Posted by jpluimers on 2019/01/24
I was amazed that this was marked as “Closed; won’t fix” as every respectable IDE I use but Delphi has a package manager that by now can download and update packages in the background without blocking the IDE [RSP-10484] GetIt shouldn’t block the IDE – Embarcadero Technologies.
–jeroen
Posted in Delphi, Development, Software Development | 1 Comment »
Posted by jpluimers on 2019/01/24
Cult code via [WayBack] Fast inverse square root – Wikipedia part of [WayBack] Quake-III-Arena/blob/master/code/game/q_math.c:
float Q_rsqrt( float number ) { long i; float x2, y; const float threehalfs = 1.5F; x2 = number * 0.5F; y = number; i = * ( long * ) &y; // evil floating point bit level hacking i = 0x5f3759df - ( i >> 1 ); // what the fuck? y = * ( float * ) &i; y = y * ( threehalfs - ( x2 * y * y ) ); // 1st iteration // y = y * ( threehalfs - ( x2 * y * y ) ); // 2nd iteration, this can be removed return y; }
It is a really fast way to approximate the square root for 32-bit IEEE754 calculations having origins around 1986:
Cleve Moler replied on June 27th, 2012 9:35 pm UTC :
Jotaf — Thanks very much for your comment, and for reminding me about the fast inverse square root hack. I didn’t realize that the trick had attained a kind of cult status in the graphics community. The trick uses bit-fiddling integer operations on a floating point number to get a good starting approximation for Newton’s iteration. The Wikipedia article that you link to describes the trick in great detail, and also links to an article by Rys Sommefeldt about its origins. Sommefeldt goes back to the late ’80s and to me and my colleague Greg Walsh at Ardent Computer. I actually learned about trick from code written by Velvel Kahan and K.C. Ng at Berkeley around 1986. Here is a link to their description, in comments at the end of the fdlibm code for sqrt. http://www.netlib.org/fdlibm/e_sqrt.c . — Cleve
By now there is also a constant for 64-bit IEEE754 calculations 0x5fe6ec85e7de30da by [WayBack] 2003 research from Chris Lomont who also found a better 32-bit constant 0x5f375a86.
Note you need to be careful with boundary values like zero and infinity. This holds for approximations in general: [WayBack] performance – Why is SSE scalar sqrt(x) slower than rsqrt(x) * x? – Stack Overflow
–jeroen
Posted in Algorithms, C, Development, History, Software Development | Leave a Comment »
Posted by jpluimers on 2019/01/24
While doing some research, I bumped into Chuck Jazdzewski on Twitter: “Doing some historical posts to resurrect my blog. http://t.co/kSXy3ARUhR” so I decided to archive a few more links about Chuck because few of the early Delphi R&D team on-line history is slowly fading away into bit-heaven.
Back in the Delphi days, together with Anders Hejlsberg, Chuck Jazdzweski he has co-architected the the Delphi VCL component architecture and the foundations of the Delphi IDE.
Nowadays he’s working at Google and even speaking on conferences, grown far beyond his “be at conferences, but just chat with people” in the Delphi days: [WayBack] Chuck Jazdzewski – NG-Conf April 18–20th 2018 – The World’s Original Angular Conference
Chuck is a Software Engineer on the Angular team at Google. He is a programming language geek, UI framework and component library veteran, and has a passion for simplifying the task of programming. Before Google, he worked at Microsoft and Borland.
–jeroen
Posted in Delphi, Development, Software Development | 2 Comments »
Posted by jpluimers on 2019/01/24
Migrating KPN ISDN MSNs to XS4ALL VoIP: via https://mijn.xs4all.nl:
Reminder to self to finish this when the final ISDN A/D dependency has been resolved.
–jeroen
Posted in ISDN, LifeHacker, Power User, Telephony, VoIP | Leave a Comment »
Posted by jpluimers on 2019/01/23
Still need to research this: [WayBack] I search for way to automatically generate class body from interface definition… – Jacek Laskowski – Google+
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, ModelMaker Code Explorer, Software Development | 2 Comments »
Posted by jpluimers on 2019/01/23
Don’t forget your padding: Hello,I’m playing with the APK format of a sample “Hello world” Android application.my (first) goal is to be able to rebuild an APK from a unzipped one… – Paul TOTH – Google+
References: RSA Algorithm
–jeroen
Posted in Android, Development, Encryption, Mobile Development, Power User, Security, Software Development | Leave a Comment »
Posted by jpluimers on 2019/01/23
As a back-end person, sometimes I wondered about CDATA in front-end HTML code was for, especially in JavaScript and CSS style elements.
[WayBack] HTML vs. XHTML – WHATWG Wiki explains how to be compatible with XHTML, HTML, XML based tools and older browsers:
The following code with escaping can ensure script and style elements will work in both XHTML and HTML, including older browsers.
In both cases, XML ignores the first comment and then uses the
CDATAsection to avoid the need for escaping special characters<and&within the rest of the contents (with subsequent JavaScript comments added within to ensure the HTML-oriented code is ignored by JavaScript).In HTML, older browsers might display the content without the content being within a comment, so comments are used to hide this from them (while modern HTML browsers will run code inside the comments). The subsequent JavaScript comment is added to negate the text added for the sake of XHTML.
The
<style>requires the/**/comments since CSS does not support the single line ones.<!----> ... //--><style type="text/css"><!--/*--><![CDATA[/*><!--*/ ... /*]]>*/--></style>If not concerned about much older browsers (from which one is hiding the HTML) one can use the simpler:
//<style>/*<![CDATA[*/ /*]]>*/</style>Also note that the sequence “
]]>” is not allowed within aCDATAsection, so it cannot be used in true XHTML-embedded JavaScript without escaping.
–jeroen
via:
Posted in CSS, Development, HTML, HTML5, JavaScript/ECMAScript, Scripting, Software Development, Web Development | Leave a Comment »
Posted by jpluimers on 2019/01/22
Interesting code generator from 3D models into Xamarin, Delphi or Oxygene code:
[WayBack] Petra Sketch Plugin | Melbourne | Applying Code
Convert Sketch drawings to iOS, macOS, Android and Windows native drawing code.
[WayBack] Documentation of Petra Sketch Plugin | Melbourne | Applying Code
Via:
–jeroen
Posted in .NET, C#, Delphi, Development, Software Development, Xamarin Studio | Leave a Comment »
Posted by jpluimers on 2019/01/22
- The caption says, “Saint Dogbert enters the Land of Cubicles searching for the demons of stupidity.” Dogbert walks down the hall wearing a bishop’s miter and holding a scepter.
- The caption says, “Suddenly he finds an over-promoted computer guru spouting useless database concepts.” A man sits at a conference table with two glassy-eyed co-workers. The man says, “You’d be fools to ignore the boolean anti-binary least-square approach.”
- The caption says, “The monster is dispatched to the dark world by the sight of its most feared object.” Dogbert stands on the conference table holding a document in front of the man. Dogbert says, “Look! Actual code!” The man’s head melts into his shirt and a co-worker says, “Cool!”
Source: [WayBack] Dilbert Comic Strip on 1995-11-09 | Dilbert by Scott Adams
–jeroen
via: [WayBack] architecture – Why does the .NET framework have no concept of classes as first-class types? – Software Engineering Stack Exchange
Posted in Development, Software Development | Leave a Comment »
Posted by jpluimers on 2019/01/22
Note: if the system you SSH from is ever compromised, then assume the passwordless targets are also compromised!
–jeroen
Posted in *nix, *nix-tools, Communications Development, Development, Internet protocol suite, Linux, openSuSE, Power User, SSH, SuSE Linux, TCP, Tumbleweed | Leave a Comment »
The Wiert Corner - irregular stream of stuff 