// GUI
private void WindowGUI(int windowID)
{
// General GUI window information
GUIStyle mySty = new GUIStyle(GUI.skin.button);
mySty.normal.textColor = mySty.focused.textColor = Color.white;
mySty.hover.textColor = mySty.active.textColor = Color.yellow;
mySty.onNormal.textColor = mySty.onFocused.textColor = mySty.onHover.textColor = mySty.onActive.textColor = Color.green;
mySty.padding = new RectOffset(2, 2, 2, 2);
GUILayout.BeginVertical();
GUILayout.Label("Buoyancy on:");
currentSelection = GUILayout.SelectionGrid(currentSelection, selStringArray, 1);
currentBody = BodyRef[currentSelection];
GUILayout.Label("Envelope Volume: " + TotalEnvelopeVolume);
string mass = "?";
double buoyancy = ComputeMaxBuoyancy();
mass = TotalMass.ToString("00.00");
// weight
double weight = TotalMass * FlightGlobals.Bodies[currentBody].GeeASL * 9.81;
double netForce = buoyancy - weight;
GUILayout.Label("Vessel Mass: " + mass + "T");
GUILayout.Label("Net Buoyancy: " + netForce.ToString("00.00") + "KN");
try
{
if (netForce > 0)
{
float tippingPoint = 0f;
Keyframe[] frames = null;
float maxAltitude = 100000;
int frameIndex = 0;
bool useCurve = true;
if (useCurve)
{
frames = FlightGlobals.Bodies[currentBody].atmosphereTemperatureCurve.Curve.keys;
maxAltitude = frames[frames.Length - 1].time;
}
// compute equilibrium altitude
for (float i = 100f; i < maxAltitude; i += 100f)
{
double pressure = FlightGlobals.Bodies[currentBody].GetPressure(i);
// Compute the buoyant force
// KSP provides the density based on local atmospheric pressure.
double atmosDensity = pressure / (287.058 * FlightGlobals.Bodies[currentBody].atmosphereTemperatureSeaLevel);
if (useCurve)
{
// walk the curve forward if needed
if (frameIndex < frames.Length - 1 && i > frames[frameIndex + 1].time)
{
frameIndex++;
}
// linear interpolation is close enough for now
float tempCurve = ((i - frames[frameIndex].time) / (frames[frameIndex + 1].time - frames[frameIndex].time)) * (frames[frameIndex + 1].value - frames[frameIndex].value) + frames[frameIndex].value;
atmosDensity = pressure / (287.058 * tempCurve);
}
// The maximum buoyancy of the envelope is equal to the weight of the displaced air
// Force (Newtons) = - Gravitational Acceleration (meters per second squared) * Density (kilograms / meter cubed) * Volume (meters cubed)
double maxBuoyancy = FlightGlobals.Bodies[currentBody].GeeASL * 9.81 * atmosDensity * TotalEnvelopeVolume;
if (maxBuoyancy < weight)
{
tippingPoint = i;
break;
}
}
if (tippingPoint > 0)
{
GUILayout.Label("Equilibrium Altitude : " + tippingPoint.ToString() + "m");
}
}
else
{
GUILayout.Label("Equilibrium Altitude : Won't Fly");
}
}
catch (Exception)
{
GUILayout.Label("Equilibrium Altitude : Unknown");
}
GUILayout.EndVertical();
GUI.DragWindow(new Rect(0, 0, 500, 20));
}
