因此,我开始使用 Physics Body Editor 作为 libgdx 的扩展。我还使用 Android Studio 编译代码,因此可以在真实设备上运行应用程序。但是,不幸的是,当我创建一个新的加载器时,如下所示:
BodyEditorLoader loader = new BodyEditorLoader(Gdx.files.internal("tnkA.json"));
logcat给我以下错误:
java.lang.NoSuchMethodError: No virtual method parse(Ljava/lang/String;)Ljava/lang/Object;
显然, 物理主体编辑器存在问题 。有没有什么办法解决这一问题?谢谢!
有完整的错误:
02-12 13:39:15.406 2372-2387/com.tynibattles04.game.android E/AndroidRuntime﹕ FATAL EXCEPTION: GLThread 172 Process: com.tynibattles04.game.android, PID: 2372 java.lang.NoSuchMethodError: No virtual method parse(Ljava/lang/String;)Ljava/lang/Object; in class Lcom/badlogic/gdx/utils/JsonReader; or its super classes (declaration of 'com.badlogic.gdx.utils.JsonReader' appears in /data/app/com.tynibattles04.game.android-1/base.apk) at aurelienribon.bodyeditor.BodyEditorLoader.readJson(BodyEditorLoader.java:179) at aurelienribon.bodyeditor.BodyEditorLoader.<init>(BodyEditorLoader.java:41) at com.tynibattles04.game.TinyBattles.createBottle(TinyBattles.java:127) at com.tynibattles04.game.TinyBattles.create(TinyBattles.java:74) at com.badlogic.gdx.backends.android.AndroidGraphics.onSurfaceChanged(AndroidGraphics.java:241) at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1511) at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1239)
看起来这也许可以帮助任何事情:
https://code.google.com/p/box2d-editor/issues/detail?id=25
https://gist.github.com/zudov/5566204
package aurelienribon.bodyeditor; import com.badlogic.gdx.files.FileHandle; import com.badlogic.gdx.math.Vector2; import com.badlogic.gdx.physics.box2d.Body; import com.badlogic.gdx.physics.box2d.CircleShape; import com.badlogic.gdx.physics.box2d.FixtureDef; import com.badlogic.gdx.physics.box2d.PolygonShape; import com.badlogic.gdx.utils.Array; import com.badlogic.gdx.utils.JsonReader; import com.badlogic.gdx.utils.JsonValue; import java.util.ArrayList; import java.util.HashMap; import java.util.List; import java.util.Map; /** * Loads the collision fixtures defined with the Physics Body Editor * application. You only need to give it a body and the corresponding fixture * name, and it will attach these fixtures to your body. * * @author Aurelien Ribon | http://www.aurelienribon.com */ public class BodyEditorLoader { // Model private final Model model; // Reusable stuff private final List<Vector2> vectorPool = new ArrayList<Vector2>(); private final PolygonShape polygonShape = new PolygonShape(); private final CircleShape circleShape = new CircleShape(); private final Vector2 vec = new Vector2(); // ------------------------------------------------------------------------- // Ctors // ------------------------------------------------------------------------- public BodyEditorLoader(FileHandle file) { if (file == null) throw new NullPointerException("file is null"); model = readJson(file.readString()); } public BodyEditorLoader(String str) { if (str == null) throw new NullPointerException("str is null"); model = readJson(str); } // ------------------------------------------------------------------------- // Public API // ------------------------------------------------------------------------- /** * Creates and applies the fixtures defined in the editor. The name * parameter is used to retrieve the right fixture from the loaded file. * <br/><br/> * * The body reference point (the red cross in the tool) is by default * located at the bottom left corner of the image. This reference point * will be put right over the BodyDef position point. Therefore, you should * place this reference point carefully to let you place your body in your * world easily with its BodyDef.position point. Note that to draw an image * at the position of your body, you will need to know this reference point * (see {@link #getOrigin(java.lang.String, float)}. * <br/><br/> * * Also, saved shapes are normalized. As shown in the tool, the width of * the image is considered to be always 1 meter. Thus, you need to provide * a scale factor so the polygons get resized according to your needs (not * every body is 1 meter large in your game, I guess). * * @param body The Box2d body you want to attach the fixture to. * @param name The name of the fixture you want to load. * @param fd The fixture parameters to apply to the created body fixture. * @param scale The desired scale of the body. The default width is 1. */ public void attachFixture(Body body, String name, FixtureDef fd, float scale) { RigidBodyModel rbModel = model.rigidBodies.get(name); if (rbModel == null) throw new RuntimeException("Name '" + name + "' was not found."); Vector2 origin = vec.set(rbModel.origin).mul(scale); for (int i=0, n=rbModel.polygons.size(); i<n; i++) { PolygonModel polygon = rbModel.polygons.get(i); Vector2[] vertices = polygon.buffer; for (int ii=0, nn=vertices.length; ii<nn; ii++) { vertices[ii] = newVec().set(polygon.vertices.get(ii)).mul(scale); vertices[ii].sub(origin); } polygonShape.set(vertices); fd.shape = polygonShape; body.createFixture(fd); for (int ii=0, nn=vertices.length; ii<nn; ii++) { free(vertices[ii]); } } for (int i=0, n=rbModel.circles.size(); i<n; i++) { CircleModel circle = rbModel.circles.get(i); Vector2 center = newVec().set(circle.center).mul(scale); float radius = circle.radius * scale; circleShape.setPosition(center); circleShape.setRadius(radius); fd.shape = circleShape; body.createFixture(fd); free(center); } } /** * Gets the image path attached to the given name. */ public String getImagePath(String name) { RigidBodyModel rbModel = model.rigidBodies.get(name); if (rbModel == null) throw new RuntimeException("Name '" + name + "' was not found."); return rbModel.imagePath; } /** * Gets the origin point attached to the given name. Since the point is * normalized in [0,1] coordinates, it needs to be scaled to your body * size. Warning: this method returns the same Vector2 object each time, so * copy it if you need it for later use. */ public Vector2 getOrigin(String name, float scale) { RigidBodyModel rbModel = model.rigidBodies.get(name); if (rbModel == null) throw new RuntimeException("Name '" + name + "' was not found."); return vec.set(rbModel.origin).scl(scale); } /** * <b>For advanced users only.</b> Lets you access the internal model of * this loader and modify it. Be aware that any modification is permanent * and that you should really know what you are doing. */ public Model getInternalModel() { return model; } // ------------------------------------------------------------------------- // Json Models // ------------------------------------------------------------------------- public static class Model { public final Map<String, RigidBodyModel> rigidBodies = new HashMap<String, RigidBodyModel>(); } public static class RigidBodyModel { public String name; public String imagePath; public final Vector2 origin = new Vector2(); public final List<PolygonModel> polygons = new ArrayList<PolygonModel>(); public final List<CircleModel> circles = new ArrayList<CircleModel>(); } public static class PolygonModel { public final List<Vector2> vertices = new ArrayList<Vector2>(); private Vector2[] buffer; // used to avoid allocation in attachFixture() } public static class CircleModel { public final Vector2 center = new Vector2(); public float radius; } // ------------------------------------------------------------------------- // Json reading process // ------------------------------------------------------------------------- private Model readJson(String str) { Model m = new Model(); JsonValue map = new JsonReader().parse(str); JsonValue bodyElem = map.getChild("rigidBodies"); for (; bodyElem != null; bodyElem = bodyElem.next()) { RigidBodyModel rbModel = readRigidBody(bodyElem); m.rigidBodies.put(rbModel.name, rbModel); } return m; } private RigidBodyModel readRigidBody(JsonValue bodyElem) { RigidBodyModel rbModel = new RigidBodyModel(); rbModel.name = bodyElem.getString("name"); rbModel.imagePath = bodyElem.getString("imagePath"); JsonValue originElem = bodyElem.get("origin"); rbModel.origin.x = originElem.getFloat("x"); rbModel.origin.y = originElem.getFloat("y"); // polygons JsonValue polygonsElem = bodyElem.getChild("polygons"); for (; polygonsElem != null ;polygonsElem = polygonsElem.next()){ PolygonModel polygon = new PolygonModel(); rbModel.polygons.add(polygon); JsonValue vertexElem = polygonsElem.child(); for (; vertexElem != null; vertexElem = vertexElem.next()) { float x = vertexElem.getFloat("x"); float y = vertexElem.getFloat("y"); polygon.vertices.add(new Vector2(x, y)); } polygon.buffer = new Vector2[polygon.vertices.size()]; } // circles JsonValue circleElem = bodyElem.getChild("circles"); for (; circleElem != null; circleElem = circleElem.next()) { CircleModel circle = new CircleModel(); rbModel.circles.add(circle); circle.center.x = circleElem.getFloat("cx"); circle.center.y = circleElem.getFloat("cy"); circle.radius = circleElem.getFloat("r"); } return rbModel; } // ------------------------------------------------------------------------- // Helpers // ------------------------------------------------------------------------- private Vector2 newVec() { return vectorPool.isEmpty() ? new Vector2() : vectorPool.remove(0); } private void free(Vector2 v) { vectorPool.add(v); } }
这段代码在GitHub上,但是由于用户帐户更改而被reporsitorio删除了,我将其张贴在这里,因此它们不依赖于帐户Git(代码也有所更改)。