[orx-compute-graph] Add compute graph code

orx-compute-graph/README.md

@@ -0,0 +1,55 @@
+# orx-compute-graph
+
+A graph for computation.
+
+## Status
+
+In development. Things may change without prior notice.
+
+## Usage
+
+```
+fun main() = application {
+    program {
+        val linkNode: ComputeNode
+        val cg = computeGraph {
+            val randomNode = node {
+                var seed: Int by inputs
+                seed = 0
+                var points: List<Vector2> by outputs
+                points = emptyList()
+                compute {
+                    val r = Random(seed)
+                    points = (0 until 1000).map {
+                        val x = r.nextDouble(0.0, width.toDouble())
+                        val y = r.nextDouble(0.0, height.toDouble())
+                        Vector2(x, y)
+                    }
+                }
+            }
+            linkNode = node {
+                var seed: Int by inputs
+                seed = 0
+                val points: List<Vector2> by randomNode.outputs
+                var links: List<LineSegment> by outputs
+                compute {
+                    val r = Random(seed)
+                    val shuffled = points.shuffled(r)
+                    links = shuffled.windowed(2, 2).map { 
+                        LineSegment(it[0], it[1])
+                    }
+                }
+            }
+            randomNode.dependOn(root)
+            linkNode.dependOn(randomNode)
+        }
+        cg.dispatch(dispatcher) {}
+        extend {
+            drawer.clear(ColorRGBa.WHITE)
+            drawer.stroke = ColorRGBa.BLACK
+            val links: List<LineSegment> by linkNode.outputs
+            drawer.lineSegments(links)
+        }
+    }
+}
+```