[orx-composition] reverse argument order in draw()

Add demos with comments

orx-composition/src/jvmDemo/kotlin/DemoCompositionDrawer04.kt

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+import org.openrndr.MouseButton
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.composition.composition
+import org.openrndr.extra.composition.draw
+import org.openrndr.extra.composition.drawComposition
+import org.openrndr.math.Polar
+import org.openrndr.math.Vector2
+import kotlin.math.sin
+
+/**
+ * Demonstrates how to add content to and how to clear an existing Composition.
+ *
+ * A number of circles are added when the program starts.
+ * Dragging the mouse button adds more circles.
+ * Right-clicking the mouse clears the Composition.
+ */
+fun main() = application {
+    program {
+        val composition = drawComposition { }
+
+        // initial Composition content
+        repeat(360) {
+            composition.draw {
+                fill = ColorRGBa.WHITE
+                val r = sin(it / 90.0) * 30 + 40
+                circle(
+                    drawer.bounds.center + Polar(it * 5.0, r * 2).cartesian,
+                    r
+                )
+            }
+        }
+
+        extend {
+            drawer.clear(ColorRGBa.PINK)
+            drawer.composition(composition)
+        }
+
+        // To avoid drawing too many circles when dragging the mouse,
+        // we require a minimum separation between them
+        var lastPosition = Vector2.INFINITY
+        val minSeparation = 10.0
+
+        mouse.dragged.listen {
+            if(it.position.distanceTo(lastPosition) > minSeparation) {
+                composition.draw {
+                    fill = ColorRGBa.WHITE
+                    // the drag speed affects the radius
+                    circle(it.position, 5.0 + it.dragDisplacement.length * 5.0)
+                }
+                lastPosition = it.position
+            }
+        }
+
+        mouse.buttonDown.listen {
+            if (it.button == MouseButton.RIGHT) {
+                composition.clear()
+            }
+        }
+    }
+}