image_framework_ymj/include/open3d/3rdparty/math/mat3.h
2024-12-06 16:25:16 +08:00

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/*
* Copyright 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MATH_MAT3_H_
#define MATH_MAT3_H_
#include <math/quat.h>
#include <math/TMatHelpers.h>
#include <math/vec3.h>
#include <math/compiler.h>
#include <limits.h>
#include <stdint.h>
#include <sys/types.h>
namespace filament {
namespace math {
// -------------------------------------------------------------------------------------
namespace details {
/**
* A 3x3 column-major matrix class.
*
* Conceptually a 3x3 matrix is a an array of 3 column vec3:
*
* mat3 m =
* \f$
* \left(
* \begin{array}{ccc}
* m[0] & m[1] & m[2] \\
* \end{array}
* \right)
* \f$
* =
* \f$
* \left(
* \begin{array}{ccc}
* m[0][0] & m[1][0] & m[2][0] \\
* m[0][1] & m[1][1] & m[2][1] \\
* m[0][2] & m[1][2] & m[2][2] \\
* \end{array}
* \right)
* \f$
* =
* \f$
* \left(
* \begin{array}{ccc}
* m(0,0) & m(0,1) & m(0,2) \\
* m(1,0) & m(1,1) & m(1,2) \\
* m(2,0) & m(2,1) & m(2,2) \\
* \end{array}
* \right)
* \f$
*
* m[n] is the \f$ n^{th} \f$ column of the matrix and is a vec3.
*
*/
template<typename T>
class MATH_EMPTY_BASES TMat33 :
public TVecUnaryOperators<TMat33, T>,
public TVecComparisonOperators<TMat33, T>,
public TVecAddOperators<TMat33, T>,
public TMatProductOperators<TMat33, T, TVec3>,
public TMatSquareFunctions<TMat33, T>,
public TMatTransform<TMat33, T>,
public TMatHelpers<TMat33, T> {
public:
enum no_init {
NO_INIT
};
typedef T value_type;
typedef T& reference;
typedef T const& const_reference;
typedef size_t size_type;
typedef TVec3<T> col_type;
typedef TVec3<T> row_type;
static constexpr size_t COL_SIZE = col_type::SIZE; // size of a column (i.e.: number of rows)
static constexpr size_t ROW_SIZE = row_type::SIZE; // size of a row (i.e.: number of columns)
static constexpr size_t NUM_ROWS = COL_SIZE;
static constexpr size_t NUM_COLS = ROW_SIZE;
private:
/*
* <-- N columns -->
*
* a[0][0] a[1][0] a[2][0] ... a[N][0] ^
* a[0][1] a[1][1] a[2][1] ... a[N][1] |
* a[0][2] a[1][2] a[2][2] ... a[N][2] M rows
* ... |
* a[0][M] a[1][M] a[2][M] ... a[N][M] v
*
* COL_SIZE = M
* ROW_SIZE = N
* m[0] = [ a[0][0] a[0][1] a[0][2] ... a[0][M] ]
*/
col_type m_value[NUM_COLS];
public:
// array access
inline constexpr col_type const& operator[](size_t column) const noexcept {
assert(column < NUM_COLS);
return m_value[column];
}
inline constexpr col_type& operator[](size_t column) noexcept {
assert(column < NUM_COLS);
return m_value[column];
}
/**
* constructors
*/
/**
* leaves object uninitialized. use with caution.
*/
constexpr explicit TMat33(no_init) noexcept {}
/**
* initialize to identity.
*
* \f$
* \left(
* \begin{array}{ccc}
* 1 & 0 & 0 \\
* 0 & 1 & 0 \\
* 0 & 0 & 1 \\
* \end{array}
* \right)
* \f$
*/
constexpr TMat33() noexcept;
/**
* initialize to Identity*scalar.
*
* \f$
* \left(
* \begin{array}{ccc}
* v & 0 & 0 \\
* 0 & v & 0 \\
* 0 & 0 & v \\
* \end{array}
* \right)
* \f$
*/
template<typename U>
constexpr explicit TMat33(U v) noexcept;
/**
* sets the diagonal to a vector.
*
* \f$
* \left(
* \begin{array}{ccc}
* v[0] & 0 & 0 \\
* 0 & v[1] & 0 \\
* 0 & 0 & v[2] \\
* \end{array}
* \right)
* \f$
*/
template<typename U>
constexpr explicit TMat33(const TVec3<U>& v) noexcept;
/**
* construct from another matrix of the same size
*/
template<typename U>
constexpr explicit TMat33(const TMat33<U>& rhs) noexcept;
/**
* construct from 3 column vectors.
*
* \f$
* \left(
* \begin{array}{ccc}
* v0 & v1 & v2 \\
* \end{array}
* \right)
* \f$
*/
template<typename A, typename B, typename C>
constexpr TMat33(const TVec3<A>& v0, const TVec3<B>& v1, const TVec3<C>& v2) noexcept;
/** construct from 9 elements in column-major form.
*
* \f$
* \left(
* \begin{array}{ccc}
* m[0][0] & m[1][0] & m[2][0] \\
* m[0][1] & m[1][1] & m[2][1] \\
* m[0][2] & m[1][2] & m[2][2] \\
* \end{array}
* \right)
* \f$
*/
template<
typename A, typename B, typename C,
typename D, typename E, typename F,
typename G, typename H, typename I>
constexpr explicit TMat33(A m00, B m01, C m02,
D m10, E m11, F m12,
G m20, H m21, I m22) noexcept;
struct row_major_init {
template<
typename A, typename B, typename C,
typename D, typename E, typename F,
typename G, typename H, typename I>
constexpr explicit row_major_init(A m00, B m01, C m02,
D m10, E m11, F m12,
G m20, H m21, I m22) noexcept
: m(m00, m10, m20,
m01, m11, m21,
m02, m12, m22) {}
private:
friend TMat33;
TMat33 m;
};
constexpr explicit TMat33(row_major_init c) noexcept : TMat33(std::move(c.m)) {}
/**
* construct from a quaternion
*/
template<typename U>
constexpr explicit TMat33(const TQuaternion<U>& q) noexcept;
/**
* orthogonalize only works on matrices of size 3x3
*/
friend inline
constexpr TMat33 orthogonalize(const TMat33& m) noexcept {
TMat33 ret(TMat33::NO_INIT);
ret[0] = normalize(m[0]);
ret[2] = normalize(cross(ret[0], m[1]));
ret[1] = normalize(cross(ret[2], ret[0]));
return ret;
}
/**
* Returns a matrix suitable for transforming normals
*
* Note that the inverse-transpose of a matrix is equal to its cofactor matrix divided by its
* determinant:
*
* transpose(inverse(M)) = cof(M) / det(M)
*
* The cofactor matrix is faster to compute than the inverse-transpose, and it can be argued
* that it is a more correct way of transforming normals anyway. Some references from Dale
* Weiler, Nathan Reed, Inigo Quilez, and Eric Lengyel:
*
* - https://github.com/graphitemaster/normals_revisited
* - http://www.reedbeta.com/blog/normals-inverse-transpose-part-1/
* - https://www.shadertoy.com/view/3s33zj
* - FGED Volume 1, section 1.7.5 "Inverses of Small Matrices"
* - FGED Volume 1, section 3.2.2 "Transforming Normal Vectors"
*
* In "Transforming Normal Vectors", Lengyel notes that there are two types of transformed
* normals: one that uses the transposed adjugate (aka cofactor matrix) and one that uses the
* transposed inverse. He goes on to say that this difference is inconsequential, except when
* mirroring is involved.
*
* @param m the transform applied to vertices
* @return a matrix to apply to normals
*
* @warning normals transformed by this matrix must be normalized
*/
static constexpr TMat33 getTransformForNormals(const TMat33& m) noexcept {
return matrix::cof(m);
}
/**
* Packs the tangent frame represented by the specified matrix into a quaternion.
* Reflection is preserved by encoding it as the sign of the w component in the
* resulting quaternion. Since -0 cannot always be represented on the GPU, this
* function computes a bias to ensure values are always either positive or negative,
* never 0. The bias is computed based on the specified storageSize, which defaults
* to 2 bytes, making the resulting quaternion suitable for storage into an SNORM16
* vector.
*/
static constexpr TQuaternion<T> packTangentFrame(
const TMat33& m, size_t storageSize = sizeof(int16_t)) noexcept;
template<typename A>
static constexpr TMat33 translation(const TVec3<A>& t) noexcept {
TMat33 r;
r[2] = t;
return r;
}
template<typename A>
static constexpr TMat33 scaling(const TVec3<A>& s) noexcept {
return TMat33{ s };
}
template<typename A>
static constexpr TMat33 scaling(A s) noexcept {
return TMat33{ TVec3<T>{ s }};
}
};
// ----------------------------------------------------------------------------------------
// Constructors
// ----------------------------------------------------------------------------------------
// Since the matrix code could become pretty big quickly, we don't inline most
// operations.
template<typename T>
constexpr TMat33<T>::TMat33() noexcept
: m_value{
col_type(1, 0, 0),
col_type(0, 1, 0),
col_type(0, 0, 1) } {
}
template<typename T>
template<typename U>
constexpr TMat33<T>::TMat33(U v) noexcept
: m_value{
col_type(v, 0, 0),
col_type(0, v, 0),
col_type(0, 0, v) } {
}
template<typename T>
template<typename U>
constexpr TMat33<T>::TMat33(const TVec3<U>& v) noexcept
: m_value{
col_type(v[0], 0, 0),
col_type(0, v[1], 0),
col_type(0, 0, v[2]) } {
}
// construct from 16 scalars. Note that the arrangement
// of values in the constructor is the transpose of the matrix
// notation.
template<typename T>
template<
typename A, typename B, typename C,
typename D, typename E, typename F,
typename G, typename H, typename I>
constexpr TMat33<T>::TMat33(A m00, B m01, C m02,
D m10, E m11, F m12,
G m20, H m21, I m22) noexcept
: m_value{
col_type(m00, m01, m02),
col_type(m10, m11, m12),
col_type(m20, m21, m22) } {
}
template<typename T>
template<typename U>
constexpr TMat33<T>::TMat33(const TMat33<U>& rhs) noexcept {
for (size_t col = 0; col < NUM_COLS; ++col) {
m_value[col] = col_type(rhs[col]);
}
}
// Construct from 3 column vectors.
template<typename T>
template<typename A, typename B, typename C>
constexpr TMat33<T>::TMat33(const TVec3<A>& v0, const TVec3<B>& v1, const TVec3<C>& v2) noexcept
: m_value{ v0, v1, v2 } {
}
template<typename T>
template<typename U>
constexpr TMat33<T>::TMat33(const TQuaternion<U>& q) noexcept : m_value{} {
const U n = q.x * q.x + q.y * q.y + q.z * q.z + q.w * q.w;
const U s = n > 0 ? 2 / n : 0;
const U x = s * q.x;
const U y = s * q.y;
const U z = s * q.z;
const U xx = x * q.x;
const U xy = x * q.y;
const U xz = x * q.z;
const U xw = x * q.w;
const U yy = y * q.y;
const U yz = y * q.z;
const U yw = y * q.w;
const U zz = z * q.z;
const U zw = z * q.w;
m_value[0] = col_type(1 - yy - zz, xy + zw, xz - yw); // NOLINT
m_value[1] = col_type(xy - zw, 1 - xx - zz, yz + xw); // NOLINT
m_value[2] = col_type(xz + yw, yz - xw, 1 - xx - yy); // NOLINT
}
//------------------------------------------------------------------------------
template<typename T>
constexpr TQuaternion<T> TMat33<T>::packTangentFrame(const TMat33<T>& m, size_t storageSize) noexcept {
TQuaternion<T> q = TMat33<T>{ m[0], cross(m[2], m[0]), m[2] }.toQuaternion();
q = positive(normalize(q));
// Ensure w is never 0.0
// Bias is 2^(nb_bits - 1) - 1
const T bias = T(1.0) / T((1 << (storageSize * CHAR_BIT - 1)) - 1);
if (q.w < bias) {
q.w = bias;
const T factor = (T)(std::sqrt(1.0 - (double)bias * (double)bias));
q.xyz *= factor;
}
// If there's a reflection ((n x t) . b <= 0), make sure w is negative
if (dot(cross(m[0], m[2]), m[1]) < T(0)) {
q = -q;
}
return q;
}
} // namespace details
// ----------------------------------------------------------------------------------------
typedef details::TMat33<double> mat3;
typedef details::TMat33<float> mat3f;
// ----------------------------------------------------------------------------------------
} // namespace math
} // namespace filament
namespace std {
template<typename T>
constexpr void swap(filament::math::details::TMat33<T>& lhs,
filament::math::details::TMat33<T>& rhs) noexcept {
// This generates much better code than the default implementation
// It's unclear why, I believe this is due to an optimization bug in the clang.
//
// filament::math::details::TMat33<T> t(lhs);
// lhs = rhs;
// rhs = t;
//
// clang always copy lhs on the stack, even if it's never using it (it's using the
// copy it has in registers).
const T t00 = lhs[0][0];
const T t01 = lhs[0][1];
const T t02 = lhs[0][2];
const T t10 = lhs[1][0];
const T t11 = lhs[1][1];
const T t12 = lhs[1][2];
const T t20 = lhs[2][0];
const T t21 = lhs[2][1];
const T t22 = lhs[2][2];
lhs[0][0] = rhs[0][0];
lhs[0][1] = rhs[0][1];
lhs[0][2] = rhs[0][2];
lhs[1][0] = rhs[1][0];
lhs[1][1] = rhs[1][1];
lhs[1][2] = rhs[1][2];
lhs[2][0] = rhs[2][0];
lhs[2][1] = rhs[2][1];
lhs[2][2] = rhs[2][2];
rhs[0][0] = t00;
rhs[0][1] = t01;
rhs[0][2] = t02;
rhs[1][0] = t10;
rhs[1][1] = t11;
rhs[1][2] = t12;
rhs[2][0] = t20;
rhs[2][1] = t21;
rhs[2][2] = t22;
}
}
#endif // MATH_MAT3_H_