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-fx/src/jvmDemo/kotlin/DemoSpectralBlend01.kt

@@ -8,38 +8,36 @@ import org.openrndr.extra.fx.patterns.Checkers
 import org.openrndr.math.Vector2
 import kotlin.math.sin
 
-fun main() {
-    application {
-        configure {
-            width = 800
-            height = 800
+fun main() = application {
+    configure {
+        width = 800
+        height = 800
+    }
+    program {
+        val a = drawImage(width, height) {
+            drawer.stroke = null
+            drawer.fill = ColorRGBa.BLUE
+            drawer.circle(drawer.bounds.center - Vector2(100.0, 0.0), drawer.width * 0.25)
         }
-        program {
-            val a = drawImage(width, height) {
-                drawer.stroke = null
-                drawer.fill = ColorRGBa.BLUE
-                drawer.circle(drawer.bounds.center - Vector2(100.0, 0.0), drawer.width * 0.25)
-            }
-            val b = drawImage(width, height) {
-                drawer.clear(ColorRGBa.TRANSPARENT)
-                drawer.stroke = ColorRGBa.RED
-                drawer.strokeWeight = 10.0
-                drawer.fill = ColorRGBa.YELLOW.opacify(1.0)
-                drawer.circle(drawer.bounds.center + Vector2(100.0, 0.0), drawer.width * 0.25)
-            }
-            BoxBlur().apply { window = 10 }.apply(b, b)
-            val checked = a.createEquivalent()
-            Checkers().apply(emptyArray(), checked)
+        val b = drawImage(width, height) {
+            drawer.clear(ColorRGBa.TRANSPARENT)
+            drawer.stroke = ColorRGBa.RED
+            drawer.strokeWeight = 10.0
+            drawer.fill = ColorRGBa.YELLOW.opacify(1.0)
+            drawer.circle(drawer.bounds.center + Vector2(100.0, 0.0), drawer.width * 0.25)
+        }
+        BoxBlur().apply { window = 10 }.apply(b, b)
+        val checked = a.createEquivalent()
+        Checkers().apply(emptyArray(), checked)
 
-            val mixed = a.createEquivalent()
-            val blendSpectral = BlendSpectral()
-            extend {
-                drawer.image(checked)
-                blendSpectral.fill = sin(seconds) * 0.5 + 0.5
-                blendSpectral.clip = seconds.mod(4.0) > 2.0
-                blendSpectral.apply(a, b, mixed)
-                drawer.image(mixed)
-            }
+        val mixed = a.createEquivalent()
+        val blendSpectral = BlendSpectral()
+        extend {
+            drawer.image(checked)
+            blendSpectral.fill = sin(seconds) * 0.5 + 0.5
+            blendSpectral.clip = seconds.mod(4.0) > 2.0
+            blendSpectral.apply(a, b, mixed)
+            drawer.image(mixed)
         }
     }
-}
+}