+/*
+Copyright (C) 2003, 2010 - Wolfire Games
+Copyright (C) 2010-2016 - Lugaru contributors (see AUTHORS file)
+
+This file is part of Lugaru.
+
+Lugaru is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+Lugaru is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with Lugaru. If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _PHYSICSMATH_HPP_
+#define _PHYSICSMATH_HPP_
+
+#include "MacCompatibility.hpp"
+
+//------------------------------------------------------------------------//
+// Misc. Constants
+//------------------------------------------------------------------------//
+
+float const pi = 3.14159265f;
+float const g = -32.174f; // acceleration due to gravity, ft/s^2
+float const rho = 0.0023769f; // desity of air at sea level, slugs/ft^3
+float const tol = 0.0000000001f; // float type tolerance
+
+
+//------------------------------------------------------------------------//
+// Misc. Functions
+//------------------------------------------------------------------------//
+inline float DegreesToRadians(float deg);
+inline float RadiansToDegrees(float rad);
+
+inline float DegreesToRadians(float deg)
+{
+ return deg * pi / 180.0f;
+}
+
+inline float RadiansToDegrees(float rad)
+{
+ return rad * 180.0f / pi;
+}
+
+//------------------------------------------------------------------------//
+// Vector Class and vector functions
+//------------------------------------------------------------------------//
+class Vector
+{
+public:
+ float x;
+ float y;
+ float z;
+
+ Vector(void);
+ Vector(float xi, float yi, float zi);
+
+ float Magnitude(void);
+ void Normalize(void);
+ void Reverse(void);
+
+ Vector& operator+=(Vector u); // vector addition
+ Vector& operator-=(Vector u); // vector subtraction
+ Vector& operator*=(float s); // scalar multiply
+ Vector& operator/=(float s); // scalar divide
+
+ Vector operator-(void);
+
+};
+
+inline Vector operator+(Vector u, Vector v);
+inline Vector operator-(Vector u, Vector v);
+inline Vector operator^(Vector u, Vector v);
+inline float operator*(Vector u, Vector v);
+inline Vector operator*(float s, Vector u);
+inline Vector operator*(Vector u, float s);
+inline Vector operator/(Vector u, float s);
+inline float TripleScalarProduct(Vector u, Vector v, Vector w);
+/*
+float fast_sqrt2 (register float arg);
+float fast_sqrt2 (register float arg)
+{
+// Can replace with slower return std::sqrt(arg);
+register float result;
+
+if (arg == 0.0) return 0.0;
+
+asm {
+frsqrte result,arg // Calculate Square root
+}
+
+// Newton Rhapson iterations.
+result = result + 0.5 * result * (1.0 - arg * result * result);
+result = result + 0.5 * result * (1.0 - arg * result * result);
+
+return result * arg;
+}
+*/
+inline Vector::Vector(void)
+{
+ x = 0;
+ y = 0;
+ z = 0;
+}
+
+inline Vector::Vector(float xi, float yi, float zi)
+{
+ x = xi;
+ y = yi;
+ z = zi;
+}
+
+inline float Vector::Magnitude(void)
+{
+ return (float) sqrt(x * x + y * y + z * z);
+}
+
+inline void Vector::Normalize(void)
+{
+ float m = (float) sqrt(x * x + y * y + z * z);
+ if (m <= tol)
+ m = 1;
+ x /= m;
+ y /= m;
+ z /= m;
+
+ if (fabs(x) < tol)
+ x = 0.0f;
+ if (fabs(y) < tol)
+ y = 0.0f;
+ if (fabs(z) < tol)
+ z = 0.0f;
+}
+
+inline void Vector::Reverse(void)
+{
+ x = -x;
+ y = -y;
+ z = -z;
+}
+
+inline Vector& Vector::operator+=(Vector u)
+{
+ x += u.x;
+ y += u.y;
+ z += u.z;
+ return *this;
+}
+
+inline Vector& Vector::operator-=(Vector u)
+{
+ x -= u.x;
+ y -= u.y;
+ z -= u.z;
+ return *this;
+}
+
+inline Vector& Vector::operator*=(float s)
+{
+ x *= s;
+ y *= s;
+ z *= s;
+ return *this;
+}
+
+inline Vector& Vector::operator/=(float s)
+{
+ x /= s;
+ y /= s;
+ z /= s;
+ return *this;
+}
+
+inline Vector Vector::operator-(void)
+{
+ return Vector(-x, -y, -z);
+}
+
+
+inline Vector operator+(Vector u, Vector v)
+{
+ return Vector(u.x + v.x, u.y + v.y, u.z + v.z);
+}
+
+inline Vector operator-(Vector u, Vector v)
+{
+ return Vector(u.x - v.x, u.y - v.y, u.z - v.z);
+}
+
+// Vector cross product (u cross v)
+inline Vector operator^(Vector u, Vector v)
+{
+ return Vector( u.y * v.z - u.z * v.y,
+ -u.x * v.z + u.z * v.x,
+ u.x * v.y - u.y * v.x );
+}
+
+// Vector dot product
+inline float operator*(Vector u, Vector v)
+{
+ return (u.x * v.x + u.y * v.y + u.z * v.z);
+}
+
+inline Vector operator*(float s, Vector u)
+{
+ return Vector(u.x * s, u.y * s, u.z * s);
+}
+
+inline Vector operator*(Vector u, float s)
+{
+ return Vector(u.x * s, u.y * s, u.z * s);
+}
+
+inline Vector operator/(Vector u, float s)
+{
+ return Vector(u.x / s, u.y / s, u.z / s);
+}
+
+// triple scalar product (u dot (v cross w))
+inline float TripleScalarProduct(Vector u, Vector v, Vector w)
+{
+ return float( (u.x * (v.y * w.z - v.z * w.y)) +
+ (u.y * (-v.x * w.z + v.z * w.x)) +
+ (u.z * (v.x * w.y - v.y * w.x)) );
+ //return u*(v^w);
+
+}
+
+
+
+//------------------------------------------------------------------------//
+// Matrix Class and matrix functions
+//------------------------------------------------------------------------//
+
+class Matrix3x3
+{
+public:
+ // elements eij: i -> row, j -> column
+ float e11, e12, e13, e21, e22, e23, e31, e32, e33;
+
+ Matrix3x3(void);
+ Matrix3x3( float r1c1, float r1c2, float r1c3,
+ float r2c1, float r2c2, float r2c3,
+ float r3c1, float r3c2, float r3c3 );
+
+ float det(void);
+ Matrix3x3 Transpose(void);
+ Matrix3x3 Inverse(void);
+
+ Matrix3x3& operator+=(Matrix3x3 m);
+ Matrix3x3& operator-=(Matrix3x3 m);
+ Matrix3x3& operator*=(float s);
+ Matrix3x3& operator/=(float s);
+};
+
+inline Matrix3x3 operator+(Matrix3x3 m1, Matrix3x3 m2);
+inline Matrix3x3 operator-(Matrix3x3 m1, Matrix3x3 m2);
+inline Matrix3x3 operator/(Matrix3x3 m, float s);
+inline Matrix3x3 operator*(Matrix3x3 m1, Matrix3x3 m2);
+inline Matrix3x3 operator*(Matrix3x3 m, float s);
+inline Matrix3x3 operator*(float s, Matrix3x3 m);
+inline Vector operator*(Matrix3x3 m, Vector u);
+inline Vector operator*(Vector u, Matrix3x3 m);
+
+
+
+
+
+inline Matrix3x3::Matrix3x3(void)
+{
+ e11 = 0;
+ e12 = 0;
+ e13 = 0;
+ e21 = 0;
+ e22 = 0;
+ e23 = 0;
+ e31 = 0;
+ e32 = 0;
+ e33 = 0;
+}
+
+inline Matrix3x3::Matrix3x3( float r1c1, float r1c2, float r1c3,
+ float r2c1, float r2c2, float r2c3,
+ float r3c1, float r3c2, float r3c3 )
+{
+ e11 = r1c1;
+ e12 = r1c2;
+ e13 = r1c3;
+ e21 = r2c1;
+ e22 = r2c2;
+ e23 = r2c3;
+ e31 = r3c1;
+ e32 = r3c2;
+ e33 = r3c3;
+}
+
+inline float Matrix3x3::det(void)
+{
+ return e11 * e22 * e33 -
+ e11 * e32 * e23 +
+ e21 * e32 * e13 -
+ e21 * e12 * e33 +
+ e31 * e12 * e23 -
+ e31 * e22 * e13;
+}
+
+inline Matrix3x3 Matrix3x3::Transpose(void)
+{
+ return Matrix3x3(e11, e21, e31, e12, e22, e32, e13, e23, e33);
+}
+
+inline Matrix3x3 Matrix3x3::Inverse(void)
+{
+ float d = e11 * e22 * e33 -
+ e11 * e32 * e23 +
+ e21 * e32 * e13 -
+ e21 * e12 * e33 +
+ e31 * e12 * e23 -
+ e31 * e22 * e13;
+
+ if (d == 0)
+ d = 1;
+
+ return Matrix3x3( (e22 * e33 - e23 * e32) / d,
+ -(e12 * e33 - e13 * e32) / d,
+ (e12 * e23 - e13 * e22) / d,
+ -(e21 * e33 - e23 * e31) / d,
+ (e11 * e33 - e13 * e31) / d,
+ -(e11 * e23 - e13 * e21) / d,
+ (e21 * e32 - e22 * e31) / d,
+ -(e11 * e32 - e12 * e31) / d,
+ (e11 * e22 - e12 * e21) / d );
+}
+
+inline Matrix3x3& Matrix3x3::operator+=(Matrix3x3 m)
+{
+ e11 += m.e11;
+ e12 += m.e12;
+ e13 += m.e13;
+ e21 += m.e21;
+ e22 += m.e22;
+ e23 += m.e23;
+ e31 += m.e31;
+ e32 += m.e32;
+ e33 += m.e33;
+ return *this;
+}
+
+inline Matrix3x3& Matrix3x3::operator-=(Matrix3x3 m)
+{
+ e11 -= m.e11;
+ e12 -= m.e12;
+ e13 -= m.e13;
+ e21 -= m.e21;
+ e22 -= m.e22;
+ e23 -= m.e23;
+ e31 -= m.e31;
+ e32 -= m.e32;
+ e33 -= m.e33;
+ return *this;
+}
+
+inline Matrix3x3& Matrix3x3::operator*=(float s)
+{
+ e11 *= s;
+ e12 *= s;
+ e13 *= s;
+ e21 *= s;
+ e22 *= s;
+ e23 *= s;
+ e31 *= s;
+ e32 *= s;
+ e33 *= s;
+ return *this;
+}
+
+inline Matrix3x3& Matrix3x3::operator/=(float s)
+{
+ e11 /= s;
+ e12 /= s;
+ e13 /= s;
+ e21 /= s;
+ e22 /= s;
+ e23 /= s;
+ e31 /= s;
+ e32 /= s;
+ e33 /= s;
+ return *this;
+}
+
+inline Matrix3x3 operator+(Matrix3x3 m1, Matrix3x3 m2)
+{
+ return Matrix3x3( m1.e11 + m2.e11,
+ m1.e12 + m2.e12,
+ m1.e13 + m2.e13,
+ m1.e21 + m2.e21,
+ m1.e22 + m2.e22,
+ m1.e23 + m2.e23,
+ m1.e31 + m2.e31,
+ m1.e32 + m2.e32,
+ m1.e33 + m2.e33);
+}
+
+inline Matrix3x3 operator-(Matrix3x3 m1, Matrix3x3 m2)
+{
+ return Matrix3x3( m1.e11 - m2.e11,
+ m1.e12 - m2.e12,
+ m1.e13 - m2.e13,
+ m1.e21 - m2.e21,
+ m1.e22 - m2.e22,
+ m1.e23 - m2.e23,
+ m1.e31 - m2.e31,
+ m1.e32 - m2.e32,
+ m1.e33 - m2.e33);
+}
+
+inline Matrix3x3 operator/(Matrix3x3 m, float s)
+{
+ return Matrix3x3( m.e11 / s,
+ m.e12 / s,
+ m.e13 / s,
+ m.e21 / s,
+ m.e22 / s,
+ m.e23 / s,
+ m.e31 / s,
+ m.e32 / s,
+ m.e33 / s);
+}
+
+inline Matrix3x3 operator*(Matrix3x3 m1, Matrix3x3 m2)
+{
+ return Matrix3x3( m1.e11 * m2.e11 + m1.e12 * m2.e21 + m1.e13 * m2.e31,
+ m1.e11 * m2.e12 + m1.e12 * m2.e22 + m1.e13 * m2.e32,
+ m1.e11 * m2.e13 + m1.e12 * m2.e23 + m1.e13 * m2.e33,
+ m1.e21 * m2.e11 + m1.e22 * m2.e21 + m1.e23 * m2.e31,
+ m1.e21 * m2.e12 + m1.e22 * m2.e22 + m1.e23 * m2.e32,
+ m1.e21 * m2.e13 + m1.e22 * m2.e23 + m1.e23 * m2.e33,
+ m1.e31 * m2.e11 + m1.e32 * m2.e21 + m1.e33 * m2.e31,
+ m1.e31 * m2.e12 + m1.e32 * m2.e22 + m1.e33 * m2.e32,
+ m1.e31 * m2.e13 + m1.e32 * m2.e23 + m1.e33 * m2.e33 );
+}
+
+inline Matrix3x3 operator*(Matrix3x3 m, float s)
+{
+ return Matrix3x3( m.e11 * s,
+ m.e12 * s,
+ m.e13 * s,
+ m.e21 * s,
+ m.e22 * s,
+ m.e23 * s,
+ m.e31 * s,
+ m.e32 * s,
+ m.e33 * s);
+}
+
+inline Matrix3x3 operator*(float s, Matrix3x3 m)
+{
+ return Matrix3x3( m.e11 * s,
+ m.e12 * s,
+ m.e13 * s,
+ m.e21 * s,
+ m.e22 * s,
+ m.e23 * s,
+ m.e31 * s,
+ m.e32 * s,
+ m.e33 * s);
+}
+
+inline Vector operator*(Matrix3x3 m, Vector u)
+{
+ return Vector( m.e11 * u.x + m.e12 * u.y + m.e13 * u.z,
+ m.e21 * u.x + m.e22 * u.y + m.e23 * u.z,
+ m.e31 * u.x + m.e32 * u.y + m.e33 * u.z);
+}
+
+inline Vector operator*(Vector u, Matrix3x3 m)
+{
+ return Vector( u.x * m.e11 + u.y * m.e21 + u.z * m.e31,
+ u.x * m.e12 + u.y * m.e22 + u.z * m.e32,
+ u.x * m.e13 + u.y * m.e23 + u.z * m.e33);
+}
+
+//------------------------------------------------------------------------//
+// Quaternion Class and Quaternion functions
+//------------------------------------------------------------------------//
+
+class Quaternion
+{
+public:
+ float n; // number (scalar) part
+ Vector v; // vector part: v.x, v.y, v.z
+
+ Quaternion(void);
+ Quaternion(float e0, float e1, float e2, float e3);
+
+ float Magnitude(void);
+ Vector GetVector(void);
+ float GetScalar(void);
+ Quaternion operator+=(Quaternion q);
+ Quaternion operator-=(Quaternion q);
+ Quaternion operator*=(float s);
+ Quaternion operator/=(float s);
+ Quaternion operator~(void) const {
+ return Quaternion(n, -v.x, -v.y, -v.z);
+ }
+};
+
+inline Quaternion operator+(Quaternion q1, Quaternion q2);
+inline Quaternion operator-(Quaternion q1, Quaternion q2);
+inline Quaternion operator*(Quaternion q1, Quaternion q2);
+inline Quaternion operator*(Quaternion q, float s);
+inline Quaternion operator*(float s, Quaternion q);
+inline Quaternion operator*(Quaternion q, Vector v);
+inline Quaternion operator*(Vector v, Quaternion q);
+inline Quaternion operator/(Quaternion q, float s);
+inline float QGetAngle(Quaternion q);
+inline Vector QGetAxis(Quaternion q);
+inline Quaternion QRotate(Quaternion q1, Quaternion q2);
+inline Vector QVRotate(Quaternion q, Vector v);
+inline Quaternion MakeQFromEulerAngles(float x, float y, float z);
+inline Vector MakeEulerAnglesFromQ(Quaternion q);
+
+
+inline Quaternion::Quaternion(void)
+{
+ n = 0;
+ v.x = 0;
+ v.y = 0;
+ v.z = 0;
+}
+
+inline Quaternion::Quaternion(float e0, float e1, float e2, float e3)
+{
+ n = e0;
+ v.x = e1;
+ v.y = e2;
+ v.z = e3;
+}
+
+inline float Quaternion::Magnitude(void)
+{
+ return (float) sqrt(n * n + v.x * v.x + v.y * v.y + v.z * v.z);
+}
+
+inline Vector Quaternion::GetVector(void)
+{
+ return Vector(v.x, v.y, v.z);
+}
+
+inline float Quaternion::GetScalar(void)
+{
+ return n;
+}
+
+inline Quaternion Quaternion::operator+=(Quaternion q)
+{
+ n += q.n;
+ v.x += q.v.x;
+ v.y += q.v.y;
+ v.z += q.v.z;
+ return *this;
+}
+
+inline Quaternion Quaternion::operator-=(Quaternion q)
+{
+ n -= q.n;
+ v.x -= q.v.x;
+ v.y -= q.v.y;
+ v.z -= q.v.z;
+ return *this;
+}
+
+inline Quaternion Quaternion::operator*=(float s)
+{
+ n *= s;
+ v.x *= s;
+ v.y *= s;
+ v.z *= s;
+ return *this;
+}
+
+inline Quaternion Quaternion::operator/=(float s)
+{
+ n /= s;
+ v.x /= s;
+ v.y /= s;
+ v.z /= s;
+ return *this;
+}
+
+/*inline Quaternion Quaternion::operator~()
+{
+return Quaternion(n, -v.x, -v.y, -v.z);
+}*/
+
+inline Quaternion operator+(Quaternion q1, Quaternion q2)
+{
+ return Quaternion( q1.n + q2.n,
+ q1.v.x + q2.v.x,
+ q1.v.y + q2.v.y,
+ q1.v.z + q2.v.z);
+}
+
+inline Quaternion operator-(Quaternion q1, Quaternion q2)
+{
+ return Quaternion( q1.n - q2.n,
+ q1.v.x - q2.v.x,
+ q1.v.y - q2.v.y,
+ q1.v.z - q2.v.z);
+}
+
+inline Quaternion operator*(Quaternion q1, Quaternion q2)
+{
+ return Quaternion( q1.n * q2.n - q1.v.x * q2.v.x - q1.v.y * q2.v.y - q1.v.z * q2.v.z,
+ q1.n * q2.v.x + q1.v.x * q2.n + q1.v.y * q2.v.z - q1.v.z * q2.v.y,
+ q1.n * q2.v.y + q1.v.y * q2.n + q1.v.z * q2.v.x - q1.v.x * q2.v.z,
+ q1.n * q2.v.z + q1.v.z * q2.n + q1.v.x * q2.v.y - q1.v.y * q2.v.x);
+}
+
+inline Quaternion operator*(Quaternion q, float s)
+{
+ return Quaternion(q.n * s, q.v.x * s, q.v.y * s, q.v.z * s);
+}
+
+inline Quaternion operator*(float s, Quaternion q)
+{
+ return Quaternion(q.n * s, q.v.x * s, q.v.y * s, q.v.z * s);
+}
+
+inline Quaternion operator*(Quaternion q, Vector v)
+{
+ return Quaternion( -(q.v.x * v.x + q.v.y * v.y + q.v.z * v.z),
+ q.n * v.x + q.v.y * v.z - q.v.z * v.y,
+ q.n * v.y + q.v.z * v.x - q.v.x * v.z,
+ q.n * v.z + q.v.x * v.y - q.v.y * v.x);
+}
+
+inline Quaternion operator*(Vector v, Quaternion q)
+{
+ return Quaternion( -(q.v.x * v.x + q.v.y * v.y + q.v.z * v.z),
+ q.n * v.x + q.v.z * v.y - q.v.y * v.z,
+ q.n * v.y + q.v.x * v.z - q.v.z * v.x,
+ q.n * v.z + q.v.y * v.x - q.v.x * v.y);
+}
+
+inline Quaternion operator/(Quaternion q, float s)
+{
+ return Quaternion(q.n / s, q.v.x / s, q.v.y / s, q.v.z / s);
+}
+
+inline float QGetAngle(Quaternion q)
+{
+ return (float) (2 * acosf(q.n));
+}
+
+inline Vector QGetAxis(Quaternion q)
+{
+ Vector v;
+ float m;
+
+ v = q.GetVector();
+ m = v.Magnitude();
+
+ if (m <= tol)
+ return Vector();
+ else
+ return v / m;
+}
+
+inline Quaternion QRotate(Quaternion q1, Quaternion q2)
+{
+ return q1 * q2 * (~q1);
+}
+
+inline Vector QVRotate(Quaternion q, Vector v)
+{
+ Quaternion t;
+
+
+ t = q * v * (~q);
+
+ return t.GetVector();
+}
+
+inline Quaternion MakeQFromEulerAngles(float x, float y, float z)
+{
+ Quaternion q;
+ double roll = DegreesToRadians(x);
+ double pitch = DegreesToRadians(y);
+ double yaw = DegreesToRadians(z);
+
+ double cyaw, cpitch, croll, syaw, spitch, sroll;
+ double cyawcpitch, syawspitch, cyawspitch, syawcpitch;
+
+ cyaw = cos(0.5f * yaw);
+ cpitch = cos(0.5f * pitch);
+ croll = cos(0.5f * roll);
+ syaw = sin(0.5f * yaw);
+ spitch = sin(0.5f * pitch);
+ sroll = sin(0.5f * roll);
+
+ cyawcpitch = cyaw * cpitch;
+ syawspitch = syaw * spitch;
+ cyawspitch = cyaw * spitch;
+ syawcpitch = syaw * cpitch;
+
+ q.n = (float) (cyawcpitch * croll + syawspitch * sroll);
+ q.v.x = (float) (cyawcpitch * sroll - syawspitch * croll);
+ q.v.y = (float) (cyawspitch * croll + syawcpitch * sroll);
+ q.v.z = (float) (syawcpitch * croll - cyawspitch * sroll);
+
+ return q;
+}
+
+inline Vector MakeEulerAnglesFromQ(Quaternion q)
+{
+ double r11, r21, r31, r32, r33;
+ double q00, q11, q22, q33;
+ double tmp;
+ Vector u;
+
+ q00 = q.n * q.n;
+ q11 = q.v.x * q.v.x;
+ q22 = q.v.y * q.v.y;
+ q33 = q.v.z * q.v.z;
+
+ r11 = q00 + q11 - q22 - q33;
+ r21 = 2 * (q.v.x * q.v.y + q.n * q.v.z);
+ r31 = 2 * (q.v.x * q.v.z - q.n * q.v.y);
+ r32 = 2 * (q.v.y * q.v.z + q.n * q.v.x);
+ r33 = q00 - q11 - q22 + q33;
+
+ tmp = fabs(r31);
+ if (tmp > 0.999999) {
+ double r12 = 2 * (q.v.x * q.v.y - q.n * q.v.z);
+ double r13 = 2 * (q.v.x * q.v.z + q.n * q.v.y);
+
+ u.x = RadiansToDegrees(0.0f); //roll
+ u.y = RadiansToDegrees((float) (-(pi / 2) * r31 / tmp)); // pitch
+ u.z = RadiansToDegrees((float) atan2(-r12, -r31 * r13)); // yaw
+ return u;
+ }
+
+ u.x = RadiansToDegrees((float) atan2(r32, r33)); // roll
+ u.y = RadiansToDegrees((float) asinf(-r31)); // pitch
+ u.z = RadiansToDegrees((float) atan2(r21, r11)); // yaw
+ return u;
+
+
+}
+
+
+
+
+
+#endif