Add descriptions to demos

orx-shapes/src/jvmDemo/kotlin/hobbycurve/DemoHobbyCurve04.kt

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+package hobbycurve
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.noise.scatter
+import org.openrndr.extra.shapes.hobbycurve.hobbyCurve
+import org.openrndr.extra.shapes.ordering.hilbertOrder
+import kotlin.random.Random
+
+/**
+ * Demonstrates the use of the `tensions` argument when creating a Hobby curve.
+ *
+ * The program starts by creating a random set of scattered points with enough separation between them.
+ * The points are sorted using `hilbertOrder` to minimize the travel distance when visiting all the points.
+ * Finally, we draw a set of 40 hobby translucent curves using those same points but with varying tensions.
+ */
+fun main() = application {
+    configure {
+        width = 720
+        height = 720
+    }
+    program {
+        extend {
+            for (i in -20..20) {
+                val t = i / 10.0
+                val points = drawer.bounds.offsetEdges(-50.0)
+                    .scatter(25.0, random = Random(0))
+                    .hilbertOrder()
+
+                drawer.stroke = ColorRGBa.WHITE.opacify(0.5)
+                drawer.fill = null
+                drawer.contour(hobbyCurve(points, closed = false, tensions = { i, inAngle, outAngle ->
+                    Pair(t, t)
+                }))
+            }
+        }
+    }
+}

orx-shapes/src/jvmDemo/kotlin/hobbycurve/DemoHobbyCurve05.kt

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+package hobbycurve
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.color.presets.WHITE_SMOKE
+import org.openrndr.extra.noise.simplex
+import org.openrndr.extra.noise.uniform
+import org.openrndr.extra.shapes.hobbycurve.hobbyCurve
+import org.openrndr.extra.shapes.ordering.hilbertOrder
+import org.openrndr.math.Vector2
+
+/**
+ * Demonstrates the creation of a 40 hobby curves with 10 points each.
+ * The control points in all hobby curves are almost identical, varying only
+ * due to a slight increase in one of the arguments of a simplex noise call.
+ *
+ * The program shows that minor displacements in control points can have
+ * a large impact in the resulting curve.
+ */
+fun main() = application {
+    program {
+        val seed = 68040
+        val curves = List(40) { n ->
+            hobbyCurve(List(10) {
+                Vector2(
+                    simplex(seed, it * 13.3, n * 0.001) * 300.0 + 320.0,
+                    simplex(seed / 2, it * 77.4, n * 0.001) * 300.0 + 240.0
+                )
+            }.hilbertOrder(), true)
+        }
+        extend {
+            drawer.clear(ColorRGBa.WHITE_SMOKE)
+            drawer.fill = null
+            drawer.stroke = ColorRGBa.BLACK.opacify(0.3)
+            drawer.contours(curves)
+        }
+    }
+}

orx-shapes/src/jvmDemo/kotlin/primitives/DemoRectangleIrregularGrid02.kt

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+package primitives
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.color.presets.CORAL
+import org.openrndr.extra.shapes.primitives.column
+import org.openrndr.extra.shapes.primitives.irregularGrid
+import org.openrndr.extra.shapes.primitives.row
+import kotlin.random.Random
+
+/**
+ * Demonstrates how to use `Rectangle.irregularGrid()` to create a grid with varying column widths
+ * and row heights. The widths and heights are specified as a list of 13 `Double` values, each
+ * picked randomly between the values 1.0 and 4.0. This produces two types of columns and two
+ * types of rows only: wide ones and narrow ones.
+ *
+ * The program also demonstrates how to query a `row()` and a `column()` from a `RectangleGrid` instance,
+ * both of which return a `List<Rectangle>`. Both `Rectangle` lists are rendered with translucent
+ * colors, which makes the intersection of the column and the row slightly brighter.
+ *
+ */
+fun main() = application {
+    configure {
+        width = 720
+        height = 720
+    }
+    program {
+        extend {
+            val r = Random(100)
+            val grid = drawer.bounds.irregularGrid(
+                List(13) { listOf(1.0, 4.0).random(r) },
+                List(13) { listOf(1.0, 4.0).random(r) }
+            )
+
+            drawer.fill = null
+            drawer.stroke = ColorRGBa.WHITE
+            drawer.rectangles(grid.flatten())
+
+            drawer.stroke = ColorRGBa.BLACK
+            drawer.fill = ColorRGBa.PINK.opacify(0.5)
+            drawer.rectangles(grid.column(2))
+
+            drawer.fill = ColorRGBa.CORAL.opacify(0.5)
+            drawer.rectangles(grid.row(6))
+        }
+    }
+}

orx-shapes/src/jvmDemo/kotlin/primitives/DemoTear02.kt

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+package primitives
+
+import org.openrndr.application
+import org.openrndr.color.ColorRGBa
+import org.openrndr.extra.noise.scatter
+import org.openrndr.extra.shapes.primitives.Tear
+import org.openrndr.shape.Circle
+
+/**
+ * Demonstrates the use of `Tear()` to create drop-like shapes out of a Vector2 point and a Circle.
+ *
+ * The tear locations are calculated using the `Rectangle.scatter()` function. Locations near the
+ * center of the window are filtered out.
+ *
+ * The radii of each tear is randomly chosen between three values. The orientation of each tear
+ * is calculated by getting the normalized difference between the tear and the center of the window,
+ * making them look as being emitted at the center of the window.
+ */
+fun main() = application {
+    configure {
+        width = 720
+        height = 720
+    }
+    program {
+        val points = drawer.bounds.scatter(40.0, distanceToEdge = 80.0).filter {
+            it.distanceTo(drawer.bounds.center) > 80.0
+        }
+
+        val tears = points.map {
+            val radius = listOf(5.0, 10.0, 20.0).random()
+            val offset = (it - drawer.bounds.center).normalized * radius
+            Tear(it - offset, Circle(it + offset, radius))
+        }
+
+        extend {
+            drawer.clear(ColorRGBa.WHITE)
+            drawer.fill = ColorRGBa.PINK
+            drawer.stroke = ColorRGBa.BLACK
+            drawer.contours(tears.map { it.contour })
+        }
+    }
+}