glm::mat3 RotateY(float fElapsedTime)
{
float fAngRad = ComputeAngleRad(fElapsedTime, 2.0);
float fCos = cosf(fAngRad);
float fSin = sinf(fAngRad);
glm::mat3 theMat(1.0f);
theMat[0].x = fCos; theMat[2].x = fSin;
theMat[0].z = -fSin; theMat[2].z = fCos;
return theMat;
}
glm::mat3 RotateAxis(float fElapsedTime) {
float fAngRad = ComputeAngleRad(fElapsedTime, 2.0);
float fCos = cosf(fAngRad);
float fInvCos = 1.0f - fCos;
float fSin = sinf(fAngRad);
float fInvSin = 1.0f - fSin;
glm::vec3 axis(1.0f, 1.0f, 1.0f);
axis = glm::normalize(axis);
glm::mat3 theMat(1.0f);
theMat[0].x = (axis.x * axis.x) + ((1 - axis.x * axis.x) * fCos);
theMat[1].x = axis.x * axis.y * (fInvCos) - (axis.z * fSin);
theMat[2].x = axis.x * axis.z * (fInvCos) + (axis.y * fSin);
theMat[0].y = axis.x * axis.y * (fInvCos) + (axis.z * fSin);
theMat[1].y = (axis.y * axis.y) + ((1 - axis.y * axis.y) * fCos);
theMat[2].y = axis.y * axis.z * (fInvCos) - (axis.x * fSin);
theMat[0].z = axis.x * axis.z * (fInvCos) - (axis.y * fSin);
theMat[1].z = axis.y * axis.z * (fInvCos) + (axis.x * fSin);
theMat[2].z = (axis.z * axis.z) + ((1 - axis.z * axis.z) * fCos);
return theMat;
}