Some working code for the latitude-longitude conversion project

Thursday, February 21, 2008, 10:39 PM
Source Code by John

An email came in tonight that had some trouble applying the information from the post about building a system that converts latitudes and longitudes into X-Y co-ordinates for use with images generated by GD with PHP.

In the interest of promoting a little more applicability, I'm going to post the code that generates an actual PNG file from the map database.

This loads all the co-ordinates into three arrays. One for the rivers in the county. Another for the roads. A third for the county political boundaries.

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Then it goes through the arrays, and draws the lines onto the image. The line colors and thicknesses are based on the type of river or stream listed from the original shapefiles.

This probably doesn't make things any clearer, but it at least gives you a look at proven production code.

And, for the critics... please refer to the post where I admit that I am very lazy about constructing anything into a usable object class. Yeah, I know the functions is significantly more recursive and could be done better with some OOP. I just don't care, because the code works.

Anyhow... I hope this gives some folks who were looking at the lat-long post something with a little more meat to chew on.

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Welcome!

Wonder where to start with your web design business?

This blog follows along with my efforts to build and grow a website design business, Pro Content and Design.

The goal of this blog is to fill in blanks that may be empty as you get your business rolling.

This blog, particularly the source code section, is not intended for beginners. If you are not comfortable with databases, Ajax, DOM objects and other advanced methods, I strongly suggest you go take a look over at W3 Schools before even reading -- let alone tinkering with -- any of the code here.

I hope this blog has some value to web designers as they attempt to get their businesses going.

Good luck, and happy reading.

Thank you,
John Crawford
Pro Content and Design