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你能帮我吗。想要绘制一个多边形（不同角度的光束）并将二维盒子应用到它上面。你能告诉我如何创建一个多边形形状的 CCSprite 任何例子都会帮助干杯

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  1. 创建多边形主体。

    -(void) createDynamicPoly {  
    b2BodyDef bodyDefPoly;    
    bodyDefPoly.type = b2_dynamicBody;
    bodyDefPoly.position.Set(3.0f, 10.0f);
    b2Body *polyBody = world->CreateBody(&bodyDefPoly);
    int count = 8;
    b2Vec2 vertices[8];
    vertices[0].Set(0.0f / PTM_RATIO,0.0f / PTM_RATIO);
    vertices[1].Set(48.0f/PTM_RATIO,0.0f/PTM_RATIO);
    vertices[2].Set(48.0f/PTM_RATIO,30.0f/PTM_RATIO);
    vertices[3].Set(42.0f/PTM_RATIO,30.0f/PTM_RATIO);
    vertices[4].Set(30.0f/PTM_RATIO,18.0f/PTM_RATIO);
    vertices[5].Set(18.0f/PTM_RATIO,12.0f/PTM_RATIO);
    vertices[6].Set(6.0f/PTM_RATIO,18.0f/PTM_RATIO);
    vertices[7].Set(0.0f/PTM_RATIO,30.0f/PTM_RATIO);
    b2PolygonShape polygon;
    polygon.Set(vertices, count);
    b2FixtureDef fixtureDefPoly;
    fixtureDefPoly.shape = &polygon;
    fixtureDefPoly.density = 1.0f;
    fixtureDefPoly.friction = 0.3f;
    polyBody->CreateFixture(&fixtureDefPoly);    
}

  2. 创建你的精灵

  3. 通过 Fixture 和 UserData 将您的精灵附加到多边形主体

    fixtureDefPoly.SetUserData() = spriteObject;  
b2Fixture *fixture;  
fixture = circleBody->CreateFixture(&fixtureDefPoly);  
fixture->SetUserData(@"spriteObject");

  4. 然后在您的更新方法中将精灵迭代到主体。

于 2011-03-23T12:44:53.100 回答
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最简单的方法是打开图像编辑器（例如绘画或 photoshop）并创建所需的图像。在你的程序中使用它。

使用 cocos2d box2d 模板创建 xcode 应用程序时还有一个 helloWorld 场景。它创建了一组带有纹理的正方形。

于 2011-03-19T08:19:52.097 回答
0 
    CGPoint startPt = edge.start ;
    CGPoint endpt = edge.end ;

    //length of the stick body
    float len = abs(ccpDistance(startPt, endpt))/PTM_RATIO;

    //to calculate the angle and position of the body.
    float dx = endpt.x-startPt.x;
    float dy = endpt.y-startPt.y;

    //position of the body
    float xPos = startPt.x+dx/2.0f;
    float yPos = startPt.y+dy/2.0f;

    //width of the body.
    float width = 1.0f/PTM_RATIO;

    b2BodyDef bodyDef;
    bodyDef.position.Set(xPos/PTM_RATIO, yPos/PTM_RATIO);
    bodyDef.angle = atan(dy/dx);
    NSLog([NSString stringWithFormat:@"Setting angle %f",bodyDef.angle]);
    CCSprite *sp = [CCSprite spriteWithFile:@"material-wood.png" rect:CGRectMake(0, 0, 12, 12)];

    //TODO: fix shape
    [self addChild:sp z:1 ];

    bodyDef.userData = sp;
    bodyDef.type = b2_dynamicBody;

    b2Body* body = world->CreateBody(&bodyDef);

    b2PolygonShape shape;
    b2Vec2 rectangle1_vertices[4];
    rectangle1_vertices[0].Set(-len/2, -width/2);
    rectangle1_vertices[1].Set(len/2, -width/2);
    rectangle1_vertices[2].Set(len/2, width/2);
    rectangle1_vertices[3].Set(-len/2, width/2);
    shape.Set(rectangle1_vertices, 4);

    b2FixtureDef fd;
    fd.shape = &shape;
    fd.density = 1.0f;
    fd.friction = 0.300000f;
    fd.restitution = 0.600000f;
    body->CreateFixture(&fd);
于 2011-03-23T18:53:56.343 回答