Through the Interface

Using a jig to rotate an AutoCAD entity via .NET

An interesting request came in via a previous post followed up by a similar question came in via another post. The original problem was to rotate a rectangular polyline entity around its centre, and be able to continue rotating it afterwards. A few things were interesting to me: Rectangles are simply polylines between four points, so have no inherent concept of either a centre point or a rotation angle The obvious answer (to me, at least) being to calculate the centre and store the rotation as XData on the polyline To modify an entity graphically it makes sense to... Read more →

Embedding AutoCAD 2009 in a standalone dialog

This post takes a look at another topic outlined in this overview of the new API features in AutoCAD 2009. AutoCAD 2009 introduces the ability to embed the application in a standalone dialog or form via an ActiveX control. This capability has been around for a number of releases of AutoCAD OEM, but this feature has now been made available in the main AutoCAD product. The way the control works is to launch an instance of AutoCAD in the background (it should go without saying that AutoCAD needs to be installed on the system, but I've said it, anyway... Read more →

Initialization code in your F# AutoCAD application

Back from a nice long weekend, although I spent most of it sick with a cold. I find this increasing... Read more →

Implementing your own AutoCAD color combobox control using .NET

A big thanks to Scott McFarlane, from Geotropix, Inc., for sharing the code in this post. Here's an email I received from Scott: I was reading this blog entry on “Through the Interface” and some folks were asking about how to implement .NET combo box versions of the color and linetype ActiveX controls that are available. I just wanted to share a simple .NET implementation of a color combo box. The color combo is quite easy, really. The linetype one would be more difficult. Attached is the source code. This is just a generic color combo, that loads up... Read more →

A simple taxonomy of programming languages

Someone asked me recently how I categorize different programming paradigms. I thought it was a very interesting question, so here's what I responded. Please bear in mind that this is very much the way I see things, and is neither an exhaustive nor a formally-ratified taxonomy. One way to look at languages is whether they're declarative or imperative: Declarative programming languages map the way things are by building up “truths”: this category includes functional programming languages (such as Miranda, Haskell and Erlang) which tend to be mathematical in nature (you define equations) and start with lambda calculus as a... Read more →

Getting the full path of the active drawing in AutoCAD using .NET

I had a question come in by email about how to find out the full path of a drawing open inside AutoCAD. Here's some C# code that does just this: using Autodesk.AutoCAD.Runtime; using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.DatabaseServices; namespace PathTest { public class Commands { [CommandMethod("PTH")] public void DrawingPath() { Document doc = Application.DocumentManager.MdiActiveDocument; HostApplicationServices hs = HostApplicationServices.Current; string path = hs.FindFile( doc.Name, doc.Database, FindFileHint.Default ); doc.Editor.WriteMessage( "\nFile was found in: " + path ); } } } Here's what happens when you run the PTH command, with a file opened from an obscure location, just to be sure: Command: pth... Read more →

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 →