Animate by using the frame counter.

Animate with expressions

Using the frame counter to drive the animation.

The variable f is a counter incremented at every frame. The first frame starts with 0. It is implemented as an “unsigned int”. Takes time to get this counter to overflow.

When the display server owns the keyboard focus you can press the z key to reset the counter.

Generate colors

(ns lv.demo)
(use 'lv.core)

(layout "grid" [ras0 ras1]
               [ras2 ras3])
(render)

(rgb :ras0 []
  (r (sin (* x 0.011 f)))
  (g (+ x y (usin (* 0.023 f))))
  (b (sin (* 0.071 f)))
)

(hsv :ras1 []
  (v (* r 2 (usin (* 0.21 f))))
)

(hsv :ras2 [ras0 ras1]
  (s ras0.h)
  (h 0.45)
  (v (pos? (sin (* 0.51 f)) ras0.v ras1.v))
)

(hsv :ras3 [ras0 ras1]
  (h ras0.h)
  (s ras0.s)
  (v (- 1 ras1.v))
)