Fiddling with L-System (part 2)


Part 1 left us with a large cryptic looking string (a recursively applied grammar applied to an axiom, for the purists).

In part 2 we’ll go from that big string to a visual representation, by making use of that string as a set of commands for a turtle language.

Turtle graphics came to fame in the days of Darwin’s voyage to the Galapagos the Logo programming language, and in many ways are the grand-daddy of vector graphics languages like SVG.

For more details, read the turtle graphics article in wikipedia, it’s (at the moment) short and to the point.

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Fiddling with L-System (part 1)

The class of grammar-based fractals known as Lindenmayer system allows generating an interesting variety of geometrical and botanical visuals.

To the right is a representation of a “Fractal Plant”, which is generated from just two simple (if cryptic-looking) rules applied recursively.

In simple terms, L-System starts from a string (called an axiom), to which rules are applied recursively. Rules are a set of substitution strings for characters in the original string.

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Defeat “Print Screen” with Visual Cryptography

padlockTime for some summer fun! Someone asked in the delphi win32 newsgroup how to prevent users from doing a “Print Screen”. The answer to that is that you can’t really, since screen capture can be invoked from other applications, or your app can be hosted in a Virtual Machine, accessed over RDP, or a frame can be grabbed directly from the screen cable.

However all hope is not lost! Even if you can’t defeat a “Print Screen” or screen capture, it’s possible to make such a capture useless.

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