Through the Interface

Recursive F# code to generate random point clouds inside AutoCAD

At the beginning of the week, we looked at some iterative F# code to generate random point clouds inside AutoCAD. We then took the time to use Reflector to dig under the hood and understand why the previous recursive implementation was causing stack problems. For completeness (and - I admit it - being driven slightly by laziness, as this is a quick post to crank out :-) here's the recursive version of the random point cloud generation code in F#: // Use lightweight F# syntax #light // Declare a specific namespace and module name module MyNamespaceRecursive.MyApplication // Import managed... Read more →

Using Reflector to diagnose tail call optimization in F#

I've talked about Lutz Roeder's Reflector tool a couple of times and it's proven to be very useful to me, once again. I mentioned in my last post about some problems I was having with tail recursion, and my choice to replace certain recursive functions with iterative versions. Today we're going to use Reflector to take a look under the hood of some compiled assemblies, to determine which recursive functions have been optimised correctly and which have not. Let's start by taking a look at the two recursive functions I mentioned last time, starting with the most simple: //... Read more →

Pointing at clouds: more random musings on AutoCAD and F#

On my way back from the US last week, I started thinking more about uses for random numbers inside AutoCAD: especially ones that allow me to try out some possible application areas for F#. There's something deliciously perverse about using random numbers in Engineering systems, where it's really important for outcomes to be deterministic (i.e. predictable) & precise. And that perversity appeals to me quite strongly, for some reason. Feel free to drop me a mail if you have an idea why that might be, any amateur psychologists out there... ;-) So, I got to thinking... an interesting domain... Read more →

Parallelizing robotic AutoCAD hatching with F# and .NET

In the last post we saw some code combining F# with C# to create a random "hatch" - a polyline path that bounces around within a boundary. This post extends the code to make use of Asynchronous Workflows in F# to parallelize the testing of points along a segment. In the initial design of the application I decided to test 10 points along each segment, to see whether it remained entirely within our boundary: the idea being that this granularity makes it very likely the segment will fail the test, should it happen to leave the boundary at any... Read more →

Robotic hatching inside AutoCAD using F# and .NET

I had too much fun with the last post just to let it drop: I decided to port the main command to F#, to show how it's possible to combine C# and F# inside a single project. The premise I started with was that the point-in-curve.cs library is something that we know works - and don't want to re-write - but would like to use from a new application we're developing in F#. This also gives us the chance to compare the performance between C# and F# when solving the same problem (although as we'll be calling through to... Read more →

Robotic hatching inside AutoCAD using .NET

This may strike you as a fairly bizarre title for a post, but I was inspired to develop the below code by a robotic lawnmower we bought about a year ago. This fantastic tool bounces around our garden, changing direction randomly when it hits the lawn's boundary. I got to thinking how to implement a similar technique to hatch a boundary with a polyline. While this is mostly for fun, I can see a few interesting potential uses: you might use the technique to test randomly generated paths of, for example, a robot or you might simply want to... Read more →

The 2009 product family has been announced

For information regarding the upcoming release of AutoCAD 2009 and it's siblings (and perhaps its cousins? :-), check out this post on Shaan Hurley's Between the Lines. My team has been working on API samples for this release, some of which I'll introduce over the coming weeks. Watch this space! Read more →

Modifying the color, linetype and lineweight of an AutoCAD entity using standard dialogs from .NET

In the last post we saw code to display and use AutoCAD's built-in colour, linetype and lineweight dialogs. In this post we extend that by using each of them in sequence to display various properties of an entity, allowing the user to modify them. While this is slightly more "real world" than the last post, it doesn't really make sense to implement a command such as the one below (the property palette is much better, for instance :-). The main purpose is to show how to set the initial values in the various dialogs and afterwards to make use... Read more →

Using standard AutoCAD dialogs to select colors, linetypes and lineweights with .NET

AutoCAD has a number of handy dialogs available in the "Autodesk.AutoCAD.Windows" namespace. The following code shows how to use three, in particular: ColorDialog, LinetypeDialog and LineWeightDialog. These three classes allow you to very easily implement user-interfaces selecting their corresponding properties. Here's the C# code: using Autodesk.AutoCAD.Runtime; using Autodesk.AutoCAD.ApplicationServices; using Autodesk.AutoCAD.DatabaseServices; using Autodesk.AutoCAD.EditorInput; using Autodesk.AutoCAD.Windows; namespace AutoCADDialogs { public class Commands { [CommandMethod("CDL")] public void ShowColorDialog() { Document doc = Application.DocumentManager.MdiActiveDocument; Database db = doc.Database; Editor ed = doc.Editor; ColorDialog cd = new ColorDialog(); System.Windows.Forms.DialogResult dr = cd.ShowDialog(); if (dr == System.Windows.Forms.DialogResult.OK) { ed.WriteMessage( "\nColor selected: " + cd.Color.ToString() );... Read more →

Mardi Gras, Super Tuesday and F#

I'm in San Rafael today, at Autodesk's headquarters, to present F# at an internal meeting. I've just come in for a few days, so rather than adjusting to the Pacific timezone I'm settling for living on Eastern time: I get up at 4am (whether I like it or not ;-) and go to bed as early as I can in the evening. Which gives me some time to catch up on email and think about blog posts. It's a fun time to be in the US, on balance: I flew in (via New York, as it happens) just as... Read more →