Some examples to get you started with Patterning.

Basic Polygon

Five red triangles in a ring

Note the definition of style. A style is represented as a mapping with keyword keys. For example :

{:stroke (p-color 255 100 100) :stroke-weight 2 }

Commonly used entries are :stroke, :stroke-weight and :fill. :stroke and :fill are colours defined with (p-color r g b).

Now let's make a simple pattern.

(def triangles (clock-rotate 5 (poly 0.5 0.5 0.3 3 {:stroke (p-color 255 100 100) :stroke-weight 2 }) ) )

poly creates a regular polygon. Its arguments are x-centre, y-centre, radius, number-of-sides and, optionally, style.

clock-rotate is a Layout, a function which takes an existing pattern and returns a new one.

In this case, clock-rotate takes a number, n, and a pattern, and makes the new pattern by rotating n copies of the input around the centre point.

Stack the five triangles on a blue pentagon

Let's make some grids of these

Note that grid-layout takes a list of the patterns we want to lay out on it.

Here we just use (repeat pattern) to make an infinite lazy list of them.

(grid-layout 8 (repeat a-pat))

Chequered Grid

Not massively exciting, instead let's do a chequered pattern.

The checked-layout takes two streams of patterns and interpolates between them when laying on a grid

(checked-layout 8 (repeat pentagon) (repeat triangles))

A Drunk Line

OK. change of direction, a ''drunkards walk'' is a series of points each of which is a move in a random direction from the previous one.

Patterning has a function for that, drunk-line, which takes a number of steps, a step-length and an option style

(drunk-line 10 0.1 {:stroke (p-color 100 255 100) :stroke-weight 3})

Why do we want a random wiggle? Well, they look ''a lot'' cooler when we do some more things to them.

Like clock-rotate them

(clock-rotate 12 (drunk-line 10 0.1 {:stroke (p-color 100 255 100) :stroke-weight 3}) )

Or mirror them

(four-mirror (drunk-line 10 0.1 {:stroke (p-color 100 255 100) :stroke-weight 3}))

Or both.

And did you want that mixed with our other shapes?

And perhaps on a staggered grid? The half-drop-grid-layout gives us that.

Maybe bring back a bit of blue, every other.

Continue to Tutorial Part 2