Demos: ensure all use fun main() = application {

- Adjust some demo window sizes.
- Replace Random.double by Double.uniform
- Tweak some demos so screenshots look more interesting

orx-view-box/src/jvmDemo/kotlin/DemoViewBox01.kt

@@ -1,4 +1,3 @@
-
 import org.openrndr.application
 import org.openrndr.draw.BufferMultisample
 import org.openrndr.draw.DrawPrimitive
@@ -11,56 +10,61 @@ import org.openrndr.extra.meshgenerators.boxMesh
 import org.openrndr.extra.viewbox.viewBox
 import org.openrndr.shape.Rectangle
 
-fun main() {
-    application {
-        configure {
-            width = 800
-            height = 800
-        }
-        program {
-            val vbx = viewBox(Rectangle(0.0, 0.0, 200.0, 800.0)) {
-                extend(Screenshots())
-                extend(Camera2D()).also {
-                    shouldDraw = { it.hasChanged }
-                }
-                extend {
-                    drawer.rectangle(20.0, 20.0, 100.0, 100.0)
-                }
+/**
+ * Demonstrates how to draw multiple view boxes. The first two feature
+ * interactive 2D cameras, the third one uses an Orbital 3D camera.
+ * All three can be controlled with the mouse wheel and buttons.
+ *
+ * The `shouldDraw` viewBox variable is used to avoid re-rendering the view
+ * unnecessarily when the camera has not changed.
+ *
+ */
+fun main() = application {
+    configure {
+        width = 720
+        height = 720
+    }
+    program {
+        val vbx = viewBox(Rectangle(0.0, 0.0, 200.0, height * 1.0)) {
+            extend(Screenshots())
+            extend(Camera2D()).also {
+                shouldDraw = { it.hasChanged }
             }
-
-            val vbx2 = viewBox(Rectangle(200.0, 0.0, 200.0, 800.0)) {
-                extend(Post()) {
-                    val blur = ApproximateGaussianBlur()
-                    blur.sigma = 10.0
-                    blur.window = 25
-                    post { i, o ->
-                        blur.apply(i, o)
-                    }
-                }
-                extend(Camera2D())
-                extend {
-                    drawer.rectangle(20.0, 20.0, 100.0, 100.0)
-                    drawer.circle(mouse.position, 10.0)
-                }
-            }
-
-            val vbx3d = viewBox(Rectangle(400.0, 0.0, 400.0, 800.0), multisample = BufferMultisample.SampleCount(8)) {
-                extend(Orbital()).also {
-                    this.shouldDraw = {
-                        it.hasChanged
-                    }
-                }
-                val cube = boxMesh()
-                extend {
-                    drawer.vertexBuffer(cube, DrawPrimitive.TRIANGLES)
-                }
-            }
-
             extend {
-                vbx.draw()
-                vbx2.draw()
-                vbx3d.draw()
+                drawer.rectangle(20.0, 20.0, 100.0, 100.0)
             }
         }
+
+        val vbx2 = viewBox(Rectangle(200.0, 0.0, 200.0, height * 1.0)) {
+            extend(Post()) {
+                val blur = ApproximateGaussianBlur()
+                blur.sigma = 10.0
+                blur.window = 25
+                post { i, o ->
+                    blur.apply(i, o)
+                }
+            }
+            extend(Camera2D())
+            extend {
+                drawer.rectangle(20.0, 20.0, 100.0, 100.0)
+                drawer.circle(mouse.position, 10.0)
+            }
+        }
+
+        val vbx3d = viewBox(Rectangle(400.0, 0.0, 400.0, 800.0), multisample = BufferMultisample.SampleCount(8)) {
+            extend(Orbital()).also {
+                shouldDraw = { it.hasChanged }
+            }
+            val cube = boxMesh()
+            extend {
+                drawer.vertexBuffer(cube, DrawPrimitive.TRIANGLES)
+            }
+        }
+
+        extend {
+            vbx.draw()
+            vbx2.draw()
+            vbx3d.draw()
+        }
     }
-}
+}