/// <summary>
/// Calculate the attractive force between nodes
/// </summary>
/// <param name="first">the first node</param>
/// <param name="second">the second node</param>
/// <returns>attractive force between nodes</returns>
private Vector CalculateAttractiveForceBetweenNodes(NodeLayoutData first, NodeLayoutData second)
{
double springConstant = _defaultSpringConstant;
double amplifier = _defaultSpringAmplifier;
double springStableDistance = _defaultSpringStableDistance;
double dx = first.Coordinates.X - second.Coordinates.X;
double dy = first.Coordinates.Y - second.Coordinates.Y;
double distance = Math.Sqrt((Math.Pow(dx, 2) + Math.Pow(dy, 2)));
double springMultiplier = 0;
if (!double.IsNaN(distance))
{
double distanceFromStablePoint = Math.Abs(distance - springStableDistance);
int directionModifier = -1;
if (distance < springStableDistance)
{
directionModifier = 1;
}
springMultiplier = (distanceFromStablePoint / springConstant);
if (springMultiplier > _defaultSpringMultiplierCap)
{
springMultiplier = _defaultSpringMultiplierCap;
}
springMultiplier = springMultiplier * directionModifier * amplifier;
}
return new Vector(springMultiplier * dx, springMultiplier * dy);
}
/// <summary>
/// Calculate the repulsive force between nodes
/// </summary>
/// <param name="first">the first node</param>
/// <param name="second">the second node</param>
/// <returns>A vector representing a repulsive first</returns>
private Vector CalculateRepulsiveForceBetweeNodes(NodeLayoutData first, NodeLayoutData second)
{
double repulseConstant = _defaultRepulseConstant;
double dx = first.Coordinates.X - second.Coordinates.X;
double dy = first.Coordinates.Y - second.Coordinates.Y;
double distance = Math.Sqrt((Math.Pow(dx, 2) + Math.Pow(dy, 2)));
double repulseMultiplier = 0;
if (!double.IsNaN(distance))
{
repulseMultiplier = repulseConstant / distance;
}
return new Vector(repulseMultiplier * dx, repulseMultiplier * dy);
}
/// <summary>
/// Increment the sort score of a nodes destinations
/// </summary>
/// <param name="nodeData">the current node</param>
/// <param name="visitedNodes">a list of nodes already visited, important to prevent circular processing</param>
private void AddSortScoreToDestinations(NodeLayoutData nodeData, List<NodeLayoutData> visitedNodes)
{
visitedNodes.Add(nodeData);
if (nodeData.NextNodesLayoutData != null)
{
foreach (NodeLayoutData nextNode in nodeData.NextNodesLayoutData)
{
nextNode.SortScore = nextNode.SortScore + 1;
if (!visitedNodes.Contains(nextNode))
{
AddSortScoreToDestinations(nextNode, visitedNodes);
}
}
}
}
