Coherent Graphics Ltd

Our new PDF Editor for the mac is out – get it here.

• Merge, split and rearrange files
• Edit and manage bookmarks
• Scale, rotate and crop pages
• Add text, page numbers and dates and stamp watermarks
• Edit document metadata
• Manage PDF Attachments

Technical note: Written in OCaml and Objective C with Cocoa.

Thanks to all the beta testers – your license codes will be sent out shortly.

After some unexpectedly intricate work involving encryption, we’re almost ready for the closed Beta Test of our new PDF editor for OS X, written in OCaml.

Anyone wishing to join the test should email us via the form on the front page at http://www.coherentpdf.com/

I’m beginning a closed beta test of our new PDF Editor for Mac OS X – see posts below for details.

If you’d like to be included, please use the contact form on our front page, giving if possible a short explanation of the kinds of things you might do with such a product. Feel free to pass on this invitation to friends who might be interested.

Not very mac-like or slick yet, but the core functionality is almost there. The architecture for error handling and progress-bars between Cocoa and Ocaml is now complete.

Launch sometime later this year.

Here’s a screenshot of an early version of our next product, a PDF editor for Mac OS X:

The architecture is:

• A plain C wrapper around the higher-level interface to the CamlPDF library (the same interface used by our command line tools)
• An Objective-C cocoa program using call-backs to Ocaml through the wrapper library
• Callbacks from Ocaml into C to deal with error reporting and progress-bar updates.
• CamlPDF is used for all the PDF modification. OS X Pdfkit is used for displaying the PDF and thumbnails in the document window.

The C wrapper will also be used to release a plain C version of our PDF tools to go with the .NET and command line versions, but not until the bugs are ironed out by using the same code to write the OS X product.

It ought to be possible to produce a Windows version of the product using the .NET version of CamlPDF at some point in the future.

Alan Murta’s General Polygon Clipper is the standard way of finding the intersection, union etc. of polygons.

I wrote an Ocaml interface for this many years ago for a dead project, but I’ve only just got around to packaging it up for release. You can get it here.

I’ve just completed a PDF version of the Graphics module from the standard OCaml distribution, based on CamlPDF and following the conventions of Pierre Weis’ Postscript version GraphPS.

The implementation is mostly straightforward, but there are are some complications – some shapes (arcs etc.) need to be approximated from bezier curves sections, since they don’t exist as primitives in PDF (Oddly, circles and arcs are primitive in PostScript).

In common with GraphPS, it doesn’t yet support the bitmapped image parts of the Graphics module, though that would be easy to add.

Here’s a particularly luridly coloured example (source PDF here):

GraphPDF will ship with the next release of CamlPDF.

What might be nice for the future would be a single module shipping with OCaml which can be used as the ordinary graphics module would be, and then dump the result to PDF when required.

We’d need to extend the graphics module with the ability to optionally keep a list of all commands executed thus far, but that’s about all. Getting the PDF output into Ocaml would require some license work on CamlPDF, though, so won’t happen yet.