public bool Raycast(Ray ray, out float t)
{
t = 0.0f;
// Calculate the coefficients of the quadratic equation
Vector3 sphereCenterToRayOrigin = ray.origin - _center;
float a = Vector3.SqrMagnitude(ray.direction);
float b = 2.0f * Vector3.Dot(ray.direction, sphereCenterToRayOrigin);
float c = Vector3.SqrMagnitude(sphereCenterToRayOrigin) - _radius * _radius;
// If we have a solution to the equation, the ray most likely intersects the sphere.
float t1, t2;
if (Equation.SolveQuadratic(a, b, c, out t1, out t2))
{
// Make sure the ray doesn't intersect the sphere only from behind
if (t1 < 0.0f && t2 < 0.0f)
{
return(false);
}
// Make sure we are using the smallest positive t value
if (t1 < 0.0f)
{
float temp = t1;
t1 = t2;
t2 = temp;
}
t = t1;
return(true);
}
// If we reach this point it means the ray does not intersect the sphere in any way
return(false);
}