ADDITIONAL SYSTEM INFORMATION :
openjdk version "21.0.2" 2024-01-16
OpenJDK Runtime Environment (build 21.0.2+13-58)
OpenJDK 64-Bit Server VM (build 21.0.2+13-58, mixed mode, sharing)

OS: Ubuntu 20.04.3 LTS

A DESCRIPTION OF THE PROBLEM :
GraphicsContex.clip() works slowly when doubles are used for setting clip form.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run this code. Ather that try variant #2. See the difference.


---------- BEGIN SOURCE ----------
public class JavaFxTest7 extends Application {

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

  @Override
  public void start(Stage primaryStage) {
      Canvas canvas = new Canvas(600, 600);
      GraphicsContext gc = canvas.getGraphicsContext2D();
      gc.setFill(Color.GREEN);

      var timeLine = new Timeline(new KeyFrame(Duration.millis(1000 / 50), (e) -> {
        gc.clearRect(0, 0, 600, 600);
        for (var i = 0; i < 2000; i++) {
          //variant #1
          var x = ThreadLocalRandom.current().nextInt(0, 600);
          var y = ThreadLocalRandom.current().nextInt(0, 600);
          //variant #2
// var x = ThreadLocalRandom.current().nextDouble(0, 600);
// var y = ThreadLocalRandom.current().nextDouble(0, 600);
          gc.save();
          gc.beginPath();
          gc.rect(x, y, canvas.getWidth() - x, canvas.getHeight() - y);
          gc.closePath();
          gc.clip();
          gc.fillText(String.valueOf(i), (int) x, (int) y + 20);
          gc.restore();
        }

      }));
      timeLine.setCycleCount(Timeline.INDEFINITE);
      timeLine.play();

      Pane root = new Pane();
      root.getChildren().add(canvas);
      primaryStage.setScene(new Scene(root));
      primaryStage.show();
  }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
Using int seems to solve the problem

FREQUENCY : always