GLUSvoid GLUSAPIENTRY glusVector3Refractf(GLUSfloat result[3], const GLUSfloat incident[3], const GLUSfloat normal[3], const float eta)
{
// see http://www.opengl.org/sdk/docs/manglsl/xhtml/refract.xml
// see http://en.wikipedia.org/wiki/Snell%27s_law
// see http://www.hugi.scene.org/online/coding/hugi%2023%20-%20torefrac.htm for a and b vector.
// In this implementation, the incident vector points into the interface. So the sings do change.
GLUSfloat nDotI = glusVector3Dotf(normal, incident);
GLUSfloat k = 1.0f - eta * eta * (1.0f - nDotI * nDotI);
if (k < 0.0f)
{
result[0] = 0.0f;
result[1] = 0.0f;
result[2] = 0.0f;
}
else
{
GLUSfloat a[3];
GLUSfloat b[3];
glusVector3MultiplyScalarf(a, incident, eta);
glusVector3MultiplyScalarf(b, normal, eta * nDotI + sqrtf(k));
glusVector3SubtractVector3f(result, a, b);
}
}
Vector3 Vector3::operator -(const Vector3& other) const
{
Vector3 result;
glusVector3SubtractVector3f(result.v, v, other.v);
return result;
}
GLUSboolean GLUSAPIENTRY glusVector3GramSchmidtOrthof(GLUSfloat result[3], const GLUSfloat u[3], const GLUSfloat v[3])
{
GLUSfloat uProjV[3];
GLUSfloat vDotU;
GLUSfloat uDotU = glusVector3Dotf(u, u);
if (uDotU == 0.0f)
{
return GLUS_FALSE;
}
vDotU = glusVector3Dotf(v, u);
uProjV[0] = u[0] * vDotU / uDotU;
uProjV[1] = u[1] * vDotU / uDotU;
uProjV[2] = u[2] * vDotU / uDotU;
glusVector3SubtractVector3f(result, v, uProjV);
return GLUS_TRUE;
}
GLUSvoid GLUSAPIENTRY glusVector3Reflectf(GLUSfloat result[3], const GLUSfloat incident[3], const GLUSfloat normal[3])
{
glusVector3MultiplyScalarf(result, normal, 2.0f * glusVector3Dotf(normal, incident));
glusVector3SubtractVector3f(result, incident, result);
}
Vector3& Vector3::operator -=(const Vector3& vector)
{
glusVector3SubtractVector3f(v, v, vector.v);
return *this;
}
