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Wed, 27 Jan 2016

Onion Texture in Javascript and Canvas

— SjG @ 9:23 pm

When I’m focused on other things and doodling, one of the textures that regularly emerges is a fill pattern of concentric irregular circles.

(click to enlarge)

Now, doodling is a way of letting my mind idle. Why I’d want to automate that, I couldn’t say. But for some reason, I did.

So the question was: how do I draw a “sloppy circle,” or one that’s not exactly regular, especially if I want to then draw another similar circle inside of it, and so on.

I settled on the idea of picking a set of points around a circle, with roughly the same radius. If I just drew a line between these points, it would be a regular polygon, and not as gentle as I’d like. So, instead of lines, I needed gentle Bezier curves from point to point.

To get the Bezier control points, I need to create a tangent to the radial line, and put the control points for the curve on that tangent. But how far away from the original point? Better make it a variable!

So, with some playing, I was able to get reasonable values.

You can play with it yourself!

You can easily get results like these:



(click to enlarge any of them)


Fri, 11 Dec 2015


— SjG @ 3:14 pm

Henceforth, the Mighty Fogbound Empire is only accessible over SSL.


Fri, 27 Nov 2015


— SjG @ 1:48 pm

(This is a post from the end of September. I didn’t finish writing it then, but recent events made me revisit it).

I just finished reading Camp and Community: Manzanar and the Owens Valley, an oral history compiled in the mid 1970s by Jessie A. Garrett and Ronald C. Larson. Unlike many of the oral histories of Manzanar, these interviews are not of internees. Rather, this is a collection of interviews of twenty some odd people who lived and worked in the area. Some of them worked at the camp itself (including one director of the camp), while some had no connection to it at all.

It’s a fascinating read. Not unexpectedly, people often contradict one another and the memories are rife with inconsistencies, but it paints a picture of a small, relatively isolated community being confronted with substantial change and influx of outsiders (both within the camp and with the outside personnel the camp required). The change was an economic boon in a lean time, and it brought outside attention to the area. Both of these factors affected the attitudes of the community.

There is a strong impression that some people’s feelings changed in the twenty-five to thirty years between when the events took place and the interviews occurred.

Among the people whose opinions changed against the internment, there were all of the expected explanations: it wasn’t actually so bad, some of the the internees came voluntarily, it was for their own protection, the internment was a fait accompli and there was nothing to be done, there were legitimate mutual threats against America and Japanese Americans so this was sadly necessary, and so on. Among the people who supported the internment then and now, the arguments were also the expected ones: it was war, these were people of suspect loyalty, internees were treated better than the Japanese would treat Americans, to do otherwise would be to invite disaster.

One theme, as valid today as any time, is that fear is easily stirred up and manipulated to make people do things they would ordinarily oppose. Several of the interviewed people reflected on the fact that American citizens were unconstitutionally stripped of their rights, but excused it because there was a foreign threat to the country. It was also clear that the sense of “otherness” was key. Many of the people interviewed said they’d never seen (much less met) a person of Japanese descent before the establishment of the camp.

Another theme is essentially the William Goldman adage to “follow the money.” People like newspaperman Manchester Boddy helped establish the camps — and profited greatly on buying up the property of Japanese-Americans at firesale prices when they had twenty-four hours to liquidate their belongings before being shipped out.

Some of the defenses of the creation of Manzanar are true. People were afraid. We were at war. The imperial Japanese army was terrible and cruel to captured peoples. And yet, even if true, these are irrelevant. If our rights as Americans are subject to revocation when we’re afraid, then they’re not rights. If our answer to enemy cruelty is cruelty, then we’re no different than our enemy. If we can strip citizens of their freedom and property just because they look different than the majority, then we descend into mob rule and our lofty appeals to our ideals are just so much hot air.

Wed, 11 Nov 2015

Mac Ports and X-Code Command-line tools

— SjG @ 1:59 pm

I was setting up a new Mac with Mac Ports… and ran into a weird problem.

First, installed Xcode from the App store. Took a long time, but was done. I mistakenly thought it had installed the command-line tools, because now I could run commands like “svn” from the command line. The Department of Tautologies reminds you that some command-line tools are command-line tools, and others are not.

So I tracked down my build problem to the fact that command-line tools were not installed. Following every guide everywhere, I typed:
xcode-select --install
But instead of the expected glorious dialog box and installation, I got the virtually-un-Googlable error:
xcode-select: error: no developer tools were found, and no install could be requested (perhaps no UI present), please install manually from ''.

To make a long story short, the problem was that I ran the xcode-select as root. Eventually, I found that running it as an ordinary user worked as expected.

After that, command-line tools are properly installed, and ports work as God intended them to.

There are a lot of deceptive distractions out there.
Typing, for example, xcode-select -p returns the correct /Applications/ path that you’d expect.
Similarly, the error in the port build was that the directory /usr/include does not exist.
Don’t be deceived. These are lies!

Sun, 18 Oct 2015

Yii mystery on Mac

— SjG @ 3:07 pm

I upgraded the Mac to Yosemite a year or so ago. Yesterday, I wanted to do some development on a project that I’d been idly thinking about. Unfortunately, it required a dependency in a package I’d installed via Mac Ports. I tried to upgrade it, but got an error that I was compiling for the wrong Darwin version. This means I haven’t actually updated any of my Ports since upgrading to Yosemite! For shame.

Rather than fix Mac Ports for Yosemite, and then again when I upgrade to El Capitan, I decided it was time to do that upgrade and then fix it. I went through and did so, and upgraded all my ports, and it all seemed to go well. I went from PHP 5.3 to PHP 5.5, and MySQL from 5.1 to 5.5, and it went without a snag — the web server came up and my old configuration was good, databases same. Everything seemed sweet and easy!

Ha! Sweet and easy with software? Not so fast, buckeroo! Working on another project, I found that Yii was crashing — but only from the command line!
exception 'CDbException' with message 'CDbConnection failed to open the DB connection: could not find driver' in /Users/samuelg/project/unicorn_rainbows/framework/db/CDbConnection.php:399

I quickly through a page up with phpinfo(), and saw that all the usual suspects were valid:

  • I was running the PHP I thought I was (Mac Ports version 5.5, not the built-in Mac OS version)
  • It was using the php.ini file I thought it was (in /opt/local/etc/php55/)
  • PDO was installed
  • PDO’s MySQL driver was installed
  • PHP’s configured recognized the drivers
  • Paths to any config files were correct
  • Ports were all normal
  • Default path to MySQL socket file was correct

Of course, this all makes sense, because my web pages that access the database were working.

So why not from Yii’s console program from the command line?

A quick php -version revealed the problem. It wasn’t the database configuration at all! Well, not exactly.
samuelg$ php --version
PHP 5.6.14 (cli) (built: Oct 15 2015 16:20:41)
Copyright (c) 1997-2015 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2015 Zend Technologies

Wait, what? PHP 5.6? But… how?

samuel$ port installed | grep php
php55-mysql @5.5.30_0+mysqlnd (active)
php55-sqlite @5.5.30_0 (active)
php56 @5.6.6_0+libedit
php56 @5.6.14_0+libedit (active)

Yup, somehow, I’d installed some PHP 5.6 packages as well!

To solve the problem quickly, I uninstalled PHP 5.6. I could have upgraded everything to 5.6 (or just inactivated them, I suppose), but I just wanted to work on my original problem, not spend my day on system configuration.

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