public static void ClipCameraPos(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
        {
            if (!game.CameraClipping)
            {
                pickedPos.SetAsInvalid();
                pickedPos.IntersectPoint = origin + dir * reach;
                return;
            }
            tracer.SetRayData(origin, dir);
            World     map          = game.World;
            BlockInfo info         = game.BlockInfo;
            float     reachSquared = reach * reach;
            int       iterations   = 0;
            Vector3I  pOrigin      = Vector3I.Floor(origin);

            while (iterations < 10000)
            {
                int     x = tracer.X, y = tracer.Y, z = tracer.Z;
                byte    block = GetBlock(map, x, y, z, pOrigin);
                Vector3 min   = new Vector3(x, y, z) + info.MinBB[block];
                Vector3 max   = new Vector3(x, y, z) + info.MaxBB[block];
                if (info.IsLiquid[block])
                {
                    min.Y -= 1.5f / 16; max.Y -= 1.5f / 16;
                }

                float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
                float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
                float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));

                if (dx * dx + dy * dy + dz * dz > reachSquared)
                {
                    pickedPos.SetAsInvalid();
                    pickedPos.IntersectPoint = origin + dir * reach;
                    return;
                }

                if (info.Collide[block] == CollideType.Solid && !info.IsAir[block])
                {
                    float       t0, t1;
                    const float adjust = 0.1f;
                    if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
                    {
                        Vector3 intersect = origin + dir * t0;
                        pickedPos.SetAsValid(x, y, z, min, max, block, intersect);

                        switch (pickedPos.BlockFace)
                        {
                        case CpeBlockFace.XMin:
                            pickedPos.IntersectPoint.X -= adjust; break;

                        case CpeBlockFace.XMax:
                            pickedPos.IntersectPoint.X += adjust; break;

                        case CpeBlockFace.YMin:
                            pickedPos.IntersectPoint.Y -= adjust; break;

                        case CpeBlockFace.YMax:
                            pickedPos.IntersectPoint.Y += adjust; break;

                        case CpeBlockFace.ZMin:
                            pickedPos.IntersectPoint.Z -= adjust; break;

                        case CpeBlockFace.ZMax:
                            pickedPos.IntersectPoint.Z += adjust; break;
                        }
                        return;
                    }
                }
                tracer.Step();
                iterations++;
            }
            throw new InvalidOperationException("did over 10000 iterations in ClipCameraPos(). " +
                                                "Something has gone wrong. (dir: " + dir + ")");
        }
        public static void ClipCameraPos(Game game, Vector3 origin, Vector3 dir, float reach, PickedPos pickedPos)
        {
            if (!game.CameraClipping)
            {
                pickedPos.SetAsInvalid();
                pickedPos.IntersectPoint = origin + dir * reach;
                return;
            }
            Vector3I start = Vector3I.Floor(origin);
            int      x = start.X, y = start.Y, z = start.Z;
            Vector3I step, cellBoundary;
            Vector3  tMax, tDelta;

            CalcVectors(origin, dir, out step, out cellBoundary, out tMax, out tDelta);

            Map       map          = game.Map;
            BlockInfo info         = game.BlockInfo;
            float     reachSquared = reach * reach;
            int       iterations   = 0;

            while (iterations < 10000)
            {
                byte    block = GetBlock(map, x, y, z, origin);
                Vector3 min   = new Vector3(x, y, z) + info.MinBB[block];
                Vector3 max   = new Vector3(x, y, z) + info.MaxBB[block];

                float dx = Math.Min(Math.Abs(origin.X - min.X), Math.Abs(origin.X - max.X));
                float dy = Math.Min(Math.Abs(origin.Y - min.Y), Math.Abs(origin.Y - max.Y));
                float dz = Math.Min(Math.Abs(origin.Z - min.Z), Math.Abs(origin.Z - max.Z));

                if (dx * dx + dy * dy + dz * dz > reachSquared)
                {
                    pickedPos.SetAsInvalid();
                    pickedPos.IntersectPoint = origin + dir * reach;
                    return;
                }

                if (info.CollideType[block] == BlockCollideType.Solid && !info.IsAir[block])
                {
                    float       t0, t1;
                    const float adjust = 0.1f;
                    if (Intersection.RayIntersectsBox(origin, dir, min, max, out t0, out t1))
                    {
                        Vector3 intersect = origin + dir * t0;
                        pickedPos.SetAsValid(x, y, z, min, max, block, intersect);

                        switch (pickedPos.BlockFace)
                        {
                        case CpeBlockFace.XMin:
                            pickedPos.IntersectPoint.X -= adjust; break;

                        case CpeBlockFace.XMax:
                            pickedPos.IntersectPoint.X += adjust; break;

                        case CpeBlockFace.YMin:
                            pickedPos.IntersectPoint.Y -= adjust; break;

                        case CpeBlockFace.YMax:
                            pickedPos.IntersectPoint.Y += adjust; break;

                        case CpeBlockFace.ZMin:
                            pickedPos.IntersectPoint.Z -= adjust; break;

                        case CpeBlockFace.ZMax:
                            pickedPos.IntersectPoint.Z += adjust; break;
                        }
                        return;
                    }
                }
                Step(ref tMax, ref tDelta, ref step, ref x, ref y, ref z);
                iterations++;
            }
            throw new InvalidOperationException("did over 10000 iterations in ClipCameraPos(). " +
                                                "Something has gone wrong. (dir: " + dir + ")");
        }