[orx-keyframer] Fix demo configuration, add expression evaluator demo

orx-jvm/orx-keyframer/build.gradle

@@ -37,8 +37,10 @@ dependencies {
     testRuntimeOnly(libs.spek.junit5)
     testRuntimeOnly(libs.kotlin.reflect)
     demoImplementation(project(":orx-jvm:orx-panel"))
+    demoImplementation(project(":orx-jvm:orx-gui"))
 }
 
 tasks.getByName("compileKotlin").dependsOn("generateGrammarSource")
+tasks.getByName("compileDemoKotlin").dependsOn("generateDemoGrammarSource")
 tasks.getByName("compileTestKotlin").dependsOn("generateTestGrammarSource")
 tasks.getByName("sourcesJar").dependsOn("generateGrammarSource")

orx-jvm/orx-keyframer/src/demo/kotlin/DemoExpressionEvaluator01.kt

@@ -0,0 +1,39 @@
+import org.openrndr.application
+import org.openrndr.extra.gui.GUI
+import org.openrndr.extra.gui.addTo
+import org.openrndr.extra.keyframer.evaluateExpression
+import org.openrndr.extra.parameters.TextParameter
+
+fun main() {
+    application {
+        program {
+            val gui = GUI()
+            gui.compartmentsCollapsedByDefault = false
+
+            val settings = object {
+                @TextParameter("x expression", order = 10)
+                var xExpression = "cos(t) * 50.0 + width / 2.0"
+                @TextParameter("y expression", order = 20)
+                var yExpression = "sin(t) * 50.0 + height / 2.0"
+                @TextParameter("radius expression", order = 30 )
+                var radiusExpression = "cos(t) * 50.0 + 50.0"
+            }.addTo(gui)
+
+            extend(gui)
+            extend {
+                //gui.visible = mouse.position.x < 200.0
+
+                val expressionContext = mapOf("t" to seconds, "width" to drawer.bounds.width, "height" to drawer.bounds.height)
+
+                fun eval(expression: String) : Double =
+                    try { evaluateExpression(expression, expressionContext)  ?: 0.0 } catch (e: Throwable) { 0.0 }
+
+                val x = eval(settings.xExpression)
+                val y = eval(settings.yExpression)
+                val radius = eval(settings.radiusExpression)
+
+                drawer.circle(x, y, radius)
+            }
+        }
+    }
+}