public void update(double curSpeed, double curDensity)
{
maxSpeed = 0;
breakDistance = 0;
curDensity = Math.Max(curDensity, 0.2 * vesselState.mainBody.atmDensityASL);
double curSpeedOfSound = Math.Max(vesselState.speedOfSound, vesselState.mainBody.GetSpeedOfSound(0.2 * vesselState.mainBody.atmPressureASL, 0.2 * vesselState.mainBody.atmDensityASL));
//create List by descending order of maxSpeed with drag and max chute reaction time
SortedList <double, (float, float)> parachuteTypes = new SortedList <double, (float, float)>(Comparer <double> .Create((a, b) => Math.Sign(b - a)));
foreach (var p in vesselState.parachutes)
{
if (p.deploymentState == ModuleParachute.deploymentStates.STOWED)
{
p.refDensity = curDensity;
p.CalcBaseStats();
DragCubeList simParachute = new DragCubeList();
simParachute.LoadCube(p.part.DragCubes, "DEPLOYED");
simParachute.SetPart(p.part);
simParachute.SetOcclusionMultiplier(0f);
simParachute.ResetCubeWeights();
simParachute.SetDragWeights();
simParachute.SetPartOcclusion();
//Debug.Log(String.Format("ParachuteInfo.update Parchute {0} has up Cube area={1:F1} drag={2:F1} weight={3:F1} AreaOccluded={4:F1}",
// p.part.name, simParachute.Cubes[0].Area[(int) DragCube.DragFace.YP], simParachute.Cubes[0].Drag[(int) DragCube.DragFace.YP],
// simParachute.Cubes[0].Weight, simParachute.AreaOccluded[(int)DragCube.DragFace.YP]));
DragCubeList.CubeData simDrag = new DragCubeList.CubeData();
simParachute.AddSurfaceDragDirection(Vector3.up, (float)(p.maxSafeSpeedAtRef / curSpeedOfSound), ref simDrag);
//Debug.Log(String.Format("ParachuteInfo.update Parchute {0} has areaDrag={1:F1}, crossSectionalArea={2:F1}, exposedArea={3:F1}",
// p.part.name, simDrag.areaDrag, simDrag.crossSectionalArea, simDrag.exposedArea));
if (parachuteTypes.ContainsKey(p.maxSafeSpeedAtRef))
{
parachuteTypes[p.maxSafeSpeedAtRef] = (parachuteTypes[p.maxSafeSpeedAtRef].Item1 + simDrag.areaDrag,
Mathf.Max(parachuteTypes[p.maxSafeSpeedAtRef].Item2, p.Anim[p.semiDeployedAnimation].length / p.semiDeploymentSpeed + p.Anim[p.fullyDeployedAnimation].length / p.deploymentSpeed));
}
else
{
parachuteTypes.Add(p.maxSafeSpeedAtRef, (simDrag.areaDrag, p.Anim[p.semiDeployedAnimation].length / p.semiDeploymentSpeed + p.Anim[p.fullyDeployedAnimation].length / p.deploymentSpeed));
}
}
}
float totalFriction = 0;
double lastSpeed = 0;
foreach (var pt in parachuteTypes)
{
double effSpeed = Math.Min(curSpeed, pt.Key);
// base equation deceleration term + chute reaction term with deceleration taken from moving equations with netwon friction
// during reaction time we hardly break, so assume
float friction_const = pt.Value.Item1 * 0.0005f * (float)curDensity * PhysicsGlobals.DragMultiplier
* PhysicsGlobals.DragCubeMultiplier * PhysicsGlobals.DragCurvePseudoReynolds.Evaluate((float)(effSpeed * curDensity));
if (breakDistance == 0) // first term for highest speed
{
breakDistance = (float)vesselState.mass / friction_const * Math.Log(effSpeed) + effSpeed * pt.Value.Item2;
undeployedDistance = effSpeed * pt.Value.Item2;// - vesselState.mass / friction_const ;
maxSpeed = lastSpeed = effSpeed;
totalFriction = friction_const;
//Debug.Log(String.Format("ParachuteInfo.update has first chute type with friction={0:F4} and effSpeed={1:F0}, delay={3:F1} results break dist={2:F0}", friction_const, effSpeed, breakDistance, pt.Value.Item2));
}
else
{
// calculate slowdown during parachute opening using old friction
effSpeed *= (float)vesselState.mass / (totalFriction * pt.Value.Item2 * effSpeed + vesselState.mass);
breakDistance -= (float)vesselState.mass / (totalFriction + friction_const) * friction_const / totalFriction * Math.Log(effSpeed);
undeployedDistance += pt.Value.Item2 * effSpeed;// + vesselState.mass * lastSpeed / (totalFriction * effSpeed) - vesselState.mass / (totalFriction + friction_const);
lastSpeed = effSpeed;
totalFriction += friction_const;
//Debug.Log(String.Format("ParachuteInfo.update has next chute type with friction={0:F4} and effSpeed={1:F0}, delay={3:F1} results break dist={2:F0}", friction_const, effSpeed, breakDistance, pt.Value.Item2));
}
}
if (totalFriction > 0)
{
double terminalSpeed = Math.Sqrt((float)vesselState.mass / totalFriction * vesselState.mainBody.GeeASL * PhysicsGlobals.GravitationalAcceleration);
//we are not getting slower than terminal velocity, so substract this as best guess for integration constant v
breakDistance -= (float)vesselState.mass / totalFriction * Math.Log(terminalSpeed);
//undeployedDistance += vesselState.mass * lastSpeed / (totalFriction * terminalSpeed);
//Debug.Log(String.Format("ParachuteInfo.update has terminal velocity term with friction={0:F4} and terminalSpeed={1:F0} results break dist={2:F0}", totalFriction, terminalSpeed, breakDistance));
}
Debug.Log(String.Format("ParachuteInfo.update for speed={0:F0} gives maxSpeed={1:F0} break dist={2:F0} undeployedDistance={3:F0}", curSpeed, maxSpeed, breakDistance, undeployedDistance));
}
