javaFX初探（选择）

本章主要介绍，javaFX 3D库中的PickResult API。

PickResult API 早就在2D的视角相机中就可用了，然而，当用到深度缓存的时候依旧有点限制，PickResult类在javafx。scene。input包

下，它是选择事件的容器。

创建PickResult对象

// Creates a pick result for a 2D case where no additional information// is needed. Converts the given scene coordinates to the target's local// coordinate space andstores the value as the intersected point. Sets // intersected node to the giventarget, distance to 1.0, face to // FACE_UNDEFINED and texCoord to nullPickResult(EventTarget target, double sceneX, double sceneY)// Creates a new instance of PickResult for a non-3d-shape target. Sets face// to FACE_UNDEFINED and texCoord to null.PickResult(Node node, Point3D point, double distance)// Creates a new instance of PickResultPickResult(Node node, Point3D point, double distance, int face,            Point2D texCoord)

PickResult对象的方法

// Returns the intersected node. Returns null if there was no intersection// with any node and the scene was picked.public final Node getIntersectedNode()// Returns the intersected point in local coordinate of the picked Node. If// no node was picked, it returns the intersected point with the ion // plane.public final Point3D getIntersectedPoint()// Returns the intersected distance between camera position and the // intersected pointpublic final double getIntersectedDistance()// Returns the intersected face of the picked Node, FACE_UNDEFINED if the//  node doesn't have user-specified faces or was picked on bounds.public final int getIntersectedFace() // Return the intersected texture coordinates of the picked 3d shape. If the// picked target is not Shape3D or has pickOnBounds==true, it returns null. // Returns new Point2D presenting the intersected TexCoordpublic final Point2D getIntersectedTexCoord()

PcikResult的实例

下面的例子展示了PickResult对象和方法得使用。这个实例展示了怎么从PickResult对象中获取信息，当你的鼠标在网格上移动的时候，

鼠标的位置就会显示在上边，

/* * Copyright (c) 2014, Oracle and/or its affiliates. * All rights reserved. Use is subject to license terms. * * This file is available and licensed under the following license: * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * *  - Redistributions of source code must retain the above copyright *    notice, this list of conditions and the following disclaimer. *  - Redistributions in binary form must reproduce the above copyright *    notice, this list of conditions and the following disclaimer in *    the documentation and/or other materials provided with the distribution. *  - Neither the name of Oracle nor the names of its *    contributors may be used to endorse or promote products derived *    from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */package com.chu.helloworld;import javafx.application.Application;import javafx.application.ConditionalFeature;import javafx.application.Platform;import javafx.event.EventHandler;import javafx.geometry.Point2D;import javafx.geometry.Point3D;import javafx.geometry.VPos;import javafx.scene.Camera;import javafx.scene.DepthTest;import javafx.scene.Group;import javafx.scene.Node;import javafx.scene.PerspectiveCamera;import javafx.scene.PointLight;import javafx.scene.Scene;import javafx.scene.SceneAntialiasing;import javafx.scene.SubScene;import javafx.scene.input.KeyEvent;import javafx.scene.input.MouseEvent;import javafx.scene.input.PickResult;import javafx.scene.layout.HBox;import javafx.scene.paint.Color;import javafx.scene.paint.PhongMaterial;import javafx.scene.shape.CullFace;import javafx.scene.shape.DrawMode;import javafx.scene.shape.MeshView;import javafx.scene.shape.Rectangle;import javafx.scene.shape.Shape3D;import javafx.scene.shape.TriangleMesh;import javafx.scene.text.Font;import javafx.scene.text.Text;import javafx.scene.text.TextAlignment;import javafx.stage.Stage;/** * A Simple Picking Example */public class PickMesh3D extends Application {    MeshView meshView;    final static float minX = -10;    final static float minY = -10;    final static float maxX = 10;    final static float maxY = 10;    static TriangleMesh buildTriangleMesh(int subDivX, int subDivY, float scale) {        final int pointSize = 3;        final int texCoordSize = 2;        // 3 point indices and 3 texCoord indices per triangle        final int faceSize = 6;        int numDivX = subDivX + 1;        int numVerts = (subDivY + 1) * numDivX;        float points[] = new float[numVerts * pointSize];        float texCoords[] = new float[numVerts * texCoordSize];        int faceCount = subDivX * subDivY * 2;        int faces[] = new int[faceCount * faceSize];        // Create points and texCoords        for (int y = 0; y <= subDivY; y++) {            float dy = (float) y / subDivY;            double fy = (1 - dy) * minY + dy * maxY;            for (int x = 0; x <= subDivX; x++) {                float dx = (float) x / subDivX;                double fx = (1 - dx) * minX + dx * maxX;                int index = y * numDivX * pointSize + (x * pointSize);                points[index] = (float) fx * scale;                points[index + 1] = (float) fy * scale;                points[index + 2] = 0.0f;                index = y * numDivX * texCoordSize + (x * texCoordSize);                texCoords[index] = dx;                texCoords[index + 1] = dy;            }        }        // Create faces        for (int y = 0; y < subDivY; y++) {            for (int x = 0; x < subDivX; x++) {                int p00 = y * numDivX + x;                int p01 = p00 + 1;                int p10 = p00 + numDivX;                int p11 = p10 + 1;                int tc00 = y * numDivX + x;                int tc01 = tc00 + 1;                int tc10 = tc00 + numDivX;                int tc11 = tc10 + 1;                int index = (y * subDivX * faceSize + (x * faceSize)) * 2;                faces[index + 0] = p00;                faces[index + 1] = tc00;                faces[index + 2] = p10;                faces[index + 3] = tc10;                faces[index + 4] = p11;                faces[index + 5] = tc11;                index += faceSize;                faces[index + 0] = p11;                faces[index + 1] = tc11;                faces[index + 2] = p01;                faces[index + 3] = tc01;                faces[index + 4] = p00;                faces[index + 5] = tc00;            }        }        TriangleMesh triangleMesh = new TriangleMesh();        triangleMesh.getPoints().setAll(points);        triangleMesh.getTexCoords().setAll(texCoords);        triangleMesh.getFaces().setAll(faces);        return triangleMesh;    }        public static void main(String[] args) {        launch(args);    }    @Override    public void start(Stage stage) {        if (!Platform.isSupported(ConditionalFeature.SCENE3D)) {            throw new RuntimeException("*** ERROR: common conditional SCENE3D is not supported");        }        stage.setTitle("JavaFX 3D Simple Picking demo");        final PerspectiveCamera camera = new PerspectiveCamera();        Node pickResultPanel = createOverlay();        Group root = new Group();        root.getChildren().addAll(pickResultPanel, createSubScene(camera));        Scene scene = new Scene(root, 800, 800);        scene.setFill(Color.color(0.2, 0.2, 0.2));        scene.setOnKeyTyped(new EventHandler<KeyEvent>() {            @Override            public void handle(KeyEvent e) {                switch (e.getCharacter()) {                    case "L":                        System.err.print("L ");                        boolean wireframe = meshView.getDrawMode() == DrawMode.LINE;                        meshView.setDrawMode(wireframe ? DrawMode.FILL : DrawMode.LINE);                        break;                }            }        });        stage.setScene(scene);        stage.show();        stage.requestFocus();    }    private Node createSimpleMesh() {        TriangleMesh triangleMesh = buildTriangleMesh(2, 2, 30);        meshView = new MeshView(triangleMesh);        activateShape(meshView, "Simple Mesh");        meshView.setDrawMode(DrawMode.FILL);        meshView.setCullFace(CullFace.NONE);        PhongMaterial material = new PhongMaterial();        material.setDiffuseColor(Color.GOLD);        material.setSpecularColor(Color.rgb(30, 30, 30));        meshView.setMaterial(material);                  Node group = new Group(meshView);        group.setTranslateX(550);        group.setTranslateY(550);        return group;    }    private void activateShape(final Shape3D shape, final String name) {        shape.setId(name);        EventHandler<MouseEvent> moveHandler = new EventHandler<MouseEvent>() {            @Override            public void handle(MouseEvent event) {                PickResult res = event.getPickResult();                setState(res);                event.consume();            }        };        shape.setOnMouseMoved(moveHandler);        shape.setOnMouseDragOver(moveHandler);        shape.setOnMouseEntered(new EventHandler<MouseEvent>() {            @Override            public void handle(MouseEvent event) {                PickResult res = event.getPickResult();                if (res == null) {                    System.err.println("Mouse entered has not pickResult");                }                setState(res);            }        });        shape.setOnMouseExited(new EventHandler<MouseEvent>() {            @Override            public void handle(MouseEvent event) {                PickResult res = event.getPickResult();                if (res == null) {                    System.err.println("Mouse exited has not pickResult");                }                setState(res);                event.consume();            }        });    }    Text caption, data;    private Node createOverlay() {        HBox hBox = new HBox(10);        caption = new Text("Node:\n\nPoint:\nTexture Coord:\nFace:\nDistance:");        caption.setFont(Font.font("Times New Roman", 18));        caption.setTextOrigin(VPos.TOP);        caption.setTextAlignment(TextAlignment.RIGHT);        data = new Text("-- None --\n\n\n\n");        data.setFont(Font.font("Times New Roman", 18));        data.setTextOrigin(VPos.TOP);        data.setTextAlignment(TextAlignment.LEFT);        Rectangle rect = new Rectangle(300, 150, Color.color(0.2, 0.5, 0.3, 0.8));        hBox.getChildren().addAll(caption, data);        return new Group(rect, hBox);    }    private  SubScene createSubScene(Camera camera) {        final Node simpleMesh = createSimpleMesh();        final Group parent = new Group(simpleMesh);        parent.setTranslateZ(600);        parent.setTranslateX(-150);        parent.setTranslateY(-200);        parent.setScaleX(0.8);        parent.setScaleY(0.8);        parent.setScaleZ(0.8);        final PointLight pointLight = new PointLight(Color.ANTIQUEWHITE);        pointLight.setTranslateX(100);        pointLight.setTranslateY(100);        pointLight.setTranslateZ(-300);        final Group root = new Group(parent, pointLight, new Group(camera));        root.setDepthTest(DepthTest.ENABLE);        final SubScene subScene = new SubScene(root, 800, 800, true, SceneAntialiasing.BALANCED);        subScene.setCamera(camera);        subScene.setFill(Color.TRANSPARENT);        subScene.setId("SubScene");        return subScene;    } <strong>   final void setState(PickResult result) {        if (result.getIntersectedNode() == null) {            data.setText("Scene\n\n"                    + point3DToString(result.getIntersectedPoint()) + "\n"                    + point2DToString(result.getIntersectedTexCoord()) + "\n"                    + result.getIntersectedFace() + "\n"                    + String.format("%.1f", result.getIntersectedDistance()));        } else {            data.setText(result.getIntersectedNode().getId() + "\n"                    + getCullFace(result.getIntersectedNode()) + "\n"                    + point3DToString(result.getIntersectedPoint()) + "\n"                    + point2DToString(result.getIntersectedTexCoord()) + "\n"                    + result.getIntersectedFace() + "\n"                    + String.format("%.1f", result.getIntersectedDistance()));        }    }</strong>    private static String point3DToString(Point3D pt) {        if (pt == null) {            return "null";        }        return String.format("%.1f; %.1f; %.1f", pt.getX(), pt.getY(), pt.getZ());    }    private static String point2DToString(Point2D pt) {        if (pt == null) {            return "null";        }        return String.format("%.2f; %.2f", pt.getX(), pt.getY());    }    private static String getCullFace(Node n) {        if (n instanceof Shape3D) {            return "(CullFace." + ((Shape3D) n).getCullFace() + ")";        }        return "";    }}

 

运行显示如下：