public void Update(
float deltaTime,
ref Vector3 billboardUp,
ref Vector3 billboardRight,
ref Random32 random)
{
velocity *= 1f - (damping * deltaTime);
float min = -0.5f * randomAccelStrengh;
float max = -min;
var a = new Vector3(
random.GetFloat(min, max),
random.GetFloat(min, max),
random.GetFloat(min, max));
Math.Add(ref a, ref constantAccel);
Math.Madd(ref velocity, ref a, deltaTime);
Math.Madd(ref position, ref velocity, deltaTime);
radius *= 1f - (attenuation * deltaTime);
time += deltaTime;
// 頂点座標計算
const float cos30 = 0.866025403784439f;
float rCos30x2 = radius * cos30 * 2f;
Vector3 tmpUp, tmpRight, upCenter;
Math.SetMul(out tmpUp, ref billboardUp, radius);
Math.SetMul(out tmpRight, ref billboardRight, rCos30x2);
// 上辺はcenter.y - r*sin(30) = r/2
// 下端はcenter.y + r*cos(30)
Math.SetAdd(out upCenter, ref position, ref tmpUp);
Math.SetMsub(out p0, ref position, ref tmpUp, 2f);
Math.SetSub(out p1, ref upCenter, ref tmpRight);
Math.SetAdd(out p2, ref upCenter, ref tmpRight);
}
void Fire()
{
Vector3 forward = gunPoint.forward;
Vector3 right = gunPoint.right;
Vector3 v = forward * beamParameters.speed;
Math.RotateVector(out v, ref v, ref right, Mathf.PI / 3f);
var roll = random.GetFloat(-180f, 180f);
Math.RotateVector(out v, ref v, ref forward, roll);
Fire(v);
}