_xiaofang/xiaofang/Assets/Obi/Scripts/Common/Backends/Burst/BurstMath.cs
杨号敬 bcc74f0465 add
2024-12-18 02:18:45 +08:00

1023 lines
40 KiB
C#

#if (OBI_BURST && OBI_MATHEMATICS && OBI_COLLECTIONS)
using System;
using System.Collections.Generic;
using UnityEngine;
using Unity.Collections;
using Unity.Jobs;
using Unity.Mathematics;
using Unity.Burst;
using System.Runtime.CompilerServices;
using Unity.Collections.LowLevel.Unsafe;
using System.Threading;
namespace Obi
{
public static class BurstMath
{
public const float epsilon = 0.0000001f;
public const float zero = 0;
public const float one = 1;
public static readonly float golden = (math.sqrt(5.0f) + 1) / 2.0f;
public static unsafe void AddRange<T, U>(this NativeList<T> dst, U[] array) where T : unmanaged where U : unmanaged
{
var tsize = sizeof(T);
var usize = sizeof(U);
if (tsize == usize)
{
int dstIndex = dst.Length;
dst.ResizeUninitialized(dst.Length + array.Length);
fixed (U* srcPtr = array)
{
var dstPtr = (T*)dst.GetUnsafePtr() + dstIndex;
UnsafeUtility.MemCpy(dstPtr, srcPtr, usize * array.Length);
}
}
}
public static unsafe void AddReplicate<T, U>(this NativeList<T> dst, U value, int length) where T : unmanaged where U : unmanaged
{
var tsize = sizeof(T);
var usize = sizeof(U);
if (tsize == usize)
{
int dstIndex = dst.Length;
dst.ResizeUninitialized(dst.Length + length);
var dstPtr = (T*)dst.GetUnsafePtr() + dstIndex;
var srcPtr = UnsafeUtility.AddressOf(ref value);
UnsafeUtility.MemCpyReplicate(dstPtr, srcPtr, tsize, length);
}
}
public static float AtomicAdd(ref float location, float value)
{
float newCurrentValue = location;
while (true)
{
float currentValue = newCurrentValue;
float newValue = currentValue + value;
newCurrentValue = Interlocked.CompareExchange(ref location, newValue, currentValue);
if (newCurrentValue.Equals(currentValue))
return newValue;
}
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe static void AtomicAdd(NativeArray<float4> array, int p, float4 data)
{
float4* arr = (float4*)array.GetUnsafePtr();
AtomicAdd(ref arr[p].x, data.x);
AtomicAdd(ref arr[p].y, data.y);
AtomicAdd(ref arr[p].z, data.z);
AtomicAdd(ref arr[p].w, data.w);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public unsafe static void AtomicAdd(NativeArray<float> array, int p, float data)
{
float* arr = (float*)array.GetUnsafePtr();
AtomicAdd(ref arr[p], data);
}
// multiplies a column vector by a row vector.
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float3x3 multrnsp(in float4 column, in float4 row)
{
return new float3x3(column.xyz * row[0], column.xyz * row[1], column.xyz * row[2]);
}
// multiplies a column vector by a row vector.
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4x4 multrnsp4(in float4 column, float4 row)
{
row[3] = 0;
return new float4x4(column * row[0], column * row[1], column * row[2], float4.zero);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 project(this float4 vector, float4 onto)
{
float len = math.lengthsq(onto);
if (len < epsilon)
return float4.zero;
return math.dot(onto, vector) * onto / len;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float3 project(this float3 vector, float3 onto)
{
float len = math.lengthsq(onto);
if (len < epsilon)
return float3.zero;
return math.dot(onto, vector) * onto / len;
}
/*[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetInvParticleInertiaTensor(float4 principalRadii, float invRotationalMass)
{
float4 sqrRadii = principalRadii * principalRadii;
return new float4(5 * invRotationalMass / math.max(new float3(sqrRadii[1] + sqrRadii[2],
sqrRadii[0] + sqrRadii[2],
sqrRadii[0] + sqrRadii[1]), epsilon), 0);
}*/
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetParticleInertiaTensor(float4 principalRadii, float invRotationalMass)
{
float4 sqrRadii = principalRadii * principalRadii;
return 0.2f / (invRotationalMass + epsilon) * new float4(sqrRadii[1] + sqrRadii[2],
sqrRadii[0] + sqrRadii[2],
sqrRadii[0] + sqrRadii[1], 0);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4x4 TransformInertiaTensor(float4 tensor, quaternion rotation)
{
float4x4 rotMatrix = rotation.toMatrix();
return math.mul(rotMatrix, math.mul(tensor.asDiagonal(), math.transpose(rotMatrix)));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float RotationalInvMass(float4x4 inverseInertiaTensor, float4 point, float4 direction)
{
float4 cr = math.mul(inverseInertiaTensor, new float4(math.cross(point.xyz, direction.xyz), 0));
return math.dot(math.cross(cr.xyz, point.xyz), direction.xyz);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetParticleVelocityAtPoint(float4 position, float4 prevPosition, float4 point, float dt)
{
// no angular velocity, so calculate and return linear velocity only:
return BurstIntegration.DifferentiateLinear(position, prevPosition, dt);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetParticleVelocityAtPoint(float4 position, float4 prevPosition, quaternion orientation, quaternion prevOrientation, float4 point, float dt)
{
// calculate both linear and angular velocities:
float4 linearVelocity = BurstIntegration.DifferentiateLinear(position, prevPosition, dt);
float4 angularVelocity = BurstIntegration.DifferentiateAngular(orientation, prevOrientation, dt);
return linearVelocity + new float4(math.cross(angularVelocity.xyz, (point - prevPosition).xyz), 0);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetRigidbodyVelocityAtPoint(int rigidbodyIndex,
float4 point,
NativeArray<BurstRigidbody> rigidbodies,
NativeArray<float4> linearDeltas,
NativeArray<float4> angularDeltas,
BurstInertialFrame solverToWorld)
{
float4 linear = rigidbodies[rigidbodyIndex].velocity + linearDeltas[rigidbodyIndex];
float4 angular = rigidbodies[rigidbodyIndex].angularVelocity + angularDeltas[rigidbodyIndex];
float4 r = solverToWorld.frame.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
// calculate rigidbody velocity:
float4 wsRigidbodyVelocity = linear + new float4(math.cross(angular.xyz, r.xyz), 0);
// calculate solver velocity:
float4 wsSolverVelocity = solverToWorld.velocity + new float4(math.cross(solverToWorld.angularVelocity.xyz, point.xyz), 0);
// convert the resulting velocity back to solver space:
return solverToWorld.frame.InverseTransformVector(wsRigidbodyVelocity - wsSolverVelocity);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 GetRigidbodyVelocityAtPoint(int rigidbodyIndex,
float4 point,
NativeArray<BurstRigidbody> rigidbodies,
BurstInertialFrame solverToWorld)
{
float4 linear = rigidbodies[rigidbodyIndex].velocity;
float4 angular = rigidbodies[rigidbodyIndex].angularVelocity;
float4 r = solverToWorld.frame.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
// calculate rigidbody velocity:
float4 wsRigidbodyVelocity = linear + new float4(math.cross(angular.xyz, r.xyz), 0);
// calculate solver velocity:
float4 wsSolverVelocity = solverToWorld.velocity + new float4(math.cross(solverToWorld.angularVelocity.xyz, point.xyz), 0);
// Point is assumed to be expressed in solver space. Since rigidbodies are expressed in world space, we need to convert the
// point to world space, and convert the resulting velocity back to solver space.
return solverToWorld.frame.InverseTransformVector(wsRigidbodyVelocity - wsSolverVelocity);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void ApplyImpulse(int rigidbodyIndex,
float4 impulse,
float4 point,
NativeArray<BurstRigidbody> rigidbodies,
NativeArray<float4> linearDeltas,
NativeArray<float4> angularDeltas,
BurstAffineTransform solverToWorld)
{
float4 impulseWS = solverToWorld.TransformVector(impulse);
float4 r = solverToWorld.TransformPoint(point) - rigidbodies[rigidbodyIndex].com;
float4 linearDelta = rigidbodies[rigidbodyIndex].inverseMass * impulseWS;
float4 angularDelta = math.mul(rigidbodies[rigidbodyIndex].inverseInertiaTensor, new float4(math.cross(r.xyz, impulseWS.xyz), 0));
AtomicAdd(linearDeltas, rigidbodyIndex, linearDelta);
AtomicAdd(angularDeltas, rigidbodyIndex, angularDelta);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void ApplyDeltaQuaternion(int rigidbodyIndex,
quaternion rotation,
quaternion delta,
NativeArray<float4> angularDeltas,
BurstAffineTransform solverToWorld,
float dt)
{
quaternion rotationWS = math.mul(solverToWorld.rotation, rotation);
quaternion deltaWS = math.mul(solverToWorld.rotation, delta);
// convert quaternion delta to angular acceleration:
quaternion newRotation = math.normalize(new quaternion(rotationWS.value + deltaWS.value));
AtomicAdd(angularDeltas, rigidbodyIndex, BurstIntegration.DifferentiateAngular(newRotation, rotationWS, dt));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void OneSidedNormal(float4 forward, ref float4 normal)
{
float dot = math.dot(normal.xyz, forward.xyz);
if (dot < 0) normal -= 2 * dot * forward;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float EllipsoidRadius(float4 normSolverDirection, quaternion orientation, float3 radii)
{
float3 localDir = math.mul(math.conjugate(orientation), normSolverDirection.xyz);
float sqrNorm = math.lengthsq(localDir / radii);
return sqrNorm > epsilon ? math.sqrt(1 / sqrNorm) : radii.x;
}
public static quaternion ExtractRotation(float4x4 matrix, quaternion rotation, int iterations)
{
return ExtractRotation((float3x3)matrix, rotation, iterations);
}
public static quaternion ExtractRotation(float3x3 matrix, quaternion rotation, int iterations)
{
float3x3 R;
for (int i = 0; i < iterations; ++i)
{
R = rotation.toMatrix3();
float3 omega = (math.cross(R.c0, matrix.c0) + math.cross(R.c1, matrix.c1) + math.cross(R.c2, matrix.c2)) /
(math.abs(math.dot(R.c0, matrix.c0) + math.dot(R.c1, matrix.c1) + math.dot(R.c2, matrix.c2)) + epsilon);
float w = math.length(omega);
if (w < epsilon)
break;
rotation = math.normalize(math.mul(quaternion.AxisAngle((1.0f / w) * omega, w), rotation));
}
return rotation;
}
// decomposes a quaternion in swing and twist around a given axis:
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static void SwingTwist(quaternion q, float3 twistAxis, out quaternion swing, out quaternion twist)
{
float dot = math.dot(q.value.xyz, twistAxis);
float3 p = twistAxis * dot;
twist = math.normalizesafe(new quaternion(p[0], p[1], p[2], q.value.w));
swing = math.mul(q, math.conjugate(twist));
}
public static float4x4 toMatrix(this quaternion q)
{
float xx = q.value.x * q.value.x;
float xy = q.value.x * q.value.y;
float xz = q.value.x * q.value.z;
float xw = q.value.x * q.value.w;
float yy = q.value.y * q.value.y;
float yz = q.value.y * q.value.z;
float yw = q.value.y * q.value.w;
float zz = q.value.z * q.value.z;
float zw = q.value.z * q.value.w;
return new float4x4(1 - 2 * (yy + zz), 2 * (xy - zw), 2 * (xz + yw), 0,
2 * (xy + zw), 1 - 2 * (xx + zz), 2 * (yz - xw), 0,
2 * (xz - yw), 2 * (yz + xw), 1 - 2 * (xx + yy), 0,
0, 0, 0, 1);
}
public static float3x3 toMatrix3(this quaternion q)
{
float xx = q.value.x * q.value.x;
float xy = q.value.x * q.value.y;
float xz = q.value.x * q.value.z;
float xw = q.value.x * q.value.w;
float yy = q.value.y * q.value.y;
float yz = q.value.y * q.value.z;
float yw = q.value.y * q.value.w;
float zz = q.value.z * q.value.z;
float zw = q.value.z * q.value.w;
return new float3x3(1 - 2 * (yy + zz), 2 * (xy - zw), 2 * (xz + yw),
2 * (xy + zw), 1 - 2 * (xx + zz), 2 * (yz - xw),
2 * (xz - yw), 2 * (yz + xw), 1 - 2 * (xx + yy));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4x4 asDiagonal(this float4 v)
{
return new float4x4(v.x, 0, 0, 0,
0, v.y, 0, 0,
0, 0, v.z, 0,
0, 0, 0, v.w);
}
/**
* Modulo operator that also follows intuition for negative arguments. That is , -1 mod 3 = 2, not -1.
*/
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float3 nfmod(float3 a, float3 b)
{
return a - b * math.floor(a / b);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 diagonal(this float4x4 value)
{
return new float4(value.c0[0], value.c1[1], value.c2[2], value.c3[3]);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float frobeniusNorm(this float4x4 m)
{
return math.sqrt(math.lengthsq(m.c0) + math.lengthsq(m.c1) + math.lengthsq(m.c2) + math.lengthsq(m.c3));
}
public static void EigenSolve(float3x3 D, out float3 S, out float3x3 V)
{
// D is symmetric
// S is a vector whose elements are eigenvalues
// V is a matrix whose columns are eigenvectors
S = EigenValues(D);
float3 V0, V1, V2;
if (S[0] - S[1] > S[1] - S[2])
{
V0 = EigenVector(D, S[0]);
if (S[1] - S[2] < math.FLT_MIN_NORMAL)
{
V2 = V0.unitOrthogonal();
}
else
{
V2 = EigenVector(D, S[2]); V2 -= V0 * math.dot(V0, V2); V2 = math.normalize(V2);
}
V1 = math.cross(V2, V0);
}
else
{
V2 = EigenVector(D, S[2]);
if (S[0] - S[1] < math.FLT_MIN_NORMAL)
{
V1 = V2.unitOrthogonal();
}
else
{
V1 = EigenVector(D, S[1]); V1 -= V2 * math.dot(V2, V1); V1 = math.normalize(V1);
}
V0 = math.cross(V1, V2);
}
V.c0 = V0;
V.c1 = V1;
V.c2 = V2;
}
static float3 unitOrthogonal(this float3 input)
{
// Find a vector to cross() the input with.
if (!(input.x < input.z * epsilon)
|| !(input.y < input.z * epsilon))
{
float invnm = 1 / math.length(input.xy);
return new float3(-input.y * invnm, input.x * invnm, 0);
}
else
{
float invnm = 1 / math.length(input.yz);
return new float3(0, -input.z * invnm, input.y * invnm);
}
}
// D is symmetric, S is an eigen value
static float3 EigenVector(float3x3 D, float S)
{
// Compute a cofactor matrix of D - sI.
float3 c0 = D.c0; c0[0] -= S;
float3 c1 = D.c1; c1[1] -= S;
float3 c2 = D.c2; c2[2] -= S;
// Upper triangular matrix
float3 c0p = new float3(c1[1] * c2[2] - c2[1] * c2[1], 0, 0);
float3 c1p = new float3(c2[1] * c2[0] - c1[0] * c2[2], c0[0] * c2[2] - c2[0] * c2[0], 0);
float3 c2p = new float3(c1[0] * c2[1] - c1[1] * c2[0], c1[0] * c2[0] - c0[0] * c2[1], c0[0] * c1[1] - c1[0] * c1[0]);
// Get a column vector with a largest norm (non-zero).
float C01s = c1p[0] * c1p[0];
float C02s = c2p[0] * c2p[0];
float C12s = c2p[1] * c2p[1];
float3 norm = new float3(c0p[0] * c0p[0] + C01s + C02s,
C01s + c1p[1] * c1p[1] + C12s,
C02s + C12s + c2p[2] * c2p[2]);
// index of largest:
int index = 0;
if (norm[0] > norm[1] && norm[0] > norm[2])
index = 0;
else if (norm[1] > norm[0] && norm[1] > norm[2])
index = 1;
else
index = 2;
float3 V = float3.zero;
// special case
if (norm[index] < math.FLT_MIN_NORMAL)
{
V[0] = 1; return V;
}
if (index == 0)
{
V[0] = c0p[0]; V[1] = c1p[0]; V[2] = c2p[0];
}
else if (index == 1)
{
V[0] = c1p[0]; V[1] = c1p[1]; V[2] = c2p[1];
}
else
{
V = c2p;
}
return math.normalize(V);
}
static float3 EigenValues(float3x3 D)
{
float one_third = 1 / 3.0f;
float one_sixth = 1 / 6.0f;
float three_sqrt = math.sqrt(3.0f);
float3 c0 = D.c0;
float3 c1 = D.c1;
float3 c2 = D.c2;
float m = one_third * (c0[0] + c1[1] + c2[2]);
// K is D - I*diag(S)
float K00 = c0[0] - m;
float K11 = c1[1] - m;
float K22 = c2[2] - m;
float K01s = c1[0] * c1[0];
float K02s = c2[0] * c2[0];
float K12s = c2[1] * c2[1];
float q = 0.5f * (K00 * (K11 * K22 - K12s) - K22 * K01s - K11 * K02s) + c1[0] * c2[1] * c0[2];
float p = one_sixth * (K00 * K00 + K11 * K11 + K22 * K22 + 2 * (K01s + K02s + K12s));
float p_sqrt = math.sqrt(p);
float tmp = p * p * p - q * q;
float phi = one_third * math.atan2(math.sqrt(math.max(0, tmp)), q);
float phi_c = math.cos(phi);
float phi_s = math.sin(phi);
float sqrt_p_c_phi = p_sqrt * phi_c;
float sqrt_p_3_s_phi = p_sqrt * three_sqrt * phi_s;
float e0 = m + 2 * sqrt_p_c_phi;
float e1 = m - sqrt_p_c_phi - sqrt_p_3_s_phi;
float e2 = m - sqrt_p_c_phi + sqrt_p_3_s_phi;
float aux;
if (e0 > e1)
{
aux = e0;
e0 = e1;
e1 = aux;
}
if (e0 > e2)
{
aux = e0;
e0 = e2;
e2 = aux;
}
if (e1 > e2)
{
aux = e1;
e1 = e2;
e2 = aux;
}
return new float3(e2, e1, e0);
}
public struct CachedTri
{
public float4 vertex;
public float4 edge0;
public float4 edge1;
public float4 data;
public void Cache(float4 v1,
float4 v2,
float4 v3)
{
vertex = v1;
edge0 = v2 - v1;
edge1 = v3 - v1;
data = float4.zero;
data[0] = math.dot(edge0, edge0);
data[1] = math.dot(edge0, edge1);
data[2] = math.dot(edge1, edge1);
data[3] = data[0] * data[2] - data[1] * data[1];
}
}
public static float4 NearestPointOnTri(in CachedTri tri,
float4 p,
out float4 bary)
{
float4 v0 = tri.vertex - p;
float b0 = math.dot(tri.edge0, v0);
float b1 = math.dot(tri.edge1, v0);
float t0 = tri.data[1] * b1 - tri.data[2] * b0;
float t1 = tri.data[1] * b0 - tri.data[0] * b1;
if (t0 + t1 <= tri.data[3])
{
if (t0 < zero)
{
if (t1 < zero) // region 4
{
if (b0 < zero)
{
t1 = zero;
if (-b0 >= tri.data[0]) // V0
t0 = one;
else // E01
t0 = -b0 / tri.data[0];
}
else
{
t0 = zero;
if (b1 >= zero) // V0
t1 = zero;
else if (-b1 >= tri.data[2]) // V2
t1 = one;
else // E20
t1 = -b1 / tri.data[2];
}
}
else // region 3
{
t0 = zero;
if (b1 >= zero) // V0
t1 = zero;
else if (-b1 >= tri.data[2]) // V2
t1 = one;
else // E20
t1 = -b1 / tri.data[2];
}
}
else if (t1 < zero) // region 5
{
t1 = zero;
if (b0 >= zero) // V0
t0 = zero;
else if (-b0 >= tri.data[0]) // V1
t0 = one;
else // E01
t0 = -b0 / tri.data[0];
}
else // region 0, interior
{
float invDet = one / tri.data[3];
t0 *= invDet;
t1 *= invDet;
}
}
else
{
float tmp0, tmp1, numer, denom;
if (t0 < zero) // region 2
{
tmp0 = tri.data[1] + b0;
tmp1 = tri.data[2] + b1;
if (tmp1 > tmp0)
{
numer = tmp1 - tmp0;
denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
if (numer >= denom) // V1
{
t0 = one;
t1 = zero;
}
else // E12
{
t0 = numer / denom;
t1 = one - t0;
}
}
else
{
t0 = zero;
if (tmp1 <= zero) // V2
t1 = one;
else if (b1 >= zero) // V0
t1 = zero;
else // E20
t1 = -b1 / tri.data[2];
}
}
else if (t1 < zero) // region 6
{
tmp0 = tri.data[1] + b1;
tmp1 = tri.data[0] + b0;
if (tmp1 > tmp0)
{
numer = tmp1 - tmp0;
denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
if (numer >= denom) // V2
{
t1 = one;
t0 = zero;
}
else // E12
{
t1 = numer / denom;
t0 = one - t1;
}
}
else
{
t1 = zero;
if (tmp1 <= zero) // V1
t0 = one;
else if (b0 >= zero) // V0
t0 = zero;
else // E01
t0 = -b0 / tri.data[0];
}
}
else // region 1
{
numer = tri.data[2] + b1 - tri.data[1] - b0;
if (numer <= zero) // V2
{
t0 = zero;
t1 = one;
}
else
{
denom = tri.data[0] - 2 * tri.data[1] + tri.data[2];
if (numer >= denom) // V1
{
t0 = one;
t1 = zero;
}
else // 12
{
t0 = numer / denom;
t1 = one - t0;
}
}
}
}
bary = new float4(1 - (t0 + t1), t0, t1,0);
return tri.vertex + t0 * tri.edge0 + t1 * tri.edge1;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 NearestPointOnEdge(float4 a, float4 b, float4 p, out float mu, bool clampToSegment = true)
{
float4 ap = p - a;
float4 ab = b - a;
mu = math.dot(ap, ab) / math.dot(ab, ab);
if (clampToSegment)
mu = math.saturate(mu);
return a + ab * mu;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float3 NearestPointOnEdge(float3 a, float3 b, float3 p, out float mu, bool clampToSegment = true)
{
float3 ap = p - a;
float3 ab = b - a;
mu = math.dot(ap, ab) / math.dot(ab, ab);
if (clampToSegment)
mu = math.saturate(mu);
return a + ab * mu;
}
public static float4 NearestPointsTwoEdges(float4 a, float4 b, float4 c, float4 d, out float mu1, out float mu2)
{
float4 dc = d - c;
float lineDirSqrMag = math.dot(dc, dc);
float4 inPlaneA = a - (math.dot(a - c, dc) / lineDirSqrMag * dc);
float4 inPlaneB = b - (math.dot(b - c, dc) / lineDirSqrMag * dc);
float4 inPlaneBA = inPlaneB - inPlaneA;
float t = math.dot(c - inPlaneA, inPlaneBA) / math.dot(inPlaneBA, inPlaneBA);
//t = (inPlaneA != inPlaneB) ? t : 0f; // Zero's t if parallel
float4 segABtoLineCD = math.lerp(a, b, math.saturate(t));
float4 segCDtoSegAB = NearestPointOnEdge(c, d, segABtoLineCD, out mu1);
float4 segABtoSegCD = NearestPointOnEdge(a, b, segCDtoSegAB, out mu2);
return segCDtoSegAB;
}
public static float4 BaryCoords(in float4 A,
in float4 B,
in float4 C,
in float4 P)
{
// Compute vectors
float4 v0 = C - A;
float4 v1 = B - A;
float4 v2 = P - A;
// Compute dot products
float dot00 = math.dot(v0, v0);
float dot01 = math.dot(v0, v1);
float dot02 = math.dot(v0, v2);
float dot11 = math.dot(v1, v1);
float dot12 = math.dot(v1, v2);
// Compute barycentric coordinates
float det = dot00 * dot11 - dot01 * dot01;
if (math.abs(det) > epsilon)
{
float u = (dot11 * dot02 - dot01 * dot12) / det;
float v = (dot00 * dot12 - dot01 * dot02) / det;
return new float4(1 - u - v, v, u, 0);
}
return float4.zero;
}
public static float4 BaryCoords2(in float4 A,
in float4 B,
in float4 P)
{
float4 v0 = P - A;
float4 v1 = B - A;
float y = math.sqrt(math.dot(v0, v0) / (math.dot(v1, v1) + epsilon));
return new float4(1 - y, y, 0, 0);
}
public static float4 BaryIntrpl(in float4 p1, in float4 p2, in float4 p3, in float4 coords)
{
return coords[0] * p1 + coords[1] * p2 + coords[2] * p3;
}
public static float4 BaryIntrpl(in float4 p1, in float4 p2, in float4 coords)
{
return coords[0] * p1 + coords[1] * p2;
}
public static float BaryIntrpl(float p1, float p2, float p3, float4 coords)
{
return coords[0] * p1 + coords[1] * p2 + coords[2] * p3;
}
public static float BaryIntrpl(float p1, float p2, float4 coords)
{
return coords[0] * p1 + coords[1] * p2;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float BaryScale(float4 coords)
{
return 1.0f / math.dot(coords, coords);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 BarycenterForSimplexOfSize(int simplexSize)
{
float value = 1f / simplexSize;
float4 center = float4.zero;
for (int i = 0; i < simplexSize; ++i)
center[i] = value;
return center;
}
// https://fgiesen.wordpress.com/2009/12/13/decoding-morton-codes/
// "Insert" a 0 bit after each of the 16 low bits of x
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint Part1By1(uint x)
{
x &= 0x0000ffff; // x = ---- ---- ---- ---- fedc ba98 7654 3210
x = (x ^ (x << 8)) & 0x00ff00ff; // x = ---- ---- fedc ba98 ---- ---- 7654 3210
x = (x ^ (x << 4)) & 0x0f0f0f0f; // x = ---- fedc ---- ba98 ---- 7654 ---- 3210
x = (x ^ (x << 2)) & 0x33333333; // x = --fe --dc --ba --98 --76 --54 --32 --10
x = (x ^ (x << 1)) & 0x55555555; // x = -f-e -d-c -b-a -9-8 -7-6 -5-4 -3-2 -1-0
return x;
}
// "Insert" two 0 bits after each of the 10 low bits of x
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint Part1By2(uint x)
{
x &= 0x000003ff; // x = ---- ---- ---- ---- ---- --98 7654 3210
x = (x ^ (x << 16)) & 0xff0000ff; // x = ---- --98 ---- ---- ---- ---- 7654 3210
x = (x ^ (x << 8)) & 0x0300f00f; // x = ---- --98 ---- ---- 7654 ---- ---- 3210
x = (x ^ (x << 4)) & 0x030c30c3; // x = ---- --98 ---- 76-- --54 ---- 32-- --10
x = (x ^ (x << 2)) & 0x09249249; // x = ---- 9--8 --7- -6-- 5--4 --3- -2-- 1--0
return x;
}
// Inverse of Part1By1 - "delete" all odd-indexed bits
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint Compact1By1(uint x)
{
x &= 0x55555555; // x = -f-e -d-c -b-a -9-8 -7-6 -5-4 -3-2 -1-0
x = (x ^ (x >> 1)) & 0x33333333; // x = --fe --dc --ba --98 --76 --54 --32 --10
x = (x ^ (x >> 2)) & 0x0f0f0f0f; // x = ---- fedc ---- ba98 ---- 7654 ---- 3210
x = (x ^ (x >> 4)) & 0x00ff00ff; // x = ---- ---- fedc ba98 ---- ---- 7654 3210
x = (x ^ (x >> 8)) & 0x0000ffff; // x = ---- ---- ---- ---- fedc ba98 7654 3210
return x;
}
// Inverse of Part1By2 - "delete" all bits not at positions divisible by 3
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint Compact1By2(uint x)
{
x &= 0x09249249; // x = ---- 9--8 --7- -6-- 5--4 --3- -2-- 1--0
x = (x ^ (x >> 2)) & 0x030c30c3; // x = ---- --98 ---- 76-- --54 ---- 32-- --10
x = (x ^ (x >> 4)) & 0x0300f00f; // x = ---- --98 ---- ---- 7654 ---- ---- 3210
x = (x ^ (x >> 8)) & 0xff0000ff; // x = ---- --98 ---- ---- ---- ---- 7654 3210
x = (x ^ (x >> 16)) & 0x000003ff; // x = ---- ---- ---- ---- ---- --98 7654 3210
return x;
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint EncodeMorton2(uint2 coords)
{
return (Part1By1(coords.y) << 1) + Part1By1(coords.x);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint EncodeMorton3(uint3 coords)
{
return (Part1By2(coords.z) << 2) + (Part1By2(coords.y) << 1) + Part1By2(coords.x);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint3 DecodeMorton2(uint code)
{
return new uint3(Compact1By1(code >> 0), Compact1By1(code >> 1), 0);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static uint3 DecodeMorton3(uint code)
{
return new uint3(Compact1By2(code >> 0), Compact1By2(code >> 1), Compact1By2(code >> 2));
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float4 UnpackFloatRGBA(float v)
{
uint rgba = math.asuint(v);
float r = ((rgba & 0xff000000) >> 24) / 255f;
float g = ((rgba & 0x00ff0000) >> 16) / 255f;
float b = ((rgba & 0x0000ff00) >> 8) / 255f;
float a = (rgba & 0x000000ff) / 255f;
return new float4(r, g, b, a);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float PackFloatRGBA(float4 enc)
{
uint rgba = ((uint)(enc.x * 255f) << 24) +
((uint)(enc.y * 255f) << 16) +
((uint)(enc.z * 255f) << 8) +
(uint)(enc.w * 255f);
return math.asfloat(rgba);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float2 UnpackFloatRG(float v)
{
uint rgba = math.asuint(v);
float r = ((rgba & 0xffff0000) >> 16) / 65535f;
float g = (rgba & 0x0000ffff) / 65535f;
return new float2(r, g);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
public static float PackFloatRG(float2 enc)
{
uint rgba = ((uint)(enc.x * 65535f) << 16) +
(uint)(enc.y * 65535f);
return math.asfloat(rgba);
}
[MethodImpl(MethodImplOptions.AggressiveInlining)]
static float2 OctWrap(float2 v)
{
return (1.0f - math.abs(v.yx)) * new float2(v.x >= 0.0f ? 1.0f : -1.0f, v.y >= 0.0f ? 1.0f : -1.0f);
}
// use octahedral encoding to reduce to 2 coords, then pack them as two 16 bit values in a 32 bit float.
public static float OctEncode(float3 n)
{
n /= math.abs(n.x) + math.abs(n.y) + math.abs(n.z);
n.xy = n.z >= 0.0 ? n.xy : OctWrap(n.xy);
n.xy = n.xy * 0.5f + 0.5f;
uint nx = (uint)(n.x * 0xffff);
uint ny = (uint)(n.y * 0xffff);
return math.asfloat((nx << 16) | (ny & 0xffff));
}
public static float3 OctDecode(float k)
{
uint d = math.asuint(k);
float2 f = new float2((d >> 16) / 65535f, (d & 0xffff) / 65535f) * 2f - 1f;
float3 n = new float3(f.x, f.y, 1.0f - math.abs(f.x) - math.abs(f.y));
float t = math.saturate(-n.z);
n.x += n.x >= 0.0f ? -t : t;
n.y += n.y >= 0.0f ? -t : t;
return math.normalize(n);
}
public static float Remap01(float value, float min_, float max_)
{
return (math.min(value, max_) - math.min(value, min_)) / (max_ - min_);
}
public static float3 Sort(this float3 f)
{
float aux;
if (f.x > f.y)
{
aux = f.x;
f.x = f.y;
f.y = aux;
}
if (f.x > f.z)
{
aux = f.x;
f.x = f.z;
f.z = aux;
}
if (f.y > f.z)
{
aux = f.y;
f.y = f.z;
f.z = aux;
}
return new float3(f.z,f.y,f.x);
}
public static unsafe void RemoveRangeBurst<T>(this NativeList<T> list, int index, int count)
where T : unmanaged
{
#if ENABLE_UNITY_COLLECTIONS_CHECKS
if ((uint)index >= (uint)list.Length)
{
throw new IndexOutOfRangeException(
$"Index {index} is out of range in NativeList of '{list.Length}' Length.");
}
#endif
int elemSize = UnsafeUtility.SizeOf<T>();
byte* basePtr = (byte*)list.GetUnsafePtr();
UnsafeUtility.MemMove(basePtr + (index * elemSize), basePtr + ((index + count) * elemSize), elemSize * (list.Length - count - index));
// No easy way to change length so we just loop this unfortunately.
for (var i = 0; i < count; i++)
{
list.RemoveAtSwapBack(list.Length - 1);
}
}
}
}
#endif