Box2D墙 - 相同的代码：左边的工程，右边的不是
问题描述：
我正在制作一个简单的Box2D游戏（http://iwanttobeacircle.com），其中你以三角形开始并从较大的形状反弹以获得边。Box2D墙 - 相同的代码：左边的工程，右边的不是
我与我的墙壁有一个奇怪的错误...都是从同一个班级创建的，但左侧的工程和右侧没有。如果我只是添加正确的，那么它的工作原理，但出于某种原因，添加它们都似乎在某个地方引起问题。
的WallSegment类如下：
package com.carmstrong.iwanttobeacircle {
import flash.display.DisplayObjectContainer;
import flash.display.Sprite;
import flash.display.Shape;
import Box2D.Collision.Shapes.*;
import Box2D.Dynamics.*;
import Box2D.Common.Math.b2Vec2;
import com.carmstrong.iwanttobeacircle.Config;
public class WallSegment extends Actor {
private var _shape:Sprite;
private var _shapeBody:b2Body;
private var _colour:uint = 0x666666;
private var prevEdge:int;
private var thisEdge:int;
private var side:Number;
private var name:String;
private var _pathWidth:int;
private var _parent:DisplayObjectContainer;
public function WallSegment(Width:int, Position:String, Parent:DisplayObjectContainer) {
name = "Wall";
_pathWidth = Width;
_parent = Parent;
if(Position == "left") {
side = 1;
prevEdge = (Config.WIDTH - Config.PREV_WIDTH)/2;
thisEdge = (Config.WIDTH-_pathWidth)/2;
} else {
side = -1;
prevEdge = Config.WIDTH-(Config.WIDTH - Config.PREV_WIDTH)/2;
thisEdge = Config.WIDTH-(Config.WIDTH-_pathWidth)/2;
}// check if its left or right wall
//Create the costume
drawShape();
drawBody();
super(_shapeBody, _shape);
}//DynamicWall
private function drawShape():void {
//Draw visual
_shape = new Sprite();
var left:Sprite = new Sprite();
left.graphics.beginFill(_colour, 0.5);
left.graphics.moveTo(prevEdge, Config.HEIGHT/2);
left.graphics.lineTo(prevEdge-Config.WIDTH*side, Config.HEIGHT/2);
left.graphics.lineTo(thisEdge-Config.WIDTH*side, -Config.HEIGHT/2);
left.graphics.lineTo(thisEdge, -Config.HEIGHT/2);
left.graphics.endFill();
_shape.addChild(left);
_parent.addChild(_shape);
}//drawShape
private function drawBody():void {
//Create the shape definition
var shapeDef:b2PolygonDef = new b2PolygonDef();
shapeDef.vertexCount = 4;
b2Vec2(shapeDef.vertices[0]).Set(prevEdge/Config.RATIO, Config.HEIGHT/2/Config.RATIO);
b2Vec2(shapeDef.vertices[1]).Set((prevEdge-Config.WIDTH*side)/Config.RATIO, Config.HEIGHT/2/Config.RATIO);
b2Vec2(shapeDef.vertices[2]).Set((thisEdge-Config.WIDTH*side)/Config.RATIO, -Config.HEIGHT/2/Config.RATIO);
b2Vec2(shapeDef.vertices[3]).Set(thisEdge/Config.RATIO, -Config.HEIGHT/2/Config.RATIO);
shapeDef.density = 0;
shapeDef.friction = 10;
shapeDef.restitution = 0.45;
//Create the body definition (specify location here)
var shapeBodyDef:b2BodyDef = new b2BodyDef();
shapeBodyDef.position.Set(0, -Config.HEIGHT*(Config.CURRENT_SEGMENT+1)/Config.RATIO);
//Create the body
_shapeBody = Config.world.CreateBody(shapeBodyDef);
//Create the shape
_shapeBody.CreateShape(shapeDef);
}//drawBody
}//class
}//package
要保持水平动态，墙壁上绘制只需提前在主类，每次玩家的对象，使用下面的代码：
private function addWall(Width:int) {
Config.CURRENT_SEGMENT++;
//addWalls
var leftWall:WallSegment = new WallSegment(Width, "left",camera);
var rightWall:WallSegment = new WallSegment(Width, "right",camera);
Config.PREV_WIDTH = Width;
}//addWall
我得到这个错误：
TypeError: Error #1010: A term is undefined and has no properties. at com.carmstrong.iwanttobeacircle::GameContactListener/Add() at Box2D.Dynamics.Contacts::b2CircleContact/Evaluate() at Box2D.Dynamics.Contacts::b2Contact/Update() at Box2D.Dynamics::b2ContactManager/Collide() at Box2D.Dynamics::b2World/Step() at com.carmstrong.iwanttobeacircle::IWantToBeACircle/everyFrame()
它指的是GameContactListener类，如下图所示（添加功能在底部）：
package com.carmstrong.iwanttobeacircle {
import Box2D.Collision.b2ContactPoint;
import Box2D.Dynamics.b2ContactListener;
public class GameContactListener extends b2ContactListener {
public function GameContactListener() {
}//GameContactListener
override public function Add(point:b2ContactPoint):void {
if (point.shape1.GetBody().GetUserData() is ShapeActor && point.shape2.GetBody().GetUserData() is ShapeActor) {
//trace("Two shapes collided: Shape 1 has "+ point.shape1.GetBody().GetUserData().sides + " sides and Shape 2 has " + point.shape2.GetBody().GetUserData().sides + " sides");
if (point.shape1.GetBody().GetUserData().sides > point.shape2.GetBody().GetUserData().sides) {
//remove side from shape 1 and add side to shape 2
point.shape1.GetBody().GetUserData().sides--;
point.shape2.GetBody().GetUserData().sides++;
//point.shape2.GetBody().GetUserData().updateColour;
} else if (point.shape1.GetBody().GetUserData().sides < point.shape2.GetBody().GetUserData().sides) {
//remove side from shape 2 and add side to shape 1
point.shape1.GetBody().GetUserData().sides++;
point.shape2.GetBody().GetUserData().sides--;
//point.shape2.GetBody().GetUserData().updateColour;
}// add side to smaller shape and take away from larger shape
if(point.shape1.GetBody().GetUserData().name == "player" || point.shape2.GetBody().GetUserData().name == "player") {
if(point.shape1.GetBody().GetUserData().name == "player" && point.shape2.GetBody().GetUserData().sides <= point.shape1.GetBody().GetUserData().sides) {
Config.FULFILLMENT++;
Config.SOUNDS[3+Math.ceil(Math.random()*5)][1].play();
trace(Config.FULFILLMENT);
} else if (point.shape2.GetBody().GetUserData().name == "player" && point.shape1.GetBody().GetUserData().sides <= point.shape2.GetBody().GetUserData().sides) {
Config.FULFILLMENT++;
Config.SOUNDS[Math.ceil(Math.random()*5)][1].play();
trace(Config.FULFILLMENT);
} else {
Config.SOUNDS[Math.ceil(Math.random()*3)][1].play();
Config.FULFILLMENT = int(Config.FULFILLMENT - 5);
trace(Config.FULFILLMENT);
}//if other shape is less than or equal to player
}//if one of the shapes is player
}// if both collider objects are shapes
super.Add(point);
}// override Add
}//class
}//package
我会很感激任何想法或想法。此外，这是我第一次参加Box2D，因此希望了解如何使代码更高效的任何提示。
在此先感谢
答
你问两个问题在这里
- 为什么左，右侧壁碰撞检测不工作？
- 为什么GameContactListener/Add（）方法有错误？
看起来他们可能有相同的根本问题。我看到您将墙段添加为“相机”的子项（必须跟踪发生此添加的位置......您将“相机”的引用传递到对象的构造函数中。）
i.e. var leftWall:WallSegment = new WallSegment(Width, "left",camera);
在那里，您将leftWall添加为该对象的子项。但我不确定什么是“相机”......这是游戏世界对象的这一部分吗？
另外，你的trace.shape1和point.shape2的跟踪语句是什么？ 2个物体碰撞什么？
它可能有助于缩小Add（）方法中哪些数据为null - 有很多选项：point，point.shape1，point.shape1.GetBody（）等。 – 2010-01-14 22:32:48