void Quaternion::FromAngleAxis(const Radian& rfAngle, const Vector3& rkAxis)
{
Radian fHalfAngle(rfAngle * 0.5);
float fSin = Math::Sin(fHalfAngle);
w = Math::Cos(fHalfAngle);
x = fSin*rkAxis.x;
y = fSin*rkAxis.y;
z = fSin*rkAxis.z;
}
//-----------------------------------------------------------------------
void Quaternion::FromAngleAxis(const Radian& rfAngle,
const Vector3& rkAxis)
{
// 断言: axis[] 是单位长度
//
// 这个四元数表示的旋转是
// q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
Radian fHalfAngle(0.5*rfAngle.valueRadians());
Real fSin = Math::Sin(fHalfAngle);
w = Math::Cos(fHalfAngle);
x = fSin*rkAxis.x;
y = fSin*rkAxis.y;
z = fSin*rkAxis.z;
}
// -----------------------------------------------------------------------------------------
void CPepeEngineQuaternion::fromAngleAxis(const Radian& rfAngle, const CPepeEngineVector3& rkAxis)
{
/**
* assert: axis[] is unit length
*
* The quaternion representing the rotation is
* q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
*/
Radian fHalfAngle(0.5 * rfAngle);
float fSin = CPepeEngineMath::Sin(fHalfAngle);
w = CPepeEngineMath::Cos(fHalfAngle);
x = fSin * rkAxis.x;
y = fSin * rkAxis.y;
z = fSin * rkAxis.z;
}
void fromAngleAxis(qv4& result,
const f32 rfAngle,
const v3& rkAxis)
{
// assert: axis[] is unit length
//
// The quaternion representing the rotation is
// q = cos(A/2)+sin(A/2)*(x*i+y*j+z*k)
f32 fHalfAngle(0.5f * rfAngle);
f32 fSin = std::sin(fHalfAngle);
result.w = std::cos(fHalfAngle);
result.x = fSin*rkAxis.x;
result.y = fSin*rkAxis.y;
result.z = fSin*rkAxis.z;
}
