Archive for August, 2008
Everyone knows that c0 = cd*(1-a)+cs*a for color channels, but how do you compute the final alpha channel ? Using the same equation means a0=ad*(1-a)+a*a that may not be what you would expect, for example if you have full opaque destination you may end up with a translucent image a0 < 1.
By reverse engineering of Paint.NET (and Photoshop) I came with a0 = ad*(1-a)+1*a, that is an additive blending for alpha. While I have found no real explanation why to use this formula, I had to. Oh and BTW, ActionScript’s BitmapData.copyPixels blends like crap, you’d better code your own alpha blending.
Update: Well, the correct alpha blending equations are: a0 = a+ad*(1-a) and c0 = (cd*ad*(1-a)+cs*a) / a0, from Wikipedia.
It seems to work nice but … only on Sql Server 2008 connections! This really sucks
It’s not a joke, I got my hands on one . And, yes, it has a simple Win32 stub exe that checks for JVM and installs it if not found.
I could have bet on anything that SQL Server has atomic disk writes so no crash can possibly corrupt anything, well, after a power outage I had a database marked as (Suspect) by the recovery. The only way to actually get it back running was DBCC with REPAIR_ALLOW_DATA_LOSS that indeed has lost an entire table full of data along with some other fields around.
Using this provider http://code.msdn.microsoft.com/EFOracleProvider it’s easy to change you model to use Oracle instead of SQL Server – only change the column types (for example from nvarchar to nvarchar2 etc). Unfortunately the provider then throws a bizarre error, you can see it in the comments.
to run circles around
I really did not know about it First heard in Romanian then in English.
e.GetType().InvokeMember(“onmouseover”, System.Reflection.BindingFlags.InvokeMethod, null, e, null);
where e is IHTMLElement.
The Yahoo Developer Network has some interesting articles on common patterns you may encounter in developing web applications.