Add 2d version of gradientPerturb

orx-noise/src/demo/kotlin/DemoGradientPerturb2D.kt

@@ -0,0 +1,28 @@
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.draw.colorBuffer
+import org.openrndr.extra.noise.gradientPerturbFractal
+import org.openrndr.extra.noise.simplex
+import org.openrndr.math.Vector2
+import org.openrndr.math.Vector3
+import kotlin.math.absoluteValue
+
+fun main() {
+    application {
+        program {
+            val cb = colorBuffer(width, height)
+            val shad = cb.shadow
+            extend {
+                for (y in 0 until height) {
+                    for (x in 0 until width) {
+                        val p = gradientPerturbFractal(300, frequency = 0.8, position = Vector2(seconds + x/320.0,y/240.0))
+                        val d = simplex(300, p.x, p.y+seconds, seconds).absoluteValue
+                        shad[x, y] = ColorRGBa(d, d, d, 1.0)
+                    }
+                }
+                shad.upload()
+                drawer.image(cb)
+            }
+        }
+    }
+}