private void loop() {
float max = 0;
int counter = 0;
while (nodes.size() != 0) {
Point2DInteger n = nodes.peek();
ArrayList<Point2DInteger> children = FlowDirectionUtils.getUpstreamNodes(n, flowDirection);
if (children.size() == 0) {
flowAccumulation.set(n.getX(), n.getY(), 0);
nodes.pop();
} else {
float sum = 0;
boolean hasUndefined = false;
for (Point2DInteger p : children) {
float acc = flowAccumulation.get(p.getX(), p.getY());
if (Float.isNaN(acc)) {
hasUndefined = true;
nodes.add(p);
} else {
sum += acc;
sum += getArea(p);
}
}
if (!hasUndefined) {
max = Math.max(max, sum);
flowAccumulation.set(n.getX(), n.getY(), sum);
nodes.pop();
}
}
counter++;
if ((counter & 0xffff) == 0xffff) {
System.out.println("FlowAcc " + counter + " " + max);
}
}
System.out.println("Done");
}
private float getArea(Point2DInteger area) {
float longitude1 = 1.0f * area.getX() / elementsPerDegree;
float latitude1 = 90 - 1.0f * area.getY() / elementsPerDegree;
float longitude2 = 1.0f * (area.getX() + 1) / elementsPerDegree;
float latitude2 = 90 - 1.0f * (area.getY() + 1) / elementsPerDegree;
Point3DDouble dist11 = conv.positionDeg(latitude1, longitude1, 0);
Point3DDouble dist12 = conv.positionDeg(latitude1, longitude2, 0);
Point3DDouble dist21 = conv.positionDeg(latitude2, longitude1, 0);
double distX = dist11.distance(dist12);
double distY = dist11.distance(dist21);
return (float) (distX * distY);
}