1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
|
package example
import scala.scalajs.js.annotation.JSExport
import org.scalajs.dom
import scala.util.Random
case class Point(x: Int, y: Int){
def +(p: Point) = Point(x + p.x, y + p.y)
def /(d: Int) = Point(x / d, y / d)
}
// Seems like you need this for sbt ~fastOptJS to work
// mkdir ~/.sbt/0.13/plugins/target/scala-2.10/sbt-0.13/classes
@JSExport
object ScalaJSExample {
val ctx = dom.document
.getElementById("canvas")
.asInstanceOf[dom.HTMLCanvasElement]
.getContext("2d")
.asInstanceOf[dom.CanvasRenderingContext2D]
var count = 0
var p = Point(0, 0)
val corners = Seq(Point(255, 255), Point(0, 255), Point(128, 0))
def clear() = {
ctx.fillStyle = "white"
ctx.fillRect(0, 0, 255, 255)
}
def run = for (i <- 0 until 10){
if (count % 30000 == 0) clear()
count += 1
p = (p + corners(Random.nextInt(3))) / 2
val height = 512.0 / (255 + p.y)
val r = (p.x * height).toInt
val g = ((255-p.x) * height).toInt
val b = p.y
ctx.fillStyle = s"rgb($g, $r, $b)"
ctx.fillRect(p.x, p.y, 1, 1)
}
@JSExport
def main(): Unit = {
dom.console.log("main")
dom.setInterval(() => run, 50)
}
}
|
