Exemple #1
0
        public bool Intersects(Box2d box)
        {
            // there are eight possible separating axis between two
              // boxes:
              // four from the first box,
              // four from the second box.
              // foreach such axis, we create a "ray" outgoing from the
              // corresponding edge, in the normal direction.
              // projecting the other boxes four corners onto that ray,
              // and finding out that all projections are positive,
              // means we have found a separating axis and can return
              // 'false', no intersection.

              // helpers:
              //  project points on rays
              //  creating rays from box
              //
              // what is a ray in our case? it is simply a start point,
              // and a direction vector. vector2 times two will be nice for this.

              // to compute the starting points of rays for one box, we
              // need to rotate around the anchor point and use the range information
              // available. ortho simply!
              // to compute the direction of the rays, is just a rotation of
              // either v(1,0) or v(0,1) vector
              bool one = SeparatingAxis(this, box);
              bool two = SeparatingAxis(box, this);
              bool foundSepAxis = one || two;
              return !foundSepAxis;
        }
Exemple #2
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 static bool SeparatingAxis(Box2d b1, Box2d b2)
 {
     // If i can find a projection minima that is positive,
       // I've found a separating axis.
       for (int i = 0; i < 4; i++)
       {
     Vector2 rayStart, rayDir;
     b1.GetRay(i, out rayStart, out rayDir);
     double projectionMin = 1;
     for (int j = 0; j < 4; j++)
     {
       Vector2 corner;
       b2.GetCorner(j, out corner);
       double projection = Project(rayStart, rayDir, corner);
       if (projection <= projectionMin)
     projectionMin = projection;
     }
     if (projectionMin > 0)
       return true;
       }
       return false;
 }
Exemple #3
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 public TopBox(Box2d box)
 {
     this.box = box;
 }
Exemple #4
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 public SideBox(Box2d box, double planeOffset)
 {
     this.box = box;
     this.planeOffset = planeOffset;
 }
Exemple #5
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 public BottomBox(Box2d box)
 {
     this.box = box;
 }
Exemple #6
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        void RenderBox(IRenderer renderer, Box2d box)
        {
            renderer.PushMatrix();

              renderer.Translate(Logic2World(box.X, box.Y));
              renderer.Rotate(-Vector3.UnitY, box.Rotation);

              float amin = (float)box.Amin;
              float amax = (float)box.Amax;
              float bmin = (float)box.Bmin;
              float bmax = (float)box.Bmax;

              renderer.DrawLine(new Vector3(amin, 0, bmin), new Vector3(amin, 0, bmax));
              renderer.DrawLine(new Vector3(amax, 0, bmin), new Vector3(amax, 0, bmax));
              renderer.DrawLine(new Vector3(amin, 0, bmin), new Vector3(amax, 0, bmin));
              renderer.DrawLine(new Vector3(amin, 0, bmax), new Vector3(amax, 0, bmax));

              renderer.PopMatrix();
        }