at the desired size, locking the > focus, drawing the PDF data at the desired size, unlocking the focus, then > saving the TIFF representation. Is there a better way? Your solution sounds OK. I tend to work at the CG Layer a lot so personally, I would avoid NSImage altogether and drop down to the Core Graphics layer. I would create a block of memory, use CGBitmapContextCreate to create a CG context on that bitmap, draw the graphic into that context, construct a CGImage and use Image I/O to export the image. The end result would be similar, but I'd have to go through a lot more steps than you did. > And finally, is there a way to change the resolution of a bitmap from 72dpi > to say 300dpi? My users want to be able to specify the dimensions of the > exported bitmap in inches and the resolution. They want to be able to place > their 1800 pixel wide TIFF file into Word and it show up 6 inches wide (@ > 300dpi) instead of 25 inches wide (@ 72dpi). Not a huge deal because I still > recommend our users use PDF but some of them have legacy apps that don't > support PDF. The example I was able to find on this created a new > NSBitmapImageRep and copied the image data into it and then set the size. This is one feature that Image I/O allows you to have control over. As you export each image you can provide a dictionary of image attributes, one of which is the desired image resolution. Scott _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com
