Ask HN: Please check out my web app | Hacker News Reader

Ask HN: Please check out my web app

7 pointsrortian4 comments

I'd post the link directly, but I must request that you not repost this link or use it excessively (in one day).

http://pseudomap.appspot.com

or

http://pseudomap.appspot.com/TileLayout.html?real=-0.25&imag=0&m=2&n=2&scheme=fire&colorparam=40

The second link is listed under 'Hot Diamond' in the link section.

This can be fairly called an alpha version of a google maps style explorer for a certain class of fractals. Right now you can double click to zoom in and use the mouse wheel to zoom in/out. Dragging the image around has not been implemented, but you can still get anywhere you would like. Currently you can only zoom in (doubles the sides) ~14 times.

Please check the about panel for more info/contact information. I'll check this wave:

https://wave.google.com/wave/waveref/googlewave.com/w+6hV8Fhr2A

and the discussion here of course. Thanks for the feedback.

Hey this is awesome. I would love to find out some technical background on this.

Happy to oblige. However, technical could mean:

1. Implementation details 2. Math details

Let me know 1, 2 or both and I'll fill you in.

I mean the implementation details. But both might be more useful. Maybe you can do a blog post and link it here.

Cool, I'm working a math one when it goes it will be posted at:

blog.pseudopattern.com

Alright technical details. I used GWT for the front end. Mainly because I like working in an IDE, and because I don't have to worry about browser quirks (although I need to tweak the css some.)

All the tiles are generated by a single servlet. You can sort of tell how it was developed by the way it is called:

0.23x0x14.png?...

The first number is lambda. Next is the zoom. The next number is the id of the tile. Each zoom level is broken up into (4*2^zoom)^2 tiles. I need to break the x and y coordinate into separate pieces as this scheme starts hitting integer overflow errors around zoom 15.

You may notice that the PNG files are rather small. This is because they are index based on a 256 color palette (but with 24 bit colors). I wrote my own PNG file creator for this.

This is all in Java for the most part. I prefer ruby for putting something together, but Java had all the things I needed for the most part and the speed of it is really nice for this project.

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