/**
* Creates a forced directed graph from https://cs.brown.edu/~rt/gdhandbook/chapters/force-directed.pdf
* @param optimalDistanceModifier - increases the distance between the planets
*/
private void temperatureForcedDirectedGraph(float optimalDistanceModifier)
{
int area = frameWidth * frameHeight;
List <GameObject> allPlanets = getListOfPlanets();
float optimalDistance = (float)(optimalDistanceModifier * Math.Sqrt(area / allPlanets.Count));
/**
* For each planet, push them apart from the others
*/
foreach (GameObject currentPlanet in allPlanets)
{
currentPlanet.GetComponent <Planet>().setDisplacement(new Vector3(0, 0, 0));
foreach (GameObject otherPlanet in allPlanets)
{
if (currentPlanet.GetInstanceID() != otherPlanet.GetInstanceID())
{
Vector3 differenceVector = currentPlanet.transform.position - otherPlanet.transform.position;
updateDisplacement(differenceVector, optimalDistance, currentPlanet, false);
}
}
}
/**
* For each edge, pull their two planets closer towards each other
*/
List <PlanetLine> graphEdges = new List <PlanetLine>();
foreach (GameObject currentPlanet in allPlanets)
{
List <GameObject> connections = currentPlanet.GetComponent <Planet>().getConnectedObjects();
foreach (GameObject otherPlanet in connections)
{
PlanetLine edge = new PlanetLine(currentPlanet, otherPlanet);
if (!graphEdges.Contains(edge))
{
graphEdges.Add(edge);
Vector3 differenceVector = currentPlanet.transform.position - otherPlanet.transform.position;
updateDisplacement(differenceVector, optimalDistance, currentPlanet, true, true);
updateDisplacement(differenceVector, optimalDistance, otherPlanet, true);
}
}
}
// Move the planets by their calculated forces
foreach (GameObject currentPlanet in allPlanets)
{
Vector3 currentPos = currentPlanet.transform.position;
Vector3 displacementVector = currentPlanet.GetComponent <Planet>().getDisplacement();
currentPlanet.transform.position = currentPos + ((displacementVector.normalized) * Math.Min(displacementVector.magnitude, getTemp()));
}
}
private void removeCrossingEdges(List <PlanetLine> crossings)
{
for (int i = 0; i < crossings.Count; i += 2)
{
if (crossings.ElementAtOrDefault(i) != null && crossings.ElementAtOrDefault(i + 1) != null)
{
PlanetLine firstLine = crossings.ElementAtOrDefault(i);
PlanetLine secondLine = crossings.ElementAtOrDefault(i + 1);
/**
* crossing edges look like this fixed result should look like this
* a a
| / \
| x ---- y x y
| \ /
| b b
*/
GameObject xPlanet = firstLine.firstPlanet;
GameObject yPlanet = firstLine.secondPlanet;
GameObject aPlanet = secondLine.firstPlanet;
GameObject bPlanet = secondLine.secondPlanet;
// Remove the crossing edges by destroying the trade routes between the planets
xPlanet.GetComponent <Planet>().removeConnectedPlanet(yPlanet);
yPlanet.GetComponent <Planet>().removeConnectedPlanet(xPlanet);
aPlanet.GetComponent <Planet>().removeConnectedPlanet(bPlanet);
bPlanet.GetComponent <Planet>().removeConnectedPlanet(aPlanet);
// Connect the planet to the previously conflicting trade route planets
addPlanet(xPlanet, aPlanet);
addPlanet(xPlanet, bPlanet);
addPlanet(yPlanet, aPlanet);
addPlanet(yPlanet, bPlanet);
}
}
}
/**
* Returns whether or not the intersection has already been identified (since each trade route is two-way, there are duplicates)
*/
private bool intersectionAlreadyFound(PlanetLine firstLine, PlanetLine secondLine, List <PlanetLine> intersectionsList)
{
return(intersectionsList.Contains(firstLine) && intersectionsList.Contains(secondLine));
}
