Sep 17 2011

Point of Origin

courtesy WikiCommons

One issue I’ve always had when writing games is that I’ll need multiple coordinate systems for one reason or another, and if I don’t keep good notes I’ll lose track of how they relate to each other. In the real world, coordinate systems get defined by surveyors which are used to describe the area they are measuring.  Cartographers take these surveyor measurements and combine them to draw their maps. In order to do this, markers are set out to be used as points of reference.

Since this site gets a handful of foreign visitors, a quick history review… In 1803, Thomas Jefferson negotiated the Louisiana Purchase, in which the U.S. bought a large portion of what is now the U.S.A from France. This is all of the land in the green shaded area to the right.  I personally had not realized that it encompassed part of Canada… apparently in 1818 we gave up our claim to the portion north of the 49th parallel in exchange for Great Britain giving up their claim to the Red River basin. Anyway, the territory had never been very extensively explored which is why the U.S. government sent several expeditions westward to find out what we had bought. The most famous of these was the Lewis and Clark expeditions, but the Pike expedition and a couple others were launched at about the same time for the same reason.

These general exploratory missions were not designed to map the territory however. So in 1815, when after the War of 1812 the U.S. considered granting land to veterans from that war in exchange for their service, the Robbins-Brown survey was commissioned.  Property deeds are worthless unless everyone can agree on where the property being described is located.

Robbins and Brown established the the fifth principal meridian (91 degrees, 3 minutes, 42 seconds West of Greenwhich), and drew an east-west line from the mouth of the Arkansas River. The origin (intersection of the east-west line and the north south-line) of their coordinate system (apparently called an initial point by surveyors) became the reference point for plat maps (official maps which define the boundaries of parcels of land) throughout the western states.

Marker, Louisiana Purchase State Park, Arkansas

The initial point also happens to be located in a swamp.

Although they had noted that two trees were growing at the intersection, and had made marks on trees, the initial surveying parties didn’t leave any type of permanent marker on the point itself. In 1921, surveyors found marks on trees in the swamp left by the original surveyors and identified the two gum trees (‘witness trees’) that had been noted as present at the intersection by the original surveying team. In 1924 the Daughters of the American Revolution put a stone marker at the site, and eventually the swamp was turned into a park by the State of Arkansas.

Boardwark into swamp

I visited the park today, which is about an hour and a half from where I live. I’d previously been to Toltec Mounds [Arkansas] State Park, which has a small museum, exhibits, walking paths, etc… This park has just a very small parking lot, an outhouse building and a wide boardwalk into the swamp which is probably about 300 yards long (round trip approx 1/3 mile). Panels approximately every 50 yards give information on the Louisiana Purchase, and about the swamp.

The swamp is a headwater swamp as opposed to a tailwater swamp- the famous swamps near coasts tend to be tailwater swamps. Headwater swamps have less variation in their water level over the course of the year… although the very visible water mark on the stone marker proves there is some change! These swamps were common in eastern Arkansas, but have mostly been drained and the land given over to agriculture. Since I was the only visitor (a couple from Tennessee arrived as I was leaving) I could hear the swamp wildlife moving about as I ambled down the boardwalk. I didn’t stay very long though, having not thought to bring bug repellent. (It’s still more or less summer here.) I did see a fairly large snake, but he slithered off before I could get a picture.

My coordinate systems may be buggy, but the bugs don’t actually bite and I’m fairly certain there are no snakes! :)


Sep 17 2011

Question for my readers

All 4 of you, that is. :)

Since I’ve moved, my interests have drifted away from flash games for the web. I’m thinking of broadening what software I write (e.g. Graphical Daylight), and what I write about (e.g. timelapse post). I’ve been thinking of reorganizing this site, so that it would be a showcase of software I’ve written (similar to say, the Positech front page) and moving my blog to a subdomain ( or moving my blog to a new site altogether (WordPress or Blogger) and restructuring this site.

Needless to say, this will probably break every inbound link, and it would take me some hours to accomplish. I don’t need to have a professional flash game developer style site because I’m a hobbyist, and what I have is fine for what I’m trying to accomplish- even if it looks unfocused and amateurish. I am after all an amateur.

The benefit would be that 5 years from now, nobody would end up here by following a ‘programmed by’ link from a game I’d written and wonder why I’m talking about the nutritional requirements of fish larvae. And fish larvae people wouldn’t arrive wondering why they’re reading something on a website about video games. (Fish larvae is a made up topic).

I won’t be bound by the results, but I’ve made a poll because I can’t really decide what to do:

Sep 05 2011

Graphical Daylight now available for the BlackBerry Playbook

Graphical Daylight, mentioned for the first time a few hours ago, is now available for the BlackBerry Playbook. You can get it from the BlackBerry AppWorld.

This app generates a daylight map for the current date/time. That’s… pretty much all it does. :)

– User can define darkness as starting at sunset or civil, nautical, or astronomical twilight
– 4 user configurable clocks which can display either a city’s time or a timezone
– Clocks retain your settings from session to session
– Places a marker on the map when a city is selected
– 195 major cities to choose from (and we will add more when we update if people request them!)
– 179 timezones to choose from
– Free, no ads, doesn’t talk to a server


Click on a thumbnail to enlarge.

Time from submission to approval was just under 9 hours.

Sep 05 2011


One issue I ran into on my drive from Alaska to Arkansas, was that I consistently overestimated how late the sun would stay up. Particularly in Alaska, the Yukon Territory and British Columbia, I didn’t want to drive at night due to the prevalence of large animals on the roadways. Although my computer was packed up, I used both my Playbook and my iPod during the drive- and I wished I had a daylight map similar to what gets produced by this java(?) app from the Naval Observatory. (Although, I wanted a local app that would update in near real time and did not care about historical or future daylight maps). Apps that do this exist for iOS, but I didn’t want to input my iTunes password while on hotel WiFi. I looked for an app in the BlackBerry AppWorld also, but didn’t see one.

Since arriving in Arkansas, I’ve had plenty of time on my hands during the weekends (it’s been way too hot to head into the great outdoors). Getting a daylight map generator hasn’t been a priority, so I never downloaded one of the apps from iTunes. In any case, this was an application more suited to a tablet than my iPod. So I spent about 46 hours over the past two weekends writing an app for the playbook.

The app assigns a lat/long to each pixel, and then for each pixel calculates the sun’s altitude relative to the horizon in degrees. Then it darkens the pixels where the sun is below a user selectable altitude (e.g Sunset = 0 deg, Civil twilight = -6 deg, etc). Scaled-down development screenshot below:

Click to view full size

This was a relatively straight forward project, and I’m generally happy with it. I titled it Graphical Daylight. Thinking I’d release it to the wild as a free app, after code signing, I started the process of uploading it to RIM for approval and inclusion into the AppWorld.

At which point, while choosing a category for my app,  I found out that Livingstone Services had released ‘Daylight’ on April 26,2011 which does more or less the same thing. (After looking at theirs, mine is a bit more feature rich.) This timeframe suggests that theirs was an app written to get a free Playbook when RIM was running their developer promotion prior to the release, I haven’t found a website for a developer called Livingstone Services. I’m releasing mine anyway (well, assuming it goes through QA I am).  And I’m putting mine in ‘Utilities->Clocks’ where it belongs, instead of ‘Maps and Navigation->Maps and Navigation’ (where, to be honest, it also belongs).  Grrr… 46 hours wasted…

I’ll put a note up here after the Graphical Daylight passes QA and is available in the AppWorld. It’s now available free on the BlackBerry AppWorld.