leocad/common/algebra.h
2012-02-02 03:30:26 +00:00

711 lines
22 KiB
C++

#ifndef _ALGEBRA_H_
#define _ALGEBRA_H_
#include <math.h>
//
// Simple math library and linear algebra functions.
//
// Everything is based on the Vector4 class, so changing that class should be enough
// to add support for compiler specific math intrinsics.
//
// Functions that end with 34 mean that they don't care what happens to the 4th
// component, it can either be affected or not.
//
// Matrices are represented as row-major, so we pre-multiply instead of post-multiplying
// like you would in a column major notation.
//
// OpenGL only expects a matrix to be an array of 16 floats so it doesn't matter what
// notation we use.
//
// v[0] v[1] v[2] v[3] <- x, y, z, w
//
// m[0] m[1] m[2] m[3] <- x axis
// m[4] m[5] m[6] m[7] <- y axis
// m[8] m[9] m[10] m[11] <- z axis
// m[12] m[13] m[14] m[15] <- translation
//
// TODO: Move this define to config.h
#define LC_MATH_FLOAT
//#define LC_MATH_SSE
// Classes defined in this file:
class Vector3;
class Vector4;
class Quaternion;
class Matrix44;
// ============================================================================
// Vector4 class (float version).
#ifdef LC_MATH_FLOAT
class Vector4
{
public:
// Constructors.
inline Vector4() { }
inline explicit Vector4(const float _x, const float _y, const float _z)
: x(_x), y(_y), z(_z) { }
inline explicit Vector4(const float _x, const float _y, const float _z, const float _w)
: x(_x), y(_y), z(_z), w(_w) { }
inline operator const float*() const { return (const float*)this; }
inline float& operator[](int i) const { return ((float*)this)[i]; }
// Comparison.
friend inline bool operator==(const Vector4& a, const Vector4& b)
{ return (a.x == b.x) && (a.y == b.y) && (a.z == b.z) && (a.w == b.w); }
friend inline bool Compare3(const Vector4& a, const Vector4& b)
{ return (a.x == b.x) && (a.y == b.y) && (a.z == b.z); }
// Math operations for 4 components.
friend inline Vector4 operator+(const Vector4& a, const Vector4& b)
{ return Vector4(a.x+b.x, a.y+b.y, a.z+b.z, a.w+b.w); }
friend inline Vector4 operator-(const Vector4& a, const Vector4& b)
{ return Vector4(a.x-b.x, a.y-b.y, a.z-b.z, a.w-b.w); }
friend inline Vector4 operator*(const Vector4& a, float f)
{ return Vector4(a.x*f, a.y*f, a.z*f, a.w*f); }
friend inline Vector4 operator*(const Vector4& a, const Vector4& b)
{ return Vector4(a.x*b.x, a.y*b.y, a.z*b.z, a.w*b.w); }
friend inline Vector4 operator/(const Vector4& a, float f)
{ return Vector4(a.x/f, a.y/f, a.z/f, a.w/f); }
friend inline Vector4 operator/=(Vector4& a, float f)
{ a = Vector4(a.x/f, a.y/f, a.z/f, a.w/f); return a; }
friend inline Vector4 operator-(const Vector4& a)
{ return Vector4(-a.x, -a.y, -a.z, -a.w); }
// Math operations ignoring the 4th component.
friend inline Vector4 Add34(const Vector4& a, const Vector4& b)
{ return Vector4(a.x+b.x, a.y+b.y, a.z+b.z); }
friend inline Vector4 Subtract34(const Vector4& a, const Vector4& b)
{ return Vector4(a.x-b.x, a.y-b.y, a.z-b.z); }
friend inline Vector4 Multiply34(const Vector4& a, float f)
{ return Vector4(a.x*f, a.y*f, a.z*f); }
friend inline Vector4 Multiply34(const Vector4& a, const Vector4& b)
{ return Vector4(a.x*b.x, a.y*b.y, a.z*b.z); }
friend inline Vector4 Divide34(const Vector4& a, float f)
{ return Vector4(a.x/f, a.y/f, a.z/f); }
friend inline Vector4 Negate34(const Vector4& a)
{ return Vector4(-a.x, -a.y, -a.z, -a.w); }
// Dot product.
friend inline float Dot3(const Vector4& a, const Vector4& b)
{ return a.x*b.x + a.y*b.y + a.z*b.z; }
friend inline float Dot4(const Vector4& a, const Vector4& b)
{ return a.x*b.x + a.y*b.y + a.z*b.z + a.w*b.w; }
// Cross product.
friend inline Vector4 Cross3(const Vector4& a, const Vector4& b)
{ return Vector4(a.y*b.z - a.z*b.y, a.z*b.x - a.x*b.z, a.x*b.y - a.y*b.x); }
// Other functions.
inline float Length3() const
{ return sqrtf(x*x + y*y + z*z); }
inline void Normalize34()
{
float len = 1.0f / sqrtf(x*x + y*y + z*z);
x *= len;
y *= len;
z *= len;
}
inline void Abs34()
{
if (x < 0.0f) x = -x;
if (y < 0.0f) y = -y;
if (z < 0.0f) z = -z;
}
inline void Abs()
{
if (x < 0.0f) x = -x;
if (y < 0.0f) y = -y;
if (z < 0.0f) z = -z;
if (w < 0.0f) w = -w;
}
protected:
float x, y, z, w;
};
#endif
// ============================================================================
// Vector4 class (SSE version).
#ifdef LC_MATH_SSE
// If you can't find this file you need to install the VS6 Processor Pack.
#include <xmmintrin.h>
class __declspec(align(16)) Vector4
{
public:
// Constructors.
inline Vector4() { }
inline explicit Vector4(const __m128& _xyzw)
: xyzw(_xyzw) { }
inline explicit Vector4(const float _x, const float _y, const float _z)
: xyzw(_mm_setr_ps(_x, _y, _z, _z)) { }
inline explicit Vector4(const float _x, const float _y, const float _z, const float _w)
: xyzw(_mm_setr_ps(_x, _y, _z, _w)) { }
inline float& operator[](int i) const { return ((const float*)this)[i]; }
// Comparison.
friend inline bool operator==(const Vector4& a, const Vector4& b)
{ return !_mm_movemask_ps(_mm_cmpneq_ps(a.xyzw, b.xyzw)); }
friend inline bool Compare3(const Vector4& a, const Vector4& b)
{ return (_mm_movemask_ps(_mm_cmpeq_ps(a.xyzw, b.xyzw)) & 0x7) == 0x7; }
// Math operations for 4 components.
friend inline Vector4 operator+(const Vector4& a, const Vector4& b)
{ return Vector4(_mm_add_ps(a.xyzw, b.xyzw)); }
friend inline Vector4 operator-(const Vector4& a, const Vector4& b)
{ return Vector4(_mm_sub_ps(a.xyzw, b.xyzw)); }
friend inline Vector4 operator*(const Vector4& a, float f)
{ return Vector4(_mm_mul_ps(a.xyzw, _mm_load_ps1(&f))); }
friend inline Vector4 operator*(const Vector4& a, const Vector4& b)
{ return Vector4(_mm_mul_ps(a.xyzw, b.xyzw)); }
friend inline Vector4 operator/(const Vector4& a, float f)
{ return Vector4(_mm_div_ps(a.xyzw, _mm_load_ps1(&f))); }
friend inline Vector4 operator-(const Vector4& a)
{
static const __declspec(align(16)) unsigned int Mask[4] = { 0x80000000, 0x80000000, 0x80000000, 0x80000000 }
return Vector4(_mm_xor_ps(xyzw, *(__m128*)&Mask));
}
// Math operations ignoring the 4th component.
friend inline Vector4 Add34(const Vector4& a, const Vector4& b)
{ return a*b }
friend inline Vector4 Subtract34(const Vector4& a, const Vector4& b)
{ return a-b; }
friend inline Vector4 Multiply34(const Vector4& a, float f)
{ return a*f; }
friend inline Vector4 Multiply34(const Vector4& a, const Vector4& b)
{ return a*b; }
friend inline Vector4 Divide34(const Vector4& a, float f)
{ return a/f; }
friend inline Vector4 Negate34(const Vector4& a)
{ return -a; }
// Dot product.
friend inline float Dot3(const Vector4& a, const Vector4& b)
{
__m128 tmp = _mm_mul_ps(a.xyzw, b.xyzw);
__m128 yz = _mm_add_ss(_mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(1, 1, 1, 1)), _mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(2, 2, 2, 2)));
tmp = _mm_add_ss(tmp, yz);
return *(const float*)&tmp;
}
// Cross product.
friend inline Vector4 Cross3(const Vector4& a, const Vector4& b)
{
// a(yzx)*b(zxy)-a(zxy)*b(yzx)
__m128 r1 = _mm_mul_ps(_mm_shuffle_ps(a.xyzw, a.xyzw, _MM_SHUFFLE(0, 0, 2, 1)), _mm_shuffle_ps(b.xyzw, b.xyzw, _MM_SHUFFLE(0, 1, 0, 2)));
__m128 r2 = _mm_mul_ps(_mm_shuffle_ps(a.xyzw, a.xyzw, _MM_SHUFFLE(0, 1, 0, 2)), _mm_shuffle_ps(b.xyzw, b.xyzw, _MM_SHUFFLE(0, 0, 2, 1)));
return Vector4(_mm_sub_ps(r1, r2));
}
// Other functions.
inline float Length3() const
{
__m128 tmp = _mm_mul_ps(xyzw, xyzw);
__m128 yz = _mm_add_ss(_mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(1, 1, 1, 1)), _mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(2, 2, 2, 2)));
tmp = _mm_add_ss(tmp, yz);
tmp = _mm_sqrt_ss(tmp);
return *(const float*)&tmp;
}
inline void Normalize34()
{
__m128 tmp = _mm_mul_ps(xyzw, xyzw);
__m128 yz = _mm_add_ss(_mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(1, 1, 1, 1)), _mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(2, 2, 2, 2)));
tmp = _mm_add_ss(tmp, yz);
tmp = _mm_rsqrt_ss(tmp);
tmp = _mm_shuffle_ps(tmp, tmp, _MM_SHUFFLE(0, 0, 0, 0));
xyzw = _mm_mul_ps(xyzw, tmp);
}
inline void Abs()
{
static const __declspec(align(16)) unsigned int Mask[4] = { 0x7fffffff, 0x7fffffff, 0x7fffffff, 0x7fffffff }
xyzw = _mm_and_ps(xyzw, *(__m128*)&Mask);
}
protected:
__m128 xyzw;
};
#endif
// ============================================================================
// 3D Vector class.
class Vector3
{
public:
// Constructors.
inline Vector3()
{ }
inline explicit Vector3(const Vector4& _v)
: m_Value(_v) { }
inline explicit Vector3(const float _x, const float _y, const float _z)
: m_Value(_x, _y, _z) { }
inline operator const float*() const { return (const float*)this; }
inline operator float*() { return (float*)this; }
inline const Vector4& GetValue() const { return m_Value; }
inline operator const Vector4() const
{ return Vector4(m_Value[0], m_Value[1], m_Value[2], 0.0f); }
inline float& operator[](int i) const { return m_Value[i]; }
// Math operations.
friend inline Vector3 operator+=(Vector3& a, const Vector3& b)
{ a.m_Value = a.m_Value + b.m_Value; return a; }
friend inline Vector3 operator*=(Vector3& a, float b)
{ a.m_Value = a.m_Value * b; return a; }
friend inline Vector3 operator/=(Vector3& a, float b)
{ a.m_Value = a.m_Value / b; return a; }
// Other functions.
inline float Length() const
{ return m_Value.Length3(); }
inline float LengthSquared() const
{ return Dot3(m_Value, m_Value); }
inline const Vector3& Normalize()
{ m_Value.Normalize34(); return *this; }
inline void Abs()
{ m_Value.Abs34(); }
protected:
Vector4 m_Value;
};
// ============================================================================
// Operators.
// Comparison.
inline bool operator==(const Vector3& a, const Vector3& b)
{ return Compare3(a.GetValue(), b.GetValue()); }
// Multiply by a scalar.
inline Vector3 operator*(const Vector3& a, float f)
{ return Vector3(Multiply34(a.GetValue(), f)); }
inline Vector3 operator*(float f, const Vector3& a)
{ return Vector3(Multiply34(a.GetValue(), f)); }
// Divide by a scalar.
inline Vector3 operator/(const Vector3& a, float f)
{ return Vector3(Divide34(a.GetValue(), f)); }
inline Vector3 operator/(float f, const Vector3& a)
{ return Vector3(Divide34(a.GetValue(), f)); }
// Add vectors.
inline Vector3 operator+(const Vector3& a, const Vector3& b)
{ return Vector3(Add34(a.GetValue(), b.GetValue())); }
// Subtract vectors.
inline Vector3 operator-(const Vector3& a, const Vector3& b)
{ return Vector3(Subtract34(a.GetValue(), b.GetValue())); }
// Negate.
inline Vector3 operator-(const Vector3& a)
{ return Vector3(Negate34(a.GetValue())); }
// Dot product.
inline float Dot3(const Vector3& a, const Vector3& b)
{ return Dot3(a.GetValue(), b.GetValue()); }
// Cross product.
inline Vector3 Cross3(const Vector3& a, const Vector3& b)
{ return Vector3(Cross3(a.GetValue(), b.GetValue())); }
// ============================================================================
// Quaternion class.
class Quaternion
{
public:
// Constructors.
inline Quaternion()
{ }
inline explicit Quaternion(const Vector4& _v)
: m_Value(_v) { }
inline explicit Quaternion(const float _x, const float _y, const float _z, const float _w)
: m_Value(_x, _y, _z, _w) { }
// Get/Set functions.
inline const float operator[](int i) const { return m_Value[i]; }
// Conversions.
inline void FromAxisAngle(const Vector4& AxisAngle)
{
float s = sinf(AxisAngle[3] / 2.0f);
m_Value = Vector4(AxisAngle[0] * s, AxisAngle[1] * s, AxisAngle[2] * s, cosf(AxisAngle[3] / 2.0f));
}
inline void CreateRotationX(float Radians)
{
m_Value = Vector4(sinf(Radians / 2.0f), 0, 0, cosf(Radians / 2.0f));
}
inline void CreateRotationY(float Radians)
{
m_Value = Vector4(0, sinf(Radians / 2.0f), 0, cosf(Radians / 2.0f));
}
inline void CreateRotationZ(float Radians)
{
m_Value = Vector4(0, 0, sinf(Radians / 2.0f), cosf(Radians / 2.0f));
}
inline void ToAxisAngle(Vector4& AxisAngle) const
{
float Len = m_Value[0]*m_Value[0] + m_Value[1]*m_Value[1] + m_Value[2]*m_Value[2];
if (Len > 0.0001f)
{
float f = 1.0f / sqrtf(Len);
AxisAngle = Vector4(m_Value[0] * f, m_Value[1] * f, m_Value[2] * f, acosf(m_Value[3]) * 2.0f);
}
else
{
AxisAngle = Vector4(0, 0, 1, 0);
}
}
// Operators.
friend inline Quaternion Mul(const Quaternion& a, const Quaternion& b)
{
float x = a.m_Value[0] * b.m_Value[3] + a.m_Value[1] * b.m_Value[2] - a.m_Value[2] * b.m_Value[1] + a.m_Value[3] * b.m_Value[0];
float y = -a.m_Value[0] * b.m_Value[2] + a.m_Value[1] * b.m_Value[3] + a.m_Value[2] * b.m_Value[0] + a.m_Value[3] * b.m_Value[1];
float z = a.m_Value[0] * b.m_Value[1] - a.m_Value[1] * b.m_Value[0] + a.m_Value[2] * b.m_Value[3] + a.m_Value[3] * b.m_Value[2];
float w = -a.m_Value[0] * b.m_Value[0] - a.m_Value[1] * b.m_Value[1] - a.m_Value[2] * b.m_Value[2] + a.m_Value[3] * b.m_Value[3];
return Quaternion(x, y, z, w);
}
friend inline Vector3 Mul(const Vector3& a, const Quaternion& b)
{
// Faster to transform to a matrix and multiply.
float Tx = 2.0f*b[0];
float Ty = 2.0f*b[1];
float Tz = 2.0f*b[2];
float Twx = Tx*b[3];
float Twy = Ty*b[3];
float Twz = Tz*b[3];
float Txx = Tx*b[0];
float Txy = Ty*b[0];
float Txz = Tz*b[0];
float Tyy = Ty*b[1];
float Tyz = Tz*b[1];
float Tzz = Tz*b[2];
Vector3 Rows[3];
Rows[0] = Vector3(1.0f-(Tyy+Tzz), Txy+Twz, Txz-Twy);
Rows[1] = Vector3(Txy-Twz, 1.0f-(Txx+Tzz), Tyz+Twx);
Rows[2] = Vector3(Txz+Twy, Tyz-Twx, 1.0f-(Txx+Tyy));
return Vector3(Rows[0].GetValue()*a[0] + Rows[1].GetValue()*a[1] + Rows[2].GetValue()*a[2]);
}
protected:
Vector4 m_Value;
};
// ============================================================================
// 3x3 Matrix class.
class Matrix33
{
public:
// Constructors.
inline Matrix33()
{ }
inline Matrix33(const Vector3& Row0, const Vector3& Row1, const Vector3& Row2)
{ m_Rows[0] = Row0; m_Rows[1] = Row1; m_Rows[2] = Row2; }
inline void LoadIdentity()
{
m_Rows[0] = Vector3(1.0f, 0.0f, 0.0f);
m_Rows[1] = Vector3(0.0f, 1.0f, 0.0f);
m_Rows[2] = Vector3(0.0f, 0.0f, 1.0f);
}
inline void CreateFromAxisAngle(const Vector3& Axis, const float Radians)
{
float s, c, mag, xx, yy, zz, xy, yz, zx, xs, ys, zs, one_c;
s = sinf(Radians);
c = cosf(Radians);
mag = Axis.Length();
if (mag == 0.0f)
{
LoadIdentity();
return;
}
Vector3 Normal = Axis * (1.0f / mag);
xx = Normal[0] * Normal[0];
yy = Normal[1] * Normal[1];
zz = Normal[2] * Normal[2];
xy = Normal[0] * Normal[1];
yz = Normal[1] * Normal[2];
zx = Normal[2] * Normal[0];
xs = Normal[0] * s;
ys = Normal[1] * s;
zs = Normal[2] * s;
one_c = 1.0f - c;
m_Rows[0] = Vector3((one_c * xx) + c, (one_c * xy) + zs, (one_c * zx) - ys);
m_Rows[1] = Vector3((one_c * xy) - zs, (one_c * yy) + c, (one_c * yz) + xs);
m_Rows[2] = Vector3((one_c * zx) + ys, (one_c * yz) - xs, (one_c * zz) + c);
}
friend inline Vector3 Mul(const Vector3& a, const Matrix33& b)
{ return Vector3(b.m_Rows[0]*a[0] + b.m_Rows[1]*a[1] + b.m_Rows[2]*a[2]); }
protected:
Vector3 m_Rows[3];
friend class Matrix44;
};
// ============================================================================
// 4x4 Matrix class.
class Matrix44
{
public:
inline Matrix44()
{ }
inline Matrix44(const Vector4& Row0, const Vector4& Row1, const Vector4& Row2, const Vector4& Row3)
{ m_Rows[0] = Row0; m_Rows[1] = Row1; m_Rows[2] = Row2; m_Rows[3] = Row3; }
inline operator const float*() const { return (const float*)this; }
inline const Vector4& operator[](int i) const { return m_Rows[i]; }
inline Vector4& operator[](int i) { return m_Rows[i]; }
inline void LoadIdentity()
{
m_Rows[0] = Vector4(1.0f, 0.0f, 0.0f, 0.0f);
m_Rows[1] = Vector4(0.0f, 1.0f, 0.0f, 0.0f);
m_Rows[2] = Vector4(0.0f, 0.0f, 1.0f, 0.0f);
m_Rows[3] = Vector4(0.0f, 0.0f, 0.0f, 1.0f);
}
// Math operations.
friend inline Vector3 Mul31(const Vector3& a, const Matrix44& b)
{ return Vector3(b.m_Rows[0]*a[0] + b.m_Rows[1]*a[1] + b.m_Rows[2]*a[2] + b.m_Rows[3]); }
friend inline Vector3 Mul30(const Vector3& a, const Matrix44& b)
{ return Vector3(b.m_Rows[0]*a[0] + b.m_Rows[1]*a[1] + b.m_Rows[2]*a[2]); }
friend inline Vector4 Mul4(const Vector4& a, const Matrix44& b)
{ return Vector4(b.m_Rows[0]*a[0] + b.m_Rows[1]*a[1] + b.m_Rows[2]*a[2] + b.m_Rows[3]*a[3]); }
friend inline Matrix44 Mul(const Matrix44& a, const Matrix44& b)
{
Vector4 Col0(b.m_Rows[0][0], b.m_Rows[1][0], b.m_Rows[2][0], b.m_Rows[3][0]);
Vector4 Col1(b.m_Rows[0][1], b.m_Rows[1][1], b.m_Rows[2][1], b.m_Rows[3][1]);
Vector4 Col2(b.m_Rows[0][2], b.m_Rows[1][2], b.m_Rows[2][2], b.m_Rows[3][2]);
Vector4 Col3(b.m_Rows[0][3], b.m_Rows[1][3], b.m_Rows[2][3], b.m_Rows[3][3]);
Vector4 Ret0(Dot4(a.m_Rows[0], Col0), Dot4(a.m_Rows[0], Col1), Dot4(a.m_Rows[0], Col2), Dot4(a.m_Rows[0], Col3));
Vector4 Ret1(Dot4(a.m_Rows[1], Col0), Dot4(a.m_Rows[1], Col1), Dot4(a.m_Rows[1], Col2), Dot4(a.m_Rows[1], Col3));
Vector4 Ret2(Dot4(a.m_Rows[2], Col0), Dot4(a.m_Rows[2], Col1), Dot4(a.m_Rows[2], Col2), Dot4(a.m_Rows[2], Col3));
Vector4 Ret3(Dot4(a.m_Rows[3], Col0), Dot4(a.m_Rows[3], Col1), Dot4(a.m_Rows[3], Col2), Dot4(a.m_Rows[3], Col3));
return Matrix44(Ret0, Ret1, Ret2, Ret3);
}
inline Matrix44& operator=(const Matrix33& a)
{
m_Rows[0] = Vector4(a.m_Rows[0][0], a.m_Rows[0][1], a.m_Rows[0][2], 0.0f);
m_Rows[1] = Vector4(a.m_Rows[1][0], a.m_Rows[1][1], a.m_Rows[1][2], 0.0f);
m_Rows[2] = Vector4(a.m_Rows[2][0], a.m_Rows[2][1], a.m_Rows[2][2], 0.0f);
m_Rows[3] = Vector4(0.0f, 0.0f, 0.0f, 1.0f);
return *this;
}
inline void Transpose3()
{
Vector4 a = m_Rows[0], b = m_Rows[1], c = m_Rows[2];
m_Rows[0] = Vector4(a[0], b[0], c[0], a[3]);
m_Rows[1] = Vector4(a[1], b[1], c[1], b[3]);
m_Rows[2] = Vector4(a[2], b[2], c[2], c[3]);
}
inline void SetTranslation(const Vector3& a)
{ m_Rows[3] = Vector4(a[0], a[1], a[2], 1.0f); }
friend Matrix44 Inverse(const Matrix44& m);
void CreateLookAt(const Vector3& Eye, const Vector3& Target, const Vector3& Up);
void CreatePerspective(float FoVy, float Aspect, float Near, float Far);
void CreateOrtho(float Left, float Right, float Bottom, float Top, float Near, float Far);
void CreateFromAxisAngle(const Vector3& Axis, float Radians)
{
Matrix33 Mat;
Mat.CreateFromAxisAngle(Axis, Radians);
*this = Mat;
}
Vector4 ToAxisAngle()
{
Matrix33 tmp(Vector3(m_Rows[0]).Normalize(), Vector3(m_Rows[1]).Normalize(), Vector3(m_Rows[2]).Normalize());
// Determinant should be 1 for rotation matrices.
float Determinant = tmp.m_Rows[0][0] * tmp.m_Rows[1][1] * tmp.m_Rows[2][2] + tmp.m_Rows[0][1] * tmp.m_Rows[1][2] * tmp.m_Rows[2][0] +
tmp.m_Rows[0][2] * tmp.m_Rows[1][0] * tmp.m_Rows[2][1] - tmp.m_Rows[0][0] * tmp.m_Rows[1][2] * tmp.m_Rows[2][1] -
tmp.m_Rows[0][1] * tmp.m_Rows[1][0] * tmp.m_Rows[2][2] - tmp.m_Rows[0][2] * tmp.m_Rows[1][1] * tmp.m_Rows[2][0];
if (Determinant < 0.0f)
tmp.m_Rows[0] *= -1.0f;
float Trace = tmp.m_Rows[0][0] + tmp.m_Rows[1][1] + tmp.m_Rows[2][2];
float Cos = 0.5f * (Trace - 1.0f);
Vector4 rot;
if (Cos < -1.0f)
Cos = -1.0f;
else if (Cos > 1.0f)
Cos = 1.0f;
rot[3] = acosf(Cos); // in [0,PI]
if (rot[3] > 0.01f)
{
if (fabsf(3.141592f - rot[3]) > 0.01f)
{
rot[0] = tmp.m_Rows[1][2] - tmp.m_Rows[2][1];
rot[1] = tmp.m_Rows[2][0] - tmp.m_Rows[0][2];
rot[2] = tmp.m_Rows[0][1] - tmp.m_Rows[1][0];
float inv = 1.0f / sqrtf(rot[0]*rot[0] + rot[1]*rot[1] + rot[2]*rot[2]);
rot[0] *= inv;
rot[1] *= inv;
rot[2] *= inv;
}
else
{
// angle is PI
float HalfInverse;
if (tmp.m_Rows[0][0] >= tmp.m_Rows[1][1])
{
// r00 >= r11
if (tmp.m_Rows[0][0] >= tmp.m_Rows[2][2])
{
// r00 is maximum diagonal term
rot[0] = 0.5f * sqrtf(tmp.m_Rows[0][0] - tmp.m_Rows[1][1] - tmp.m_Rows[2][2] + 1.0f);
HalfInverse = 0.5f / rot[0];
rot[1] = HalfInverse * tmp.m_Rows[1][0];
rot[2] = HalfInverse * tmp.m_Rows[2][0];
}
else
{
// r22 is maximum diagonal term
rot[2] = 0.5f * sqrtf(tmp.m_Rows[2][2] - tmp.m_Rows[0][0] - tmp.m_Rows[1][1] + 1.0f);
HalfInverse = 0.5f / rot[2];
rot[0] = HalfInverse * tmp.m_Rows[2][0];
rot[1] = HalfInverse * tmp.m_Rows[2][1];
}
}
else
{
// r11 > r00
if (tmp.m_Rows[1][1] >= tmp.m_Rows[2][2])
{
// r11 is maximum diagonal term
rot[1] = 0.5f * sqrtf(tmp.m_Rows[1][1] - tmp.m_Rows[0][0] - tmp.m_Rows[2][2] + 1.0f);
HalfInverse = 0.5f / rot[1];
rot[0] = HalfInverse * tmp.m_Rows[1][0];
rot[2] = HalfInverse * tmp.m_Rows[2][1];
}
else
{
// r22 is maximum diagonal term
rot[2] = 0.5f * sqrtf(tmp.m_Rows[2][2] - tmp.m_Rows[0][0] - tmp.m_Rows[1][1] + 1.0f);
HalfInverse = 0.5f / rot[2];
rot[0] = HalfInverse * tmp.m_Rows[2][0];
rot[1] = HalfInverse * tmp.m_Rows[2][1];
}
}
}
}
else
{
// The angle is 0 and the matrix is the identity.
rot[0] = 0.0f;
rot[1] = 0.0f;
rot[2] = 1.0f;
}
return rot;
}
protected:
Vector4 m_Rows[4];
};
// ============================================================================
// Linear Algebra Functions.
Vector3 ZoomExtents(const Vector3& Position, const Matrix44& WorldView, const Matrix44& Projection, const Vector3* Points, int NumPoints);
Vector3 ProjectPoint(const Vector3& Point, const Matrix44& ModelView, const Matrix44& Projection, const int Viewport[4]);
void ProjectPoints(Vector3* Points, int NumPoints, const Matrix44& ModelView, const Matrix44& Projection, const int Viewport[4]);
Vector3 UnprojectPoint(const Vector3& Point, const Matrix44& ModelView, const Matrix44& Projection, const int Viewport[4]);
void UnprojectPoints(Vector3* Points, int NumPoints, const Matrix44& ModelView, const Matrix44& Projection, const int Viewport[4]);
void PolygonPlaneClip(Vector3* InPoints, int NumInPoints, Vector3* OutPoints, int* NumOutPoints, const Vector4& Plane);
bool LinePlaneIntersection(Vector3& Intersection, const Vector3& Start, const Vector3& End, const Vector4& Plane);
bool LineTriangleMinIntersection(const Vector3& p1, const Vector3& p2, const Vector3& p3, const Vector3& Start, const Vector3& End, float& MinDist, Vector3& Intersection);
bool LineQuadMinIntersection(const Vector3& p1, const Vector3& p2, const Vector3& p3, const Vector3& p4, const Vector3& Start, const Vector3& End, float& MinDist, Vector3& Intersection);
#endif