public (bool, float, float) intersect(Vec3f rayorig, Vec3f raydir)
{
float t0 = 0.0f;
float t1 = 0.0f;
Vec3f l = center - rayorig;
float tca = l.dot(raydir);
if (tca < 0)
{
return(false, t0, t1);
}
float d2 = l.dot(l) - tca * tca;
if (d2 > radius2)
{
return(false, t0, t1);
}
float thc = (float)Math.Sqrt(radius2 - d2);
t0 = tca - thc;
t1 = tca + thc;
return(true, t0, t1);
}
public static Mat4f lookAtLH(Vec3f eye, Vec3f center, Vec3f up)
{
Vec3f f = (center - eye).normal();
Vec3f s = (f * up).normal();
Vec3f u = s * f;
Mat4f Result = new Mat4f();
Result.data[0][0] = s.x;
Result.data[1][0] = s.y;
Result.data[2][0] = s.z;
Result.data[0][1] = u.x;
Result.data[1][1] = u.y;
Result.data[2][1] = u.z;
Result.data[0][2] = f.x;
Result.data[1][2] = f.y;
Result.data[2][2] = f.z;
Result.data[3][0] = -(s.dot(eye));
Result.data[3][1] = -(u.dot(eye));
Result.data[3][2] = -(f.dot(eye));
return(Result);
}
