Add poisson demo (#111)

* Add poisson fill demo

* Add missing screenshot code in demo

orx-poisson-fill/build.gradle

@@ -1,3 +1,19 @@
+sourceSets {
+    demo {
+        java {
+            srcDirs = ["src/demo/kotlin"]
+            compileClasspath += main.getCompileClasspath()
+            runtimeClasspath += main.getRuntimeClasspath()
+        }
+    }
+}
 dependencies {
     implementation project(":orx-fx")
-}
+    implementation project(":orx-noise")
+
+    demoImplementation("org.openrndr:openrndr-core:$openrndrVersion")
+    demoImplementation("org.openrndr:openrndr-extensions:$openrndrVersion")
+    demoRuntimeOnly("org.openrndr:openrndr-gl3:$openrndrVersion")
+    demoRuntimeOnly("org.openrndr:openrndr-gl3-natives-$openrndrOS:$openrndrVersion")
+    demoImplementation(sourceSets.getByName("main").output)
+}

orx-poisson-fill/src/demo/kotlin/DemoPoissonFill01.kt

@@ -0,0 +1,92 @@
+import org.openrndr.MouseButton
+import org.openrndr.application
+import org.openrndr.color.ColorHSVa
+import org.openrndr.color.ColorRGBa
+import org.openrndr.color.rgb
+import org.openrndr.draw.ColorType
+import org.openrndr.draw.colorBuffer
+import org.openrndr.draw.isolatedWithTarget
+import org.openrndr.draw.renderTarget
+import org.openrndr.extensions.SingleScreenshot
+import org.openrndr.extra.noise.Random
+import org.openrndr.math.Polar
+import org.openrndr.math.clamp
+import org.openrndr.math.mix
+import org.openrndr.poissonfill.PoissonFill
+import org.openrndr.shape.Rectangle
+import kotlin.math.sin
+
+data class Thing(val color: ColorRGBa, var pos: Polar, val speed: Polar)
+
+fun main() {
+    application {
+        program {
+
+            // -- this block is for automation purposes only
+            if (System.getProperty("takeScreenshot") == "true") {
+                extend(SingleScreenshot()) {
+                    this.outputFile = System.getProperty("screenshotPath")
+                }
+            }
+
+            val dry = renderTarget(width, height) {
+                colorBuffer(type = ColorType.FLOAT32)
+            }
+            val wet = colorBuffer(width, height)
+
+            val fx = PoissonFill()
+
+            var borderOpacity = 0.0
+
+            // Create a list of things with
+            // color, polar position and polar speed
+            val things = List(10) {
+                Thing(
+                        ColorHSVa(it * 182.0,
+                                Random.double(0.3, 0.6),
+                                Random.double(0.1, 0.9)).toRGBa(),
+                        Polar(Random.double0(360.0),
+                                100.0 + it * 10.0),
+                        Polar(Random.double(-1.0, 1.0), 0.0))
+            }
+
+            extend {
+                drawer.isolatedWithTarget(dry) {
+                    stroke = null
+                    clear(ColorRGBa.TRANSPARENT)
+
+                    // draw color circles
+                    things.forEach { thing ->
+                        fill = thing.color.shade(0.9 +
+                                0.1 * sin(thing.pos.theta * 0.3))
+                        circle(thing.pos.cartesian + bounds.center, 5.0)
+                        // A. Use after fix in Polar.kt
+                        //thing.pos += thing.speed
+                        // B. temporary solution
+                        thing.pos = Polar(thing.pos.theta +
+                                thing.speed.theta, thing.pos.radius)
+                    }
+
+                    // draw dark gray window border.
+                    // hold mouse button to fade in.
+                    borderOpacity += if (MouseButton.LEFT in mouse.pressedButtons) 0.01 else -0.01
+                    borderOpacity = borderOpacity.clamp(0.0, 1.0)
+                    stroke = rgb(0.2).opacify(borderOpacity)
+                    fill = null
+                    strokeWeight = 3.0
+                    rectangle(bounds)
+                }
+
+                fx.apply(dry.colorBuffer(0), wet)
+                drawer.image(wet)
+
+                // draw white rectangle
+                drawer.stroke = ColorRGBa.WHITE.opacify(0.9)
+                drawer.fill = null
+                drawer.strokeWeight = 6.0
+                drawer.rectangle(Rectangle.fromCenter(drawer.bounds.center,
+                        300.0, 300.0))
+            }
+        }
+    }
+}