Code Exchange (new threads) http://kogics.wikidot.com/forum/c-109808/code-exchange Threads in the forum category "Code Exchange" - Show your code. Learn from code written by others. Sun, 19 Jul 2026 21:23:39 +0000 http://kogics.wikidot.com/forum/t-14392493 Penrose tilings http://kogics.wikidot.com/forum/t-14392493/penrose-tilings Tue, 21 Dec 2021 15:46:26 +0000 Joost Winter Congratulations to the devs for this awesome project! I am just getting started in Kojo and wrote a little small program to draw some rhombus-type Penrose tilings. So this here is really my first program using Kojo (and in fact, also my first program ever in Scala):

var baseOne = 2 * math.sin(math.Pi * 54 / 180) var baseTwo = 2 * math.sin(math.Pi * 18 / 180) def triangleOne(depth: Int, length: Double, mirrored: Int): Unit = { if(depth == 0) { setFillColor(cm.green) forward(length) right(mirrored * 72) forward(length) right(mirrored * 144) hop(length * baseOne) right(mirrored * 144) } else { right(mirrored * 36) hop(length) left(mirrored * 144) triangleOne(depth - 1, length / baseOne, -mirrored) hop(length / baseOne) right(180) triangleTwo(depth - 1, length / baseOne, -mirrored) hop(length / baseOne) right(-mirrored * 36) hop(length / baseOne) right(180) triangleOne(depth - 1, length / baseOne, mirrored) hop(length * baseOne) right(mirrored * 144) } } def triangleTwo(depth: Int, length: Double, mirrored: Int): Unit = { if(depth == 0) { setFillColor(cm.blue) forward(length) right(mirrored * 144) forward(length) right(mirrored * 108) hop(length * baseTwo) right(mirrored * 108) } else { hop(length * baseTwo * baseTwo) right(mirrored * 108) triangleTwo(depth - 1, length * baseTwo, mirrored) hop(length * baseTwo) right(mirrored * 180) triangleOne(depth - 1, length * baseTwo, mirrored) left(mirrored * 36) hop(length * baseTwo) right(mirrored * 108) } } def decagon(depth: Int, length: Double) { clear() setBackground(cm.black) setSpeed(superFast) invisible() setPenColor(cm.black) left(90) hop(length) right(180) repeat(5) { triangleTwo(depth, length, 1) triangleTwo(depth, length, -1) right(72) hop(length * baseTwo) left(36) hop(length * baseTwo) left(108) } } clear() toggleFullScreenCanvas() var depth = 0 repeat(7) { decagon(depth, 400) depth = depth + 1 Thread.sleep(3000) }
penrose.png

My compliments to the Kojo devs for creating an environment that makes it surprisingly easy to do things like this…

]]> http://kogics.wikidot.com/forum/t-982922 Beginning on Kojo http://kogics.wikidot.com/forum/t-982922/beginning-on-kojo Just found Kojo while searching for a tool to teach programming to my kid Asmita. Here are couple of basic scripts I created along with Asmita. Wed, 13 Aug 2014 04:41:34 +0000 Abhijeet Ramdhave Star

clear() setBackground(black) setPenColor(red) setFillColor(blue) for (i <- 1 to 5) { forward(200) right(144) }

Kojo Design

clear() setBackground(black) setPenColor(red) setFillColor(blue) for (i <- 1 to 12) { for (i <- 1 to 4) { forward(50) right(90) } penUp() right(180 - 180 * 10 / 12) forward(50) penDown() }
]]> http://kogics.wikidot.com/forum/t-261332 PhiLho's code http://kogics.wikidot.com/forum/t-261332/philho-s-code My code in Kojo. Also in [http://bazaar.launchpad.net/~philho/+junk/Kojo/files Kojo experiments on Launchpad] Sat, 28 Aug 2010 16:05:18 +0000 PhiLho 551317 OK, my first baby steps in Kojo… Purely imperative for now.

val ROUND = 360 val SIDE_NB = 5 val ANGLE = ROUND / SIDE_NB clear jumpTo(0, 300) write("Pentagon") jumpTo(0, 0) setAnimationDelay(42) setPenColor(blue) setPenThickness(11) for (n <- -2 until 3) { setFillColor(color(0x80 - n * 40, 0xFF, 0x80 + n * 60)) setHeading((2 + n) * ANGLE) repeat (SIDE_NB) { forward(150) turn(-ANGLE) } }

That's mostly an exploration of the API.
I saw no means to specify a translucent fill color. I tried with a 32bit color like 0x8080FF80 but it is still opaque.

There is something that puzzles me: if I replace the for loop with:

var n = 0 repeat (5)

I get an error: 
error: missing arguments for method repeat in object Builtins; follow this method with `_' if you want to treat it as a partially applied function repeat (5) ^

Not sure if it is to be expected with Scala (ie. if I didn't fully understood the syntax) or if there is a bug in the interpreter.

BTW, if I want to print a number in hexa style, what is the idiom in Scala?

]]> http://kogics.wikidot.com/forum/t-229555 Another example, with sq and dist methods http://kogics.wikidot.com/forum/t-229555/another-example-with-sq-and-dist-methods A straight port of the Array2D example from Processing. The most interesting part is the sq and dist methods, which should be generic enough (requires 2.8, I think) and possibly efficient (I'm not implementation-savvy in the Java environment). Thu, 25 Mar 2010 09:09:01 +0000 Peter Lewerin 459742 
import java.awt.Color._ def sq[A](x: A)(implicit n: Numeric[A]): A = n.times(x, x) def dist[A](x0: A, y0: A, x1: A, y1: A)(implicit n: Numeric[A]): A = { val v = n.plus(sq(n.minus(x0, x1)), sq(n.minus(y0, y1))) val r = Math.sqrt(n.toDouble(v)) if (v.isInstanceOf[Int]) r.toInt.asInstanceOf[A] else if (v.isInstanceOf[Float]) r.toFloat.asInstanceOf[A] else r.asInstanceOf[A] } clear invisible Canvas.fgClear //? val width = 200 val height = 200 // background(0) val maxDistance = dist(width/2, height/2, width, height) val distances = Seq.tabulate(width, height){ case (i, j) => dist(width/2f, height/2f, j, i)/maxDistance * 255 } for (i <- 0 until(height, 2) ; j <- 0 until(width, 2)) { val c = distances(j)(i).toInt Canvas.setPenColor(new Color(c, c, c)) Canvas.point(j, i) }
]]> http://kogics.wikidot.com/forum/t-229372 Rendering curves in grayscale http://kogics.wikidot.com/forum/t-229372/rendering-curves-in-grayscale Adapted from a Processing example, applies four different composed functions to sequence of radian values from 0 to pi and renders each as a grayscale gradient. Wed, 24 Mar 2010 14:54:12 +0000 Peter Lewerin 
import Math._ import java.awt.Color._ clear invisible val width = 180 val height = 25 val halfwave = Vector.tabulate(width){ i => toRadians(i) } def render (level: Int)(fn: Double => Double) { val y0 = level * height val y1 = (level + 1) * height (halfwave map fn zipWithIndex) foreach { case(e, i) => val c = e.toFloat Canvas.setPenColor(new Color(c, c, c)) Canvas.line(i, y0, i, y1) } } val f = { x: Double => 1 - x } render (3) { sin } render (2) { sin _ andThen f } render (1) { cos _ andThen abs } render (0) { cos _ andThen abs andThen { x => 1 - x } }
]]> http://kogics.wikidot.com/forum/t-229114 Dragon curve example. http://kogics.wikidot.com/forum/t-229114/dragon-curve-example Tue, 23 Mar 2010 13:10:28 +0000 Łukasz Lew def dragon (depth : Int, angle : Double) : Unit = {
if (depth == 0) {
forward (10)
return;
}

turn (angle)
dragon (depth-1, angle.abs)
turn (-angle)

turn (-angle)
dragon (depth-1, -angle.abs)
turn (angle)
}

clear
setAnimationDelay(0)
setPenThickness (7)

dragon (10, 45)

]]> http://kogics.wikidot.com/forum/t-228292 Welcome http://kogics.wikidot.com/forum/t-228292/welcome 'Code Exchange' Category Information Fri, 19 Mar 2010 20:21:19 +0000 lalitp 66813 Want to showcase what you're doing with Kojo? Or just browse and see what others are upto?
Then this is the place to hang out in…

You can create new threads within this category, and make new posts within existing threads, without having to register or login.

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