A convex polygon shape. Polygons have a maximum number of vertices equal to _maxPolygonVertices. In most cases you should not need many vertices for a convex polygon.
Inheritance: Shape
Example #1
0
        static void Main(string[] args)
        {
            // Static Body
            Vec2 gravity = new Vec2(0, -10);
            bool doSleep = true;
            World world = new World(gravity);
            world.SleepingAllowed = doSleep;
            BodyDef groundBodyDef = new BodyDef();
            groundBodyDef.position.set_Renamed(0, -10);
            Body groundBody = world.createBody(groundBodyDef);
            PolygonShape groundBox = new PolygonShape();
            groundBox.setAsBox(50, 10);
            groundBody.createFixture(groundBox, 0);

            // Dynamic Body
            BodyDef bodyDef = new BodyDef();
            bodyDef.type = BodyType.DYNAMIC;
            bodyDef.position.set_Renamed(0, 4);
            Body body = world.createBody(bodyDef);
            PolygonShape dynamicBox = new PolygonShape();
            dynamicBox.setAsBox(1, 1);
            FixtureDef fixtureDef = new FixtureDef();
            fixtureDef.shape = dynamicBox;
            fixtureDef.density = 1;
            fixtureDef.friction = 0.3f;
            body.createFixture(fixtureDef);

            // Setup world
            float timeStep = 1.0f / 60.0f;
            int velocityIterations = 6;
            int positionIterations = 2;

            // Run loop
            for (int i = 0; i < 60; ++i)
            {
                world.step(timeStep, velocityIterations, positionIterations);
                Vec2 position = body.Position;
                float angle = body.Angle;
                Console.WriteLine("{0:0.00} {1:0.00} {2:0.00}", position.x, position.y, angle);
            }
        }
Example #2
0
        /// <summary>
        /// Find the max separation between poly1 and poly2 using edge normals from poly1.
        /// </summary>
        /// <param name="edgeIndex"></param>
        /// <param name="poly1"></param>
        /// <param name="xf1"></param>
        /// <param name="poly2"></param>
        /// <param name="xf2"></param>
        /// <returns></returns>
        public void findMaxSeparation(EdgeResults results, PolygonShape poly1, Transform xf1, PolygonShape poly2, Transform xf2)
        {
            int count1 = poly1.m_count;
            Vec2[] normals1 = poly1.m_normals;
            //Vec2 v = poly2.m_centroid;

            // Vector pointing from the centroid of poly1 to the centroid of poly2.
            // before inline:
            Transform.mulToOutUnsafe(xf2, poly2.m_centroid, d);
            Transform.mulToOutUnsafe(xf1, poly1.m_centroid, temp);
            d.subLocal(temp);

            Rot.mulTransUnsafe(xf1.q, d, dLocal1);
            float dLocal1x = dLocal1.x;
            float dLocal1y = dLocal1.y;
            // after inline:
            // final float predy = xf2.p.y + xf2.q.ex.y * v.x + xf2.q.ey.y * v.y;
            // final float predx = xf2.p.x + xf2.q.ex.x * v.x + xf2.q.ey.x * v.y;
            // final Vec2 v1 = poly1.m_centroid;
            // final float tempy = xf1.p.y + xf1.q.ex.y * v1.x + xf1.q.ey.y * v1.y;
            // final float tempx = xf1.p.x + xf1.q.ex.x * v1.x + xf1.q.ey.x * v1.y;
            // final float dx = predx - tempx;
            // final float dy = predy - tempy;
            //
            // final Mat22 R = xf1.q;
            // final float dLocal1x = dx * R.ex.x + dy * R.ex.y;
            // final float dLocal1y = dx * R.ey.x + dy * R.ey.y;
            // end inline

            // Find edge normal on poly1 that has the largest projection onto d.
            int edge = 0;
            float dot;
            //UPGRADE_TODO: The equivalent in .NET for field 'java.lang.Float.MIN_VALUE' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
            float maxDot = Single.Epsilon;
            for (int i = 0; i < count1; i++)
            {
                Vec2 normal = normals1[i];
                dot = normal.x * dLocal1x + normal.y * dLocal1y;
                if (dot > maxDot)
                {
                    maxDot = dot;
                    edge = i;
                }
            }

            // Get the separation for the edge normal.
            float s = edgeSeparation(poly1, xf1, edge, poly2, xf2);

            // Check the separation for the previous edge normal.
            int prevEdge = edge - 1 >= 0 ? edge - 1 : count1 - 1;
            float sPrev = edgeSeparation(poly1, xf1, prevEdge, poly2, xf2);

            // Check the separation for the next edge normal.
            int nextEdge = edge + 1 < count1 ? edge + 1 : 0;
            float sNext = edgeSeparation(poly1, xf1, nextEdge, poly2, xf2);

            // Find the best edge and the search direction.
            int bestEdge;
            float bestSeparation;
            int increment;
            if (sPrev > s && sPrev > sNext)
            {
                increment = -1;
                bestEdge = prevEdge;
                bestSeparation = sPrev;
            }
            else if (sNext > s)
            {
                increment = 1;
                bestEdge = nextEdge;
                bestSeparation = sNext;
            }
            else
            {
                results.edgeIndex = edge;
                results.separation = s;
                return;
            }

            // Perform a local search for the best edge normal.
            for (; ; )
            {
                if (increment == -1)
                {
                    edge = bestEdge - 1 >= 0 ? bestEdge - 1 : count1 - 1;
                }
                else
                {
                    edge = bestEdge + 1 < count1 ? bestEdge + 1 : 0;
                }

                s = edgeSeparation(poly1, xf1, edge, poly2, xf2);

                if (s > bestSeparation)
                {
                    bestEdge = edge;
                    bestSeparation = s;
                }
                else
                {
                    break;
                }
            }

            results.edgeIndex = bestEdge;
            results.separation = bestSeparation;
        }
Example #3
0
        // djm pooling from above
        public void findIncidentEdge(ClipVertex[] c, PolygonShape poly1, Transform xf1, int edge1, PolygonShape poly2, Transform xf2)
        {
            int count1 = poly1.m_count;
            Vec2[] normals1 = poly1.m_normals;

            int count2 = poly2.m_count;
            Vec2[] vertices2 = poly2.m_vertices;
            Vec2[] normals2 = poly2.m_normals;

            Debug.Assert(0 <= edge1 && edge1 < count1);

            // Get the normal of the reference edge in poly2's frame.
            Rot.mulToOutUnsafe(xf1.q, normals1[edge1], normal1); // temporary
            // Vec2 normal1 = MulT(xf2.R, Mul(xf1.R, normals1[edge1]));
            Rot.mulTrans(xf2.q, normal1, normal1);

            // Find the incident edge on poly2.
            int index = 0;
            float minDot = Single.MaxValue;
            for (int i = 0; i < count2; ++i)
            {
                float dot = Vec2.dot(normal1, normals2[i]);
                if (dot < minDot)
                {
                    minDot = dot;
                    index = i;
                }
            }

            // Build the clip vertices for the incident edge.
            int i1 = index;
            int i2 = i1 + 1 < count2 ? i1 + 1 : 0;

            Transform.mulToOutUnsafe(xf2, vertices2[i1], c[0].v); // = Mul(xf2, vertices2[i1]);
            c[0].id.indexA = (sbyte)edge1;
            c[0].id.indexB = (sbyte)i1;
            c[0].id.typeA = (sbyte)ContactID.Type.FACE;
            c[0].id.typeB = (sbyte)ContactID.Type.VERTEX;

            Transform.mulToOutUnsafe(xf2, vertices2[i2], c[1].v); // = Mul(xf2, vertices2[i2]);
            c[1].id.indexA = (sbyte)edge1;
            c[1].id.indexB = (sbyte)i2;
            c[1].id.typeA = (sbyte)ContactID.Type.FACE;
            c[1].id.typeB = (sbyte)ContactID.Type.VERTEX;
        }
Example #4
0
        /// <summary> Find the separation between poly1 and poly2 for a given edge normal on poly1.
        /// 
        /// </summary>
        /// <param name="poly1">
        /// </param>
        /// <param name="xf1">
        /// </param>
        /// <param name="edge1">
        /// </param>
        /// <param name="poly2">
        /// </param>
        /// <param name="xf2">
        /// </param>
        public float edgeSeparation(PolygonShape poly1, Transform xf1, int edge1, PolygonShape poly2, Transform xf2)
        {
            int count1 = poly1.m_count;
            Vec2[] vertices1 = poly1.m_vertices;
            Vec2[] normals1 = poly1.m_normals;

            int count2 = poly2.m_count;
            Vec2[] vertices2 = poly2.m_vertices;

            Debug.Assert(0 <= edge1 && edge1 < count1);
            // Convert normal from poly1's frame into poly2's frame.
            // before inline:
            // Vec2 normal1World = Mul(xf1.R, normals1[edge1]);
            Rot.mulToOutUnsafe(xf1.q, normals1[edge1], normal1World);
            // Vec2 normal1 = MulT(xf2.R, normal1World);
            Rot.mulTransUnsafe(xf2.q, normal1World, normal1);
            float normal1x = normal1.x;
            float normal1y = normal1.y;
            float normal1Worldx = normal1World.x;
            float normal1Worldy = normal1World.y;
            // after inline:
            // R.mulToOut(v,out);
            // final Mat22 R = xf1.q;
            // final Vec2 v = normals1[edge1];
            // final float normal1Worldy = R.ex.y * v.x + R.ey.y * v.y;
            // final float normal1Worldx = R.ex.x * v.x + R.ey.x * v.y;
            // final Mat22 R1 = xf2.q;
            // final float normal1x = normal1Worldx * R1.ex.x + normal1Worldy * R1.ex.y;
            // final float normal1y = normal1Worldx * R1.ey.x + normal1Worldy * R1.ey.y;
            // end inline

            // Find support vertex on poly2 for -normal.
            int index = 0;
            float minDot = Single.MaxValue;

            for (int i = 0; i < count2; ++i)
            {
                Vec2 a = vertices2[i];
                float dot = a.x * normal1x + a.y * normal1y;
                if (dot < minDot)
                {
                    minDot = dot;
                    index = i;
                }
            }

            // Vec2 v1 = Mul(xf1, vertices1[edge1]);
            // Vec2 v2 = Mul(xf2, vertices2[index]);
            // before inline:
            Transform.mulToOut(xf1, vertices1[edge1], v1);
            Transform.mulToOut(xf2, vertices2[index], v2);

            float separation = Vec2.dot(v2.subLocal(v1), normal1World);
            return separation;

            // after inline:
            // final Vec2 v3 = vertices1[edge1];
            // final float v1y = xf1.p.y + R.ex.y * v3.x + R.ey.y * v3.y;
            // final float v1x = xf1.p.x + R.ex.x * v3.x + R.ey.x * v3.y;
            // final Vec2 v4 = vertices2[index];
            // final float v2y = xf2.p.y + R1.ex.y * v4.x + R1.ey.y * v4.y - v1y;
            // final float v2x = xf2.p.x + R1.ex.x * v4.x + R1.ey.x * v4.y - v1x;
            //
            // return v2x * normal1Worldx + v2y * normal1Worldy;
            // end inline
        }
Example #5
0
        /// <summary>
        /// Compute the collision manifold between two polygons.
        /// </summary>
        /// <param name="manifold"></param>
        /// <param name="polygon1"></param>
        /// <param name="xf1"></param>
        /// <param name="polygon2"></param>
        /// <param name="xf2"></param>
        public void collidePolygons(Manifold manifold, PolygonShape polyA, Transform xfA, PolygonShape polyB, Transform xfB)
        {
            // Find edge normal of max separation on A - return if separating axis is found
            // Find edge normal of max separation on B - return if separation axis is found
            // Choose reference edge as min(minA, minB)
            // Find incident edge
            // Clip

            // The normal points from 1 to 2

            manifold.pointCount = 0;
            float totalRadius = polyA.m_radius + polyB.m_radius;

            findMaxSeparation(results1, polyA, xfA, polyB, xfB);
            if (results1.separation > totalRadius)
            {
                return;
            }

            findMaxSeparation(results2, polyB, xfB, polyA, xfA);
            if (results2.separation > totalRadius)
            {
                return;
            }

            PolygonShape poly1; // reference polygon
            PolygonShape poly2; // incident polygon
            Transform xf1, xf2;
            int edge1; // reference edge
            bool flip;
            float k_relativeTol = 0.98f;
            float k_absoluteTol = 0.001f;

            if (results2.separation > k_relativeTol * results1.separation + k_absoluteTol)
            {
                poly1 = polyB;
                poly2 = polyA;
                xf1 = xfB;
                xf2 = xfA;
                edge1 = results2.edgeIndex;
                manifold.type = Manifold.ManifoldType.FACE_B;
                flip = true;
            }
            else
            {
                poly1 = polyA;
                poly2 = polyB;
                xf1 = xfA;
                xf2 = xfB;
                edge1 = results1.edgeIndex;
                manifold.type = Manifold.ManifoldType.FACE_A;
                flip = false;
            }

            findIncidentEdge(incidentEdge, poly1, xf1, edge1, poly2, xf2);

            int count1 = poly1.m_count;
            Vec2[] vertices1 = poly1.m_vertices;

            int iv1 = edge1;
            int iv2 = edge1 + 1 < count1 ? edge1 + 1 : 0;
            v11.set_Renamed(vertices1[iv1]);
            v12.set_Renamed(vertices1[iv2]);
            localTangent.set_Renamed(v12).subLocal(v11);
            localTangent.normalize();

            Vec2.crossToOutUnsafe(localTangent, 1f, localNormal); // Vec2 localNormal = Vec2.cross(dv,
            // 1.0f);

            planePoint.set_Renamed(v11).addLocal(v12).mulLocal(.5f); // Vec2 planePoint = 0.5f * (v11
            // + v12);

            Rot.mulToOutUnsafe(xf1.q, localTangent, tangent); // Vec2 sideNormal = Mul(xf1.R, v12
            // - v11);
            Vec2.crossToOutUnsafe(tangent, 1f, normal); // Vec2 frontNormal = Vec2.cross(sideNormal,
            // 1.0f);

            Transform.mulToOut(xf1, v11, v11);
            Transform.mulToOut(xf1, v12, v12);
            // v11 = Mul(xf1, v11);
            // v12 = Mul(xf1, v12);

            // Face offset
            float frontOffset = Vec2.dot(normal, v11);

            // Side offsets, extended by polytope skin thickness.
            float sideOffset1 = -Vec2.dot(tangent, v11) + totalRadius;
            float sideOffset2 = Vec2.dot(tangent, v12) + totalRadius;

            // Clip incident edge against extruded edge1 side edges.
            // ClipVertex clipPoints1[2];
            // ClipVertex clipPoints2[2];
            int np;

            // Clip to box side 1
            // np = ClipSegmentToLine(clipPoints1, incidentEdge, -sideNormal, sideOffset1);
            tangent.negateLocal();
            np = clipSegmentToLine(clipPoints1, incidentEdge, tangent, sideOffset1, iv1);
            tangent.negateLocal();

            if (np < 2)
            {
                return;
            }

            // Clip to negative box side 1
            np = clipSegmentToLine(clipPoints2, clipPoints1, tangent, sideOffset2, iv2);

            if (np < 2)
            {
                return;
            }

            // Now clipPoints2 contains the clipped points.
            manifold.localNormal.set_Renamed(localNormal);
            manifold.localPoint.set_Renamed(planePoint);

            int pointCount = 0;
            for (int i = 0; i < Settings.maxManifoldPoints; ++i)
            {
                float separation = Vec2.dot(normal, clipPoints2[i].v) - frontOffset;

                if (separation <= totalRadius)
                {
                    ManifoldPoint cp = manifold.points[pointCount];
                    Transform.mulTransToOut(xf2, clipPoints2[i].v, cp.localPoint);
                    // cp.m_localPoint = MulT(xf2, clipPoints2[i].v);
                    cp.id.set_Renamed(clipPoints2[i].id);
                    if (flip)
                    {
                        // Swap features
                        cp.id.flip();
                    }
                    ++pointCount;
                }
            }

            manifold.pointCount = pointCount;
        }
Example #6
0
        /// <summary>
        /// Compute the collision manifold between a polygon and a circle.
        /// </summary>
        /// <param name="manifold"></param>
        /// <param name="polygon"></param>
        /// <param name="xfA"></param>
        /// <param name="circle"></param>
        /// <param name="xfB"></param>
        public void collidePolygonAndCircle(Manifold manifold, PolygonShape polygon, Transform xfA, CircleShape circle, Transform xfB)
        {
            manifold.pointCount = 0;
            //Vec2 v = circle.m_p;

            // Compute circle position in the frame of the polygon.
            // before inline:
            Transform.mulToOut(xfB, circle.m_p, c);
            Transform.mulTransToOut(xfA, c, cLocal);

            float cLocalx = cLocal.x;
            float cLocaly = cLocal.y;
            // after inline:
            // final float cy = xfB.p.y + xfB.q.ex.y * v.x + xfB.q.ey.y * v.y;
            // final float cx = xfB.p.x + xfB.q.ex.x * v.x + xfB.q.ey.x * v.y;
            // final float v1x = cx - xfA.p.x;
            // final float v1y = cy - xfA.p.y;
            // final Vec2 b = xfA.q.ex;
            // final Vec2 b1 = xfA.q.ey;
            // final float cLocaly = v1x * b1.x + v1y * b1.y;
            // final float cLocalx = v1x * b.x + v1y * b.y;
            // end inline

            // Find the min separating edge.
            int normalIndex = 0;
            //UPGRADE_TODO: The equivalent in .NET for field 'java.lang.Float.MIN_VALUE' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'"
            float separation = Single.Epsilon;
            float radius = polygon.m_radius + circle.m_radius;
            int vertexCount = polygon.m_count;

            Vec2[] vertices = polygon.m_vertices;
            Vec2[] normals = polygon.m_normals;

            for (int i = 0; i < vertexCount; i++)
            {
                // before inline
                // temp.set(cLocal).subLocal(vertices[i]);
                // float s = Vec2.dot(normals[i], temp);
                // after inline
                Vec2 vertex = vertices[i];
                float tempx = cLocalx - vertex.x;
                float tempy = cLocaly - vertex.y;
                Vec2 normal = normals[i];
                float s = normal.x * tempx + normal.y * tempy;

                if (s > radius)
                {
                    // early out
                    return;
                }

                if (s > separation)
                {
                    separation = s;
                    normalIndex = i;
                }
            }

            // Vertices that subtend the incident face.
            int vertIndex1 = normalIndex;
            int vertIndex2 = vertIndex1 + 1 < vertexCount ? vertIndex1 + 1 : 0;
            Vec2 v1 = vertices[vertIndex1];
            Vec2 v2 = vertices[vertIndex2];

            // If the center is inside the polygon ...
            if (separation < Settings.EPSILON)
            {
                manifold.pointCount = 1;
                manifold.type = Manifold.ManifoldType.FACE_A;

                // before inline:
                // manifold.localNormal.set(normals[normalIndex]);
                // manifold.localPoint.set(v1).addLocal(v2).mulLocal(.5f);
                // manifold.points[0].localPoint.set(circle.m_p);
                // after inline:
                Vec2 normal = normals[normalIndex];
                manifold.localNormal.x = normal.x;
                manifold.localNormal.y = normal.y;
                manifold.localPoint.x = (v1.x + v2.x) * .5f;
                manifold.localPoint.y = (v1.y + v2.y) * .5f;
                ManifoldPoint mpoint = manifold.points[0];
                mpoint.localPoint.x = circle.m_p.x;
                mpoint.localPoint.y = circle.m_p.y;
                mpoint.id.zero();
                // end inline
                return;
            }

            // Compute barycentric coordinates
            // before inline:
            // temp.set(cLocal).subLocal(v1);
            // temp2.set(v2).subLocal(v1);
            // float u1 = Vec2.dot(temp, temp2);
            // temp.set(cLocal).subLocal(v2);
            // temp2.set(v1).subLocal(v2);
            // float u2 = Vec2.dot(temp, temp2);
            // after inline:
            float tempX = cLocalx - v1.x;
            float tempY = cLocaly - v1.y;
            float temp2X = v2.x - v1.x;
            float temp2Y = v2.y - v1.y;
            float u1 = tempX * temp2X + tempY * temp2Y;

            float temp3X = cLocalx - v2.x;
            float temp3Y = cLocaly - v2.y;
            float temp4X = v1.x - v2.x;
            float temp4Y = v1.y - v2.y;
            float u2 = temp3X * temp4X + temp3Y * temp4Y;
            // end inline

            if (u1 <= 0f)
            {
                // inlined
                float dx = cLocalx - v1.x;
                float dy = cLocaly - v1.y;
                if (dx * dx + dy * dy > radius * radius)
                {
                    return;
                }

                manifold.pointCount = 1;
                manifold.type = Manifold.ManifoldType.FACE_A;
                // before inline:
                // manifold.localNormal.set(cLocal).subLocal(v1);
                // after inline:
                manifold.localNormal.x = cLocalx - v1.x;
                manifold.localNormal.y = cLocaly - v1.y;
                // end inline
                manifold.localNormal.normalize();
                manifold.localPoint.set_Renamed(v1);
                manifold.points[0].localPoint.set_Renamed(circle.m_p);
                manifold.points[0].id.zero();
            }
            else if (u2 <= 0.0f)
            {
                // inlined
                float dx = cLocalx - v2.x;
                float dy = cLocaly - v2.y;
                if (dx * dx + dy * dy > radius * radius)
                {
                    return;
                }

                manifold.pointCount = 1;
                manifold.type = Manifold.ManifoldType.FACE_A;
                // before inline:
                // manifold.localNormal.set(cLocal).subLocal(v2);
                // after inline:
                manifold.localNormal.x = cLocalx - v2.x;
                manifold.localNormal.y = cLocaly - v2.y;
                // end inline
                manifold.localNormal.normalize();
                manifold.localPoint.set_Renamed(v2);
                manifold.points[0].localPoint.set_Renamed(circle.m_p);
                manifold.points[0].id.zero();
            }
            else
            {
                // Vec2 faceCenter = 0.5f * (v1 + v2);
                // (temp is faceCenter)
                // before inline:
                // temp.set(v1).addLocal(v2).mulLocal(.5f);
                //
                // temp2.set(cLocal).subLocal(temp);
                // separation = Vec2.dot(temp2, normals[vertIndex1]);
                // if (separation > radius) {
                // return;
                // }
                // after inline:
                float fcx = (v1.x + v2.x) * .5f;
                float fcy = (v1.y + v2.y) * .5f;

                float tx = cLocalx - fcx;
                float ty = cLocaly - fcy;
                Vec2 normal = normals[vertIndex1];
                separation = tx * normal.x + ty * normal.y;
                if (separation > radius)
                {
                    return;
                }
                // end inline

                manifold.pointCount = 1;
                manifold.type = Manifold.ManifoldType.FACE_A;
                manifold.localNormal.set_Renamed(normals[vertIndex1]);
                manifold.localPoint.x = fcx; // (faceCenter)
                manifold.localPoint.y = fcy;
                manifold.points[0].localPoint.set_Renamed(circle.m_p);
                manifold.points[0].id.zero();
            }
        }
Example #7
0
 public virtual void collideEdgeAndPolygon(Manifold manifold, EdgeShape edgeA, Transform xfA, PolygonShape polygonB, Transform xfB)
 {
     collider.collide(manifold, edgeA, xfA, polygonB, xfB);
 }
Example #8
0
            public virtual void collide(Manifold manifold, EdgeShape edgeA, Transform xfA, PolygonShape polygonB, Transform xfB)
            {
                Transform.mulTransToOutUnsafe(xfA, xfB, m_xf);
                Transform.mulToOutUnsafe(m_xf, polygonB.m_centroid, m_centroidB);

                m_v0 = edgeA.m_vertex0;
                m_v1 = edgeA.m_vertex1;
                m_v2 = edgeA.m_vertex2;
                m_v3 = edgeA.m_vertex3;

                bool hasVertex0 = edgeA.m_hasVertex0;
                bool hasVertex3 = edgeA.m_hasVertex3;

                edge1.set_Renamed(m_v2).subLocal(m_v1);
                edge1.normalize();
                m_normal1.set_Renamed(edge1.y, -edge1.x);
                float offset1 = Vec2.dot(m_normal1, temp.set_Renamed(m_centroidB).subLocal(m_v1));
                float offset0 = 0.0f, offset2 = 0.0f;
                bool convex1 = false, convex2 = false;

                // Is there a preceding edge?
                if (hasVertex0)
                {
                    edge0.set_Renamed(m_v1).subLocal(m_v0);
                    edge0.normalize();
                    m_normal0.set_Renamed(edge0.y, -edge0.x);
                    convex1 = Vec2.cross(edge0, edge1) >= 0.0f;
                    offset0 = Vec2.dot(m_normal0, temp.set_Renamed(m_centroidB).subLocal(m_v0));
                }

                // Is there a following edge?
                if (hasVertex3)
                {
                    edge2.set_Renamed(m_v3).subLocal(m_v2);
                    edge2.normalize();
                    m_normal2.set_Renamed(edge2.y, -edge2.x);
                    convex2 = Vec2.cross(edge1, edge2) > 0.0f;
                    offset2 = Vec2.dot(m_normal2, temp.set_Renamed(m_centroidB).subLocal(m_v2));
                }

                // Determine front or back collision. Determine collision normal limits.
                if (hasVertex0 && hasVertex3)
                {
                    if (convex1 && convex2)
                    {
                        m_front = offset0 >= 0.0f || offset1 >= 0.0f || offset2 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal0);
                            m_upperLimit.set_Renamed(m_normal2);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                            m_upperLimit.set_Renamed(m_normal1).negateLocal();
                        }
                    }
                    else if (convex1)
                    {
                        m_front = offset0 >= 0.0f || (offset1 >= 0.0f && offset2 >= 0.0f);
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal0);
                            m_upperLimit.set_Renamed(m_normal1);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal2).negateLocal();
                            m_upperLimit.set_Renamed(m_normal1).negateLocal();
                        }
                    }
                    else if (convex2)
                    {
                        m_front = offset2 >= 0.0f || (offset0 >= 0.0f && offset1 >= 0.0f);
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal1);
                            m_upperLimit.set_Renamed(m_normal2);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                            m_upperLimit.set_Renamed(m_normal0).negateLocal();
                        }
                    }
                    else
                    {
                        m_front = offset0 >= 0.0f && offset1 >= 0.0f && offset2 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal1);
                            m_upperLimit.set_Renamed(m_normal1);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal2).negateLocal();
                            m_upperLimit.set_Renamed(m_normal0).negateLocal();
                        }
                    }
                }
                else if (hasVertex0)
                {
                    if (convex1)
                    {
                        m_front = offset0 >= 0.0f || offset1 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal0);
                            m_upperLimit.set_Renamed(m_normal1).negateLocal();
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal1);
                            m_upperLimit.set_Renamed(m_normal1).negateLocal();
                        }
                    }
                    else
                    {
                        m_front = offset0 >= 0.0f && offset1 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal1);
                            m_upperLimit.set_Renamed(m_normal1).negateLocal();
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal1);
                            m_upperLimit.set_Renamed(m_normal0).negateLocal();
                        }
                    }
                }
                else if (hasVertex3)
                {
                    if (convex2)
                    {
                        m_front = offset1 >= 0.0f || offset2 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                            m_upperLimit.set_Renamed(m_normal2);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                            m_upperLimit.set_Renamed(m_normal1);
                        }
                    }
                    else
                    {
                        m_front = offset1 >= 0.0f && offset2 >= 0.0f;
                        if (m_front)
                        {
                            m_normal.set_Renamed(m_normal1);
                            m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                            m_upperLimit.set_Renamed(m_normal1);
                        }
                        else
                        {
                            m_normal.set_Renamed(m_normal1).negateLocal();
                            m_lowerLimit.set_Renamed(m_normal2).negateLocal();
                            m_upperLimit.set_Renamed(m_normal1);
                        }
                    }
                }
                else
                {
                    m_front = offset1 >= 0.0f;
                    if (m_front)
                    {
                        m_normal.set_Renamed(m_normal1);
                        m_lowerLimit.set_Renamed(m_normal1).negateLocal();
                        m_upperLimit.set_Renamed(m_normal1).negateLocal();
                    }
                    else
                    {
                        m_normal.set_Renamed(m_normal1).negateLocal();
                        m_lowerLimit.set_Renamed(m_normal1);
                        m_upperLimit.set_Renamed(m_normal1);
                    }
                }

                // Get polygonB in frameA
                m_polygonB.count = polygonB.m_count;
                for (int i = 0; i < polygonB.m_count; ++i)
                {
                    Transform.mulToOutUnsafe(m_xf, polygonB.m_vertices[i], m_polygonB.vertices[i]);
                    Rot.mulToOutUnsafe(m_xf.q, polygonB.m_normals[i], m_polygonB.normals[i]);
                }

                m_radius = 2.0f * Settings.polygonRadius;

                manifold.pointCount = 0;

                computeEdgeSeparation(edgeAxis);

                // If no valid normal can be found than this edge should not collide.
                if (edgeAxis.type == EPAxis.Type.UNKNOWN)
                {
                    return;
                }

                if (edgeAxis.separation > m_radius)
                {
                    return;
                }

                computePolygonSeparation(polygonAxis);
                if (polygonAxis.type != EPAxis.Type.UNKNOWN && polygonAxis.separation > m_radius)
                {
                    return;
                }

                // Use hysteresis for jitter reduction.
                float k_relativeTol = 0.98f;
                float k_absoluteTol = 0.001f;

                EPAxis primaryAxis;
                if (polygonAxis.type == EPAxis.Type.UNKNOWN)
                {
                    primaryAxis = edgeAxis;
                }
                else if (polygonAxis.separation > k_relativeTol * edgeAxis.separation + k_absoluteTol)
                {
                    primaryAxis = polygonAxis;
                }
                else
                {
                    primaryAxis = edgeAxis;
                }

                // ClipVertex[] ie = new ClipVertex[2];
                if (primaryAxis.type == EPAxis.Type.EDGE_A)
                {
                    manifold.type = Manifold.ManifoldType.FACE_A;

                    // Search for the polygon normal that is most anti-parallel to the edge normal.
                    int bestIndex = 0;
                    float bestValue = Vec2.dot(m_normal, m_polygonB.normals[0]);
                    for (int i = 1; i < m_polygonB.count; ++i)
                    {
                        float value_Renamed = Vec2.dot(m_normal, m_polygonB.normals[i]);
                        if (value_Renamed < bestValue)
                        {
                            bestValue = value_Renamed;
                            bestIndex = i;
                        }
                    }

                    int i1 = bestIndex;
                    int i2 = i1 + 1 < m_polygonB.count ? i1 + 1 : 0;

                    ie[0].v.set_Renamed(m_polygonB.vertices[i1]);
                    ie[0].id.indexA = 0;
                    ie[0].id.indexB = (sbyte)i1;
                    ie[0].id.typeA = (sbyte)ContactID.Type.FACE;
                    ie[0].id.typeB = (sbyte)ContactID.Type.VERTEX;

                    ie[1].v.set_Renamed(m_polygonB.vertices[i2]);
                    ie[1].id.indexA = 0;
                    ie[1].id.indexB = (sbyte)i2;
                    ie[1].id.typeA = (sbyte)ContactID.Type.FACE;
                    ie[1].id.typeB = (sbyte)ContactID.Type.VERTEX;

                    if (m_front)
                    {
                        rf.i1 = 0;
                        rf.i2 = 1;
                        rf.v1.set_Renamed(m_v1);
                        rf.v2.set_Renamed(m_v2);
                        rf.normal.set_Renamed(m_normal1);
                    }
                    else
                    {
                        rf.i1 = 1;
                        rf.i2 = 0;
                        rf.v1.set_Renamed(m_v2);
                        rf.v2.set_Renamed(m_v1);
                        rf.normal.set_Renamed(m_normal1).negateLocal();
                    }
                }
                else
                {
                    manifold.type = Manifold.ManifoldType.FACE_B;

                    ie[0].v.set_Renamed(m_v1);
                    ie[0].id.indexA = 0;
                    ie[0].id.indexB = (sbyte)primaryAxis.index;
                    ie[0].id.typeA = (sbyte)ContactID.Type.VERTEX;
                    ie[0].id.typeB = (sbyte)ContactID.Type.FACE;

                    ie[1].v.set_Renamed(m_v2);
                    ie[1].id.indexA = 0;
                    ie[1].id.indexB = (sbyte)primaryAxis.index;
                    ie[1].id.typeA = (sbyte)ContactID.Type.VERTEX;
                    ie[1].id.typeB = (sbyte)ContactID.Type.FACE;

                    rf.i1 = primaryAxis.index;
                    rf.i2 = rf.i1 + 1 < m_polygonB.count ? rf.i1 + 1 : 0;
                    rf.v1.set_Renamed(m_polygonB.vertices[rf.i1]);
                    rf.v2.set_Renamed(m_polygonB.vertices[rf.i2]);
                    rf.normal.set_Renamed(m_polygonB.normals[rf.i1]);
                }

                rf.sideNormal1.set_Renamed(rf.normal.y, -rf.normal.x);
                rf.sideNormal2.set_Renamed(rf.sideNormal1).negateLocal();
                rf.sideOffset1 = Vec2.dot(rf.sideNormal1, rf.v1);
                rf.sideOffset2 = Vec2.dot(rf.sideNormal2, rf.v2);

                // Clip incident edge against extruded edge1 side edges.
                int np;

                // Clip to box side 1
                np = clipSegmentToLine(clipPoints1, ie, rf.sideNormal1, rf.sideOffset1, rf.i1);

                if (np < Settings.maxManifoldPoints)
                {
                    return;
                }

                // Clip to negative box side 1
                np = clipSegmentToLine(clipPoints2, clipPoints1, rf.sideNormal2, rf.sideOffset2, rf.i2);

                if (np < Settings.maxManifoldPoints)
                {
                    return;
                }

                // Now clipPoints2 contains the clipped points.
                if (primaryAxis.type == EPAxis.Type.EDGE_A)
                {
                    manifold.localNormal.set_Renamed(rf.normal);
                    manifold.localPoint.set_Renamed(rf.v1);
                }
                else
                {
                    manifold.localNormal.set_Renamed(polygonB.m_normals[rf.i1]);
                    manifold.localPoint.set_Renamed(polygonB.m_vertices[rf.i1]);
                }

                int pointCount = 0;
                for (int i = 0; i < Settings.maxManifoldPoints; ++i)
                {
                    float separation;

                    separation = Vec2.dot(rf.normal, temp.set_Renamed(clipPoints2[i].v).subLocal(rf.v1));

                    if (separation <= m_radius)
                    {
                        ManifoldPoint cp = manifold.points[pointCount];

                        if (primaryAxis.type == EPAxis.Type.EDGE_A)
                        {
                            // cp.localPoint = MulT(m_xf, clipPoints2[i].v);
                            Transform.mulTransToOutUnsafe(m_xf, clipPoints2[i].v, cp.localPoint);
                            cp.id.set_Renamed(clipPoints2[i].id);
                        }
                        else
                        {
                            cp.localPoint.set_Renamed(clipPoints2[i].v);
                            cp.id.typeA = clipPoints2[i].id.typeB;
                            cp.id.typeB = clipPoints2[i].id.typeA;
                            cp.id.indexA = clipPoints2[i].id.indexB;
                            cp.id.indexB = clipPoints2[i].id.indexA;
                        }

                        ++pointCount;
                    }
                }

                manifold.pointCount = pointCount;
            }
Example #9
0
 public override Shape Clone()
 {
     PolygonShape shape = new PolygonShape();
     shape.Centroid.Set(Centroid);
     for (int i = 0; i < shape.Normals.Length; i++)
     {
         shape.Normals[i].Set(Normals[i]);
         shape.Vertices[i].Set(Vertices[i]);
     }
     shape.Radius = Radius;
     shape.VertexCount = VertexCount;
     return shape;
 }
Example #10
0
 public override Shape Clone()
 {
     PolygonShape shape = new PolygonShape();
     shape.m_centroid.set_Renamed(this.m_centroid);
     for (int i = 0; i < shape.m_normals.Length; i++)
     {
         shape.m_normals[i].set_Renamed(m_normals[i]);
         shape.m_vertices[i].set_Renamed(m_vertices[i]);
     }
     shape.Radius = this.Radius;
     shape.m_count = this.m_count;
     return shape;
 }
Example #11
0
        private void InitializeWorld()
        {
            // Static Body
            Vec2 gravity = new Vec2(0, -10);
            bool doSleep = true;
            world = new World(gravity);
            world.SleepingAllowed = doSleep;
            BodyDef groundBodyDef = new BodyDef();
            groundBodyDef.Position.Set(0, -10);
            Body groundBody = world.CreateBody(groundBodyDef);
            PolygonShape groundBox = new PolygonShape();
            groundBox.SetAsBox(50, 10);
            groundBody.CreateFixture(groundBox, 0);

            {
                // Dynamic Body
                BodyDef bodyDef = new BodyDef();
                bodyDef.Type = BodyType.Dynamic;
                bodyDef.Position.Set(5, 4);
                bodyDef.Angle = (float)(2 * Math.PI / 3);
                Body body = world.CreateBody(bodyDef);
                PolygonShape dynamicBox = new PolygonShape();
                dynamicBox.SetAsBox(1, 1);
                FixtureDef fixtureDef = new FixtureDef();
                fixtureDef.Shape = dynamicBox;
                fixtureDef.Density = 1;
                fixtureDef.Friction = 0.3f;
                body.CreateFixture(fixtureDef);
                Bodies.Add(new BodyAdapter(body));
            }

            {
                // Dynamic Body
                BodyDef bodyDef = new BodyDef();
                bodyDef.Type = BodyType.Dynamic;
                bodyDef.Position.Set(5, 10);
                bodyDef.Angle = (float)(Math.PI / 3);
                Body body = world.CreateBody(bodyDef);
                PolygonShape dynamicBox = new PolygonShape();
                dynamicBox.SetAsBox(1, 1);
                FixtureDef fixtureDef = new FixtureDef();
                fixtureDef.Shape = dynamicBox;
                fixtureDef.Density = 1;
                fixtureDef.Friction = 0.3f;
                body.CreateFixture(fixtureDef);
                Bodies.Add(new BodyAdapter(body));
            }

            {
                // Dynamic Body
                BodyDef bodyDef = new BodyDef();
                bodyDef.Type = BodyType.Dynamic;
                bodyDef.Position.Set(4.5f, 7);
                bodyDef.AngularVelocity = (float)(2 * Math.PI);
                Body body = world.CreateBody(bodyDef);
                PolygonShape dynamicBox = new PolygonShape();
                dynamicBox.SetAsBox(1, 1);
                FixtureDef fixtureDef = new FixtureDef();
                fixtureDef.Shape = dynamicBox;
                fixtureDef.Density = 1;
                fixtureDef.Friction = 0.3f;
                body.CreateFixture(fixtureDef);
                Bodies.Add(new BodyAdapter(body));
            }
        }
Example #12
0
            public void Collide(Manifold manifold, EdgeShape edgeA, Transform xfA, PolygonShape polygonB, Transform xfB)
            {
                Transform.MulTransToOutUnsafe(xfA, xfB, xf);
                Transform.MulToOutUnsafe(xf, polygonB.Centroid, centroidB);

                v0 = edgeA.Vertex0;
                v1 = edgeA.Vertex1;
                v2 = edgeA.Vertex2;
                v3 = edgeA.Vertex3;

                bool hasVertex0 = edgeA.HasVertex0;
                bool hasVertex3 = edgeA.HasVertex3;

                edge1.Set(v2).SubLocal(v1);
                edge1.Normalize();
                normal1.Set(edge1.Y, -edge1.X);
                float offset1 = Vec2.Dot(normal1, temp.Set(centroidB).SubLocal(v1));
                float offset0 = 0.0f, offset2 = 0.0f;
                bool convex1 = false, convex2 = false;

                // Is there a preceding edge?
                if (hasVertex0)
                {
                    edge0.Set(v1).SubLocal(v0);
                    edge0.Normalize();
                    normal0.Set(edge0.Y, -edge0.X);
                    convex1 = Vec2.Cross(edge0, edge1) >= 0.0f;
                    offset0 = Vec2.Dot(normal0, temp.Set(centroidB).SubLocal(v0));
                }

                // Is there a following edge?
                if (hasVertex3)
                {
                    edge2.Set(v3).SubLocal(v2);
                    edge2.Normalize();
                    normal2.Set(edge2.Y, -edge2.X);
                    convex2 = Vec2.Cross(edge1, edge2) > 0.0f;
                    offset2 = Vec2.Dot(normal2, temp.Set(centroidB).SubLocal(v2));
                }

                // Determine front or back collision. Determine collision normal limits.
                if (hasVertex0 && hasVertex3)
                {
                    if (convex1 && convex2)
                    {
                        front = offset0 >= 0.0f || offset1 >= 0.0f || offset2 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal0);
                            upperLimit.Set(normal2);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal1).NegateLocal();
                            upperLimit.Set(normal1).NegateLocal();
                        }
                    }
                    else if (convex1)
                    {
                        front = offset0 >= 0.0f || (offset1 >= 0.0f && offset2 >= 0.0f);
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal0);
                            upperLimit.Set(normal1);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal2).NegateLocal();
                            upperLimit.Set(normal1).NegateLocal();
                        }
                    }
                    else if (convex2)
                    {
                        front = offset2 >= 0.0f || (offset0 >= 0.0f && offset1 >= 0.0f);
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal1);
                            upperLimit.Set(normal2);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal1).NegateLocal();
                            upperLimit.Set(normal0).NegateLocal();
                        }
                    }
                    else
                    {
                        front = offset0 >= 0.0f && offset1 >= 0.0f && offset2 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal1);
                            upperLimit.Set(normal1);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal2).NegateLocal();
                            upperLimit.Set(normal0).NegateLocal();
                        }
                    }
                }
                else if (hasVertex0)
                {
                    if (convex1)
                    {
                        front = offset0 >= 0.0f || offset1 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal0);
                            upperLimit.Set(normal1).NegateLocal();
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal1);
                            upperLimit.Set(normal1).NegateLocal();
                        }
                    }
                    else
                    {
                        front = offset0 >= 0.0f && offset1 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal1);
                            upperLimit.Set(normal1).NegateLocal();
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal1);
                            upperLimit.Set(normal0).NegateLocal();
                        }
                    }
                }
                else if (hasVertex3)
                {
                    if (convex2)
                    {
                        front = offset1 >= 0.0f || offset2 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal1).NegateLocal();
                            upperLimit.Set(normal2);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal1).NegateLocal();
                            upperLimit.Set(normal1);
                        }
                    }
                    else
                    {
                        front = offset1 >= 0.0f && offset2 >= 0.0f;
                        if (front)
                        {
                            normal.Set(normal1);
                            lowerLimit.Set(normal1).NegateLocal();
                            upperLimit.Set(normal1);
                        }
                        else
                        {
                            normal.Set(normal1).NegateLocal();
                            lowerLimit.Set(normal2).NegateLocal();
                            upperLimit.Set(normal1);
                        }
                    }
                }
                else
                {
                    front = offset1 >= 0.0f;
                    if (front)
                    {
                        normal.Set(normal1);
                        lowerLimit.Set(normal1).NegateLocal();
                        upperLimit.Set(normal1).NegateLocal();
                    }
                    else
                    {
                        normal.Set(normal1).NegateLocal();
                        lowerLimit.Set(normal1);
                        upperLimit.Set(normal1);
                    }
                }

                // Get polygonB in frameA
                this.polygonB.Count = polygonB.VertexCount;
                for (int i = 0; i < polygonB.VertexCount; ++i)
                {
                    Transform.MulToOutUnsafe(xf, polygonB.Vertices[i], this.polygonB.Vertices[i]);
                    Rot.MulToOutUnsafe(xf.Q, polygonB.Normals[i], this.polygonB.Normals[i]);
                }

                radius = 2.0f * Settings.POLYGON_RADIUS;

                manifold.PointCount = 0;

                ComputeEdgeSeparation(edgeAxis);

                // If no valid normal can be found than this edge should not collide.
                if (edgeAxis.Type == EPAxis.EPAxisType.Unknown)
                {
                    return;
                }

                if (edgeAxis.Separation > radius)
                {
                    return;
                }

                ComputePolygonSeparation(polygonAxis);
                if (polygonAxis.Type != EPAxis.EPAxisType.Unknown && polygonAxis.Separation > radius)
                {
                    return;
                }

                // Use hysteresis for jitter reduction.
                const float k_relativeTol = 0.98f;
                const float k_absoluteTol = 0.001f;

                EPAxis primaryAxis;
                if (polygonAxis.Type == EPAxis.EPAxisType.Unknown)
                {
                    primaryAxis = edgeAxis;
                }
                else if (polygonAxis.Separation > k_relativeTol * edgeAxis.Separation + k_absoluteTol)
                {
                    primaryAxis = polygonAxis;
                }
                else
                {
                    primaryAxis = edgeAxis;
                }

                // ClipVertex[] ie = new ClipVertex[2];
                if (primaryAxis.Type == EPAxis.EPAxisType.EdgeA)
                {
                    manifold.Type = Manifold.ManifoldType.FaceA;

                    // Search for the polygon normal that is most anti-parallel to the edge normal.
                    int bestIndex = 0;
                    float bestValue = Vec2.Dot(normal, this.polygonB.Normals[0]);
                    for (int i = 1; i < this.polygonB.Count; ++i)
                    {
                        float value = Vec2.Dot(normal, this.polygonB.Normals[i]);
                        if (value < bestValue)
                        {
                            bestValue = value;
                            bestIndex = i;
                        }
                    }

                    int i1 = bestIndex;
                    int i2 = i1 + 1 < this.polygonB.Count ? i1 + 1 : 0;

                    ie[0].V.Set(this.polygonB.Vertices[i1]);
                    ie[0].Id.IndexA = 0;
                    ie[0].Id.IndexB = (sbyte)i1;
                    ie[0].Id.TypeA = (sbyte)ContactID.Type.Face;
                    ie[0].Id.TypeB = (sbyte)ContactID.Type.Vertex;

                    ie[1].V.Set(this.polygonB.Vertices[i2]);
                    ie[1].Id.IndexA = 0;
                    ie[1].Id.IndexB = (sbyte)i2;
                    ie[1].Id.TypeA = (sbyte)ContactID.Type.Face;
                    ie[1].Id.TypeB = (sbyte)ContactID.Type.Vertex;

                    if (front)
                    {
                        rf.I1 = 0;
                        rf.I2 = 1;
                        rf.V1.Set(v1);
                        rf.V2.Set(v2);
                        rf.Normal.Set(normal1);
                    }
                    else
                    {
                        rf.I1 = 1;
                        rf.I2 = 0;
                        rf.V1.Set(v2);
                        rf.V2.Set(v1);
                        rf.Normal.Set(normal1).NegateLocal();
                    }
                }
                else
                {
                    manifold.Type = Manifold.ManifoldType.FaceB;

                    ie[0].V.Set(v1);
                    ie[0].Id.IndexA = 0;
                    ie[0].Id.IndexB = (sbyte)primaryAxis.Index;
                    ie[0].Id.TypeA = (sbyte)ContactID.Type.Vertex;
                    ie[0].Id.TypeB = (sbyte)ContactID.Type.Face;

                    ie[1].V.Set(v2);
                    ie[1].Id.IndexA = 0;
                    ie[1].Id.IndexB = (sbyte)primaryAxis.Index;
                    ie[1].Id.TypeA = (sbyte)ContactID.Type.Vertex;
                    ie[1].Id.TypeB = (sbyte)ContactID.Type.Face;

                    rf.I1 = primaryAxis.Index;
                    rf.I2 = rf.I1 + 1 < this.polygonB.Count ? rf.I1 + 1 : 0;
                    rf.V1.Set(this.polygonB.Vertices[rf.I1]);
                    rf.V2.Set(this.polygonB.Vertices[rf.I2]);
                    rf.Normal.Set(this.polygonB.Normals[rf.I1]);
                }

                rf.SideNormal1.Set(rf.Normal.Y, -rf.Normal.X);
                rf.SideNormal2.Set(rf.SideNormal1).NegateLocal();
                rf.SideOffset1 = Vec2.Dot(rf.SideNormal1, rf.V1);
                rf.SideOffset2 = Vec2.Dot(rf.SideNormal2, rf.V2);

                // Clip incident edge against extruded edge1 side edges.
                int np;

                // Clip to box side 1
                np = ClipSegmentToLine(clipPoints1, ie, rf.SideNormal1, rf.SideOffset1, rf.I1);

                if (np < Settings.MAX_MANIFOLD_POINTS)
                {
                    return;
                }

                // Clip to negative box side 1
                np = ClipSegmentToLine(clipPoints2, clipPoints1, rf.SideNormal2, rf.SideOffset2, rf.I2);

                if (np < Settings.MAX_MANIFOLD_POINTS)
                {
                    return;
                }

                // Now clipPoints2 contains the clipped points.
                if (primaryAxis.Type == EPAxis.EPAxisType.EdgeA)
                {
                    manifold.LocalNormal.Set(rf.Normal);
                    manifold.LocalPoint.Set(rf.V1);
                }
                else
                {
                    manifold.LocalNormal.Set(polygonB.Normals[rf.I1]);
                    manifold.LocalPoint.Set(polygonB.Vertices[rf.I1]);
                }

                int pointCount = 0;
                for (int i = 0; i < Settings.MAX_MANIFOLD_POINTS; ++i)
                {
                    float separation = Vec2.Dot(rf.Normal, temp.Set(clipPoints2[i].V).SubLocal(rf.V1));

                    if (separation <= radius)
                    {
                        ManifoldPoint cp = manifold.Points[pointCount];

                        if (primaryAxis.Type == EPAxis.EPAxisType.EdgeA)
                        {
                            // cp.localPoint = MulT(m_xf, clipPoints2[i].v);
                            Transform.MulTransToOutUnsafe(xf, clipPoints2[i].V, cp.LocalPoint);
                            cp.Id.Set(clipPoints2[i].Id);
                        }
                        else
                        {
                            cp.LocalPoint.Set(clipPoints2[i].V);
                            cp.Id.TypeA = clipPoints2[i].Id.TypeB;
                            cp.Id.TypeB = clipPoints2[i].Id.TypeA;
                            cp.Id.IndexA = clipPoints2[i].Id.IndexB;
                            cp.Id.IndexB = clipPoints2[i].Id.IndexA;
                        }

                        ++pointCount;
                    }
                }

                manifold.PointCount = pointCount;
            }