Ga::GaQuat Class Reference

#include "GaTypes.h"

Collaboration diagram for Ga::GaQuat:

Public Member Functions
GaExpInl	GaQuat ()
GaExpInl	GaQuat (GaFloat W, const GaVec3 &V)
GaExpInl	GaQuat (GaFloat W, GaFloat X, GaFloat Y, GaFloat Z)
	GaQuat (const GaRadian &a, const GaVec3 &axis)
	GaQuat (const GaMat3x3 &rot)
GaExpInl GaVec3	operator* (const GaVec3 &vec) const
GaExpInl GaQuat	operator* (const GaQuat &oth) const
GaExpInl GaQuat &	operator= (const GaQuat &oth)
GaQuat &	operator= (const Parameter &oth)
	GaQuat (const Parameter &oth)
GaQuat	inverse () const

Public Attributes
GaFloat	w
GaVec3	v

Static Public Attributes
static GaQuat	IDENTITY = GaQuat(1,0,0,0)
static GaQuat	ZERO = GaQuat(0,0,0,0)

Detailed Description

Definition at line 218 of file GaTypes.h.

Constructor & Destructor Documentation

GaExpInl Ga::GaQuat::GaQuat ( )

inline

Definition at line 224 of file GaTypes.h.

Referenced by inverse().

:w(0),v(0,0,0){}

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GaExpInl Ga::GaQuat::GaQuat ( GaFloat  W, const GaVec3 &  V  )

inline

Definition at line 225 of file GaTypes.h.

:w(W),v(V){}

GaExpInl Ga::GaQuat::GaQuat ( GaFloat  W, GaFloat  X, GaFloat  Y, GaFloat  Z  )

inline

Definition at line 226 of file GaTypes.h.

:w(W),v(X,Y,Z){}

GaQuat::GaQuat	(	const GaRadian &	a,
		const GaVec3 &	axis
	)

Definition at line 27 of file GaTypes.cpp.

References Ga::Math::cosine(), Ga::GaRadian::r, Ga::Math::sine(), v, w, Ga::GaVec3::x, Ga::GaVec3::y, and Ga::GaVec3::z.

{
    w = Math::cosine(a.r * 0.5);

    GaFloat sin_a = Math::sine(a.r * 0.5);
    v.x = axis.x * sin_a;
    v.y = axis.y * sin_a;
    v.z = axis.z * sin_a;

    v.x *= 57.2957795131;   //  180/pi (rad->deg)
    v.y *= 57.2957795131;   //  180/pi (rad->deg)
    v.z *= 57.2957795131;   //  180/pi (rad->deg)

    if (v.x < 0)
        v.x += 360;
    if (v.y < 0)
        v.y += 360;
    if (v.z < 0)
        v.z += 360;
}

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GaQuat::GaQuat

(

const GaMat3x3 &

rot

)

Definition at line 298 of file GaTypes.cpp.

References Ga::Math::squareRoot(), v, w, Ga::GaVec3::x, Ga::GaVec3::y, and Ga::GaVec3::z.

{
    // Algorithm in Ken Shoemake's article in 1987 SIGGRAPH course notes
    // article "Quaternion Calculus and Fast Animation".

    GaFloat fTrace = rot[0][0]+rot[1][1]+rot[2][2];
    GaFloat fRoot;

    if ( fTrace > 0.0f )
    {
        // |w| > 1/2, may as well choose w > 1/2
        fRoot = Math::squareRoot(fTrace + 1.0f);  // 2w
        w = 0.5f*fRoot;
        fRoot = 0.5f/fRoot;  // 1/(4w)
        v.x = (rot[2][1]-rot[1][2])*fRoot;
        v.y = (rot[0][2]-rot[2][0])*fRoot;
        v.z = (rot[1][0]-rot[0][1])*fRoot;
    }
    else
    {
        // |w| <= 1/2
        static GaUint s_iNext[3] = { 1, 2, 0 };
        GaUint i = 0;
        if ( rot[1][1] > rot[0][0] )
            i = 1;
        if ( rot[2][2] > rot[i][i] )
            i = 2;
        GaUint j = s_iNext[i];
        GaUint k = s_iNext[j];

        fRoot = Math::squareRoot(rot[i][i]-rot[j][j]-rot[k][k] + 1.0f);
        GaFloat* apkQuat[3] = { &v.x, &v.y, &v.z };
        *apkQuat[i] = 0.5f*fRoot;
        fRoot = 0.5f/fRoot;
        w = (rot[k][j]-rot[j][k])*fRoot;
        *apkQuat[j] = (rot[j][i]+rot[i][j])*fRoot;
        *apkQuat[k] = (rot[k][i]+rot[i][k])*fRoot;
    }
}

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Ga::GaQuat::GaQuat

(

const Parameter &

oth

)

Member Function Documentation

GaQuat GaQuat::inverse

(

)

const

Definition at line 338 of file GaTypes.cpp.

References GaQuat(), v, w, Ga::GaVec3::x, Ga::GaVec3::y, and Ga::GaVec3::z.

{
    GaFloat nrm = w*w + v.x*v.x + v.y*v.y + v.z*v.z;
    if(nrm > 0.0)
    {
        GaFloat inv = 1.0f/nrm;
        return GaQuat(w*inv,-v.x*inv,-v.y*inv,-v.z*inv);
    }
    else
    {
        return GaQuat(0,0,0,0);
    }
}

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GaExpInl GaVec3 Ga::GaQuat::operator* ( const GaVec3 &  vec ) const

inline

Definition at line 231 of file GaTypes.h.

References Ga::GaVec3::crossProduct(), Ga::GaVec3::x, Ga::GaVec3::y, and Ga::GaVec3::z.

        {
            GaVec3 uv = v.crossProduct(vec);
            GaVec3 uuv = v.crossProduct(uv);

            uv *= (2.0f * w);
            uuv *= 2.0f;

            return GaVec3(vec.x + uv.x + uuv.x,vec.y + uv.y + uuv.y,vec.z + uv.z + uuv.z);
        }

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GaExpInl GaQuat Ga::GaQuat::operator* ( const GaQuat &  oth ) const

inline

Definition at line 242 of file GaTypes.h.

References v, w, Ga::GaVec3::x, Ga::GaVec3::y, and Ga::GaVec3::z.

        {
            return GaQuat
            (
                w * oth.w   - v.x * oth.v.x - v.y * oth.v.y - v.z * oth.v.z,
                w * oth.v.x + v.x * oth.w   + v.y * oth.v.z - v.z * oth.v.y,
                w * oth.v.y + v.y * oth.w   + v.z * oth.v.x - v.x * oth.v.z,
                w * oth.v.z + v.z * oth.w   + v.x * oth.v.y - v.y * oth.v.x
            );
        }

GaExpInl GaQuat& Ga::GaQuat::operator= ( const GaQuat &  oth )

inline

Definition at line 253 of file GaTypes.h.

References v, and w.

        {
            w = oth.w;
            v = oth.v;

            return *this;
        }

GaQuat& Ga::GaQuat::operator=

(

const Parameter &

oth

)

Member Data Documentation

GaQuat GaQuat::IDENTITY = GaQuat(1,0,0,0)

static

Definition at line 221 of file GaTypes.h.

GaVec3 Ga::GaQuat::v

Definition at line 267 of file GaTypes.h.

Referenced by Ga::GaMat3x3::GaMat3x3(), GaQuat(), inverse(), operator*(), operator=(), and Ga::GaVec3::rotationTo().

GaFloat Ga::GaQuat::w

Definition at line 266 of file GaTypes.h.

Referenced by Ga::GaMat3x3::GaMat3x3(), GaQuat(), inverse(), operator*(), and operator=().

GaQuat GaQuat::ZERO = GaQuat(0,0,0,0)

static

Definition at line 222 of file GaTypes.h.

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The documentation for this class was generated from the following files:

• /backups/local/src/eve/EvEmu_Crucible/dep/gangsta/GaTypes.h
• /backups/local/src/eve/EvEmu_Crucible/dep/gangsta/GaTypes.cpp