/// <summary>
/// Cycles through a list of points and creates a fractal
/// version of the points by splitting each one in half and
/// moving it a random amount.
/// </summary>
/// <returns>A true if at least one point was changed.</returns>
public static bool StaggerPoints(
CenterPointList points,
MersenneRandom random,
float minimumDistance)
{
// Ignores blanks and null
if (points == null)
throw new ArgumentException("points cannot be null");
if (random == null)
throw new ArgumentException("random cannot be null");
if (points.Count < 2)
return false;
// Go through each set of points
CenterPointList newPoints = new CenterPointList();
bool changed = false;
for (int i = 0; i < points.Count - 1; i++)
{
// Get the points
CenterPoint p1 = points[i];
CenterPoint p2 = points[i + 1];
// Add the first point
newPoints.Add(p1);
// Get the distance
float distance = CalculateDistance(p1.Point, p2.Point);
if (distance > minimumDistance)
{
// These two are far enough to calculate a new point
CenterPoint mp =
new CenterPoint((p1.X + p2.X) / 2, (p1.Y + p2.Y) / 2);
float delta = distance * Constants.FractalDecay;
float diff = random.NextSingle(-delta, delta);
// Calculate the new point
float dy = p2.Y - p1.Y;
float dx = p2.X - p1.X;
if (dy == 0)
{
// This is a horizontal line
mp.Y += diff;
}
else if (dx == 0)
{
// This is a vertical line
mp.X += diff;
}
else
{
// Figure out the slope of the line
double theta1 = Math.Tanh(dy / dx);
double theta2 = theta1 - Math.PI / 2;
mp.X = (float) (mp.X + diff * Math.Cos(theta2));
mp.Y = (float) (mp.Y + diff * Math.Sin(theta2));
}
// Add the created point
newPoints.Add(mp);
changed = true;
}
// Add the second point
newPoints.Add(p2);
}
// See if we changes something
if (changed)
{
// Swap the points
points.Clear();
points.AddAll(newPoints);
newPoints.Clear();
}
// Return our status
return changed;
}
/// <summary>
/// Loops through the points and staggers them repeatedly.
/// </summary>
public static void StaggerPoints(
CenterPointList points,
MersenneRandom random,
float minimumDistance,
int passes)
{
// Go through the minimum number of passes
for (int i = 0; i < passes; i++)
{
if (!StaggerPoints(points, random, minimumDistance))
break;
}
}
/// <summary>
/// Creates a segment from a child junction to its parent.
/// </summary>
public Segment Create(
Junction child, PointF childPoint, double distance)
{
// Sanity checking
if (child.ParentJunction == null)
throw new Exception("Cannot generate with a null parent");
// Get the distance between the two points
Segment segment = new Segment();
Junction parent = child.ParentJunction;
// Add the two end points
CenterPointList points = new CenterPointList();
points.Add(new CenterPoint(0, 0));
points.Add(new CenterPoint(childPoint));
// Split apart the line
#if DEBUG
Stopwatch stopwatch = Stopwatch.StartNew();
#endif
// Stagger (fractalize) the points
Geometry.StaggerPoints(points, parent.Random,
Constants.MinimumSegmentDistance,
Constants.StaggerSegmentPasses);
#if DEBUG
// Show timing information
stopwatch.Stop();
Log.Debug("Fractal Time: {0}", stopwatch.Elapsed);
stopwatch.Reset();
stopwatch.Start();
#endif
// Once we generated a set of center points, we go through
// and add a randomly-sized and angled square to each
// point, unioning the results to get the shape of the
// entire segment.
IPoly shape = null;
float log = 0;
if (distance > 0)
log = (float) Math.Log(distance) * 10;
foreach (CenterPoint point in points)
{
// Keep track of our retries
int retry = 1;
while (true)
{
// Create a shape
IPoly p = Geometry.CreateShape(parent, point.Point,
retry * (Constants.SegmentAverageWidth - log));
// If we have no shape, this is automatically
// included.
if (shape == null)
{
shape = p;
break;
}
// We have another shape, so we want to build up
// an intersection to make sure they are touching.
if (!shape.HasIntersection(p))
{
// If there is no intersection, then we need
// to try again and make the radius range larger.
retry++;
continue;
}
// Make a union of the two shapes
IPoly union = shape.Union(p);
// See if we have two shapes
if (union.InnerPolygonCount > 1)
{
// We didn't quite reach each other
retry++;
continue;
}
// Set the new shape
shape = union;
break;
}
}
// Remove both junction shapes from this
//shape = shape.Difference(parent.InternalShape);
//shape = shape.Difference(child.InternalShape);
#if DEBUG
// Show timing information
stopwatch.Stop();
Log.Debug(" Shape Time: {0}", stopwatch.Elapsed);
stopwatch.Reset();
stopwatch.Start();
#endif
// Add the shape to the list
segment.InternalShape = shape;
// Set up the center line and optimize it
segment.CenterPoints.AddAll(points);
segment.CenterPoints.Optimize();
#if DEBUG
// Show timing information
stopwatch.Stop();
Log.Debug("Optimze Time: {0}", stopwatch.Elapsed);
#endif
// Return the results
return segment;
}
