Vibrating rectangles: Difference between revisions

=={{header|Nim}}==

{{libheader|gintro}}

Should work on any platform where Gtk is available. Tested on Linux.

<lang Nim>import sugar

import gintro/[gobject, gdk, gtk, gio, cairo]

import gintro/glib except Pi

const

Width = 640

Height = 480

X0 = Width div 2 - 1

Y0 = Height div 2 - 1

Colors = [(0.0, 0.0, 0.0), (255.0, 0.0, 0.0), (0.0, 255.0, 0.0), (0.0, 0.0, 255.0),

(255.0, 0.0, 255.0), (0.0, 255.0, 255.0), (255.0, 255.0, 0.0), (255.0, 255.0, 255.0)]

Sizes = collect(newSeq, for size in countdown(Width, 4, 16): float(size))

type

# Description of the simulation.

Simulation = ref object

area: DrawingArea # Drawing area.

isize: Natural # Size index.

icolor: Natural # Color index.

#---------------------------------------------------------------------------------------------------

proc newSimulation(area: DrawingArea): Simulation =

## Allocate and initialize the simulation object.

new(result)

result.area = area

result.isize = 0

#---------------------------------------------------------------------------------------------------

proc draw(sim: Simulation; context: cairo.Context) =

## Draw the rectangles.

context.setSource(Colors[sim.icolor])

let width = Sizes[sim.isize]

let height = width * 3 / 4

context.rectangle(X0 - width * 0.5, Y0 - height * 0.5, width, height)

context.stroke()

#---------------------------------------------------------------------------------------------------

proc update(sim: Simulation): gboolean =

## Update the simulation state.

sim.isize = (sim.isize + 1) mod Sizes.len

if sim.isize == 0:

# Change color for next cycle.

sim.icolor = (sim.icolor + 1) mod Colors.len

sim.draw(sim.area.window.cairoCreate())

result = gboolean(1)

#---------------------------------------------------------------------------------------------------

proc activate(app: Application) =

## Activate the application.

let window = app.newApplicationWindow()

window.setSizeRequest(Width, Height)

window.setTitle("Vibrating rectangles")

let area = newDrawingArea()

window.add(area)

let sim = newSimulation(area)

timeoutAdd(40, update, sim)

window.showAll()

#———————————————————————————————————————————————————————————————————————————————————————————————————

let app = newApplication(Application, "Rosetta.vibrating_rectangles")

discard app.connect("activate", activate)

discard app.run()</lang>