Through the Interface

Using AutoCAD 2009's new transient graphics API to show point clouds from F#

To start off my series of more in-depth looks at the new APIs provided in AutoCAD 2009, I decided to extend some recently posted F# code to generate and draw transient point clouds to be slightly less transient: we'll see how to use the new transient graphics API in AutoCAD to display a cache of transient graphics, even after the view has been changed. Some of you may be wondering about the amount of code I'm posting in F#. I find the technology extremely interesting and am also increasingly productive with it, so I've found myself gravitating towards using... Read more →

New APIs in AutoCAD 2009

I've been taking some time this week to dive into some of the new APIs available in AutoCAD 2009. I'm going to post a very quick overview of the APIs available in this post, following up with a more in-depth look at some of the individual APIs in posts over the coming weeks. I've used material presented at our most recent ADN Developer Days tour as a source of information (a big thanks to Fenton Webb, from DevTech Americas, who was largely responsible for developing this content). Before talking about the new APIs, the first thing to note is... Read more →

"AutoCAD: 10 easy ways to crash your AutoCAD addin" webcast recording available for download

The recording of the October 4 session from the AutoCAD Development Masterclass series, "AutoCAD: 10 easy ways to crash your AutoCAD addin", has been posted here. I will let you know as soon as the recording of the October 18 webcast, "AutoCAD: .NET for LISP Programmers", has been posted. Enjoy! :-) Read more →

"Custom Objects Masterclass" webcast recording available for download

As promised in this earlier post, here's the recording of the "Custom Objects Masterclass" session held on July 12. The next in the series, "Creating an Installer", is scheduled for Thursday August 16. You can go here to register (like all in this series, this session is free for all to attend). Read more →

Free advanced AutoCAD .NET/ObjectARX webcasts

Over the last few years my team has been delivering more and more webcasts about the APIs to our various products. I'd strongly recommend checking the schedule on http://www.autodesk.com/apitraining from time to time, to see what's there. These webcasts are free to everyone, not just ADN members (although the ADN site does reference the various recorded presentations). Right now we're in the process of delivering a series of webcasts covering advanced AutoCAD programming topics, with information relevant to those programming with either ObjectARX or .NET. The first was delivered a few weeks ago, and covered "Storing Custom Data in... Read more →

Loading the right version of an ObjectARX module into 32- or 64-bit AutoCAD

This question has come in from a number of developers... How can I tell when my application is running inside a 64-bit version of AutoCAD? As mentioned in this previous post, AutoCAD 2008 installs as native 64-bit binaries on a supported 64-bit OS, just as 32-bit binaries get installed on a supported 32-bit OS. A minor complication is that certain of our AutoCAD-based products do not yet have native 64-bit versions. Our Engineering teams are working on this, but in the meantime, your application might well be working inside a 32-bit Autodesk product on a 64-bit OS. So how... Read more →

AutoCAD 2008 – other new APIs

In the previous two posts we looked at the new ObjectARX samples and the new .NET samples available for AutoCAD 2008. AutoCAD 2008 also exposes a number of new APIs (and enhancements to old ones) for which we don’t have new SDK samples. Take a look of the ‘Migration Guide for Applications’ for a comprehensive list of new classes and new methods and properties within classes. Check the AutoCAD Managed Class Reference for Managed equivalents. And once again - let me know if there are any of specific interest to you, and we'll see what we can do. :-)... Read more →

AutoCAD 2008 - new ObjectARX samples

The coming posts will look at the various new APIs in AutoCAD 2008. Here is the way I’ve decided to serialize the information: New ObjectARX samples - this post New .NET samples - the next post Other new APIs - the following post So this post focuses on the new C++ samples on the ObjectARX SDK for AutoCAD 2008, talking about their corresponding features and APIs. Thanks to Stephen Preston, our DevTech Americas Manager and the presenter you may seen in the previous post, for providing the bulk of this information. Annotation Scaling One of the most highly anticipated... Read more →

AutoCAD 2008 – 64-bit application migration

We’ve been talking to ADN members (under non-disclosure agreements) for a number of months about the 2008 family of Autodesk products, and with these products officially announced I can now talk more publicly about their features and APIs. This week I’ll focus on AutoCAD, but I plan to describe the new feature-/API-sets of other Autodesk products over the coming weeks. So what’s new in AutoCAD 2008? There are a number of very interesting new features and APIs, which I'll talk about in coming posts, but for now I want to address the more fundamental question around application migration. Firstly,... Read more →

Protecting intellectual property in AutoCAD application modules

This is an interesting topic – and one that I’m far from being expert in – so it would be great if readers could submit comments with additional information. Intellectual property protection is a major concern for software developers, and issues that are seen today with .NET languages have been troubling AutoCAD developers since the introduction of AutoLISP. So, what are these issues? As a professional software developer, if you ship source-code to your customers there is substantial risk of it being borrowed or stolen for use in other unlicensed situations. This is true if you ship the actual... Read more →

Per-document data in ObjectARX

As discussed in the previous post, AutoCAD is now largely an MDI application, and this can have an impact on the design of applications. Let’s talk about the theoretical issue with migrating applications into a multiple-document environment. We used to highlight this nicely, back when we first started talking about MDI in AutoCAD 2000. We demonstrated a simple ObjectARX application that defined an alternative RECTANGLE command. The code used in the demo can still be found in the ObjectARX SDK, under samples\editor\rect. The original command - as defined in the badrectang.cpp file – makes use of static member variables... Read more →

Working with specific AutoCAD object types in .NET

Most of the functions to access objects in the AutoCAD drawing return generic objects/entities. The base type for objects stored in the AutoCAD database is “DBObject” – which can be used to access common persistence information such as the handle, etc. – but there is no such thing as a pure DBObject: all DBObjects actually belong to a type that is derived from this base (whether that’s a “Line”, “Circle”, “BlockReference”, etc.). The next level up in the hierarchy is “Entity”, from where you can access graphical properties such as color, layer, linetype, material, etc. The sample code in... Read more →

Selecting the edge of a nested solid in ObjectARX

This entry was contributed by Adam Nagy, a member of DevTech EMEA based in Prague. The question is really a combination of two problems: Selecting a subentity Selecting a nested entity Selecting a subentity First we should clarify what a subentity is: A subentity is a pseudo entity which is a logical part of a real entity. In our sample drawing the solid is the real entity [AcDb3dSolid] and the edge is the pseudo entity (there is no AcDbEdge class). In AutoCAD we rely on IDs called GS (short for graphics system) markers to get to these subentities. The... Read more →

More fun with Autoexp.dat - let's see those resbufs

I had a nice surprise this weekend. Jorge Lopez, an old friend and colleague, had been reading this blog entry and decided to create a Visual Studio AddIn that allows you to see resbufs content expanding automatically while debugging. Jorge and I go back a long way - he used to work in DevTech (before it was called that) in our Americas team, back when I was based in Europe the first time. He later went on to join AutoCAD Engineering, and was one of the key contributors to AutoCAD's COM Automation API (although back then it was called... Read more →

Cancelling an active command in AutoCAD

Thanks to Alexander Rivilis for this topic (he submitted a comment to my previous post that got me thinking about this addendum). When you're asking AutoCAD to execute commands by submitting them to its command-line, it helps to make sure no command is currently active. The accepted approach is to send two escape characters to the command-line... this is adopted by our menu & toolbar macros that consistently start with ^C^C in MNU and now CUI files. Why two? The first is to cancel the "most active" command, and the second is to drop out of either the dimension... Read more →

Techniques for calling AutoCAD commands programmatically

It's quite common to want to call commands from one or other of AutoCAD's programming environments. While it's cleanest (from a purist's perspective) to use an API to perform the task you want, the quickest way - and the one which will appeal to the pragmatists (and the lazy) among us is often to call a sequence of commands. And there are, of course, a few places in AutoCAD where APIs have not been exposed, so scripting commands is the only way to achieve what you want. Let's take the simple example of adding a line. Here's what you'd... Read more →

Advanced Visual Studio debugging: how to stop stepping into certain functions

While debugging it's sometimes very frustrating to find yourself repeatedly stepping into an irrelevant function. For instance, complex statements pretty commonly include object constructors etc. that you know function perfectly well, but the debugger routinely takes you into them. The Visual Studio IDE has an undocumented (and unsupported) mechanism to help with this. During the VC 6.0 timeframe it was implemented via our old friend the autoexp.dat file (see my previous post on this), in a special section called [ExecutionControl]. Since VC 7.0 this has been moved to the Registry. For VC 7.0 and 7.1, it was in the... Read more →

Advanced Visual Studio debugging: automatic expansion of watched variables

I've been using Visual C++ (and afterwards Visual Studio) since it was 16-bit, back in version 1.52. OK, maybe that's not so long ago, relatively (11 short years), but the point is that in spite of having followed the Visual Studio technology over this period, I've so far been completely unaware of the autoexp.dat file. This feature of the Visual Studio was brought to my attention by Ahsan Ali, a programmer in the Inventor Engineering team who was based over in Bangalore at the same time I was (we had both previously worked in the US - he had... Read more →

Migrating ObjectARX applications to support Unicode - some resources

The work we did to migrate AutoCAD 2007 to use Unicode (rather than MBCS), has impacted many developers around the world. For those that are yet to go through the pain themselves, I thought I'd talk about the resources that are available to ObjectARX developers needing to port their applications to Unicode. Firstly, you should check out the Migration Guide that ships with the ObjectARX 2007 SDK (docs/acad_xmg.chm): There's a whole section called "Upgrading to Unicode", with lots of useful information. A good deal of the material in the guide was compiled during the development phase of AutoCAD 2007,... Read more →

Calling ObjectARX functions from a .NET application

One of the really compelling features of .NET is its ability to call "legacy" unmanaged C++ APIs. I say "legacy", but we use this facility regularly to call APIs that are far from being considered defunct (the C++ version of ObjectARX is alive and kicking, believe me! :-). Autodesk understands that our development partners have invested many years in application development, and can't afford to throw that investment away to support the latest & greatest (and sometimes "flavor of the month") programming technology. For example, over the years we've made sure it was possible to create a VB or... Read more →