L-systems

I wrote a Delphi program to generate L-system images. Below are some interesting results.

Dictionary

F	Move forward in the current direction
J	Move forward in the current direction, but don't draw a line
+	Rotate angle step clockwise
-	Rotate angle step counter clockwise
\|	Rotate 180°
[	Push current state onto the stack
]	Pull latest pushed state from the stack

Kolam

Author: Steven Van Hulle

Axiom: A-A
Angle: 90°
Rules:

A → +BB
B → -AFA

Cross

Author: Steven Van Hulle

Axiom: AA
Angle: 135°
Rules:

A → FFBBFF
B → FAB--BAF

Cross

Author: Steven Van Hulle

Axiom: A----A----A----A
Angle: 135°
Rules:

A → B++FB
B → +AA++AA+

Squares

Author: Steven Van Hulle

Axiom: A+FA+F
Angle: 90°
Rules:

A → +BF+B-
B → -AF+F-A+

Diamond

Author: Steven Van Hulle

Axiom: A-A-A-A
Angle: 90°
Rules:

A → FBAFFABF
B → AAB-BAA

Diamond

Author: Steven Van Hulle

Axiom: AFAFAFAF
Angle: 135°
Rules:

A → B+FF+B
B → AFA

Dragon Curve

Author: David and Knuth, 1970 (Attr.)

Axiom: FA
Angle: 90°
Rules:

A → A+BF+
B → -FA-B

Fan-out

Author: Steven Van Hulle

Axiom: A
Angle: 90°
Rules:

A → FFABB
B → F+A

Carpet

Author: Steven Van Hulle

Evolution

Author: Steven Van Hulle

Fortress

Author: Steven Van Hulle

Axiom: A++A
Angle: 72°
Rules:

A → -BBB-
B → AB-F-BA

Hilbert Curve

Author: David Hilbert

Axiom: A
Angle: 90°
Rules:

A → -BF+AFA+FB-
B → +AF-BFB-FA+

Lace

Author: Steven Van Hulle

Axiom: A++A++A++A
Angle: 135°
Rules:

A → B+BB++BB+B
B → FA++AF

Magnetic core memory

Author: Steven Van Hulle

Axiom: A-F-A-F
Angle: 135°
Rules:

A → +BFB+
B → -AFA-

Bird

Author: Steven Van Hulle

Axiom: A
Angle: 72°
Rules:

A → -B-
B → F+F++FA-

Peano curve

Author: Giuseppe Peano

Axiom: A
Angle: 90°
Rules:

A → AFBFA-F-BFAFB+F+AFBFA
B → BFAFB+F+AFBFA-F-BFAFB

Peano-Gosper curve

Author: Bill Gosper

Axiom: A
Angle: 60°
Rules:

A → A+BF++BF-FA--FAFA-BF+
B → -FA+BFBF++BF+FA--FA-B

A square

Author: Steven Van Hulle

Axiom: AAAA
Angle: 90°
Rules:

A → ABF+FBA
B → FFFAAAFFF

Sierpinski Triangle

Author: Waclaw Sierpinski

Axiom: AF-BF-BF
Angle: 120°
Rules:

A → AF-BF+AF+BF-A
B → BFB

Snowflake

Author: Steven Van Hulle

Axiom: A-A-A-A-A-A
Angle: 60°
Rules:

A → -BF+A+FB-
B → +AF-A-FA+

A square

Author: Steven Van Hulle

Axiom: A-F-A-F
Angle: 90°
Rules:

A → +BFB+
B → -AF+A-

A square

Author: Steven Van Hulle

Axiom: A++F-A++F
Angle: 90°
Rules:

A → +B-FB+
B → -AFA-

Cross

Author: Steven Van Hulle

Axiom: A-FF-A-FF
Angle: 90°
Rules:

A → +BFFB+
B → -AF+FA-

Diamond

Author: Steven Van Hulle

Axiom: AFFFAFFF
Angle: 135°
Rules:

A → BFFFB
B → A-FF-A

Square

Author: Steven Van Hulle

Axiom: A-F-A-F
Angle: 135°
Rules:

A → +BFB+
B → -AFFA-

Triangle

Author: Steven Van Hulle

Axiom: A
Angle: 60°
Rules:

A → -BF+A+FB-
B → +AF-B-FA+

Tessellation

Author: Steven Van Hulle

Axiom: A
Angle: 90°
Rules:

A → ++B-
B → FAAAAF

Triangle

Author: Steven Van Hulle

Axiom: BB
Angle: 60°
Rules:

A → -BB-F-BB-
B → +A++A+

Square

Author: Steven Van Hulle

Axiom: A+FF+A+FF
Angle: 135°
Rules:

A → B+FF+B
B → AFA

Zig-zag

Author: Steven Van Hulle

Axiom: A
Angle: 135°
Rules:

A → BBBB++BBBB
B → AF+F-F