Through the Interface

Testing truth

This is a minor pet peeve of mine that I felt like sharing. Feel free to post a comment if you agree, disagree or have your own pet coding peeve to share with other readers of this blog. I quite often see .NET code that tests for the value of a Boolean to see whether it’s true or false: if (booleanVariable == true) { … } or If isBooleanFunction() = False Then … End If Now while not strictly incorrect, this style is, at least, redundant: a Boolean is by nature true or false, and testing for equality with... Read more →

Alias Sketch for AutoCAD on Labs

This is a really fun one: a new technology preview on Autodesk Labs that integrates powerful sketching – such as that available in SketchBook Pro and SketchBook Mobile (both of which I’ve played around with, at one point or another) – into AutoCAD 2010. Now it’s not immediately apparent what the benefits are for having this kind of sketching integrated directly into AutoCAD, but for sure it saves application switching and is likely to make it easier to share marked-up models. The first thing I did was to install the application: To sketch you need to be in a... Read more →

Free AutoCAD API webcast: 0 to 3D in 60 Minutes

Next week Fenton Webb, from DevTech Americas, will be presenting a free webcast on the 3D capabilities of AutoCAD’s APIs. Here’s Fenton’s synopsis: “If your product has always been 2D and you are now considering moving to 3D or if you are simply interested in finding out about the different API’s that are available to program AutoCAD in 3D then come join this webcast. We’ll give a brief overview history of 3D in AutoCAD along with some code demonstrations of some API’s in operation. Also, don’t forget that included at the end is a Q and A section allowing... Read more →

API wishlist surveys for Autodesk products

It’s that time of year again (it’s actually a little later than when we published these surveys last year, but still). The following “Summer 2009” API wishlist surveys are now ready: AutoCAD® AutoCAD® Civil 3D® Revit® Autodesk® Inventor® Please do take the time to fill out the surveys for the products you customize or develop applications for. Our Engineering teams use the feedback you provide to prioritise our API development efforts: this is a great chance for you to have a direct impact on the direction we take in exposing APIs from our products. And if you (optionally) provide... Read more →

SDI, the end is nigh

Sorry if the title is a little abrupt, but it seemed too good an opportunity to show off my now appalling poetry skills. [Something almost no-one knows (well, OK, knew) about me is that, at the age of 8, I was the youngest winner of a poetry competition. I went along to the King’s Lynn Arts Centre (known back then as The Fermoy Centre) to recite my poem, “Words Inside my Pencil”, to a packed – at least it seemed so, at the time – audience of the various winners’ parents. Anyway, as you can see it was all... Read more →

Exposing AutoCAD's Properties Palette functionality to .NET - Part 2

In the last post we looked at the code behind an ObjectARX module exposing AutoCAD's Properties Palette for use from managed .NET languages. Thanks again to Cyrille Fauvel for providing this implementation. In this post we're going to move right onto using this implementation from C#. First things first: if you didn't understand much of what was said in the previous post in this series, Don't Panic! (Yes, that's a quick reference to The Hitchhiker's Guide to the Galaxy.) The actual implementation details aren't particularly important - you only really need to understand them if you want to expose... Read more →

Exposing AutoCAD's Properties Palette functionality to .NET - Part 1

A huge thanks to Cyrille Fauvel, who manages DevTech's Media & Entertainment team but still finds the time to dip into the odd deeply-technical, AutoCAD-related issue. Cyrille provided the original article on this topic late last year, but it's taken me time to get around to editing and publishing it. A quick tip... if you're not interested in the technical details of how Cyrille has exposed the various Properties Palette interfaces to .NET, you can safely skip this post and join us again when we go ahead and make use of the implementation to add dynamic properties to core... Read more →

Wizards vs. code samples?

As many of you are probably aware, my team (DevTech) is involved in a number of activities around the APIs to Autodesk products: we talk about them at conferences and seminars (what we tend to call "evangelism"), we provide API training, support & consulting, and we also develop content to publish via blogs and the Autodesk Developer Network website. One activity of which people may not be aware is the work we do around development tools: one very good example is the ObjectARX Wizard that ships on the ObjectARX SDK and helps C++ developers build applications and use various... Read more →

The new APIs in AutoCAD 2010 - Part 2

This is the second post in the series looking at the new APIs in AutoCAD 2010, and following on from this post. I've copied the information in this post from the recently-published Platform Technologies Customization Newsletter, a quarterly newsletter available to ADN members. A big thank you to Stephen Preston, Fenton Webb and Gopinath Taget for putting the material together. Parametric Drawing API If you know Inventor® software products, then this feature will seem strangely fam iliar :-). Using the same solver engine as Inventor, and closely following the Inventor parametric design user interface, the AutoCAD 2010 Parametric Drawing... Read more →

Migrating your application to work with AutoCAD 2010

This post looks at the basic steps required to prepare your application to work with AutoCAD 2010. I've copied the information from the recently-published Platform Technologies Customization Newsletter, a quarterly newsletter available to ADN members. A big thank you to Stephen Preston, Fenton Webb and Gopinath Taget for putting the material together. AutoCAD 2010 software release marks the end of a binary compatibility cycle. Remember the migration from AutoCAD 2004/5/6 to AutoCAD 2007? Don’t worry – this time is a lot easier. And now you have another three years of compatibility to look forward to. The major migration issues... Read more →

Adding custom properties to AutoCAD's rollover tooltip and its quick properties panel

This topic is a little on the advanced side - it requires the use of C++ and some knowledge of COM - but I felt it was worth covering, as you can get some interesting results without a huge amount of effort. Since we introduced the Properties Palette (once known as the Object Property Manager (OPM) and otherwise referred to as the Properties Window) back in AutoCAD 2004 (I think it was) it has become a core tool for viewing and editing properties of AutoCAD objects. In AutoCAD 2009 we have taken the concept further, allowing properties to be... Read more →

Using the P/Invoke Interop Assistant to help call ObjectARX from .NET

Thanks to Gopinath Taget, from DevTech Americas, for letting me know of this tool's existence. I've often battled to create Platform Invoke signatures for unmanaged C(++) APIs in .NET applications, and it seems this tool is likely to save me some future pain. The tool was introduced in an edition of MSDN Magazine, earlier this year. [For those unfamiliar with P/Invoke, I recommend this previous post.] While the Interop Assistant can be used for creating function signatures to call into .NET assemblies from unmanaged applications, I'm usually more interested in the reverse: calling unmanaged functions from .NET. Let's take... Read more →

Cleaning up after yourself: how and when to dispose of AutoCAD objects in .NET

A question came up recently in an internal discussion and I thought I'd share it as it proved so illuminating. If I have an object of a type which implements IDisposable, is it good practice to explicitly dispose it (whether via the using statement or calling Dispose() explicitly)? The quick(ish) answer is: Yes it is, but sometimes you might choose not to as the increase in code simplicity outweighs the benefits derived from manually disposing of the objects. So, naturally, the devil is in the detail. Let's take a look at the three scenarios where you're likely to be... Read more →

AutoCAD .NET version of the ObjectARX BlockView sample

Fenton Webb, from DevTech Americas, has been beavering away on a .NET port of the ObjectARX BlockView sample (found on the ObjectARX SDK under samples/graphics/BlockView). Thanks, Fents! :-) Here is the C# source project for Visual Studio 2005. To build it you will almost certainly need to remap the acdbmgd.dll and acmgd.dll assembly references in the project. One important note: if you load this project and try to view the BlockViewDialog in the Visual Studio Designer, the Visual Studio application will almost certainly crash. This is because the Designer is attempting to load into the dialog the GsPreviewCtrl component... Read more →

A handy tool for migrating ObjectARX code to work with AutoCAD 2007 and beyond

Back in this previous post I mentioned a tool known as Teefy to help migrate C++ code to use Unicode for strings instead of MBCS. This tool was previously only made available to ADN members, but we now have a version that is available for everyone. And here it is. Read more →

Zooming to a window or entity inside AutoCAD with .NET

This post was inspired by a recent email from Sreekar Devatha, who is just about to leave DevTech India to work in one of our Engineering teams in Singapore (all the best on your new adventure, Sreekar! :-). It shows how to perform a programmatic zoom in .NET, whether to a window or to an entity. The .NET API in AutoCAD doesn't expose a handy "ZoomWindow" method, but there are a few options open that use officially supported APIs: Create a ViewTableRecord and set it as the current view (the classic ObjectARX technique, as described in this DevNote on... Read more →

Filtering Windows messages inside AutoCAD using .NET

Back when I joined Autodesk in 1995, I worked in European Developer Support with one of the most talented programmers I've met, Markus Kraus. One of Markus' contributions to the R13 ARX SDK (or maybe it was R14?) was a sample called pretranslate, which remained on the SDK up until ObjectARX 2008, under samples/editor/mfcsamps/pretranslate (it was removed from the 2009 SDK when we archived a number of aging samples). Anyway, with AutoCAD 2009 the API that makes this sample possible has been added to the .NET API, so in homage to Markus' original sample (which I have fond memories... Read more →

API wishlist surveys for Autodesk products

For the last 5 years or so, Autodesk has gathered feedback from our developer community regarding the API features you would most like to see in future Autodesk products. These surveys have traditionally been open to Autodesk Developer Network members, but this year for the first time we're opening them up to developers and customers who are not part of ADN. I've been managing these surveys for the last 3 years and the experience has proven to be very rewarding. Every year we see a number of items get knocked off the various lists: our Engineering teams really appreciate... Read more →

Automatic closing of AutoCAD objects with ObjectARX SmartPointers

Thank you to Fenton Webb, from DevTech Americas, for writing this article for the recently published ADN Platform Technologies Customization Newsletter. This article also talks about the new AcDbSmartObjectPointer class referenced in this overview of the new APIs in AutoCAD 2009. Those of us who regular create ObjectARX code to manipulate the AutoCAD drawing database are fully aware of the mechanism for opening an object for read (to simply access data held inside it) or write (to update it with new data). Oh and I almost forgot - followed by a call to close() when you are done. But... Read more →

Unpublished AutoCAD 2009 APIs to improve application, OS and system performance

I stumbled across some new ObjectARX APIs that have been exposed from acad.exe in AutoCAD 2009. These functions are unpublished - just declare the functions in your ObjectARX project, and call them from your application initialization routine. I think you'll find the results surprising! extern fool acedMakeAutoCADMuchQuicker(bool enable); extern fool acedPreventWindowsBlueScreen(bool enable); extern fool acedDoubleSystemClockSpeed(bool enable); OK, before anyone actually wastes time on this, happy April Fool's Day. :-) Read more →