For the past few months I’ve been a technical editor for a book my good friend and colleague, Doug Finke, is writing entitled PowerShell for Developers which has just recently become available on Amazon. The purpose of the book is to show how easy it is to accomplish normally mundane, repetitive, or clunky tasks with PowerShell, a simple, concise scripting language that you already have installed on your box.
On my current project, I was recently tasked with setting up the build for our project. Of course, build scripts aren’t exactly glorious or interesting in any way and the prospect of dealing with MSBuild’s XML files gives me a fleeting sense of vertigo.
But fortunately, there’s a much, much less painful way to make build scripts by using psake. Continue reading “Leveraging Templates in psake”
I’ve been using Powershell for just over a year now, and its effect on my development workflow has been steadily increasing. Looking back, I have no doubt that it is the most important tool in my belt – to be perfectly honest, I’d rather have Powershell than Visual Studio now. Of course, that’s not to say Visual Studio isn’t useful – it is – but rather more that Poweshell fills an important role in the development process that isn’t even approached by other tools on the platform. Visual Studio may be the best IDE on the market, but at the end of the day, there are other tools that can replace it, albeit imperfectly.
To take some shavings off of the top top of the iceberg that is why I use Powershell, I’d like to share a recent experience of Powershell delivering for me. Continue reading “Why I Use Powershell”
The other day I was given the task of converting a particularly poorly designed VisualBrush into a LinearGradientBrush. One of the problems I came across very quickly was the use of semi-transparent colors layered on top of each other, and, of course, I needed a “flattened” color for my GradientStop. Now, I could have used Paint.NET or GIMP or Photoshop to put out a couple layers of colors, set the transparencies and used the color dropper to get the result. Of course, since I’m not a designer, I don’t have any of those things installed on my work computer, so I decided to just find the equation to blend the channels myself. It didn’t take long, and Wikipedia delivered the goods. According to [[Alpha_compositing|the article]], the formula to merge two colors, [latex]C_a[/latex] and [latex]C_b[/latex], into some output color, [latex]C_o[/latex], looks like this:
[latex]C_o = C_a\alpha_a+C_b\alpha_b(1-\alpha_a)[/latex]
Since a color can be thought of as a three-tuple of its R, G, and B channels, the formula is easily distributed to each of these values.
At this point, I decided I could probably just pull out a calculator and crunch the numbers. But maybe, in about the same time, I could also whip something together, say in PowerShell, to do it for me. Since I’m still learning PowerShell, I figured the learning experience would be worth at least something. Continue reading “Alpha-Blending Colors in PowerShell”