Exemplo n.º 1
0
        public unsafe void Test(ref BoxWide a, ref ConvexHullWide b, ref Vector <float> speculativeMargin, ref Vector3Wide offsetB, ref QuaternionWide orientationA, ref QuaternionWide orientationB, int pairCount, out Convex4ContactManifoldWide manifold)
        {
            Matrix3x3Wide.CreateFromQuaternion(orientationA, out var boxOrientation);
            Matrix3x3Wide.CreateFromQuaternion(orientationB, out var hullOrientation);
            Matrix3x3Wide.MultiplyByTransposeWithoutOverlap(boxOrientation, hullOrientation, out var hullLocalBoxOrientation);

            Matrix3x3Wide.TransformByTransposedWithoutOverlap(offsetB, hullOrientation, out var localOffsetB);
            Vector3Wide.Negate(localOffsetB, out var localOffsetA);
            Vector3Wide.Length(localOffsetA, out var centerDistance);
            Vector3Wide.Scale(localOffsetA, Vector <float> .One / centerDistance, out var initialNormal);
            var useInitialFallback = Vector.LessThan(centerDistance, new Vector <float>(1e-8f));

            initialNormal.X = Vector.ConditionalSelect(useInitialFallback, Vector <float> .Zero, initialNormal.X);
            initialNormal.Y = Vector.ConditionalSelect(useInitialFallback, Vector <float> .One, initialNormal.Y);
            initialNormal.Z = Vector.ConditionalSelect(useInitialFallback, Vector <float> .Zero, initialNormal.Z);
            var hullSupportFinder = default(ConvexHullSupportFinder);
            var boxSupportFinder  = default(BoxSupportFinder);

            ManifoldCandidateHelper.CreateInactiveMask(pairCount, out var inactiveLanes);
            b.EstimateEpsilonScale(inactiveLanes, out var hullEpsilonScale);
            var epsilonScale   = Vector.Min(Vector.Max(a.HalfWidth, Vector.Max(a.HalfHeight, a.HalfLength)), hullEpsilonScale);
            var depthThreshold = -speculativeMargin;

            DepthRefiner <ConvexHull, ConvexHullWide, ConvexHullSupportFinder, PhysicsBox, BoxWide, BoxSupportFinder> .FindMinimumDepth(
                b, a, localOffsetA, hullLocalBoxOrientation, ref hullSupportFinder, ref boxSupportFinder, initialNormal, inactiveLanes, 1e-5f *epsilonScale, depthThreshold,
                out var depth, out var localNormal, out var closestOnHull);

            inactiveLanes = Vector.BitwiseOr(inactiveLanes, Vector.LessThan(depth, depthThreshold));
            //Not every lane will generate contacts. Rather than requiring every lane to carefully clear all contactExists states, just clear them up front.
            manifold = default;
            manifold.Contact0Exists = default;
            manifold.Contact1Exists = default;
            manifold.Contact2Exists = default;
            manifold.Contact3Exists = default;
            if (Vector.LessThanAll(inactiveLanes, Vector <int> .Zero))
            {
                //No contacts generated.
                return;
            }


            //Identify the box face.
            Matrix3x3Wide.TransformByTransposedWithoutOverlap(localNormal, hullLocalBoxOrientation, out var localNormalInA);
            Vector3Wide.Abs(localNormalInA, out var absLocalNormalInA);
            var useX = Vector.BitwiseAnd(Vector.GreaterThan(absLocalNormalInA.X, absLocalNormalInA.Y), Vector.GreaterThan(absLocalNormalInA.X, absLocalNormalInA.Z));
            var useY = Vector.AndNot(Vector.GreaterThan(absLocalNormalInA.Y, absLocalNormalInA.Z), useX);

            Vector3Wide.ConditionalSelect(useX, hullLocalBoxOrientation.X, hullLocalBoxOrientation.Z, out var boxFaceNormal);
            Vector3Wide.ConditionalSelect(useY, hullLocalBoxOrientation.Y, boxFaceNormal, out boxFaceNormal);
            Vector3Wide.ConditionalSelect(useX, hullLocalBoxOrientation.Y, hullLocalBoxOrientation.X, out var boxFaceX);
            Vector3Wide.ConditionalSelect(useY, hullLocalBoxOrientation.Z, boxFaceX, out boxFaceX);
            Vector3Wide.ConditionalSelect(useX, hullLocalBoxOrientation.Z, hullLocalBoxOrientation.Y, out var boxFaceY);
            Vector3Wide.ConditionalSelect(useY, hullLocalBoxOrientation.X, boxFaceY, out boxFaceY);
            var negateFace =
                Vector.ConditionalSelect(useX, Vector.GreaterThan(localNormalInA.X, Vector <float> .Zero),
                                         Vector.ConditionalSelect(useY, Vector.GreaterThan(localNormalInA.Y, Vector <float> .Zero), Vector.GreaterThan(localNormalInA.Z, Vector <float> .Zero)));

            Vector3Wide.ConditionallyNegate(negateFace, ref boxFaceNormal);
            //Winding is important; flip the face bases if necessary.
            Vector3Wide.ConditionallyNegate(Vector.OnesComplement(negateFace), ref boxFaceX);
            var boxFaceHalfWidth    = Vector.ConditionalSelect(useX, a.HalfHeight, Vector.ConditionalSelect(useY, a.HalfLength, a.HalfWidth));
            var boxFaceHalfHeight   = Vector.ConditionalSelect(useX, a.HalfLength, Vector.ConditionalSelect(useY, a.HalfWidth, a.HalfHeight));
            var boxFaceNormalOffset = Vector.ConditionalSelect(useX, a.HalfWidth, Vector.ConditionalSelect(useY, a.HalfHeight, a.HalfLength));

            Vector3Wide.Scale(boxFaceNormal, boxFaceNormalOffset, out var boxFaceCenterOffset);
            Vector3Wide.Add(boxFaceCenterOffset, localOffsetA, out var boxFaceCenter);
            Vector3Wide.Scale(boxFaceX, boxFaceHalfWidth, out var boxFaceXOffset);
            Vector3Wide.Scale(boxFaceY, boxFaceHalfHeight, out var boxFaceYOffset);
            Vector3Wide.Subtract(boxFaceCenter, boxFaceXOffset, out var v0);
            Vector3Wide.Add(boxFaceCenter, boxFaceXOffset, out var v1);
            Vector3Wide.Subtract(v0, boxFaceYOffset, out var v00);
            Vector3Wide.Add(v0, boxFaceYOffset, out var v01);
            Vector3Wide.Subtract(v1, boxFaceYOffset, out var v10);
            Vector3Wide.Add(v1, boxFaceYOffset, out var v11);

            //To find the contact manifold, we'll clip the box edges against the hull face as usual, but we're dealing with potentially
            //distinct convex hulls. Rather than vectorizing over the different hulls, we vectorize within each hull.
            Helpers.FillVectorWithLaneIndices(out var slotOffsetIndices);
            var boundingPlaneEpsilon = 1e-3f * epsilonScale;
            //There can be no more than 8 contacts (provided there are no numerical errors); 2 per box edge.
            var candidates = stackalloc ManifoldCandidateScalar[8];

            for (int slotIndex = 0; slotIndex < pairCount; ++slotIndex)
            {
                if (inactiveLanes[slotIndex] < 0)
                {
                    continue;
                }
                ref var hull = ref b.Hulls[slotIndex];
                ConvexHullTestHelper.PickRepresentativeFace(ref hull, slotIndex, ref localNormal, closestOnHull, slotOffsetIndices, ref boundingPlaneEpsilon, out var slotFaceNormal, out var slotLocalNormal, out var bestFaceIndex);

                //Test each face edge plane against the box face.
                //Note that we do not use the faceNormal x edgeOffset edge plane, but rather edgeOffset x localNormal.
                //The faces are wound counterclockwise in right handed coordinates.
                //X is 00->10; Y is 10->11; Z is 11->01; W is 01->00.
                ref var v00Slot        = ref GatherScatter.GetOffsetInstance(ref v00, slotIndex);