예제 #1
0
        public ContainmentType Contains(BoundingBox box)
        {
            XMVector centerA  = this.center;
            XMVector extentsA = this.extents;

            XMVector centerB  = box.center;
            XMVector extentsB = box.extents;

            XMVector minA = centerA - extentsA;
            XMVector maxA = centerA + extentsA;

            XMVector minB = centerB - extentsB;
            XMVector maxB = centerB + extentsB;

            // for each i in (x, y, z) if a_min(i) > b_max(i) or b_min(i) > a_max(i) then return false
            XMVector disjoint = XMVector.OrInt(XMVector.Greater(minA, maxB), XMVector.Greater(minB, maxA));

            if (Internal.XMVector3AnyTrue(disjoint))
            {
                return(ContainmentType.Disjoint);
            }

            // for each i in (x, y, z) if a_min(i) <= b_min(i) and b_max(i) <= a_max(i) then A contains B
            XMVector inside = XMVector.AndInt(XMVector.LessOrEqual(minA, minB), XMVector.LessOrEqual(maxB, maxA));

            return(Internal.XMVector3AllTrue(inside) ? ContainmentType.Contains : ContainmentType.Intersects);
        }
예제 #2
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        public ContainmentType ContainedBy(
            XMVector plane0,
            XMVector plane1,
            XMVector plane2,
            XMVector plane3,
            XMVector plane4,
            XMVector plane5)
        {
            // Load the box.
            XMVector v_center  = this.center;
            XMVector v_extents = this.extents;

            // Set w of the center to one so we can dot4 with a plane.
            v_center.W = 1.0f;

            XMVector outside, inside;

            // Test against each plane.
            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane0, out outside, out inside);

            XMVector anyOutside = outside;
            XMVector allInside  = inside;

            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane1, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane2, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane3, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane4, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectAxisAlignedBoxPlane(v_center, v_extents, plane5, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            // If the box is outside any plane it is outside.
            if (XMVector4.EqualInt(anyOutside, XMVector.TrueInt))
            {
                return(ContainmentType.Disjoint);
            }

            // If the box is inside all planes it is inside.
            if (XMVector4.EqualInt(allInside, XMVector.TrueInt))
            {
                return(ContainmentType.Contains);
            }

            // The box is not inside all planes or outside a plane, it may intersect.
            return(ContainmentType.Intersects);
        }
예제 #3
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        public bool Intersects(XMVector origin, XMVector direction, out float distance)
        {
            Debug.Assert(Internal.XMVector3IsUnit(direction), "Reviewed");

            // Load the box.
            XMVector v_center  = this.center;
            XMVector v_extents = this.extents;

            // Adjust ray origin to be relative to center of the box.
            XMVector t_origin = v_center - origin;

            // Compute the dot product againt each axis of the box.
            // Since the axii are (1,0,0), (0,1,0), (0,0,1) no computation is necessary.
            XMVector axisDotOrigin    = t_origin;
            XMVector axisDotDirection = direction;

            // if (fabs(AxisDotDirection) <= Epsilon) the ray is nearly parallel to the slab.
            XMVector isParallel = XMVector.LessOrEqual(axisDotDirection.Abs(), CollisionGlobalConstants.RayEpsilon);

            // Test against all three axii simultaneously.
            XMVector inverseAxisDotDirection = axisDotDirection.Reciprocal();
            XMVector t1 = (axisDotOrigin - v_extents) * inverseAxisDotDirection;
            XMVector t2 = (axisDotOrigin + v_extents) * inverseAxisDotDirection;

            // Compute the max of min(t1,t2) and the min of max(t1,t2) ensuring we don't
            // use the results from any directions parallel to the slab.
            XMVector t_min = XMVector.Select(XMVector.Min(t1, t2), CollisionGlobalConstants.FltMin, isParallel);
            XMVector t_max = XMVector.Select(XMVector.Max(t1, t2), CollisionGlobalConstants.FltMax, isParallel);

            // t_min.x = maximum( t_min.x, t_min.y, t_min.z );
            // t_max.x = minimum( t_max.x, t_max.y, t_max.z );
            t_min = XMVector.Max(t_min, XMVector.SplatY(t_min));  // x = max(x,y)
            t_min = XMVector.Max(t_min, XMVector.SplatZ(t_min));  // x = max(max(x,y),z)
            t_max = XMVector.Min(t_max, XMVector.SplatY(t_max));  // x = min(x,y)
            t_max = XMVector.Min(t_max, XMVector.SplatZ(t_max));  // x = min(min(x,y),z)

            // if ( t_min > t_max ) return false;
            XMVector noIntersection = XMVector.Greater(XMVector.SplatX(t_min), XMVector.SplatX(t_max));

            // if ( t_max < 0.0f ) return false;
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(XMVector.SplatX(t_max), XMGlobalConstants.Zero));

            // if (IsParallel && (-Extents > AxisDotOrigin || Extents < AxisDotOrigin)) return false;
            XMVector parallelOverlap = axisDotOrigin.InBounds(v_extents);

            noIntersection = XMVector.OrInt(noIntersection, XMVector.AndComplementInt(isParallel, parallelOverlap));

            if (!Internal.XMVector3AnyTrue(noIntersection))
            {
                // Store the x-component to *pDist
                t_min.StoreFloat(out distance);
                return(true);
            }

            distance = 0.0f;
            return(false);
        }
        public bool Intersects(XMVector v0, XMVector v1, XMVector v2)
        {
            // Load the sphere.
            XMVector v_center = this.center;
            XMVector v_radius = XMVector.Replicate(this.radius);

            // Compute the plane of the triangle (has to be normalized).
            XMVector n = XMVector3.Normalize(XMVector3.Cross(v1 - v0, v2 - v0));

            // Assert that the triangle is not degenerate.
            Debug.Assert(!XMVector3.Equal(n, XMGlobalConstants.Zero), "Reviewed");

            // Find the nearest feature on the triangle to the sphere.
            XMVector dist = XMVector3.Dot(v_center - v0, n);

            // If the center of the sphere is farther from the plane of the triangle than
            // the radius of the sphere, then there cannot be an intersection.
            XMVector noIntersection = XMVector.Less(dist, -v_radius);

            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(dist, v_radius));

            // Project the center of the sphere onto the plane of the triangle.
            XMVector point = v_center - (n * dist);

            // Is it inside all the edges? If so we intersect because the distance
            // to the plane is less than the radius.
            XMVector intersection = Internal.PointOnPlaneInsideTriangle(point, v0, v1, v2);

            // Find the nearest point on each edge.
            XMVector radiusSq = v_radius * v_radius;

            // Edge 0,1
            point = Internal.PointOnLineSegmentNearestPoint(v0, v1, v_center);

            // If the distance to the center of the sphere to the point is less than
            // the radius of the sphere then it must intersect.
            intersection = XMVector.OrInt(intersection, XMVector.LessOrEqual(XMVector3.LengthSquare(v_center - point), radiusSq));

            // Edge 1,2
            point = Internal.PointOnLineSegmentNearestPoint(v1, v2, v_center);

            // If the distance to the center of the sphere to the point is less than
            // the radius of the sphere then it must intersect.
            intersection = XMVector.OrInt(intersection, XMVector.LessOrEqual(XMVector3.LengthSquare(v_center - point), radiusSq));

            // Edge 2,0
            point = Internal.PointOnLineSegmentNearestPoint(v2, v0, v_center);

            // If the distance to the center of the sphere to the point is less than
            // the radius of the sphere then it must intersect.
            intersection = XMVector.OrInt(intersection, XMVector.LessOrEqual(XMVector3.LengthSquare(v_center - point), radiusSq));

            return(XMVector4.EqualInt(XMVector.AndComplementInt(intersection, noIntersection), XMVector.TrueInt));
        }
        public bool Intersects(XMVector origin, XMVector direction, out float distance)
        {
            Debug.Assert(Internal.XMVector3IsUnit(direction), "Reviewed");

            XMVector v_center = this.center;
            XMVector v_radius = XMVector.Replicate(this.radius);

            // l is the vector from the ray origin to the center of the sphere.
            XMVector l = v_center - origin;

            // s is the projection of the l onto the ray direction.
            XMVector s = XMVector3.Dot(l, direction);

            XMVector l2 = XMVector3.Dot(l, l);

            XMVector r2 = v_radius * v_radius;

            // m2 is squared distance from the center of the sphere to the projection.
            XMVector m2 = l2 - (s * s);

            XMVector noIntersection;

            // If the ray origin is outside the sphere and the center of the sphere is
            // behind the ray origin there is no intersection.
            noIntersection = XMVector.AndInt(XMVector.Less(s, XMGlobalConstants.Zero), XMVector.Greater(l2, r2));

            // If the squared distance from the center of the sphere to the projection
            // is greater than the radius squared the ray will miss the sphere.
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(m2, r2));

            // The ray hits the sphere, compute the nearest intersection point.
            XMVector q  = (r2 - m2).Sqrt();
            XMVector t1 = s - q;
            XMVector t2 = s + q;

            XMVector originInside = XMVector.LessOrEqual(l2, r2);
            XMVector t            = XMVector.Select(t1, t2, originInside);

            if (XMVector4.NotEqualInt(noIntersection, XMVector.TrueInt))
            {
                // Store the x-component to *pDist.
                t.StoreFloat(out distance);
                return(true);
            }

            distance = 0.0f;
            return(false);
        }
예제 #6
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        public bool Intersects(BoundingBox box)
        {
            XMVector centerA  = this.center;
            XMVector extentsA = this.extents;

            XMVector centerB  = box.center;
            XMVector extentsB = box.extents;

            XMVector minA = centerA - extentsA;
            XMVector maxA = centerA + extentsA;

            XMVector minB = centerB - extentsB;
            XMVector maxB = centerB + extentsB;

            // for each i in (x, y, z) if a_min(i) > b_max(i) or b_min(i) > a_max(i) then return false
            XMVector disjoint = XMVector.OrInt(XMVector.Greater(minA, maxB), XMVector.Greater(minB, maxA));

            return(!Internal.XMVector3AnyTrue(disjoint));
        }
예제 #7
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        public static bool Intersects(XMVector origin, XMVector direction, XMVector v0, XMVector v1, XMVector v2, out float uCoordinate, out float vCoordinate, out float distance)
        {
            Debug.Assert(Internal.XMVector3IsUnit(direction), "Reviewed");

            XMVector zero = XMGlobalConstants.Zero;

            XMVector e1 = v1 - v0;
            XMVector e2 = v2 - v0;

            // p = Direction ^ e2;
            XMVector p = XMVector3.Cross(direction, e2);

            // det = e1 * p;
            XMVector det = XMVector3.Dot(e1, p);

            XMVector u, v, t;

            if (XMVector3.GreaterOrEqual(det, CollisionGlobalConstants.RayEpsilon))
            {
                // Determinate is positive (front side of the triangle).
                XMVector s = origin - v0;

                // u = s * p;
                u = XMVector3.Dot(s, p);

                XMVector noIntersection = XMVector.Less(u, zero);
                noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(u, det));

                // q = s ^ e1;
                XMVector q = XMVector3.Cross(s, e1);

                // v = Direction * q;
                v = XMVector3.Dot(direction, q);

                noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(v, zero));
                noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(u + v, det));

                // t = e2 * q;
                t = XMVector3.Dot(e2, q);

                noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(t, zero));

                if (XMVector4.EqualInt(noIntersection, XMVector.TrueInt))
                {
                    uCoordinate = 0.0f;
                    vCoordinate = 0.0f;
                    distance    = 0.0f;
                    return(false);
                }
            }
            else if (XMVector3.LessOrEqual(det, CollisionGlobalConstants.RayNegEpsilon))
            {
                // Determinate is negative (back side of the triangle).
                XMVector s = origin - v0;

                // u = s * p;
                u = XMVector3.Dot(s, p);

                XMVector noIntersection = XMVector.Greater(u, zero);
                noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(u, det));

                // q = s ^ e1;
                XMVector q = XMVector3.Cross(s, e1);

                // v = Direction * q;
                v = XMVector3.Dot(direction, q);

                noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(v, zero));
                noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(u + v, det));

                // t = e2 * q;
                t = XMVector3.Dot(e2, q);

                noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(t, zero));

                if (XMVector4.EqualInt(noIntersection, XMVector.TrueInt))
                {
                    uCoordinate = 0.0f;
                    vCoordinate = 0.0f;
                    distance    = 0.0f;
                    return(false);
                }
            }
            else
            {
                // Parallel ray.
                uCoordinate = 0.0f;
                vCoordinate = 0.0f;
                distance    = 0.0f;
                return(false);
            }

            // (u / det) and (v / dev) are the barycentric coordinates of the intersection.

            u = XMVector.Divide(u, det);
            v = XMVector.Divide(v, det);
            t = XMVector.Divide(t, det);

            // Store the x-component to *pDist
            u.StoreFloat(out uCoordinate);
            v.StoreFloat(out vCoordinate);
            t.StoreFloat(out distance);

            return(true);
        }
예제 #8
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        public static ContainmentType ContainedBy(
            XMVector v0,
            XMVector v1,
            XMVector v2,
            XMVector plane0,
            XMVector plane1,
            XMVector plane2,
            XMVector plane3,
            XMVector plane4,
            XMVector plane5)
        {
            XMVector one = XMGlobalConstants.One;

            // Set w of the points to one so we can dot4 with a plane.
            XMVector tV0 = new XMVector(v0.X, v0.Y, v0.Z, one.W);
            XMVector tV1 = new XMVector(v1.X, v1.Y, v1.Z, one.W);
            XMVector tV2 = new XMVector(v2.X, v2.Y, v2.Z, one.W);

            XMVector outside, inside;

            // Test against each plane.
            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane0, out outside, out inside);

            XMVector anyOutside = outside;
            XMVector allInside  = inside;

            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane1, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane2, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane3, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane4, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            Internal.FastIntersectTrianglePlane(tV0, tV1, tV2, plane5, out outside, out inside);
            anyOutside = XMVector.OrInt(anyOutside, outside);
            allInside  = XMVector.AndInt(allInside, inside);

            // If the triangle is outside any plane it is outside.
            if (XMVector4.EqualInt(anyOutside, XMVector.TrueInt))
            {
                return(ContainmentType.Disjoint);
            }

            // If the triangle is inside all planes it is inside.
            if (XMVector4.EqualInt(allInside, XMVector.TrueInt))
            {
                return(ContainmentType.Contains);
            }

            // The triangle is not inside all planes or outside a plane, it may intersect.
            return(ContainmentType.Intersects);
        }
예제 #9
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        public static bool Intersects(XMVector a0, XMVector a1, XMVector a2, XMVector b0, XMVector b1, XMVector b2)
        {
            XMVector selectY    = XMVector.FromInt((uint)XMSelection.Select0, (uint)XMSelection.Select1, (uint)XMSelection.Select0, (uint)XMSelection.Select0);
            XMVector selectZ    = XMVector.FromInt((uint)XMSelection.Select0, (uint)XMSelection.Select0, (uint)XMSelection.Select1, (uint)XMSelection.Select0);
            XMVector select0111 = XMVector.FromInt((uint)XMSelection.Select0, (uint)XMSelection.Select1, (uint)XMSelection.Select1, (uint)XMSelection.Select1);
            XMVector select1011 = XMVector.FromInt((uint)XMSelection.Select1, (uint)XMSelection.Select0, (uint)XMSelection.Select1, (uint)XMSelection.Select1);
            XMVector select1101 = XMVector.FromInt((uint)XMSelection.Select1, (uint)XMSelection.Select1, (uint)XMSelection.Select0, (uint)XMSelection.Select1);

            XMVector zero = XMGlobalConstants.Zero;

            // Compute the normal of triangle A.
            XMVector n1 = XMVector3.Cross(a1 - a0, a2 - a0);

            // Assert that the triangle is not degenerate.
            Debug.Assert(!XMVector3.Equal(n1, zero), "Reviewed");

            // Test points of B against the plane of A.
            XMVector b_dist = XMVector3.Dot(n1, b0 - a0);

            b_dist = XMVector.Select(b_dist, XMVector3.Dot(n1, b1 - a0), selectY);
            b_dist = XMVector.Select(b_dist, XMVector3.Dot(n1, b2 - a0), selectZ);

            // Ensure robustness with co-planar triangles by zeroing small distances.
            XMComparisonRecord b_distIsZeroCR;
            XMVector           b_distIsZero = XMVector.GreaterR(out b_distIsZeroCR, CollisionGlobalConstants.RayEpsilon, b_dist.Abs());

            b_dist = XMVector.Select(b_dist, zero, b_distIsZero);

            XMComparisonRecord b_distIsLessCR;
            XMVector           b_distIsLess = XMVector.GreaterR(out b_distIsLessCR, zero, b_dist);

            XMComparisonRecord b_distIsGreaterCR;
            XMVector           b_distIsGreater = XMVector.GreaterR(out b_distIsGreaterCR, b_dist, zero);

            // If all the points are on the same side we don't intersect.
            if (b_distIsLessCR.IsAllTrue || b_distIsGreaterCR.IsAllTrue)
            {
                return(false);
            }

            // Compute the normal of triangle B.
            XMVector n2 = XMVector3.Cross(b1 - b0, b2 - b0);

            // Assert that the triangle is not degenerate.
            Debug.Assert(!XMVector3.Equal(n2, zero), "Reviewed");

            // Test points of A against the plane of B.
            XMVector a_dist = XMVector3.Dot(n2, a0 - b0);

            a_dist = XMVector.Select(a_dist, XMVector3.Dot(n2, a1 - b0), selectY);
            a_dist = XMVector.Select(a_dist, XMVector3.Dot(n2, a2 - b0), selectZ);

            // Ensure robustness with co-planar triangles by zeroing small distances.
            XMComparisonRecord a_distIsZeroCR;
            XMVector           a_distIsZero = XMVector.GreaterR(out a_distIsZeroCR, CollisionGlobalConstants.RayEpsilon, b_dist.Abs());

            a_dist = XMVector.Select(a_dist, zero, a_distIsZero);

            XMComparisonRecord a_distIsLessCR;
            XMVector           a_distIsLess = XMVector.GreaterR(out a_distIsLessCR, zero, a_dist);

            XMComparisonRecord a_distIsGreaterCR;
            XMVector           a_distIsGreater = XMVector.GreaterR(out a_distIsGreaterCR, a_dist, zero);

            // If all the points are on the same side we don't intersect.
            if (a_distIsLessCR.IsAllTrue || a_distIsGreaterCR.IsAllTrue)
            {
                return(false);
            }

            // Special case for co-planar triangles.
            if (a_distIsZeroCR.IsAllTrue || b_distIsZeroCR.IsAllTrue)
            {
                XMVector axis, dist, minDist;

                // Compute an axis perpindicular to the edge (points out).
                axis = XMVector3.Cross(n1, a1 - a0);
                dist = XMVector3.Dot(axis, a0);

                // Test points of B against the axis.
                minDist = XMVector3.Dot(b0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(b1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(b2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                // Edge (A1, A2)
                axis = XMVector3.Cross(n1, a2 - a1);
                dist = XMVector3.Dot(axis, a1);

                minDist = XMVector3.Dot(b0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(b1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(b2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                // Edge (A2, A0)
                axis = XMVector3.Cross(n1, a0 - a2);
                dist = XMVector3.Dot(axis, a2);

                minDist = XMVector3.Dot(b0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(b1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(b2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                // Edge (B0, B1)
                axis = XMVector3.Cross(n2, b1 - b0);
                dist = XMVector3.Dot(axis, b0);

                minDist = XMVector3.Dot(a0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(a1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(a2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                // Edge (B1, B2)
                axis = XMVector3.Cross(n2, b2 - b1);
                dist = XMVector3.Dot(axis, b1);

                minDist = XMVector3.Dot(a0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(a1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(a2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                // Edge (B2,B0)
                axis = XMVector3.Cross(n2, b0 - b2);
                dist = XMVector3.Dot(axis, b2);

                minDist = XMVector3.Dot(a0, axis);
                minDist = XMVector.Min(minDist, XMVector3.Dot(a1, axis));
                minDist = XMVector.Min(minDist, XMVector3.Dot(a2, axis));
                if (XMVector4.GreaterOrEqual(minDist, dist))
                {
                    return(false);
                }

                return(true);
            }

            //// Find the single vertex of A and B (ie the vertex on the opposite side
            //// of the plane from the other two) and reorder the edges so we can compute
            //// the signed edge/edge distances.
            ////
            //// if ( (V0 >= 0 && V1 <  0 && V2 <  0) ||
            ////      (V0 >  0 && V1 <= 0 && V2 <= 0) ||
            ////      (V0 <= 0 && V1 >  0 && V2 >  0) ||
            ////      (V0 <  0 && V1 >= 0 && V2 >= 0) ) then V0 is singular;
            ////
            //// If our singular vertex is not on the positive side of the plane we reverse
            //// the triangle winding so that the overlap comparisons will compare the
            //// correct edges with the correct signs.

            XMVector a_distIsLessEqual    = XMVector.OrInt(a_distIsLess, a_distIsZero);
            XMVector a_distIsGreaterEqual = XMVector.OrInt(a_distIsGreater, a_distIsZero);

            XMVector aa0, aa1, aa2;
            bool     b_positiveA;

            if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreaterEqual, a_distIsLess, select0111)) ||
                Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreater, a_distIsLessEqual, select0111)))
            {
                // A0 is singular, crossing from positive to negative.
                aa0         = a0;
                aa1         = a1;
                aa2         = a2;
                b_positiveA = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsLessEqual, a_distIsGreater, select0111)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(a_distIsLess, a_distIsGreaterEqual, select0111)))
            {
                // A0 is singular, crossing from negative to positive.
                aa0         = a0;
                aa1         = a2;
                aa2         = a1;
                b_positiveA = false;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreaterEqual, a_distIsLess, select1011)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreater, a_distIsLessEqual, select1011)))
            {
                // A1 is singular, crossing from positive to negative.
                aa0         = a1;
                aa1         = a2;
                aa2         = a0;
                b_positiveA = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsLessEqual, a_distIsGreater, select1011)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(a_distIsLess, a_distIsGreaterEqual, select1011)))
            {
                // A1 is singular, crossing from negative to positive.
                aa0         = a1;
                aa1         = a0;
                aa2         = a2;
                b_positiveA = false;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreaterEqual, a_distIsLess, select1101)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(a_distIsGreater, a_distIsLessEqual, select1101)))
            {
                // A2 is singular, crossing from positive to negative.
                aa0         = a2;
                aa1         = a0;
                aa2         = a1;
                b_positiveA = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(a_distIsLessEqual, a_distIsGreater, select1101)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(a_distIsLess, a_distIsGreaterEqual, select1101)))
            {
                // A2 is singular, crossing from negative to positive.
                aa0         = a2;
                aa1         = a1;
                aa2         = a0;
                b_positiveA = false;
            }
            else
            {
                Debug.Assert(false, "Reviewed");
                return(false);
            }

            XMVector b_distIsLessEqual    = XMVector.OrInt(b_distIsLess, b_distIsZero);
            XMVector b_distIsGreaterEqual = XMVector.OrInt(b_distIsGreater, b_distIsZero);

            XMVector bb0, bb1, bb2;
            bool     b_positiveB;

            if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreaterEqual, b_distIsLess, select0111)) ||
                Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreater, b_distIsLessEqual, select0111)))
            {
                // B0 is singular, crossing from positive to negative.
                bb0         = b0;
                bb1         = b1;
                bb2         = b2;
                b_positiveB = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsLessEqual, b_distIsGreater, select0111)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(b_distIsLess, b_distIsGreaterEqual, select0111)))
            {
                // B0 is singular, crossing from negative to positive.
                bb0         = b0;
                bb1         = b2;
                bb2         = b1;
                b_positiveB = false;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreaterEqual, b_distIsLess, select1011)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreater, b_distIsLessEqual, select1011)))
            {
                // B1 is singular, crossing from positive to negative.
                bb0         = b1;
                bb1         = b2;
                bb2         = b0;
                b_positiveB = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsLessEqual, b_distIsGreater, select1011)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(b_distIsLess, b_distIsGreaterEqual, select1011)))
            {
                // B1 is singular, crossing from negative to positive.
                bb0         = b1;
                bb1         = b0;
                bb2         = b2;
                b_positiveB = false;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreaterEqual, b_distIsLess, select1101)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(b_distIsGreater, b_distIsLessEqual, select1101)))
            {
                // B2 is singular, crossing from positive to negative.
                bb0         = b2;
                bb1         = b0;
                bb2         = b1;
                b_positiveB = true;
            }
            else if (Internal.XMVector3AllTrue(XMVector.Select(b_distIsLessEqual, b_distIsGreater, select1101)) ||
                     Internal.XMVector3AllTrue(XMVector.Select(b_distIsLess, b_distIsGreaterEqual, select1101)))
            {
                // B2 is singular, crossing from negative to positive.
                bb0         = b2;
                bb1         = b1;
                bb2         = b0;
                b_positiveB = false;
            }
            else
            {
                Debug.Assert(false, "Reviewed");
                return(false);
            }

            XMVector delta0, delta1;

            // Reverse the direction of the test depending on whether the singular vertices are
            // the same sign or different signs.
            if (b_positiveA ^ b_positiveB)
            {
                delta0 = bb0 - aa0;
                delta1 = aa0 - bb0;
            }
            else
            {
                delta0 = aa0 - bb0;
                delta1 = bb0 - aa0;
            }

            // Check if the triangles overlap on the line of intersection between the
            // planes of the two triangles by finding the signed line distances.
            XMVector dist0 = XMVector3.Dot(delta0, XMVector3.Cross(bb2 - bb0, aa2 - aa0));

            if (XMVector4.Greater(dist0, zero))
            {
                return(false);
            }

            XMVector dist1 = XMVector3.Dot(delta1, XMVector3.Cross(bb1 - bb0, aa1 - aa0));

            if (XMVector4.Greater(dist1, zero))
            {
                return(false);
            }

            return(true);
        }
예제 #10
0
        public bool Intersects(XMVector v0, XMVector v1, XMVector v2)
        {
            XMVector zero = XMGlobalConstants.Zero;

            // Load the box.
            XMVector v_center  = this.center;
            XMVector v_extents = this.extents;

            XMVector boxMin = v_center - v_extents;
            XMVector boxMax = v_center + v_extents;

            // Test the axes of the box (in effect test the AAB against the minimal AAB
            // around the triangle).
            XMVector triMin = XMVector.Min(XMVector.Min(v0, v1), v2);
            XMVector triMax = XMVector.Max(XMVector.Max(v0, v1), v2);

            // for each i in (x, y, z) if a_min(i) > b_max(i) or b_min(i) > a_max(i) then disjoint
            XMVector disjoint = XMVector.OrInt(XMVector.Greater(triMin, boxMax), XMVector.Greater(boxMin, triMax));

            if (Internal.XMVector3AnyTrue(disjoint))
            {
                return(false);
            }

            // Test the plane of the triangle.
            XMVector normal = XMVector3.Cross(v1 - v0, v2 - v0);
            XMVector dist   = XMVector3.Dot(normal, v0);

            // Assert that the triangle is not degenerate.
            Debug.Assert(!XMVector3.Equal(normal, zero), "Reviewed");

            // for each i in (x, y, z) if n(i) >= 0 then v_min(i)=b_min(i), v_max(i)=b_max(i)
            // else v_min(i)=b_max(i), v_max(i)=b_min(i)
            XMVector normalSelect = XMVector.Greater(normal, zero);
            XMVector v_min        = XMVector.Select(boxMax, boxMin, normalSelect);
            XMVector v_max        = XMVector.Select(boxMin, boxMax, normalSelect);

            // if n dot v_min + d > 0 || n dot v_max + d < 0 then disjoint
            XMVector minDist = XMVector3.Dot(v_min, normal);
            XMVector maxDist = XMVector3.Dot(v_max, normal);

            XMVector noIntersection = XMVector.Greater(minDist, dist);

            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(maxDist, dist));

            // Move the box center to zero to simplify the following tests.
            XMVector tV0 = v0 - v_center;
            XMVector tV1 = v1 - v_center;
            XMVector tV2 = v2 - v_center;

            // Test the edge/edge axes (3*3).
            XMVector e0 = tV1 - tV0;
            XMVector e1 = tV2 - tV1;
            XMVector e2 = tV0 - tV2;

            // Make w zero.
            e0.W = zero.W;
            e1.W = zero.W;
            e2.W = zero.W;

            XMVector axis;
            XMVector p0, p1, p2;
            XMVector min, max;
            XMVector radius;

            //// Axis == (1,0,0) x e0 = (0, -e0.z, e0.y)
            axis = new XMVector(e1.W, -e0.Z, e1.Y, e1.X);
            p0   = XMVector3.Dot(tV0, axis);
            //// p1 = XMVector3Dot( V1, Axis ); // p1 = p0;
            p2             = XMVector3.Dot(tV2, axis);
            min            = XMVector.Min(p0, p2);
            max            = XMVector.Max(p0, p2);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (1,0,0) x e1 = (0, -e1.z, e1.y)
            axis = new XMVector(e1.W, -e1.Z, e1.Y, e1.X);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p1;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (1,0,0) x e2 = (0, -e2.z, e2.y)
            axis = new XMVector(e2.W, -e2.Z, e2.Y, e2.X);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p0;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,1,0) x e0 = (e0.z, 0, -e0.x)
            axis = new XMVector(e0.Z, e0.W, -e0.X, e0.Y);
            p0   = XMVector3.Dot(tV0, axis);
            //// p1 = XMVector3Dot( V1, Axis ); // p1 = p0;
            p2             = XMVector3.Dot(tV2, axis);
            min            = XMVector.Min(p0, p2);
            max            = XMVector.Max(p0, p2);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,1,0) x e1 = (e1.z, 0, -e1.x)
            axis = new XMVector(e1.Z, e1.W, -e1.X, e1.Y);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p1;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,0,1) x e2 = (e2.z, 0, -e2.x)
            axis = new XMVector(e2.Z, e2.W, -e2.X, e2.Y);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p0;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,0,1) x e0 = (-e0.y, e0.x, 0)
            axis = new XMVector(-e0.Y, e0.X, e0.W, e0.Z);
            p0   = XMVector3.Dot(tV0, axis);
            //// p1 = XMVector3Dot( V1, Axis ); // p1 = p0;
            p2             = XMVector3.Dot(tV2, axis);
            min            = XMVector.Min(p0, p2);
            max            = XMVector.Max(p0, p2);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,0,1) x e1 = (-e1.y, e1.x, 0)
            axis = new XMVector(-e1.Y, e1.X, e1.W, e1.Z);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p1;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            //// Axis == (0,0,1) x e2 = (-e2.y, e2.x, 0)
            axis = new XMVector(-e2.Y, e2.X, e2.W, e2.Z);
            p0   = XMVector3.Dot(tV0, axis);
            p1   = XMVector3.Dot(tV1, axis);
            //// p2 = XMVector3Dot( V2, Axis ); // p2 = p0;
            min            = XMVector.Min(p0, p1);
            max            = XMVector.Max(p0, p1);
            radius         = XMVector3.Dot(v_extents, axis.Abs());
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Greater(min, radius));
            noIntersection = XMVector.OrInt(noIntersection, XMVector.Less(max, -radius));

            return(XMVector4.NotEqualInt(noIntersection, XMVector.TrueInt));
        }