Through the Interface

At AU 2010

It was a bit of a schlep, but I got here. My flight out of Geneva was delayed due to inclement weather: the first (actually quite mild) snowstorm of the season. The runway was closed for some time and there was a 1+-hour backlog on de-icing, so I sat helplessly watching my connection time in Heathrow dissipate to nothing. In the end, after a 3-hour delay, this initial flight arrived 5 minutes after my direct connection to Las Vegas had left. I had the choice of waiting a full 24-hours – as BA fly once a day direct to... Read more →

Adding a 2D spatial filter to perform a simple xclip on an external reference in AutoCAD using .NET

I’ve now checked in for my flight to Las Vegas – and, thanks to Jeremy Tammik’s recent troubles, I luckily renewed my ESTA – so I’m pretty much all set for my trip to AU 2010, at least from a travel perspective. I’m just keeping my fingers crossed that the gastric 'flu my kids seem to have come down with doesn’t hit me before I leave (or once I’m at AU… what a grim thought). I was going to keep today’s post light, just like the last one, but then decided to dip into my email folder of externally... Read more →

C#/.NET Little Wonders

I’m heads-down in final preparation mode for AU 2010 and so won’t post anything very detailed for the rest of the week, but I did just want to share a series of programming gems that I stumbled across the other day. James Michael Hare has published a great series entitled “C#/.NET Little Wonders”: C#/.NET Five Little Wonders (part 1) The Null Coalescing Operator (??) The As Cast Auto-Properties The Stopwatch Class TimeSpan factory methods C#/.NET Five More Little Wonders (part 2) string.IsNullOrEmpty() and string.IsNullOrWhiteSpace() string.Equals() using Statements static Class Modifier Object and Collection Initializers C#/.NET Five Final Little Wonders... Read more →

Misusing mutable state with F# Asynchronous Workflows

Or perhaps the title should really be “why it’s really a good idea to avoid misusing mutable state when using F# Asynchronous Workflows”. Ultimately I wanted to share a brief (or not, we’ll see), cautionary tale about the dangers of shared state when implementing concurrent tasks. I’ve been using F# for some time, and have it fairly well drilled into my skull by this point that shared, mutable state is bad. And yet occasionally it somehow creeps in as an expedient way to solve certain issues: perhaps it’s just a lack of discipline on my part or the years... Read more →

Generating C# code to create associative, lofted surfaces between selected AutoCAD polylines using .NET

That has to be one of my favourite post titles, to-date: it’ll be interesting to see how Twitterfeed handles it. :-) In this post we’re going to combine the approaches from a couple of previous posts to place source code to generate associative, lofted surfaces on the clipboard, ready for pasting into a C# project. When we did this before for polylines, we didn’t really care about grouping them: we could just select all of the polylines in a drawing and they would (hopefully) be reproduced when the generated code was executed in the target drawing. This is a... Read more →

Creating an associative, lofted surface in AutoCAD using .NET

As mentioned a few posts ago, I’m working towards generating a set of surfaces from some polyline profiles, to programmatically create a space shuttle. Most of the surfaces are “lofted”, so that seems a good place to start. Today we’re going to implement a simple command that creates a lofted surface from three circular profiles. This is based on functionality added in AutoCAD 2011, so apologies to those using prior versions. If anyone’s interested in where the term “lofted” comes from, the ever-useful Wikipedia has some information for us: The term lofting originally came from the shipbuilding industry where... Read more →

AU 2010 Handout: Integrate F# into Your C# or VB.NET Application for an 8x Performance Boost

This handout is for the companion class to the one whose handout formed my last post. While that class was user-focused, this one, “CP322-2 - Integrate F# into Your C# or VB.NET Application for an 8x Performance Boost”, is more developer-focused and takes the hood off the implementation of the BrowsePhotosynth application. The code for this special version of the application – which imports synchronously via C# and synchronously/asynchronously via F# – is available here for download. Introduction This class takes a look at the implementation of BrowsePhotosynth for AutoCAD, the ADN Plugin of the Month from October 2010... Read more →

AU 2010 Handout: Point Clouds on a Shoestring

I’ve been a little slow getting my AU material together, this year (I’ve been called onto more pressing issues fairly consistently over the last weeks/months), so I’m very much up against Monday’s content submission deadline. I’ll certainly have the handouts ready, but the presentations will have to come later. As I’ve done in the past, I like to post my handouts here for people to take a look at (and provide feedback on in time for me to correct prior to the event ;-). Today’s post is the handout for my AutoCAD user-focused class, “AC427-4 - Point Clouds on... Read more →

Solving a fun little geometry problem in C# and F#

A colleague set me a fun little geometry-related challenge a couple of days ago: to write C# and F# applications to make AutoCAD draw lines between a number of points spaced evenly around the circumference of a circle. Here’s the first C# version I wrote, which makes use of a function to collect the various points before indexing into the collection from a nested loop: using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.Runtime; using Autodesk.AutoCAD.DatabaseServices; using Autodesk.AutoCAD.Geometry; using System; namespace CircleOfLines { public class Commands { public static Point3dCollection pointsOnCircle( Point3d center, double radius, int n ) { double alpha = Math.PI *... Read more →

Generating C# code for selected AutoCAD polylines using .NET

Here’s an idea I’ve been playing around with for some time: say you want to capture geometry as code for pasting back into your application, how do you do it? For instance, sometimes you might want to model geometry using AutoCAD and then capture it as code for later generation at runtime. I have a specific example in mind, of course: I have some boundary loops that can be used to generate the outer shell of a space shuttle using the surfacing capabilities introduced in AutoCAD 2010. I’d really like to use code to store these loops and –... Read more →

Two minor fixes to Clipboard Manager and much data-bound frustration

I spent more time than I wanted tunneling down a rabbit-hole, today. Thankfully I really didn’t have a great deal of time to focus on the problem at hand, otherwise I might have spent even more time down there. But perhaps the time wasn’t all wasted – at least I’ve made a blog post out of it, even if it’s mainly to vent my frustration. :-) I started – on a positive note – by fixing the focus issues when certain uses of the Clipboard Manager result in AutoCAD not having focus (presumably the palette has it, instead): P/Invoking... Read more →

Exporting to DWG from the Clipboard Manager

I’ve made a couple of updates to the Clipboard Manager in this latest version. Firstly I wanted to remove a peculiar situation that occurred in the previous versions when you copy something to the clipboard that isn’t AutoCAD geometry: for some reason this act invalidates the ability to access data – such as the preview images – from the items in the Clipboard Manager. The pasting into the drawing still works, as setting an AutoCAD object back onto the clipboard re-enables access to AutoCAD data. You can try this with the previous version by creating a number of entries... Read more →