Clock Option for Vulcan 3D Chess

Maybe it's just me, but I really dislike playing chess against a program where a clock is displayed showing the time I and the program each take to make a move. The clock's presence is a distraction and creates an undesirable sense of tension. On top of that, it subtly suggests the my inferiority by constantly highlighting how much faster the computer 'thinks' than I do. My inclination, thus, is to disable such a clock as quickly as possible.

Vulcan includes such a clock but unfortunately I found it to include no option to disable the clock. I was quite dismayed.

To correct this oversight, my first course of action was to find the point in the program where the clock was displayed and hack it so as to disable the display. This worked great! Problem solved! Then I thought about other people and how they might or might not want the clock displayed depending on their mood, and I started feeling guilty...

So, I went on to add an option to the Options menu to enable turning the clock on and off. This was fine for starters. But the clock defaulted to on, I wanted it to default to off, and others might still want it to default to on. Not wanting to dictate the default to anybody, I added the command line option -t (the program already has a -c command line option; '-t' stands for 'time clock'). When included on the command line when launching the program, this option starts the program with the clock off; otherwise the program starts with the clock on.

The result is all wrapped up in a free patch that's available at http://sourceforge.net/projects/vulcanchessmods/files/feature_patches/clock_option/.

Hiding Blog Post Rearrangement

Changing the order of Blogger blog posts using JavaScript, such as with the Post Reversal Script, has the drawback that the posts need to be loaded before they can be rearranged. The result is an unsightly load of posts in one order followed by a delayed apparent reload of the posts in the intended order.

The reloading effect can be masked by hacking the template to hide the widget containing the blog posts and only display it after the posts have been rearranged. The code for accomplishing this is simple but, unfortunately, must be placed at two remote positions in a blog's template.

To hide the posts, add the following to the stylesheet code toward the top of the template, such as before the line "/* Content" or some other line beginning with "/*":

/* Start Post Rearrangement Hiding CSS */
#Blog1 {visibility:hidden;}
/* End Post Rearrangement Hiding CSS */

Then to show the posts after they have been rearranged, add the following script just after whatever post reordering script you have added to your template and just before the closing BODY tag:

<!-- Start Post Rearrangement Hiding Code -->
<script type='text/javascript'>
//<![CDATA[
  document.getElementById("Blog1").style.visibility = "visible";
//]]>
</script>
<!-- End Post Rearrangement Hiding Code -->

Viewing the blog, you should initially see an empty area where the posts normally appear followed by the posts appearing in the intended order.

An alternative to the empty area is to add a background image to the container underlying the blog post widget. The image could be, for example, a TV test pattern or a "Please wait..." message. The CSS code for this is shown below, where url-to-an-image-file is the URL to an image you have uploaded to Blogger or that is located elsewhere on the net.

/* Start Post Rearrangement Hiding CSS */
#main {
  background-image: url( url-to-an-image-file );
  background-repeat: no-repeat;
}
#Blog1 {
  visibility:hidden;
}
/* End Post Rearrangement Hiding CSS */

Then to show the posts, use the following script. The background image is removed here in case the blog post container is transparent, in which case the underlying container's background image would be visible behind the blog posts.

<!-- Start Post Rearrangement Hiding Code -->
<script type='text/javascript'>
//<![CDATA[
  document.getElementById("main").style.backgroundImage = "none";
  document.getElementById("Blog1").style.visibility = "visible";
//]]>
</script>
<!-- End Post Rearrangement Hiding Code -->

Depending on the speed of a viewer's browser, the selected image will be displayed while the posts are being rearranged, followed by the posts appearing in the intended order.

King Bug Fix for Vulcan 3D Chess

While testing a prototype game save feature for Vulcan, I ran into a nasty little bug. I would move my king off of it's attack board, the program would start 'thinking', and then it would crash. The crash was at an assertion indicating that the program couldn't find my king anywhere on the board.

After much investigation, which among other things included rerunning the same move a zillion times and adding an ASCII print of the entire board at a couple of points just before the crash, the problem became apparent. I found that the program had 'imagined' that its queen had captured my king as part of it's 'thinking' process. From there, tracing back through a long chain of function calls turned up the bug. There seemed to be nothing to keep the program from considering moves where one of its pieces would capture the king. Adding an additional condition to an existing 'if' statement squashed the bug.

I've gotta say, I got lucky in the timing of finding this bug. It would have taken a lot longer to fix without having already implemented an ability to return to the game state just before the crash.

A patch to fix this bug can be downloaded from http://sourceforge.net/projects/vulcanchessmods/files/cricital_patches/king_bug/.

Getting Microblog-Purple to Work

Microblog-purple is an open source plug-in for Pidgin and other Libpurple-based IM clients. It enables accessing Twitter feeds through an IM client. If you're trying to compile and install microblog-purple from source and are having trouble getting it to work, you may need to change the permissions of a few of the installed files.

In my case, I had troubles getting microblog-purple working from source in Pidgin on Fedora Linux.It was necessary to change the permissions of the following files from 750 to 755, giving read and execute permission to other users:

• /usr/lib/purple-2/libidentica.so
• /usr/lib/purple-2/libtwitter.so
• /usr/lib/purple-2/twitgin.so

This I figured out by reading the screen output from running make install, locating the files, and comparing the files’ permissions to those of a file corresponding to a known working Pidgin plug-in.

The microblog-purple plug-in, listed as Twitgin, showed up in Pidgin’s plug-in list once the aforementioned permissions were changed. Making sure it was checked in the list, I then set up access to my Twitter account by adding it through the Manage Accounts dialog as if it were an IM account. After that, it was up and running.

Mouse Bug Fix for Vulcan 3D Chess

Standard chess programs are easy to find, but 3D chess programs á la Star Trek are comparatively rare. As far as I've been able to find, there's Parmen by Doug Keenan for Windows, and there's Vulcan by Mauro Persano for Linux and probably anywhere else X11 or SDL can be used*.

Parmen would have been the easiest to install and is purportedly the more mature of the two, but I really wanted a 3D chess game to play on one of my Linux machines, so I tried Vulcan first. Compilation and install went fine after installing the necessary packages and adding -Wl,-rpath,/usr/lib/tls to LDFLAGS in the Makefile to pick up one library file the compiler couldn't find.  It seemed to work...when it would recognize mouse events. Unfortunately, the length of time and number of clicks it took to get it to respond made it too awkward to use.

Disappointed, I turned to Parmen. Installation was the usual Windows simplicity: just download and run ParmenSetup exe. All looked good upon running the installed program until about the second or third move, whereat Parmen crashed. Trying again a couple more times and trying it on a different machine yielded the same results. Admittedly, the two XP SP3 machines I tried it on were both fairly low end, so you may have a better experience.

Frustrated, I turned back to Vulcan and the promise of open source software. A lot of experimenting and research helped to isolate the problem primarily to a single line of code. With that line removed... It worked! And it didn't crash!

It's just speculation, but I'm thinking the bug may have arisen due to changes in X11 which occurred since Vulcan's last update, particularly somewhere in X11R7.4 (X server 1.5.1) through X11R7.6 (X server 1.9). Regardless of the cause, I've put up a free patch to fix the bug and improve Vulcan's response to mouse events at http://sourceforge.net/projects/vulcan-mbpatch/. (UPDATE: As of 9/10/2012, this patch may now be found at http://sourceforge.net/projects/vulcanchessmods/files/cricital_patches/mouse_bug/.)

If you know of any other Star Trek style 3D chess program, please post a comment and let us all know about it.

* Mac OS X for Unix Geeks by Jepson & Rothman (O'Reilly, 2003) has a whole chapter on installing and using X11 on a Mac OS X system!

Swapping to Reverse Post Order on Blogger

Sometimes an oldest-to-newest order of blog posts would be better than Blogger's standard newest-to-oldest arrangement. A blog about a project is an example. The posts would proceed from oldest to newest so a visitor to the blog could start reading at the project introduction and proceed from there. Unfortunately, Blogger doesn't provide this as an option.

There are a number of existing approaches to this problem but, for various reasons, none of those exactly fit my needs. So I decided to roll my own.

David Merriman's script served as the starting point in locating post container nodes in Blogger's template. From there, the idea was to create a script that locates the blog's post container and then searches concurrently for posts from both the top and bottom of that container. When a post is reached at each end, those posts would be swapped. The concurrent search would then continue on toward the center of the container. The search would end once the center is reached, at which point the contained posts would have been reversed by the preceding swaps. The process is then repeated for each day of posts to reorder multiple posts within days.

The resulting drop-in hack is shown below. To use it, copy and paste the entire script into your Blogger template just before the </body> tag and then save the template. View your blog, reloading if needed, and your posts should be displayed in reverse order. Take a look at http://diyreader.blogspot.com to see it in use.

<!-- Start Post Reversal Code -->
<script type='text/javascript'>
//<![CDATA[
  // -----------------------------------------------------------------------------------------
  // Name   : PRS - Post Reversal Script for Blogger - Version 1.0
  // Author : David Yockey
  // URL    : http://techsquirrels.blogspot.com/2012/04/swapping-to-reverse-post-order-on.html
  // -----------------------------------------------------------------------------------------

  // Temp variable used to shorten classname references
  var cn;

  // This function is called as needed in the main program below.
  function ReversePosts(BlogPostContainer,PostClass) {

    // Arguments:
    //    BlogPostContainer -- The node containing the posts to be reversed.
    //    PostClass -- The className of each of the posts in the container to be reversed.
    //                 (may be a single name from among names in the class attribute of the posts)

    // Flag for checking whether any posts are found
    var found=false;

    var BlogPosts = BlogPostContainer.childNodes;  // May include text-nodes containing
                                                   // whitespace in addition to post-nodes

    // Set index variables to top and bottom of BlogPosts list
    var i=0;
    var j=BlogPosts.length-1;

    for( ; ; ) {     // Start Endless Loop

      // Find next Post from the top
      while( (i < j) && (!(cn=BlogPosts[i].className) || !(cn.match(PostClass))) )
        ++i;

      // Find next Post from the bottom
      while( (i < j) && (!(cn=BlogPosts[j].className) || !(found=cn.match(PostClass))) ) // (see Footnote 1)
        --j;

      if( found && i < j ) {
        // Swap Posts (see Footnote 2)
        var tempi = BlogPosts[i].cloneNode(true);           // Store a copy of Post i in tempi
        var tempj = BlogPosts[j].cloneNode(true);           // Store a copy of Post j in tempj
        BlogPostContainer.replaceChild(tempi,BlogPosts[j]); // Replace Post j with Post i in tempi
        BlogPostContainer.replaceChild(tempj,BlogPosts[i]); // Replace Post i with Post j in tempj
      } else {
        // Done
        break;        // Break out of Endless Loop
      }

      ++i; --j;
    }
  }
  // Footnote 1:
  //   If a post is found from one end, then a post must necessarily be found from the other.
  //   So, recording and later checking for a post from one end is sufficient to ensure that
  //   one was found from both.
  //
  // Footnote 2:
  //   At least in Firefox 11.0 on Fedora Linux, replacing a child directly with another child
  //   causes some text-nodes containing whitespace to be deleted. That node deletion messes up
  //   the positions of the posts in the BlogPosts list. This is avoided by cloning both posts
  //   rather than just one and replacing both posts from the cloned copies.


  // *** MAIN POST REVERSAL PROGRAM ***

  // Magic Words
  var BlogWidget             = 'Blog1';
  var BlogPostContainerClass = 'blog-posts';
  var BlogPostClass          = 'date-outer';
  var DatePostContainerClass = 'date-posts';
  var DatePostClass          = 'post-outer';

  var Blog1 = document.getElementById(BlogWidget);

  // Find the node containing the blog posts
  var BlogPostContainer;
  var x=0;
  do {
    BlogPostContainer = Blog1.childNodes[x++];
  } while ( !(cn=BlogPostContainer.className) || !(cn.match(BlogPostContainerClass)) );

  // Reverse different day posts
  ReversePosts(BlogPostContainer,BlogPostClass);

  // Reverse same day posts - Loop thru contents of BlogPostContainer to find each day's posts
  var BlogPosts = BlogPostContainer.childNodes;
  for ( i = 0; i < BlogPosts.length; ++i ) {

    // Check for an actual post-node rather than a text-node or such
    if ( (cn=BlogPosts[i].className) && cn.match(BlogPostClass) ) {
      var DatePostContainer;
      x=0;

      // Find the node containing the posts to be reversed for the current day being processed
      do {
        DatePostContainer = BlogPosts[i].childNodes[x++];
      } while ( !(cn=DatePostContainer.className) || !(cn.match(DatePostContainerClass)) );

      ReversePosts(DatePostContainer,DatePostClass);
    }
  }
//]]>
</script>
<!-- End Post Reversal Code -->

Code highlighting (if your browser displays it...) powered by google-code-prettify.

The script doesn't include an option to select whether or not to reverse the order. If you need this option, you might want to try MS-potilas's script, although I haven't tried it myself.

My thanks go to David Merriman and MS-potilas for their prior work on this problem and the guidance it provided.

09/25/2012 -- You may also be interested in: Hiding Blog Post Manipulation

Sideblog: DIY Reader

A place for details on modding an old laptop into a stationary tablet-like reader. Post questions and comments about aspects of interest to you. http://diyreader.blogspot.com

Controlled Rotation when PDF File is Opened

There are online services that provide books viewed through a browser with a PDF viewer plugin. Wholesale copying is hindered by serving each page as a separate PDF file, where the plugin closes and reopens each time a new page is viewed. While a bit of a kludge, it works fairly well, except when a reader wants to rotate all of the pages and their device doesn't support display rotation.

I wanted to view all of the pages of such a book rotated 90° on a laptop display held sideways, thereby to reduce scrolling. Unfortunately, the particular laptop was an older model that didn't support display rotation.* Rotating the PDF in the plugin worked for a page, but the rotation didn't hold between pages since the plugin was loaded with each turn of the page. Consequently, annoying keypresses or mouse clicks were needed to rotate each new page.

Searching for a PDF viewer with any option to set the initial rotation when opening a file was fruitless. But I did find an open source PDF viewer called Xpdf that had just about every startup option you'd want except rotation. Finding nothing better to serve the purpose, I decided to add the option myself.

Having ran across others looking in vain for the same functionality during my search, I decided to put up a patch in hopes of helping at least somebody out there. My Rotation Control Patch to add rotation options to Xpdf is freely available at http://sourceforge.net/projects/xpdf-rcpatch/, and updated manpages are also available in the files section. The latest version of the source code for Xpdf itself is freely available from http://www.foolabs.com/xpdf/. Note that Xpdf can be compiled to run on a number of other operating systems than Linux, including Windows.

There was one significant problem I ran into when building Xpdf. A note in the INSTALL file accompanying the Xpdf source reads:

(The include path is the directory which contains the freetype2 directory, i.e., do NOT include "freetype2" in the --with-freetype2-includes path. For example, with the default installation, the library path is /usr/local/lib and the include path is /usr/local/include/freetype2.)

This doesn't seem to make sense. After stating, with EMPHASIS, that freetype2 shouldn't be included in the include path, it goes on to show an example where the include path includes freetype2. To complicate matters, my distro didn't install freetype2 in /usr/local, a fact I didn't realize until after a bit of head banging. In the end, the configure line that worked for me was:

./configure --with-freetype2-library=/usr/lib --with-freetype2-includes=/usr/include/freetype2 --with-Xm-library=/usr/lib --with-Xm-includes=/usr/include/Xm

Your mileage may vary.

* It may instead have been the display driver I had to use, since no Linux driver was available from the manufacturer, but I'm not reloading Win98 on it to find out. :)

Suppress diff Missing File Messages

To suppress the missing file messages diff generates when creating a patch for multiple files, just filter them out with grep.  For example:

diff -rc olddir newdir | grep -v -e "^Only in" > diffs.patch

Solved: XP Repair Install Hanging at Installing Network

A Repair Install is required to get a hard drive with XP to boot after being moved to a new computer. However, it's apparently not uncommon for the Repair Install to hang somewhere in the process.

In my case of moving a hard drive with a retail version of XP installed from one computer to another, the Repair Install hung upon reaching "Installing Network" at about 31 minutes left in the install. To get around this problem, I did the following:

• Hit Shift + F10 to open a command prompt.
• Ran taskmgr.exe to bring up the Task Manager.
• Examined the Processes and found spoolsv.exe, the "Print Spooler" service, to be consuming practically all of the CPU time.
• Returned to the command prompt and ran services.msc to get to the Services window.
• Clicked the Standard tab.
• Located Print Spooler and right-clicked on it.
• Selected Stop in the popup menu.

...and the Repair Install resumed immediately after the Print Spooler service was stopped.

The Repair Install hung once again later in the process around 9 minutes left. Task Manager showed that the spoolsv.exe was again hogging all of the CPU time. Repeating the Print Spooler stop again got the Repair Install to immediately resume, and it then continued to completion uninterrupted.

This solution was the result of a lot of searching and followed many unsuccessful attempts involving hardware changes, BIOS configuration changes, and software removal. Kudos to the people who posted the content on the following pages, from which my solution was pieced together:

Changing a Motherboard or Moving a Hard Drive with XP Installed

xp repair reinstall hangs at Installing Network (Microsoft XP)

What is the Windows spoolsv.exe file / process?

Run Command Shortcuts for Administrative Tools