Archive for August, 2004
Using OpenGL is hard. OpenGL itself is fairly straightforward, at least at the level I’m using. The problem is that OpenGL has all this state. What you do at any time might affect anything you do through the rest of the drawing cycle. That means that you need to be careful to look at what appears before and after an OpenGL call. Unfortunately, people tend to encapsulate their OpenGL calls within cutesy little functions: Polygon::Draw(), for instance. However, the assumptions about state entering and leaving the function are rarely articulated, which means that to know the state at any line in the code, you have to look through every bit of drawing code that comes before that line. That can require quite a bit of digging. Then, errors can be found in the damnedest places.
Basically, OpenGL drawing code should either 1) be perfectly flat or 2) make really damn clear what it does.
It’s official: I’m a sloppy coder. I was working on finishing up my physics stuff, right? And I kept getting segfaults. I finally managed to trace it down, and an innocent little delete was causing it. That’s normal enough. But I couldn’t find out what was wrong with the delete! The array seemed to be fine. I eventually just gave up and created a memory leak (not a significant one, at least), because I need more results ASAP. But I’m not proud of it.
What’s the worst experience you can have on a plane? A terrorist attack probably tops the list, but sitting next to an evangelical preacher probably takes a close second. Fortunately, I had a book, and the TV was entertaining for a while, but I ran out of entertainment with about an hour left to go, so I took a risk and spoke to the passenger next to me. Upon finding out she was an evangelist, I thought I might be able to debate with her, but the sheer volume of unsubstantiated claims she was spewing soon overwhelmed me. Whenever I tried to debate, she merely paraphrased more and more out-of-context scripture, so my resistance soon gave out. I was then evangelized for the next hour.
Fortunately, there were a few interesting aspects of the whole experience. This was an evangelical preacher with a history. She claimed to have performed with and dated Prince and even appeared in 7 (or was it 17?) feature films under the name Vanity. However, she suffered from kidney failure, internal bleeding, a heart attack, and a stroke simultaneously (sounded like a drug overdose to me; I even asked her, but she said it, like all disease, was just God “spanking his children” as punishment for sin). The doctors said she’d be lucky to live a week, but she found faith and God saved her. Now, she travels from church to church evangelizing. (Incidentally, she struck me as not too bright; she made spelling mistakes and asked lots of questions about words’ meanings. Plus, she said in her past life she had been living in “fornication.”)
So, now she has given up her life of fame and fortune and travels around doing good deeds, like evangelizing her fellow passengers. She must really believe, to yap at me for a full hour without any profit. But she complained that there wasn’t enough room in first class for her on the flight, and she spoke of how her fast car would get her home quickly. Apparently, she drives a Crossfire, which she described as “the car Halle Berry drove in that James Bond movie”. She even had “Chrysler Crossfire”-brand luggage. Clearly, she has given up quite a lot. When I asked her about it, she said that God wanted Christians to prosper so that other people would want to be Christians. Obviously, that’s fucking nonsense, since she’s making all this money from Christians. The whole thing smacks of greed and hypocrisy, except for the curious fact that she jabbered at me for an hour without any profit in it.
She seemed to use a few tricks when speaking to me. For starters, she got far closer than a normal human would have felt comfortable with. She was definitely invading my personal space. Then, when speaking about the “strong arm of God,” she touched my arm in demonstration. Finally, towards the end, her voice got very quiet, which could have been to make me lean closer, which could make me be more interested. However, it may have been because we were descending, so she couldn’t tell how loud her voice was; or her voice could have been giving out. I asked her if she had any training at speaking, and she said that God put words into her mouth. Nevertheless, I think she’s learned a few tricks to drive interest.
Somewhere during the evangelism, I finally realized how these tactics can make people believe in God. I, a convinced atheist, was about ready to pray for her to shut up.
She paraphrased and took scripture out of context so much it hurt. For example, she said that Isaiah predicted the Jews would stop making sacrifices, and this predicted Jesus. But I’ve learned about Isaiah, and he was a pessimistic prophet, saying that the Jews had forgotten their religion and would be punished by God. So the evangelist was definitely reading into the writings things the author had not meant. That’s the example I can remember, but it struck me throughout that she was twisting things.
Finally, I looked at her web page, DeniseMatthews.com. She has a list of churches that she’s scheduled to visit. Should I contact them to let them know how much money she’s making out of this, and how she doesn’t believe in giving it to charity?
On her website, there are instructions for how to treat her when she’s coming to your church. It includes such bits of wisdom as “If possible, please put me on the top floor [of the hotel], not close to an elevator.” and “Please do not ring my hotel phone in the morning (unless it is an emergency) as I may be in prayer.” Riiight, prayer.
Fox News sucks. They focus heavily on terror alerts and criminal cases. I’ve heard people say that news is focusing on scaring people, and it’s clear that’s true for Fox. I mean really; I saw the terror alert status (Amber, by the way) tick across the bottom of the screen. Kate and I had a whole discussion about how their discussion show has a Republican and a Democrat, but the “Democrat” keeps saying negative things about democrats. The whole thing is just shady.
The reason I’m coming into contact with this “fair and unbiased” news source is that it’s playing in the cafe where Ruth (my sister) is working and I’m sitting with my laptop until she drives me to the airport. Welcome to Tennessee: where every place of business assaults you with conservative crap.
Today, I had a revelation as to Linux’s power. My laptop, a poor slow Pentium 1 with 32 MB of RAM was having trouble compiling my work. It did it, but with much churning of memory; it kept swapping back and forth to disk. Fortunately, I came to the realization that my family’s computer could be convinced to do the laptop’s job.
The critical problem I had to work around, instead of just using my family’s computer from the start, was that my work required a surprising number of dependencies, which were too much of a pain to install on the desktop for just a week’s work. However, I was able to work around this problem.
The solution was NFS. By exporting the entire filesystem on the laptop, I could mount it and chroot to it on my family’s desktop. So, I could have a shell that was convinced it lived in the laptop’s filesystem, yet had all the power and memory of the desktop. A truly excellent solution, in my opinion.
Time passes; Leon plays with his creation.
Well, it wasn’t completely successful. Processor-bound tasks (3D point transformation) got much faster, but compilation was still awfully slow. I was unable to tell what the bottleneck was. All disk drives, processors, and network connections were apparently idle, but the compilation still took a while. I don’t get it. I was able to verify that the processing was occurring on the fast computer; calculating 10000! was nice and speedy.
Old people are boneheads.
Specifically, old people’s brains calcify and harden, so they stop thinking. New tricks simply are out of reach for them. For evidence, I point to old people and computers.
My grandmother has used computers for years. She had an old 286 and used Lotus to do whatever it is Lotus does. The thing is, something in her head has changed. Now, she deals with computers very much differently; in fact, she needs detailed instructions just to turn on my uncle’s. In fact, this weekend she called to say that she couldn’t turn his computer on, so, emailless, she was going to call for information on my family’s trip while my uncle is away.
Now, that’s not really terrible. She never uses computers anymore, so maybe she doesn’t know anything about them. But this is just a single case symptomatic of something almost everyone in college has experienced. Old people just don’t get it. See, I think young people and old people think about computers in very different ways. When you’re young, you look at a computer and try to understand its rules. You press [Alt] in a Microsoft program, and suddenly the keys don’t do the same thing, because the program is in menu mode. So, you, as a young person, decide that the computer has internal state: it can be in menu-mode or out of menu-mode. Your mental model of the computer is now more complex. In my experience, however, old people are more likely to want to know nothing about the computer, just to use it for their task without making any mental models.
(Some people defend this by saying that computers should be perfectly easy to use. However, I argue that anyone must have a mental model of their tool to use it properly, and a computer is no exception. Consider the hammer. It has two sides, and striking with the wrong side will put claw-marks in your wood, rather than driving in a nail. Granted, this behavior is visible to the user, but so is menu-mode in a Microsoft program–the cursor stops blinking, and a menu entry is highlighted. Only in the software industry does anyone think you should be able to use a tool without any kind of learning.)
I think my point is that this suggests old people have difficulty making mental models, and that’s scary. Someday I’ll be an old person, and I don’t want to be crippled like that. Is there a way to prevent it? I see difficulties and confusions like this occuring to people my parents’ age. Is the death of learning only a measly few decades away? Am I halfway through the part of my life where I’m flexible?
I’ve come to the conclusion, through my travels, that Pittsburgh has the best airport. It’s fairly large, but the layout is good enough that walking from gate to gate isn’t too bad. It should also be mentioned that they provide free wireless access.
Here in the Charlotte airport, the situation is quite different. The place involves too much walking. Granted, they have those slide walks, but they seem to be full of people who just want to stroll, or who like to stand side-by-side blocking traffic. And they don’t seem to procide any sort of internet access, not even the pay sort.
Granted, there are things to be said for really small airports, like Oakland and Tri Cities (which is really tiny). Everything is convenient, security doesn’t involve as much waiting, and they’re easier to get to. Nevertheless, it’s really the internet access that makes or breaks the airport (from my point of view), which pretty much eliminates any small airports.