如何沿贝塞尔曲线写文字？

Question

如何沿贝塞尔曲线写文字？

gon*_*ard 17 java javafx-2 javafx-8

我希望在javafx 2.2中或至少在javafx 8中执行类似的操作.我浏览了没有结果的Text javadoc和css引用.

在此输入图像描述

可以通过在WebView中显示和svg来实现此效果.但我的应用程序必须显示大量具有此效果的文本.WebView是一个太重的组件,用于绘制具有此效果的文本.

我在oracle技术网络上问了同样的问题.

Answer 1

jew*_*sea 25

这是滥用PathTransition以获取沿Bézier曲线绘制的文本.

该程序允许您拖动控制点以定义曲线,然后沿该曲线绘制文本.文本中的字符间隔等距离,因此如果曲线的总长度非常接近文本宽度与"正常"间距匹配,则效果最佳,并且不会对字距调整等内容进行调整.

以下示例显示:

带有发光效果的弯曲文本.
一些没有效果的弯曲文本.
用于定义弯曲路径的控制操作点被绘制为没有效果的文本.

弯曲的文本与辉光弯曲的文字曲线操纵器

解决方案是基于StackOverflow问题的答案快速入侵:CubicCurve JavaFX.我相信可以通过更多的努力,时间和技巧找到更好的解决方案.

因为程序是基于过渡的,所以很容易采用它,以便文本可以动画跟随曲线,在溢出时从右到左包裹(就像你可能在选框文本或股票行情中看到的那样).

任何标准的JavaFX效果(如发光,阴影等)和字体更改都可以应用于从问题中的painthop专业文本中获取阴影效果等内容.发光效果是一种很好的效果,因为它可以巧妙地柔化旋转角色周围的锯齿状边缘.

此解决方案所基于的PathTransition可以采用任意形状作为路径的输入,因此文本可以遵循其他类型的路径,而不仅仅是三次曲线.

import javafx.animation.*;
import javafx.application.Application;
import javafx.beans.property.DoubleProperty;
import javafx.collections.*;
import javafx.event.*;
import javafx.scene.*;
import javafx.scene.control.ToggleButton;
import javafx.scene.effect.Glow;
import javafx.scene.input.MouseEvent;
import javafx.scene.paint.Color;
import javafx.scene.shape.*;
import javafx.scene.text.Text;
import javafx.stage.Stage;
import javafx.util.Duration;

/**
 * Example of drawing text along a cubic curve.
 * Drag the anchors around to change the curve.
 */
public class BezierTextPlotter extends Application {
    private static final String CURVED_TEXT = "Bézier Curve";

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

    @Override
    public void start(final Stage stage) throws Exception {
        final CubicCurve curve = createStartingCurve();

        Line controlLine1 = new BoundLine(curve.controlX1Property(), curve.controlY1Property(), curve.startXProperty(), curve.startYProperty());
        Line controlLine2 = new BoundLine(curve.controlX2Property(), curve.controlY2Property(), curve.endXProperty(), curve.endYProperty());

        Anchor start = new Anchor(Color.PALEGREEN, curve.startXProperty(), curve.startYProperty());
        Anchor control1 = new Anchor(Color.GOLD, curve.controlX1Property(), curve.controlY1Property());
        Anchor control2 = new Anchor(Color.GOLDENROD, curve.controlX2Property(), curve.controlY2Property());
        Anchor end = new Anchor(Color.TOMATO, curve.endXProperty(), curve.endYProperty());

        final Text text = new Text(CURVED_TEXT);
        text.setStyle("-fx-font-size: 40px");
        text.setEffect(new Glow());
        final ObservableList<Text> parts = FXCollections.observableArrayList();
        final ObservableList<PathTransition> transitions = FXCollections.observableArrayList();
        for (char character : text.textProperty().get().toCharArray()) {
            Text part = new Text(character + "");
            part.setEffect(text.getEffect());
            part.setStyle(text.getStyle());
            parts.add(part);
            part.setVisible(false);

            transitions.add(createPathTransition(curve, part));
        }

        final ObservableList<Node> controls = FXCollections.observableArrayList();
        controls.setAll(controlLine1, controlLine2, curve, start, control1, control2, end);

        final ToggleButton plot = new ToggleButton("Plot Text");
        plot.setOnAction(new PlotHandler(plot, parts, transitions, controls));

        Group content = new Group(controlLine1, controlLine2, curve, start, control1, control2, end, plot);
        content.getChildren().addAll(parts);

        stage.setTitle("Cubic Curve Manipulation Sample");
        stage.setScene(new Scene(content, 400, 400, Color.ALICEBLUE));
        stage.show();
    }

    private PathTransition createPathTransition(CubicCurve curve, Text text) {
        final PathTransition transition = new PathTransition(Duration.seconds(10), curve, text);

        transition.setAutoReverse(false);
        transition.setCycleCount(PathTransition.INDEFINITE);
        transition.setOrientation(PathTransition.OrientationType.ORTHOGONAL_TO_TANGENT);
        transition.setInterpolator(Interpolator.LINEAR);

        return transition;
    }

    private CubicCurve createStartingCurve() {
        CubicCurve curve = new CubicCurve();
        curve.setStartX(50);
        curve.setStartY(200);
        curve.setControlX1(150);
        curve.setControlY1(300);
        curve.setControlX2(250);
        curve.setControlY2(50);
        curve.setEndX(350);
        curve.setEndY(150);
        curve.setStroke(Color.FORESTGREEN);
        curve.setStrokeWidth(4);
        curve.setStrokeLineCap(StrokeLineCap.ROUND);
        curve.setFill(Color.CORNSILK.deriveColor(0, 1.2, 1, 0.6));
        return curve;
    }

    class BoundLine extends Line {
        BoundLine(DoubleProperty startX, DoubleProperty startY, DoubleProperty endX, DoubleProperty endY) {
            startXProperty().bind(startX);
            startYProperty().bind(startY);
            endXProperty().bind(endX);
            endYProperty().bind(endY);
            setStrokeWidth(2);
            setStroke(Color.GRAY.deriveColor(0, 1, 1, 0.5));
            setStrokeLineCap(StrokeLineCap.BUTT);
            getStrokeDashArray().setAll(10.0, 5.0);
        }
    }

    // a draggable anchor displayed around a point.
    class Anchor extends Circle {
        Anchor(Color color, DoubleProperty x, DoubleProperty y) {
            super(x.get(), y.get(), 10);
            setFill(color.deriveColor(1, 1, 1, 0.5));
            setStroke(color);
            setStrokeWidth(2);
            setStrokeType(StrokeType.OUTSIDE);

            x.bind(centerXProperty());
            y.bind(centerYProperty());
            enableDrag();
        }

        // make a node movable by dragging it around with the mouse.
        private void enableDrag() {
            final Delta dragDelta = new Delta();
            setOnMousePressed(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent mouseEvent) {
                    // record a delta distance for the drag and drop operation.
                    dragDelta.x = getCenterX() - mouseEvent.getX();
                    dragDelta.y = getCenterY() - mouseEvent.getY();
                    getScene().setCursor(Cursor.MOVE);
                }
            });
            setOnMouseReleased(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent mouseEvent) {
                    getScene().setCursor(Cursor.HAND);
                }
            });
            setOnMouseDragged(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent mouseEvent) {
                    double newX = mouseEvent.getX() + dragDelta.x;
                    if (newX > 0 && newX < getScene().getWidth()) {
                        setCenterX(newX);
                    }
                    double newY = mouseEvent.getY() + dragDelta.y;
                    if (newY > 0 && newY < getScene().getHeight()) {
                        setCenterY(newY);
                    }
                }
            });
            setOnMouseEntered(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent mouseEvent) {
                    if (!mouseEvent.isPrimaryButtonDown()) {
                        getScene().setCursor(Cursor.HAND);
                    }
                }
            });
            setOnMouseExited(new EventHandler<MouseEvent>() {
                @Override
                public void handle(MouseEvent mouseEvent) {
                    if (!mouseEvent.isPrimaryButtonDown()) {
                        getScene().setCursor(Cursor.DEFAULT);
                    }
                }
            });
        }

        // records relative x and y co-ordinates.
        private class Delta {
            double x, y;
        }
    }

    // plots text along a path defined by provided bezier control points.
    private static class PlotHandler implements EventHandler<ActionEvent> {
        private final ToggleButton plot;
        private final ObservableList<Text> parts;
        private final ObservableList<PathTransition> transitions;
        private final ObservableList<Node> controls;

        public PlotHandler(ToggleButton plot, ObservableList<Text> parts, ObservableList<PathTransition> transitions, ObservableList<Node> controls) {
            this.plot = plot;
            this.parts = parts;
            this.transitions = transitions;
            this.controls = controls;
        }

        @Override
        public void handle(ActionEvent actionEvent) {
            if (plot.isSelected()) {
                for (int i = 0; i < parts.size(); i++) {
                    parts.get(i).setVisible(true);
                    final Transition transition = transitions.get(i);
                    transition.stop();
                    transition.jumpTo(Duration.seconds(10).multiply((i + 0.5) * 1.0 / parts.size()));
                    // just play a single animation frame to display the curved text, then stop
                    AnimationTimer timer = new AnimationTimer() {
                        int frameCounter = 0;

                        @Override
                        public void handle(long l) {
                            frameCounter++;
                            if (frameCounter == 1) {
                                transition.stop();
                                stop();
                            }
                        }
                    };
                    timer.start();
                    transition.play();
                }
                plot.setText("Show Controls");
            } else {
                plot.setText("Plot Text");
            }

            for (Node control : controls) {
                control.setVisible(!plot.isSelected());
            }

            for (Node part : parts) {
                part.setVisible(plot.isSelected());
            }
        }
    }
}

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另一种可能的解决方案是测量每个文本字符,并使用数学来插入文本位置和旋转,而不使用PathTransition.但是PathTransition已经存在并且对我来说工作得很好(也许对于文本进展的曲线距离测量可能会挑战我).

其他问题的答案

您认为通过调整代码可以实现javafx.scene.effect.Effect吗？

否.实现效果需要执行数学来沿贝松曲线显示文本,我的答案没有提供(因为它只是采用现有的PathTransition来执行此操作).

此外,JavaFX 2.2中没有用于实现您自己的自定义效果的公共API.

现有的DisplacementMap效果可能用于获得类似的东西.但是,我觉得使用DisplacementMap效果(可能还有任何效果来调整文本布局)可能会扭曲文本.

IMO,沿Bezier曲线写文本与效果相关的布局更多 - 最好调整字符的布局和旋转,而不是使用效果来移动它们.

或者可能有更好的方法在JFX框架中正确集成它？

你可以继承窗格并创建一个自定义PathLayout类似于一个FlowPane,但勾画出节点沿着一个路径,而不是一条直线.要布局的节点由每个字符的Text节点组成,类似于我在答案中所做的.但即使这样,你也不能真正准确地渲染文本,因为你想要考虑比例间隔的字母,字距等等.因此,为了保证完全保真度和准确性,你需要实现自己的低级文本布局算法.如果是我的话,如果使用PathTransitions在这个答案中提供的"足够好"的解决方案证明不是足够高的质量,我只会去努力.

Answer 2

Seb*_*ian 8

您可以使用WebView和一些html来显示svg.这是一个例子:

import javafx.application.Application;
import javafx.scene.Scene;
import javafx.scene.layout.StackPane;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class CurvedText extends Application {

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

  @Override
  public void start(Stage primaryStage) throws Exception {
    StackPane root = new StackPane();
    WebView view = new WebView();
    view.getEngine().loadContent("<!DOCTYPE html>\n" +
            "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n" +
            "  <body>\n" +
            "<embed width=\"100\" height=\"100\" type=\"image/svg+xml\" src=\"path.svg\">\n" +
            "  <svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" +
            "<defs>\n" +
            "  <path id=\"textPath\" d=\"M10 50 C10 0 90 0 90 50\"/>\n" +
            "</defs>\n"+
            "<text fill=\"red\">\n" +
            "  <textPath xlink:href=\"#textPath\">Text on a Path</textPath>\n" +
            "</text>" +
            "</svg>\n" +
            "</embed>" +
            "  </body>\n" +
            "</html>");
    root.getChildren().add(view);
    Scene scene = new Scene(root, 500, 500);
    primaryStage.setScene(scene);
    primaryStage.show();
  }
}

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结果:

在此输入图像描述

这不是最佳解决方案,因为JavaFX WebView在我的体验中应该像标签一样表现得有点敏感,但它是开始的.

编辑

由于您不想直接使用WebView,因此可以使用WebView的单个实例使用html渲染场景,然后拍摄它的快照以生成ImageView.看这个例子:

import javafx.animation.AnimationTimer;
import javafx.application.Application;
import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.scene.Scene;
import javafx.scene.image.ImageView;
import javafx.scene.image.WritableImage;
import javafx.scene.layout.HBox;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class CurvedText extends Application {

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

  @Override
  public void start(Stage primaryStage) throws Exception {
    final HBox root = new HBox();
    final WebView view = new WebView();
    view.getEngine().loadContent("<!DOCTYPE html>\n" +
            "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n" +
            "  <body>\n" +
            "<embed width=\"100\" height=\"100\" type=\"image/svg+xml\" src=\"path.svg\">\n" +
            "  <svg xmlns=\"http://www.w3.org/2000/svg\" xmlns:xlink=\"http://www.w3.org/1999/xlink\">" +
            "<defs>\n" +
            "  <path id=\"textPath\" d=\"M10 50 C10 0 90 0 90 50\"/>\n" +
            "</defs>\n"+
            "<text fill=\"red\">\n" +
            "  <textPath xlink:href=\"#textPath\">Text on a Path</textPath>\n" +
            "</text>" +
            "</svg>\n" +
            "</embed>" +
            "  </body>\n" +
            "</html>");
    root.getChildren().add(view);
    view.getEngine().getLoadWorker().stateProperty().addListener(new ChangeListener<Worker.State>() {
      @Override
      public void changed(ObservableValue<? extends Worker.State> arg0, Worker.State oldState, Worker.State newState) {
        if (newState == Worker.State.SUCCEEDED) {
          // workaround for https://javafx-jira.kenai.com/browse/RT-23265
          AnimationTimer waitForViewToBeRendered = new AnimationTimer(){
            private int frames = 0;
            @Override
            public void handle(long now) {
              if (frames++ > 3){
                WritableImage snapshot = view.snapshot(null, null);
                ImageView imageView = new ImageView(snapshot);
                root.getChildren().add(imageView);
                this.stop();
              }
            }
          };
          waitForViewToBeRendered.start();
        }
      }
    });
    Scene scene = new Scene(root, 500, 500);
    primaryStage.setScene(scene);
    primaryStage.show();
  }
}

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