Esempio n. 1
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        /// <summary>
        /// The cross product of two vectors.
        /// </summary>
        /// <param name="vector1">The first vector.</param>
        /// <param name="vector2">The second vector.</param>
        /// <returns>The cross product of both vectors.</returns>
        #region public static JVector Cross(JVector vector1, JVector vector2)
        public static JVector Cross(JVector vector1, JVector vector2)
        {
            JVector result;

            JVector.Cross(ref vector1, ref vector2, out result);
            return(result);
        }
Esempio n. 2
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 /// <summary>
 /// Adds a force to the center of the body. The force gets applied
 /// the next time <see cref="World.Step"/> is called. The 'impact'
 /// of the force depends on the time it is applied to a body - so
 /// the timestep influences the energy added to the body.
 /// </summary>
 /// <param name="force">The force to add next <see cref="World.Step"/>.</param>
 /// <param name="pos">The position where the force is applied.</param>
 public void AddForce(JVector force, JVector pos)
 {
     JVector.Add(ref this.force, ref force, out this.force);
     JVector.Subtract(ref pos, ref this.position, out pos);
     JVector.Cross(ref pos, ref force, out pos);
     JVector.Add(ref pos, ref this.torque, out this.torque);
 }
Esempio n. 3
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            public void GetNormal(out JVector normal)
            {
                JVector sum;

                JVector.Subtract(ref owner.points[indices.I1].position, ref owner.points[indices.I0].position, out sum);
                JVector.Subtract(ref owner.points[indices.I2].position, ref owner.points[indices.I0].position, out normal);
                JVector.Cross(ref sum, ref normal, out normal);
            }
        // sort cached points so most isolated points come first
        private int SortCachedPoints(ref JVector realRelPos1, float pen)
        {
            //calculate 4 possible cases areas, and take biggest area
            //also need to keep 'deepest'

            int   maxPenetrationIndex = -1;
            float maxPenetration      = pen;

            for (int i = 0; i < 4; i++)
            {
                if (contactList[i].penetration > maxPenetration)
                {
                    maxPenetrationIndex = i;
                    maxPenetration      = contactList[i].penetration;
                }
            }

            float res0 = 0, res1 = 0, res2 = 0, res3 = 0;

            if (maxPenetrationIndex != 0)
            {
                JVector a0; JVector.Subtract(ref realRelPos1, ref contactList[1].relativePos1, out a0);
                JVector b0; JVector.Subtract(ref contactList[3].relativePos1, ref contactList[2].relativePos1, out b0);
                JVector cross; JVector.Cross(ref a0, ref b0, out cross);
                res0 = cross.LengthSquared();
            }
            if (maxPenetrationIndex != 1)
            {
                JVector a0; JVector.Subtract(ref realRelPos1, ref contactList[0].relativePos1, out a0);
                JVector b0; JVector.Subtract(ref contactList[3].relativePos1, ref contactList[2].relativePos1, out b0);
                JVector cross; JVector.Cross(ref a0, ref b0, out cross);
                res1 = cross.LengthSquared();
            }

            if (maxPenetrationIndex != 2)
            {
                JVector a0; JVector.Subtract(ref realRelPos1, ref contactList[0].relativePos1, out a0);
                JVector b0; JVector.Subtract(ref contactList[3].relativePos1, ref contactList[1].relativePos1, out b0);
                JVector cross; JVector.Cross(ref a0, ref b0, out cross);
                res2 = cross.LengthSquared();
            }

            if (maxPenetrationIndex != 3)
            {
                JVector a0; JVector.Subtract(ref realRelPos1, ref contactList[0].relativePos1, out a0);
                JVector b0; JVector.Subtract(ref contactList[2].relativePos1, ref contactList[1].relativePos1, out b0);
                JVector cross; JVector.Cross(ref a0, ref b0, out cross);
                res3 = cross.LengthSquared();
            }

            int biggestarea = MaxAxis(res0, res1, res2, res3);

            return(biggestarea);
        }
Esempio n. 5
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        public static JVector ComputeNormal(JVector p0, JVector p1, JVector p2, WindingTypes winding,
                                            bool shouldNormalize = true)
        {
            var v0 = JVector.Subtract(p1, p0);
            var v1 = JVector.Subtract(p2, p0);

            // This calculation is the same as the one used in a constructor below, but due to using JVector vs. vec3,
            // it's easier to just duplicate the code.
            var v = JVector.Cross(v0, v1) * (winding == WindingTypes.Clockwise ? 1 : -1);

            return(shouldNormalize ? JVector.Normalize(v) : v);
        }
Esempio n. 6
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        /// <summary>
        /// Adds a force to the center of the body. The force gets applied
        /// the next time <see cref="World.Step"/> is called. The 'impact'
        /// of the force depends on the time it is applied to a body - so
        /// the timestep influences the energy added to the body.
        /// </summary>
        /// <param name="force">The force to add next <see cref="World.Step"/>.</param>
        /// <param name="pos">The position where the force is applied.</param>
        public void AddForce(JVector force, JVector pos)
        {
            JVector.Add(ref this.force, ref force, out this.force);
            JVector.Subtract(ref pos, ref this.position, out pos);

            // 3d version
            //JVector.Cross(ref pos, ref force, out pos);
            //JVector.Add(ref pos, ref this.torque, out this.torque);

            //body->t += cpvcross(r, force);

            this.torque += JVector.Cross(pos, force);
        }
        public LimitedHingeJoint(World world, RigidBody body1, RigidBody body2, JVector position, JVector hingeAxis, float hingeFwdAngle, float hingeBckAngle) : base(world)
        {
            worldPointConstraint = new PointOnPoint[2];

            hingeAxis *= 0.5f;

            var pos1 = position;

            JVector.Add(pos1, hingeAxis, out pos1);
            var pos2 = position;

            JVector.Subtract(pos2, hingeAxis, out pos2);

            worldPointConstraint[0] = new PointOnPoint(body1, body2, pos1);
            worldPointConstraint[1] = new PointOnPoint(body1, body2, pos2);

            hingeAxis = JVector.Normalize(hingeAxis);

            var perpDir = JVector.Up;

            if (JVector.Dot(perpDir, hingeAxis) > 0.1f)
            {
                perpDir = JVector.Right;
            }

            var sideAxis = JVector.Cross(hingeAxis, perpDir);

            perpDir = JVector.Cross(sideAxis, hingeAxis);
            perpDir = JVector.Normalize(perpDir);

            float len = 10.0f * 3;

            var hingeRelAnchorPos0 = perpDir * len;

            float angleToMiddle      = 0.5f * (hingeFwdAngle - hingeBckAngle);
            var   hingeRelAnchorPos1 = JVector.Transform(hingeRelAnchorPos0, JMatrix.CreateFromAxisAngle(hingeAxis, -angleToMiddle / 360.0f * 2.0f * JMath.Pi));

            float hingeHalfAngle  = 0.5f * (hingeFwdAngle + hingeBckAngle);
            float allowedDistance = len * 2.0f * (float)System.Math.Sin(hingeHalfAngle * 0.5f / 360.0f * 2.0f * JMath.Pi);

            var hingePos = body1.Position;
            var relPos0c = hingePos + hingeRelAnchorPos0;
            var relPos1c = hingePos + hingeRelAnchorPos1;

            DistanceConstraint = new PointPointDistance(body1, body2, relPos0c, relPos1c)
            {
                Distance = allowedDistance,
                Behavior = PointPointDistance.DistanceBehavior.LimitMaximumDistance
            };
        }
Esempio n. 8
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            /// Test if point p and d lie on opposite sides of plane through abc
            public int PointOutsideOfPlane(JVector p, JVector a, JVector b, JVector c, JVector d)
            {
                JVector normal = JVector.Cross(b - a, c - a);

                float signp = JVector.Dot(p - a, normal); // [AP AB AC]
                float signd = JVector.Dot(d - a, normal); // [AD AB AC]

                //if (CatchDegenerateTetrahedron)
                if (signd * signd < (1e-4f * 1e-4f))
                {
                    return(-1);
                }

                // Points on opposite sides if expression signs are opposite
                return(signp * signd < 0f ? 1 : 0);
            }
Esempio n. 9
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        /// <summary>
        /// Applies an impulse on the specific position. Changing linear
        /// and angular velocity.
        /// </summary>
        /// <param name="impulse">Impulse direction and magnitude.</param>
        /// <param name="relativePosition">The position where the impulse gets applied
        /// in Body coordinate frame.</param>
        public void ApplyImpulse(JVector impulse, JVector relativePosition)
        {
            if (this.isStatic)
            {
                throw new InvalidOperationException("Can't apply an impulse to a static body.");
            }

            JVector temp;

            JVector.Multiply(ref impulse, inverseMass, out temp);
            JVector.Add(ref linearVelocity, ref temp, out linearVelocity);

            JVector.Cross(ref relativePosition, ref impulse, out temp);
            JVector.Transform(ref temp, ref invInertiaWorld, out temp);
            JVector.Add(ref angularVelocity, ref temp, out angularVelocity);
        }
Esempio n. 10
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        /// <summary>
        /// Sets the current shape. First <see cref="Prepare"/> has to be called.
        /// After SetCurrentShape the shape immitates another shape.
        /// </summary>
        /// <param name="index"></param>
        public override void SetCurrentShape(int index)
        {
            vecs[0] = octree.GetVertex(octree.tris[potentialTriangles[index]].I0);
            vecs[1] = octree.GetVertex(octree.tris[potentialTriangles[index]].I1);
            vecs[2] = octree.GetVertex(octree.tris[potentialTriangles[index]].I2);

            JVector sum = vecs[0];

            JVector.Add(ref sum, ref vecs[1], out sum);
            JVector.Add(ref sum, ref vecs[2], out sum);
            JVector.Multiply(ref sum, 1.0f / 3.0f, out sum);

            geomCen = sum;

            JVector.Subtract(ref vecs[1], ref vecs[0], out sum);
            JVector.Subtract(ref vecs[2], ref vecs[0], out normal);
            JVector.Cross(ref sum, ref normal, out normal);
        }
Esempio n. 11
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        // This is primarily used for tracking relative rotation on moving platforms.
        public static float ComputeYaw(this JMatrix matrix)
        {
            // See https://stackoverflow.com/a/4341489/7281613.
            JVector t = JVector.Transform(JVector.Left, matrix);
            JVector f = t - JVector.Dot(t, JVector.Up) * JVector.Up;

            f.Normalize();

            float angle = (float)Math.Acos(JVector.Dot(JVector.Left, f));
            float d     = JVector.Dot(JVector.Up, JVector.Cross(JVector.Left, f));

            if (d < 0)
            {
                angle = Constants.TwoPi - angle;
            }

            return(angle);
        }
Esempio n. 12
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        public static bool OriginInTriangle(JVector a, JVector b, JVector c)
        {
            float pab = JVector.Cross(JVector.Negate(a), b - a);
            float pbc = JVector.Cross(JVector.Negate(b), c - b);

            if (!SameSign(pab, pbc))
            {
                return(false);
            }

            float pca = JVector.Cross(JVector.Negate(c), a - c);

            if (!SameSign(pab, pca))
            {
                return(false);
            }

            return(true);
        }
Esempio n. 13
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        /// <summary>
        /// Sets the current shape. First <see cref="Prepare"/> has to be called.
        /// After SetCurrentShape the shape immitates another shape.
        /// </summary>
        /// <param name="index"></param>
        public override void SetCurrentShape(int index)
        {
            bool leftTriangle = false;

            if (index >= numX * numZ)
            {
                leftTriangle = true;
                index       -= numX * numZ;
            }

            int quadIndexX = index % numX;
            int quadIndexZ = index / numX;

            // each quad has two triangles, called 'leftTriangle' and !'leftTriangle'
            if (leftTriangle)
            {
                points[0].Set((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[1].Set((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[2].Set((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
            }
            else
            {
                points[0].Set((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[1].Set((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
                points[2].Set((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
            }

            JVector sum = points[0];

            JVector.Add(ref sum, ref points[1], out sum);
            JVector.Add(ref sum, ref points[2], out sum);
            JVector.Multiply(ref sum, 1.0f / 3.0f, out sum);
            geomCen = sum;

            JVector.Subtract(ref points[1], ref points[0], out sum);
            JVector.Subtract(ref points[2], ref points[0], out normal);
            JVector.Cross(ref sum, ref normal, out normal);
        }
Esempio n. 14
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        //public JConvexHull ConvexHull = new JConvexHull();

        public ConvexHullPrimitive(GraphicsDevice device, List <JVector> pointCloud, List <Tuple <int, int, int> > indices)
        {
            //JConvexHull.Build(pointCloud, JConvexHull.Approximation.Level5);

            int counter = 0;

            foreach (Tuple <int, int, int> face in indices)
            {
                JVector a      = pointCloud[face.Item2] - pointCloud[face.Item1];
                JVector b      = pointCloud[face.Item3] - pointCloud[face.Item1];
                JVector normal = JVector.Cross(a, b);

                AddVertex(Conversion.ToXnaVector(pointCloud[face.Item1]), Conversion.ToXnaVector(normal));
                AddVertex(Conversion.ToXnaVector(pointCloud[face.Item2]), Conversion.ToXnaVector(normal));
                AddVertex(Conversion.ToXnaVector(pointCloud[face.Item3]), Conversion.ToXnaVector(normal));

                AddIndex(counter + 0);
                AddIndex(counter + 1);
                AddIndex(counter + 2);

                counter += 3;
            }

            //foreach (JConvexHull.Face face in ConvexHull.HullFaces) {
            //    AddVertex(Conversion.ToXnaVector(pointCloud[face.VertexC]), Conversion.ToXnaVector(face.Normal));
            //    AddVertex(Conversion.ToXnaVector(pointCloud[face.VertexB]), Conversion.ToXnaVector(face.Normal));
            //    AddVertex(Conversion.ToXnaVector(pointCloud[face.VertexA]), Conversion.ToXnaVector(face.Normal));

            //    AddIndex(counter + 0);
            //    AddIndex(counter + 1);
            //    AddIndex(counter + 2);

            //    counter += 3;
            //}


            InitializePrimitive(device);
        }
Esempio n. 15
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        public void DrawTriangle(JVector pos1, JVector pos2, JVector pos3)
        {
            JVector n = JVector.Cross(pos2 - pos1, pos3 - pos1);

            n.Normalize();
            Vector3 xn = new Vector3(n.X, n.Y, n.Z);

            VertexPositionColorNormal[] tri = new VertexPositionColorNormal[3] {
                new VertexPositionColorNormal(new Vector3(pos1.X, pos1.Y, pos1.Z), Color.Green, xn),
                new VertexPositionColorNormal(new Vector3(pos3.X, pos3.Y, pos3.Z), Color.Green, xn),
                new VertexPositionColorNormal(new Vector3(pos2.X, pos2.Y, pos2.Z), Color.Green, xn),
            };

            effect.Parameters["World"].SetValue(Matrix.Identity);
            effect.Parameters["ViewProj"].SetValue(Camera.CurrentCamera.View * Camera.CurrentCamera.Projection);
            effect.CurrentTechnique = effect.Techniques["VBO"];

            foreach (EffectPass p in effect.CurrentTechnique.Passes)
            {
                p.Apply();
                device.DrawUserPrimitives(PrimitiveType.TriangleList, tri, 0, 1);
            }
        }
Esempio n. 16
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        public override void SetCurrentShape(int index)
        {
            bool leftTriangle = false;

            if (index >= numX * numZ)
            {
                leftTriangle = true;
                index       -= numX * numZ;
            }

            int quadIndexX = index % numX;
            int quadIndexZ = index / numX;

            if (leftTriangle)
            {
                points[0] = new JVector((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[1] = new JVector((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[2] = new JVector((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
            }
            else
            {
                points[0] = new JVector((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 0], (minZ + quadIndexZ + 0) * scaleZ);
                points[1] = new JVector((minX + quadIndexX + 1) * scaleX, heights[minX + quadIndexX + 1, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
                points[2] = new JVector((minX + quadIndexX + 0) * scaleX, heights[minX + quadIndexX + 0, minZ + quadIndexZ + 1], (minZ + quadIndexZ + 1) * scaleZ);
            }

            var sum = points[0];

            JVector.Add(sum, points[1], out sum);
            JVector.Add(sum, points[2], out sum);
            JVector.Multiply(sum, 1.0f / 3.0f, out sum);
            geomCen = sum;

            JVector.Subtract(points[1], points[0], out sum);
            JVector.Subtract(points[2], points[0], out normal);
            JVector.Cross(sum, normal, out normal);
        }
Esempio n. 17
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        /// <summary>
        /// Initializes a new instance of the HingeJoint class.
        /// </summary>
        /// <param name="world">The world class where the constraints get added to.</param>
        /// <param name="body1">The first body connected to the second one.</param>
        /// <param name="body2">The second body connected to the first one.</param>
        /// <param name="position">The position in world space where both bodies get connected.</param>
        /// <param name="hingeAxis">The axis if the hinge.</param>
        public LimitedHingeJoint(JitterWorld world, RigidBody body1, RigidBody body2, JVector position, JVector hingeAxis,
                                 float hingeFwdAngle, float hingeBckAngle)
            : base(world)
        {
            // Create the hinge first, two point constraints

            worldPointConstraint = new PointOnPoint[2];

            hingeAxis *= 0.5f;

            JVector pos1 = position; JVector.Add(ref pos1, ref hingeAxis, out pos1);
            JVector pos2 = position; JVector.Subtract(ref pos2, ref hingeAxis, out pos2);

            worldPointConstraint[0] = new PointOnPoint(body1, body2, pos1);
            worldPointConstraint[1] = new PointOnPoint(body1, body2, pos2);


            // Now the limit, one max distance constraint

            hingeAxis.Normalize();

            // choose a direction that is perpendicular to the hinge
            JVector perpDir = JVector.Up;

            if (JVector.Dot(perpDir, hingeAxis) > 0.1f)
            {
                perpDir = JVector.Right;
            }

            // now make it perpendicular to the hinge
            JVector sideAxis = JVector.Cross(hingeAxis, perpDir);

            perpDir = JVector.Cross(sideAxis, hingeAxis);
            perpDir.Normalize();

            // the length of the "arm" TODO take this as a parameter? what's
            // the effect of changing it?
            float len = 10.0f * 3;

            // Choose a position using that dir. this will be the anchor point
            // for body 0. relative to hinge
            JVector hingeRelAnchorPos0 = perpDir * len;


            // anchor point for body 2 is chosen to be in the middle of the
            // angle range.  relative to hinge
            float   angleToMiddle      = 0.5f * (hingeFwdAngle - hingeBckAngle);
            JVector hingeRelAnchorPos1 = JVector.Transform(hingeRelAnchorPos0, JMatrix.CreateFromAxisAngle(hingeAxis, -angleToMiddle / 360.0f * 2.0f * JMath.Pi));

            // work out the "string" length
            float hingeHalfAngle  = 0.5f * (hingeFwdAngle + hingeBckAngle);
            float allowedDistance = len * 2.0f * (float)System.Math.Sin(hingeHalfAngle * 0.5f / 360.0f * 2.0f * JMath.Pi);

            JVector hingePos = body1.Position;
            JVector relPos0c = hingePos + hingeRelAnchorPos0;
            JVector relPos1c = hingePos + hingeRelAnchorPos1;

            distance          = new PointPointDistance(body1, body2, relPos0c, relPos1c);
            distance.Distance = allowedDistance;
            distance.Behavior = PointPointDistance.DistanceBehavior.LimitMaximumDistance;
        }
Esempio n. 18
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 public void GetNormal(out JVector normal)
 {
     JVector.Subtract(Owner.points[indices.I1].position, Owner.points[indices.I0].position, out var sum);
     JVector.Subtract(Owner.points[indices.I2].position, Owner.points[indices.I0].position, out normal);
     JVector.Cross(sum, normal, out normal);
 }
Esempio n. 19
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        /// <summary>
        /// Calculates the cross product of two vectors.
        /// </summary>
        /// <param name="value1">The first vector.</param>
        /// <param name="value2">The second vector.</param>
        /// <returns>Returns the cross product of both.</returns>
        #region public static JVector operator %(JVector value1, JVector value2)
        public static JVector operator %(JVector value1, JVector value2)
        {
            JVector result; JVector.Cross(ref value1, ref value2, out result);

            return(result);
        }
Esempio n. 20
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        /// <summary>
        /// Checks two shapes for collisions.
        /// </summary>
        /// <param name="support1">The SupportMappable implementation of the first shape to test.</param>
        /// <param name="support2">The SupportMappable implementation of the seconds shape to test.</param>
        /// <param name="orientation1">The orientation of the first shape.</param>
        /// <param name="orientation2">The orientation of the second shape.</param>
        /// <param name="position1">The position of the first shape.</param>
        /// <param name="position2">The position of the second shape</param>
        /// <param name="point">The pointin world coordinates, where collision occur.</param>
        /// <param name="normal">The normal pointing from body2 to body1.</param>
        /// <param name="penetration">Estimated penetration depth of the collision.</param>
        /// <returns>Returns true if there is a collision, false otherwise.</returns>
        public static bool Detect(ISupportMappable support1, ISupportMappable support2, ref JMatrix orientation1,
                                  ref JMatrix orientation2, ref JVector position1, ref JVector position2,
                                  out JVector point, out JVector normal, out float penetration)
        {
            // Used variables
            JVector temp1, temp2;
            JVector v01, v02, v0;
            JVector v11, v12, v1;
            JVector v21, v22, v2;
            JVector v31, v32, v3;
            JVector v41, v42, v4;
            JVector mn;

            // Initialization of the output
            point       = normal = JVector.Zero;
            penetration = 0.0f;

            //JVector right = JVector.Right;

            // Get the center of shape1 in world coordinates -> v01
            support1.SupportCenter(out v01);
            JVector.Transform(ref v01, ref orientation1, out v01);
            JVector.Add(ref position1, ref v01, out v01);

            // Get the center of shape2 in world coordinates -> v02
            support2.SupportCenter(out v02);
            JVector.Transform(ref v02, ref orientation2, out v02);
            JVector.Add(ref position2, ref v02, out v02);

            // v0 is the center of the minkowski difference
            JVector.Subtract(ref v02, ref v01, out v0);

            // Avoid case where centers overlap -- any direction is fine in this case
            if (v0.IsNearlyZero())
            {
                v0 = new JVector(0.00001f, 0, 0);
            }

            // v1 = support in direction of origin
            mn = v0;
            JVector.Negate(ref v0, out normal);

            SupportMapTransformed(support1, ref orientation1, ref position1, ref mn, out v11);
            SupportMapTransformed(support2, ref orientation2, ref position2, ref normal, out v12);
            JVector.Subtract(ref v12, ref v11, out v1);

            if (JVector.Dot(ref v1, ref normal) <= 0.0f)
            {
                return(false);
            }

            // v2 = support perpendicular to v1,v0
            JVector.Cross(ref v1, ref v0, out normal);

            if (normal.IsNearlyZero())
            {
                JVector.Subtract(ref v1, ref v0, out normal);

                normal.Normalize();

                point = v11;
                JVector.Add(ref point, ref v12, out point);
                JVector.Multiply(ref point, 0.5f, out point);

                JVector.Subtract(ref v12, ref v11, out temp1);
                penetration = JVector.Dot(ref temp1, ref normal);

                //point = v11;
                //point2 = v12;
                return(true);
            }

            JVector.Negate(ref normal, out mn);
            SupportMapTransformed(support1, ref orientation1, ref position1, ref mn, out v21);
            SupportMapTransformed(support2, ref orientation2, ref position2, ref normal, out v22);
            JVector.Subtract(ref v22, ref v21, out v2);

            if (JVector.Dot(ref v2, ref normal) <= 0.0f)
            {
                return(false);
            }

            // Determine whether origin is on + or - side of plane (v1,v0,v2)
            JVector.Subtract(ref v1, ref v0, out temp1);
            JVector.Subtract(ref v2, ref v0, out temp2);
            JVector.Cross(ref temp1, ref temp2, out normal);

            float dist = JVector.Dot(ref normal, ref v0);

            // If the origin is on the - side of the plane, reverse the direction of the plane
            if (dist > 0.0f)
            {
                JVector.Swap(ref v1, ref v2);
                JVector.Swap(ref v11, ref v21);
                JVector.Swap(ref v12, ref v22);
                JVector.Negate(ref normal, out normal);
            }


            int  phase2 = 0;
            int  phase1 = 0;
            bool hit    = false;

            // Phase One: Identify a portal
            while (true)
            {
                if (phase1 > MaximumIterations)
                {
                    return(false);
                }

                phase1++;

                // Obtain the support point in a direction perpendicular to the existing plane
                // Note: This point is guaranteed to lie off the plane
                JVector.Negate(ref normal, out mn);
                SupportMapTransformed(support1, ref orientation1, ref position1, ref mn, out v31);
                SupportMapTransformed(support2, ref orientation2, ref position2, ref normal, out v32);
                JVector.Subtract(ref v32, ref v31, out v3);

                if (JVector.Dot(ref v3, ref normal) <= 0.0f)
                {
                    return(false);
                }

                // If origin is outside (v1,v0,v3), then eliminate v2 and loop
                JVector.Cross(ref v1, ref v3, out temp1);
                if (JVector.Dot(ref temp1, ref v0) < 0.0f)
                {
                    v2  = v3;
                    v21 = v31;
                    v22 = v32;
                    JVector.Subtract(ref v1, ref v0, out temp1);
                    JVector.Subtract(ref v3, ref v0, out temp2);
                    JVector.Cross(ref temp1, ref temp2, out normal);
                    continue;
                }

                // If origin is outside (v3,v0,v2), then eliminate v1 and loop
                JVector.Cross(ref v3, ref v2, out temp1);
                if (JVector.Dot(ref temp1, ref v0) < 0.0f)
                {
                    v1  = v3;
                    v11 = v31;
                    v12 = v32;
                    JVector.Subtract(ref v3, ref v0, out temp1);
                    JVector.Subtract(ref v2, ref v0, out temp2);
                    JVector.Cross(ref temp1, ref temp2, out normal);
                    continue;
                }

                // Phase Two: Refine the portal
                // We are now inside of a wedge...
                while (true)
                {
                    phase2++;

                    // Compute normal of the wedge face
                    JVector.Subtract(ref v2, ref v1, out temp1);
                    JVector.Subtract(ref v3, ref v1, out temp2);
                    JVector.Cross(ref temp1, ref temp2, out normal);

                    // Can this happen???  Can it be handled more cleanly?
                    if (normal.IsNearlyZero())
                    {
                        return(true);
                    }

                    normal.Normalize();

                    // Compute distance from origin to wedge face
                    float d = JVector.Dot(ref normal, ref v1);


                    // If the origin is inside the wedge, we have a hit
                    if (d >= 0 && !hit)
                    {
                        // HIT!!!
                        hit = true;
                    }

                    // Find the support point in the direction of the wedge face
                    JVector.Negate(ref normal, out mn);
                    SupportMapTransformed(support1, ref orientation1, ref position1, ref mn, out v41);
                    SupportMapTransformed(support2, ref orientation2, ref position2, ref normal, out v42);
                    JVector.Subtract(ref v42, ref v41, out v4);

                    JVector.Subtract(ref v4, ref v3, out temp1);
                    float delta = JVector.Dot(ref temp1, ref normal);
                    penetration = JVector.Dot(ref v4, ref normal);

                    // If the boundary is thin enough or the origin is outside the support plane for the newly discovered vertex, then we can terminate
                    if (delta <= CollideEpsilon || penetration <= 0.0f || phase2 > MaximumIterations)
                    {
                        if (hit)
                        {
                            JVector.Cross(ref v1, ref v2, out temp1);
                            float b0 = JVector.Dot(ref temp1, ref v3);
                            JVector.Cross(ref v3, ref v2, out temp1);
                            float b1 = JVector.Dot(ref temp1, ref v0);
                            JVector.Cross(ref v0, ref v1, out temp1);
                            float b2 = JVector.Dot(ref temp1, ref v3);
                            JVector.Cross(ref v2, ref v1, out temp1);
                            float b3 = JVector.Dot(ref temp1, ref v0);

                            float sum = b0 + b1 + b2 + b3;

                            if (sum <= 0)
                            {
                                b0 = 0;
                                JVector.Cross(ref v2, ref v3, out temp1);
                                b1 = JVector.Dot(ref temp1, ref normal);
                                JVector.Cross(ref v3, ref v1, out temp1);
                                b2 = JVector.Dot(ref temp1, ref normal);
                                JVector.Cross(ref v1, ref v2, out temp1);
                                b3 = JVector.Dot(ref temp1, ref normal);

                                sum = b1 + b2 + b3;
                            }

                            float inv = 1.0f / sum;

                            JVector.Multiply(ref v01, b0, out point);
                            JVector.Multiply(ref v11, b1, out temp1);
                            JVector.Add(ref point, ref temp1, out point);
                            JVector.Multiply(ref v21, b2, out temp1);
                            JVector.Add(ref point, ref temp1, out point);
                            JVector.Multiply(ref v31, b3, out temp1);
                            JVector.Add(ref point, ref temp1, out point);

                            JVector.Multiply(ref v02, b0, out temp2);
                            JVector.Add(ref temp2, ref point, out point);
                            JVector.Multiply(ref v12, b1, out temp1);
                            JVector.Add(ref point, ref temp1, out point);
                            JVector.Multiply(ref v22, b2, out temp1);
                            JVector.Add(ref point, ref temp1, out point);
                            JVector.Multiply(ref v32, b3, out temp1);
                            JVector.Add(ref point, ref temp1, out point);

                            JVector.Multiply(ref point, inv * 0.5f, out point);
                        }

                        // Compute the barycentric coordinates of the origin
                        return(hit);
                    }

                    ////// Compute the tetrahedron dividing face (v4,v0,v1)
                    //JVector.Cross(ref v4, ref v1, out temp1);
                    //float d1 = JVector.Dot(ref temp1, ref v0);


                    ////// Compute the tetrahedron dividing face (v4,v0,v2)
                    //JVector.Cross(ref v4, ref v2, out temp1);
                    //float d2 = JVector.Dot(ref temp1, ref v0);


                    // Compute the tetrahedron dividing face (v4,v0,v3)
                    JVector.Cross(ref v4, ref v0, out temp1);
                    float dot = JVector.Dot(ref temp1, ref v1);

                    if (dot >= 0.0f)
                    {
                        dot = JVector.Dot(ref temp1, ref v2);

                        if (dot >= 0.0f)
                        {
                            // Inside d1 & inside d2 ==> eliminate v1
                            v1  = v4;
                            v11 = v41;
                            v12 = v42;
                        }
                        else
                        {
                            // Inside d1 & outside d2 ==> eliminate v3
                            v3  = v4;
                            v31 = v41;
                            v32 = v42;
                        }
                    }
                    else
                    {
                        dot = JVector.Dot(ref temp1, ref v3);

                        if (dot >= 0.0f)
                        {
                            // Outside d1 & inside d3 ==> eliminate v2
                            v2  = v4;
                            v21 = v41;
                            v22 = v42;
                        }
                        else
                        {
                            // Outside d1 & outside d3 ==> eliminate v1
                            v1  = v4;
                            v11 = v41;
                            v12 = v42;
                        }
                    }
                }
            }
        }
Esempio n. 21
0
        public void PreStep(float timeStep)
        {
            float vel = car.LinearVelocity.Length();

            SideFriction    = 2.5f - JMath.Clamp(vel / 20.0f, 0.0f, 1.4f);
            ForwardFriction = 5.5f - JMath.Clamp(vel / 20.0f, 0.0f, 5.4f);

            JVector force = JVector.Zero;

            JVector worldAxis = JVector.Transform(JVector.Up, car.Orientation);
            JVector worldPos  = car.Position + JVector.Transform(Position, car.Orientation);

            JVector forward = new JVector(-car.Orientation.M31, -car.Orientation.M32, -car.Orientation.M33);

            JVector wheelFwd  = JVector.Transform(forward, JMatrix.CreateFromAxisAngle(JVector.Up, SteerAngle / 360 * 2 * JMath.Pi));
            JVector wheelLeft = JVector.Cross(JVector.Up, wheelFwd); wheelLeft.Normalize();
            JVector wheelUp   = JVector.Cross(wheelFwd, wheelLeft);

            float rayLen = 2.0f * Radius + WheelTravel;

            JVector wheelRayStart = worldPos;
            JVector wheelDelta    = -Radius * worldAxis;
            JVector wheelRayEnd   = worldPos + wheelDelta;

            float deltaFwd      = (2.0f * Radius) / (NumberOfRays + 1);
            float deltaFwdStart = deltaFwd;

            lastDisplacement = displacement;
            displacement     = 0.0f;

            lastOnFloor = false;

            JVector rayOrigin = car.Position + JVector.Transform(Position, car.Orientation);

            JVector   groundNormal = JVector.Zero;
            JVector   groundPos    = JVector.Zero;
            float     deepestFrac  = float.MaxValue;
            RigidBody worldBody    = null;

            for (int i = 0; i < NumberOfRays; i++)
            {
                float distFwd = (deltaFwdStart + i * deltaFwd) - Radius;
                float zOffset = Radius * (1.0f - (float)Math.Cos(Math.PI / 4 * (distFwd / Radius)));

                JVector newOrigin = wheelRayStart + distFwd * wheelFwd + zOffset * wheelUp;

                RigidBody body; JVector normal; float frac;
                bool      result = world.CollisionSystem.Raycast(newOrigin, wheelDelta,
                                                                 raycast, out body, out normal, out frac);



                if (result && frac <= 1.0f)
                {
                    if (frac < deepestFrac)
                    {
                        deepestFrac  = frac;
                        groundPos    = rayOrigin + frac * wheelDelta;
                        worldBody    = body;
                        groundNormal = normal;
                    }

                    lastOnFloor = true;
                }
            }

            if (!lastOnFloor)
            {
                return;
            }

            if (groundNormal.LengthSquared() > 0.0f)
            {
                groundNormal.Normalize();
            }

            // System.Diagnostics.Debug.WriteLine(groundPos.ToString());


            displacement = rayLen * (1.0f - deepestFrac);
            displacement = JMath.Clamp(displacement, 0.0f, WheelTravel);

            float displacementForceMag = displacement * Spring;

            // reduce force when suspension is par to ground
            displacementForceMag *= Math.Abs(JVector.Dot(groundNormal, worldAxis));

            // apply damping
            float dampingForceMag = upSpeed * Damping;

            float totalForceMag = displacementForceMag + dampingForceMag;

            if (totalForceMag < 0.0f)
            {
                totalForceMag = 0.0f;
            }

            JVector extraForce = totalForceMag * worldAxis;

            force += extraForce;

            JVector groundUp   = groundNormal;
            JVector groundLeft = JVector.Cross(groundNormal, wheelFwd);

            if (groundLeft.LengthSquared() > 0.0f)
            {
                groundLeft.Normalize();
            }

            JVector groundFwd = JVector.Cross(groundLeft, groundUp);

            JVector wheelPointVel = car.LinearVelocity +
                                    JVector.Cross(car.AngularVelocity, JVector.Transform(Position, car.Orientation));

            // rimVel=(wxr)*v
            JVector rimVel = angVel * JVector.Cross(wheelLeft, groundPos - worldPos);

            wheelPointVel += rimVel;

            JVector worldVel = worldBody.LinearVelocity +
                               JVector.Cross(worldBody.AngularVelocity, groundPos - worldBody.Position);

            wheelPointVel -= worldVel;

            // sideways forces
            float noslipVel  = 0.1f;
            float slipVel    = 0.1f;
            float slipFactor = 0.7f;

            float smallVel = 3;
            float friction = SideFriction;

            float sideVel = JVector.Dot(wheelPointVel, groundLeft);

            if ((sideVel > slipVel) || (sideVel < -slipVel))
            {
                friction *= slipFactor;
            }
            else
            if ((sideVel > noslipVel) || (sideVel < -noslipVel))
            {
                friction *= 1.0f - (1.0f - slipFactor) * (System.Math.Abs(sideVel) - noslipVel) / (slipVel - noslipVel);
            }

            if (sideVel < 0.0f)
            {
                friction *= -1.0f;
            }

            if (System.Math.Abs(sideVel) < smallVel)
            {
                friction *= System.Math.Abs(sideVel) / smallVel;
            }

            float sideForce = -friction * totalForceMag;

            extraForce = sideForce * groundLeft;
            force     += extraForce;

            // fwd/back forces
            friction = ForwardFriction;
            float fwdVel = JVector.Dot(wheelPointVel, groundFwd);

            if ((fwdVel > slipVel) || (fwdVel < -slipVel))
            {
                friction *= slipFactor;
            }
            else
            if ((fwdVel > noslipVel) || (fwdVel < -noslipVel))
            {
                friction *= 1.0f - (1.0f - slipFactor) * (System.Math.Abs(fwdVel) - noslipVel) / (slipVel - noslipVel);
            }

            if (fwdVel < 0.0f)
            {
                friction *= -1.0f;
            }

            if (System.Math.Abs(fwdVel) < smallVel)
            {
                friction *= System.Math.Abs(fwdVel) / smallVel;
            }

            float fwdForce = -friction * totalForceMag;

            extraForce = fwdForce * groundFwd;
            force     += extraForce;

            // fwd force also spins the wheel
            JVector wheelCentreVel = car.LinearVelocity +
                                     JVector.Cross(car.AngularVelocity, JVector.Transform(Position, car.Orientation));

            angVelForGrip = JVector.Dot(wheelCentreVel, groundFwd) / Radius;
            torque       += -fwdForce * Radius;

            // add force to car
            car.AddForce(force, groundPos + 0.5f * JVector.Up);

            // add force to the world
            if (!worldBody.IsStatic)
            {
                worldBody.AddForce(force * (-1) * 0.01f, groundPos);
            }
        }
Esempio n. 22
0
        /// <summary>
        /// PrepareForIteration has to be called before <see cref="Iterate"/>.
        /// </summary>
        /// <param name="timestep">The timestep of the simulation.</param>
        public void PrepareForIteration(float timestep)
        {
            if (body1.IsTrigger || body2.IsTrigger)
            {
                return;
            }

            float dvx, dvy;

            // relative velocity at contact point
            dvx = body2.linearVelocity.X + (-body2.angularVelocity * relativePos2.Y);
            dvy = body2.linearVelocity.Y + (body2.angularVelocity * relativePos2.X);

            dvx = dvx - body1.linearVelocity.X + (-body1.angularVelocity * relativePos1.Y);
            dvy = dvy - body1.linearVelocity.Y + (body1.angularVelocity * relativePos1.X);

            float kNormal = 0.0f;

            float rantra = 0.0f;

            // if body1 isn't static
            if (!treatBody1AsStatic)
            {
                // add it's mass to the mass normal
                kNormal += body1.inverseMass;

                // if body1 isn't a mass point (particle)
                if (!body1IsMassPoint)
                {
                    //
                    rantra = relativePos1.X * normal.Y - relativePos1.Y * normal.X;
                }
            }

            float rbntrb = 0.0f;

            // if body2 isn't static
            if (!treatBody2AsStatic)
            {
                // add it's mass to the mass normal
                kNormal += body2.inverseMass;

                // if body1 isn't a mass point (particle)
                if (!body2IsMassPoint)
                {
                    //
                    rbntrb = relativePos2.X * normal.Y - relativePos2.Y * normal.X;
                }
            }

            // compute overall mass normal
            if (!treatBody1AsStatic)
            {
                kNormal += body1.invInertia * (rantra * rantra);
            }
            if (!treatBody2AsStatic)
            {
                kNormal += body2.invInertia * (rbntrb * rbntrb);
            }

            massNormal = 1.0f / kNormal;

            tangent.X = -normal.Y;
            tangent.Y = normal.X;

            float kTangent = 0.0f;

            if (treatBody1AsStatic)
            {
                rantra = 0.0f;
            }
            else
            {
                kTangent += body1.inverseMass;

                if (!body1IsMassPoint)
                {
                    //
                    rantra = relativePos1.X * tangent.Y - relativePos1.Y * tangent.X;
                }
            }

            if (treatBody2AsStatic)
            {
                rbntrb = 0.0f;
            }
            else
            {
                kTangent += body2.inverseMass;

                if (!body2IsMassPoint)
                {
                    rantra = relativePos2.X * tangent.Y - relativePos2.Y * tangent.X;
                }
            }

            // compute overall mass tangent
            if (!treatBody1AsStatic)
            {
                kTangent += body1.invInertia * (rantra * rantra);
            }
            if (!treatBody2AsStatic)
            {
                kTangent += body2.invInertia * (rbntrb * rbntrb);
            }

            massTangent = 1.0f / kTangent;

            restitutionBias = lostSpeculativeBounce;

            speculativeVelocity = 0.0f;

            float relNormalVel = JVector.Dot(normal, body2.linearVelocity + JVector.Cross(body2.angularVelocity, relativePos2) - body1.linearVelocity + JVector.Cross(body1.angularVelocity, relativePos1));

            if (Penetration > settings.allowedPenetration)
            {
                restitutionBias = settings.bias * (1.0f / timestep) * JMath.Max(0.0f, Penetration - settings.allowedPenetration);
                restitutionBias = JMath.Clamp(restitutionBias, 0.0f, settings.maximumBias);
                //  body1IsMassPoint = body2IsMassPoint = false;
            }


            float timeStepRatio = timestep / lastTimeStep;

            accumulatedNormalImpulse  *= timeStepRatio;
            accumulatedTangentImpulse *= timeStepRatio;

            {
                // Static/Dynamic friction
                float relTangentVel     = -(tangent.X * dvx + tangent.Y * dvy);
                float tangentImpulse    = massTangent * relTangentVel;
                float maxTangentImpulse = -staticFriction * accumulatedNormalImpulse;

                if (tangentImpulse < maxTangentImpulse)
                {
                    friction = dynamicFriction;
                }
                else
                {
                    friction = staticFriction;
                }
            }

            JVector impulse;

            // Simultaneous solving and restitution is simply not possible
            // so fake it a bit by just applying restitution impulse when there
            // is a new contact.
            if (relNormalVel < -1.0f && newContact)
            {
                restitutionBias = Math.Max(-restitution * relNormalVel, restitutionBias);
            }

            // Speculative Contacts!
            // if the penetration is negative (which means the bodies are not already in contact, but they will
            // be in the future) we store the current bounce bias in the variable 'lostSpeculativeBounce'
            // and apply it the next frame, when the speculative contact was already solved.
            if (penetration < -settings.allowedPenetration)
            {
                speculativeVelocity = penetration / timestep;

                lostSpeculativeBounce = restitutionBias;
                restitutionBias       = 0.0f;
            }
            else
            {
                lostSpeculativeBounce = 0.0f;
            }

            // warm start

            impulse.X = normal.X * accumulatedNormalImpulse + tangent.X * accumulatedTangentImpulse;
            impulse.Y = normal.Y * accumulatedNormalImpulse + tangent.Y * accumulatedTangentImpulse;

            if (!treatBody1AsStatic)
            {
                body1.linearVelocity.X -= (impulse.X * body1.inverseMass);
                body1.linearVelocity.Y -= (impulse.Y * body1.inverseMass);

                if (!body1IsMassPoint)
                {
                    body1.angularVelocity -= body1.invInertia * (relativePos1.X * impulse.Y - relativePos1.Y * impulse.X);
                }
            }

            if (!treatBody2AsStatic)
            {
                body2.linearVelocity.X += (impulse.X * body2.inverseMass);
                body2.linearVelocity.Y += (impulse.Y * body2.inverseMass);

                if (!body2IsMassPoint)
                {
                    body2.angularVelocity += body2.invInertia * (relativePos2.X * impulse.Y - relativePos2.Y * impulse.X);
                }
            }

            lastTimeStep = timestep;

            newContact = false;
        }
Esempio n. 23
0
    public Vector3 GetPointVelocity(Vector3 point)
    {
        var velocity = Body.LinearVelocity + JVector.Cross(Body.AngularVelocity, point.ToJVector() - Body.Position);

        return(velocity.ToVector3());
    }