ControlPointsAnimation.java

import javafx.animation.AnimationTimer;
import javafx.application.Application;
import static javafx.application.Application.launch;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.paint.Color;
import javafx.scene.shape.CubicCurve;
import javafx.scene.shape.StrokeLineCap;
import javafx.stage.Stage;

public class ControlPointsAnimation extends Application {
    
    @Override
    public void start(Stage stage) {
        Group root = new Group();
        
        drawAnimatedCurves(root);
        
        Scene scene = new Scene(root, 400, 200);
        
        stage.setTitle("Line Animation");
        stage.setScene(scene);
        stage.show();
    }
    
    private void drawAnimatedCurves(Group parent) {
        // ベジェ曲線 1本目
        final CubicCurve curve1 = new CubicCurve();
        curve1.setStartX(40.0); curve1.setStartY(100.0);
        curve1.setEndX(360.0); curve1.setEndY(100.0);
        curve1.setStroke(Color.BLACK);
        curve1.setStrokeWidth(10.0);
        curve1.setStrokeLineCap(StrokeLineCap.ROUND);
        curve1.setFill(null);
        parent.getChildren().add(curve1);
        
        // ベジェ曲線 2本目
        final CubicCurve curve2 = new CubicCurve();
        curve2.setStartX(40.0); curve2.setStartY(100.0);
        curve2.setEndX(360.0); curve2.setEndY(100.0);
        curve2.setStroke(Color.BLACK);
        curve2.setStrokeWidth(10.0);
        curve2.setStrokeLineCap(StrokeLineCap.ROUND);
        curve2.setFill(null);
        parent.getChildren().add(curve2);

        // ベジェ曲線の制御点を円運動させるアニメーション
        AnimationTimer timer = new AnimationTimer() {
            @Override
            public void handle(long t) {
                double sin1 = 150 * Math.sin(t/400_000_000.0);
                double cos1 = 150 * Math.cos(t/400_000_000.0);

                // もう一方の制御点は180度ずらす
                double sin2 = 150 * Math.sin(t/400_000_000.0 + Math.PI);
                double cos2 = 150 * Math.cos(t/400_000_000.0 + Math.PI);

                double controlX11 = 40.0 + sin1; 
                double controlY11 = 100.0 + cos1;
                curve1.setControlX1(controlX11);
                curve1.setControlY1(controlY11);
                
                double controlX12 = 360.0 + sin2; 
                double controlY12 = 100.0 + cos2; 
                curve1.setControlX2(controlX12);
                curve1.setControlY2(controlY12);

                double controlX21 = 40.0 + sin2; 
                double controlY21 = 100.0 + cos2;
                curve2.setControlX1(controlX21);
                curve2.setControlY1(controlY21);
                
                double controlX22 = 360.0 + sin1; 
                double controlY22 = 100.0 + cos1; 
                curve2.setControlX2(controlX22);
                curve2.setControlY2(controlY22);
            }
        };
        timer.start();
    }

    public static void main(String... args) {
        launch(args);
    }
}