/**
         *  @brief Create the internal shape used to represent a TSBoxCollider.
         **/
        public override Physics2D.Shape[] CreateShapes()
        {
            if (m_Points == null || m_Points.Length == 0)
            {
                return(null);
            }

            Physics2D.Vertices v = new Physics2D.Vertices();
            for (int index = 0, length = m_Points.Length; index < length; index++)
            {
                v.Add(m_Points[index]);
            }

            List <Physics2D.Vertices> convexShapeVs = Physics2D.BayazitDecomposer.ConvexPartition(v);

            Physics2D.Shape[] result = new Physics2D.Shape[convexShapeVs.Count];
            for (int index = 0, length = result.Length; index < length; index++)
            {
                result[index] = new Physics2D.PolygonShape(convexShapeVs[index], 1);
            }

            return(result);
        }
Пример #2
0
        /// <summary>
        /// Activate the explosion at the specified position.
        /// </summary>
        /// <param name="pos">The position where the explosion happens </param>
        /// <param name="radius">The explosion radius </param>
        /// <param name="maxForce">The explosion force at the explosion point (then is inversely proportional to the square of the distance)</param>
        /// <returns>A list of bodies and the amount of force that was applied to them.</returns>
        public Dictionary <Fixture, TSVector2> Activate(TSVector2 pos, FP radius, FP maxForce)
        {
            AABB aabb;

            aabb.LowerBound = pos + new TSVector2(-radius, -radius);
            aabb.UpperBound = pos + new TSVector2(radius, radius);
            Fixture[] shapes = new Fixture[MaxShapes];

            // More than 5 shapes in an explosion could be possible, but still strange.
            Fixture[] containedShapes = new Fixture[5];
            bool      exit            = false;

            int shapeCount          = 0;
            int containedShapeCount = 0;

            // Query the world for overlapping shapes.
            World.QueryAABB(
                fixture =>
            {
                if (fixture.TestPoint(ref pos))
                {
                    if (IgnoreWhenInsideShape)
                    {
                        exit = true;
                        return(false);
                    }

                    containedShapes[containedShapeCount++] = fixture;
                }
                else
                {
                    shapes[shapeCount++] = fixture;
                }

                // Continue the query.
                return(true);
            }, ref aabb);

            if (exit)
            {
                return(new Dictionary <Fixture, TSVector2>());
            }

            Dictionary <Fixture, TSVector2> exploded = new Dictionary <Fixture, TSVector2>(shapeCount + containedShapeCount);

            // Per shape max/min angles for now.
            FP[] vals     = new FP[shapeCount * 2];
            int  valIndex = 0;

            for (int i = 0; i < shapeCount; ++i)
            {
                PolygonShape ps;
                CircleShape  cs = shapes[i].Shape as CircleShape;
                if (cs != null)
                {
                    // We create a "diamond" approximation of the circle
                    Vertices  v   = new Vertices();
                    TSVector2 vec = TSVector2.zero + new TSVector2(cs.Radius, 0);
                    v.Add(vec);
                    vec = TSVector2.zero + new TSVector2(0, cs.Radius);
                    v.Add(vec);
                    vec = TSVector2.zero + new TSVector2(-cs.Radius, cs.Radius);
                    v.Add(vec);
                    vec = TSVector2.zero + new TSVector2(0, -cs.Radius);
                    v.Add(vec);
                    ps = new PolygonShape(v, 0);
                }
                else
                {
                    ps = shapes[i].Shape as PolygonShape;
                }

                if ((shapes[i].Body.BodyType == BodyType.Dynamic) && ps != null)
                {
                    TSVector2 toCentroid      = shapes[i].Body.GetWorldPoint(ps.MassData.Centroid) - pos;
                    FP        angleToCentroid = FP.Atan2(toCentroid.y, toCentroid.x);
                    FP        min             = FP.MaxValue;
                    FP        max             = FP.MinValue;
                    FP        minAbsolute     = 0.0f;
                    FP        maxAbsolute     = 0.0f;

                    for (int j = 0; j < ps.Vertices.Count; ++j)
                    {
                        TSVector2 toVertex = (shapes[i].Body.GetWorldPoint(ps.Vertices[j]) - pos);
                        FP        newAngle = FP.Atan2(toVertex.y, toVertex.x);
                        FP        diff     = (newAngle - angleToCentroid);

                        diff = (diff - FP.Pi) % (2 * FP.Pi);
                        // the minus pi is important. It means cutoff for going other direction is at 180 deg where it needs to be

                        if (diff < 0.0f)
                        {
                            diff += 2 * FP.Pi; // correction for not handling negs
                        }
                        diff -= FP.Pi;

                        if (FP.Abs(diff) > FP.Pi)
                        {
                            continue; // Something's wrong, point not in shape but exists angle diff > 180
                        }
                        if (diff > max)
                        {
                            max         = diff;
                            maxAbsolute = newAngle;
                        }
                        if (diff < min)
                        {
                            min         = diff;
                            minAbsolute = newAngle;
                        }
                    }

                    vals[valIndex] = minAbsolute;
                    ++valIndex;
                    vals[valIndex] = maxAbsolute;
                    ++valIndex;
                }
            }

            Array.Sort(vals, 0, valIndex, _rdc);
            _data.Clear();
            bool rayMissed = true;

            for (int i = 0; i < valIndex; ++i)
            {
                Fixture fixture = null;
                FP      midpt;

                int iplus = (i == valIndex - 1 ? 0 : i + 1);
                if (vals[i] == vals[iplus])
                {
                    continue;
                }

                if (i == valIndex - 1)
                {
                    // the single edgecase
                    midpt = (vals[0] + FP.PiTimes2 + vals[i]);
                }
                else
                {
                    midpt = (vals[i + 1] + vals[i]);
                }

                midpt = midpt / 2;

                TSVector2 p1 = pos;
                TSVector2 p2 = radius * new TSVector2(FP.Cos(midpt), FP.Sin(midpt)) + pos;

                // RaycastOne
                bool hitClosest = false;
                World.RayCast((f, p, n, fr) =>
                {
                    Body body = f.Body;

                    if (!IsActiveOn(body))
                    {
                        return(0);
                    }

                    hitClosest = true;
                    fixture    = f;
                    return(fr);
                }, p1, p2);

                //draws radius points
                if ((hitClosest) && (fixture.Body.BodyType == BodyType.Dynamic))
                {
                    if ((_data.Any()) && (_data.Last().Body == fixture.Body) && (!rayMissed))
                    {
                        int       laPos = _data.Count - 1;
                        ShapeData la    = _data[laPos];
                        la.Max       = vals[iplus];
                        _data[laPos] = la;
                    }
                    else
                    {
                        // make new
                        ShapeData d;
                        d.Body = fixture.Body;
                        d.Min  = vals[i];
                        d.Max  = vals[iplus];
                        _data.Add(d);
                    }

                    if ((_data.Count > 1) &&
                        (i == valIndex - 1) &&
                        (_data.Last().Body == _data.First().Body) &&
                        (_data.Last().Max == _data.First().Min))
                    {
                        ShapeData fi = _data[0];
                        fi.Min = _data.Last().Min;
                        _data.RemoveAt(_data.Count - 1);
                        _data[0] = fi;
                        while (_data.First().Min >= _data.First().Max)
                        {
                            fi.Min  -= FP.PiTimes2;
                            _data[0] = fi;
                        }
                    }

                    int       lastPos = _data.Count - 1;
                    ShapeData last    = _data[lastPos];
                    while ((_data.Count > 0) &&
                           (_data.Last().Min >= _data.Last().Max))    // just making sure min<max
                    {
                        last.Min       = _data.Last().Min - FP.PiTimes2;
                        _data[lastPos] = last;
                    }
                    rayMissed = false;
                }
                else
                {
                    rayMissed = true; // raycast did not find a shape
                }
            }

            for (int i = 0; i < _data.Count; ++i)
            {
                if (!IsActiveOn(_data[i].Body))
                {
                    continue;
                }

                FP arclen = _data[i].Max - _data[i].Min;

                FP  first        = TSMath.Min(MaxEdgeOffset, EdgeRatio * arclen);
                int insertedRays = FP.Ceiling((((arclen - 2.0f * first) - (MinRays - 1) * MaxAngle) / MaxAngle)).AsInt();

                if (insertedRays < 0)
                {
                    insertedRays = 0;
                }

                FP offset = (arclen - first * 2.0f) / ((FP)MinRays + insertedRays - 1);

                //Note: This loop can go into infinite as it operates on FPs.
                //Added FPEquals with a large epsilon.
                for (FP j = _data[i].Min + first;
                     j < _data[i].Max || MathUtils.FPEquals(j, _data[i].Max, 0.0001f);
                     j += offset)
                {
                    TSVector2 p1        = pos;
                    TSVector2 p2        = pos + radius * new TSVector2(FP.Cos(j), FP.Sin(j));
                    TSVector2 hitpoint  = TSVector2.zero;
                    FP        minlambda = FP.MaxValue;

                    List <Fixture> fl = _data[i].Body.FixtureList;
                    for (int x = 0; x < fl.Count; x++)
                    {
                        Fixture      f = fl[x];
                        RayCastInput ri;
                        ri.Point1      = p1;
                        ri.Point2      = p2;
                        ri.MaxFraction = 50f;

                        RayCastOutput ro;
                        if (f.RayCast(out ro, ref ri, 0))
                        {
                            if (minlambda > ro.Fraction)
                            {
                                minlambda = ro.Fraction;
                                hitpoint  = ro.Fraction * p2 + (1 - ro.Fraction) * p1;
                            }
                        }

                        // the force that is to be applied for this particular ray.
                        // offset is angular coverage. lambda*length of segment is distance.
                        FP impulse = (arclen / (MinRays + insertedRays)) * maxForce * 180.0f / FP.Pi * (1.0f - TrueSync.TSMath.Min(FP.One, minlambda));

                        // We Apply the impulse!!!
                        TSVector2 vectImp = TSVector2.Dot(impulse * new TSVector2(FP.Cos(j), FP.Sin(j)), -ro.Normal) * new TSVector2(FP.Cos(j), FP.Sin(j));
                        _data[i].Body.ApplyLinearImpulse(ref vectImp, ref hitpoint);

                        // We gather the fixtures for returning them
                        if (exploded.ContainsKey(f))
                        {
                            exploded[f] += vectImp;
                        }
                        else
                        {
                            exploded.Add(f, vectImp);
                        }

                        if (minlambda > 1.0f)
                        {
                            hitpoint = p2;
                        }
                    }
                }
            }

            // We check contained shapes
            for (int i = 0; i < containedShapeCount; ++i)
            {
                Fixture fix = containedShapes[i];

                if (!IsActiveOn(fix.Body))
                {
                    continue;
                }

                FP        impulse = MinRays * maxForce * 180.0f / FP.Pi;
                TSVector2 hitPoint;

                CircleShape circShape = fix.Shape as CircleShape;
                if (circShape != null)
                {
                    hitPoint = fix.Body.GetWorldPoint(circShape.Position);
                }
                else
                {
                    PolygonShape shape = fix.Shape as PolygonShape;
                    hitPoint = fix.Body.GetWorldPoint(shape.MassData.Centroid);
                }

                TSVector2 vectImp = impulse * (hitPoint - pos);

                fix.Body.ApplyLinearImpulse(ref vectImp, ref hitPoint);

                if (!exploded.ContainsKey(fix))
                {
                    exploded.Add(fix, vectImp);
                }
            }

            return(exploded);
        }