GLUSboolean GLUSAPIENTRY glusQuaternionSlerpf(GLUSfloat result[4], const GLUSfloat quaternion0[4], const GLUSfloat quaternion1[4], const GLUSfloat t)
{
GLUSint i;
GLUSfloat cosAlpha = quaternion0[0] * quaternion1[0] + quaternion0[1] * quaternion1[1] + quaternion0[2] * quaternion1[2] + quaternion0[3] * quaternion1[3];
GLUSfloat alpha = acosf(glusMathClampf(cosAlpha, -1.0f, 1.0f));
GLUSfloat sinAlpha = sinf(alpha);
GLUSfloat a;
GLUSfloat b;
if (sinAlpha == 0.0f)
{
glusQuaternionCopyf(result, quaternion0);
return GLUS_FALSE;
}
a = sinf(alpha * (1.0f - t)) / sinAlpha;
b = sinf(alpha * t) / sinAlpha;
for (i = 0; i < 4; i++)
{
result[i] = a * quaternion0[i] + b * quaternion1[i];
}
return GLUS_TRUE;
}
GLUSvoid GLUSAPIENTRY glusQuaternionMultiplyQuaternionf(GLUSfloat result[4], const GLUSfloat quaternion0[4], const GLUSfloat quaternion1[4])
{
GLUSfloat temp[4];
temp[0] = quaternion0[3] * quaternion1[0] + quaternion0[0] * quaternion1[3] + quaternion0[1] * quaternion1[2] - quaternion0[2] * quaternion1[1];
temp[1] = quaternion0[3] * quaternion1[1] - quaternion0[0] * quaternion1[2] + quaternion0[1] * quaternion1[3] + quaternion0[2] * quaternion1[0];
temp[2] = quaternion0[3] * quaternion1[2] + quaternion0[0] * quaternion1[1] - quaternion0[1] * quaternion1[0] + quaternion0[2] * quaternion1[3];
temp[3] = quaternion0[3] * quaternion1[3] - quaternion0[0] * quaternion1[0] - quaternion0[1] * quaternion1[1] - quaternion0[2] * quaternion1[2];
glusQuaternionCopyf(result, temp);
}
