ingo@3227: package de.intevation.flys.artifacts.geom;
sascha@933:
sascha@1651: import java.util.ArrayList;
sascha@933: import java.util.List;
sascha@1651: import java.util.Iterator;
sascha@933:
sascha@933: import java.awt.geom.Point2D;
sascha@933: import java.awt.geom.Line2D;
sascha@933:
sascha@933: import de.intevation.flys.artifacts.math.Linear;
sascha@933:
sascha@938: import org.apache.log4j.Logger;
sascha@938:
sascha@1651: import gnu.trove.TDoubleArrayList;
sascha@1651:
felix@2652: /**
felix@2652: * Utility to create lines (intersect water with cross-section etc).
felix@2652: */
sascha@933: public class Lines
sascha@933: {
sascha@938: private static Logger log = Logger.getLogger(Lines.class);
sascha@938:
sascha@933: public static final double EPSILON = 1e-4;
sascha@933:
sascha@933: public static enum Mode { UNDEF, WET, DRY };
sascha@933:
felix@2681:
felix@2681: /** Never instantiate Lines, use static functions instead. */
sascha@933: protected Lines() {
sascha@933: }
sascha@933:
felix@2673:
felix@2673: /**
felix@2673: * Calculate area of polygon with four vertices.
felix@2673: * @return area of polygon with four vertices.
felix@2673: */
felix@2673: public static double area(Point2D p1, Point2D p2, Point2D p3, Point2D p4) {
felix@2688: double[] x = new double[] {p1.getX(), p2.getX(), p3.getX(), p4.getX(), p1.getX() };
felix@2688: double[] y = new double[] {p1.getY(), p2.getY(), p3.getY(), p4.getY(), p1.getY() };
felix@2673: double area = 0d;
felix@2673: for (int i=0; i <4; i++) {
felix@2688: area += (x[i] * y[i+1]) - (x[i+1] * y[i]);
felix@2673: }
felix@2688: return Math.abs(area * 0.5d);
felix@2673: }
felix@2673:
felix@2673:
felix@2652: /**
felix@2652: * Calculate the 'length' of the given lines.
felix@2681: * @param lines lines of which to calculate length.
felix@2652: */
sascha@2650: public static double length(List<Line2D> lines) {
sascha@2650: double sum = 0d;
sascha@2650: for (Line2D line: lines) {
sascha@2650: double xDiff = line.getX1() - line.getX2();
sascha@2650: double yDiff = line.getY1() - line.getY2();
sascha@2650: sum += Math.sqrt(xDiff*xDiff + yDiff*yDiff);
sascha@2650: }
sascha@2650: return sum;
sascha@2650: }
sascha@2650:
felix@2674:
felix@2674: /** List of lines and a double-precision area. */
felix@2674: private static class ListWithArea {
felix@2674: public List<Line2D> lines;
felix@2674: public double area;
felix@2674: public ListWithArea(List<Line2D> lines, double area) {
felix@2674: this.lines = lines;
felix@2674: this.area = area;
felix@2674: }
felix@2674: }
felix@2674:
felix@2674:
felix@2679: /**
felix@2679: * For a cross section given as points and a waterlevel (in meters),
felix@2679: * create a set of lines that represent the water surface, assuming it
felix@2679: * is distributed horizontally equally.
felix@2679: * @param points the points describing the river bed.
felix@2679: * @param waterLevel the height of the horizontal water line.
felix@2679: * @return A list of Lines representing the water surface and the
felix@2679: * calculated area between water surface and river bed.
felix@2679: */
felix@2674: public static ListWithArea fillWater(List<Point2D> points, double waterLevel) {
sascha@933:
sascha@938: boolean debug = log.isDebugEnabled();
sascha@938:
sascha@938: if (debug) {
sascha@938: log.debug("fillWater");
sascha@938: log.debug("----------------------------");
sascha@933: }
sascha@933:
sascha@933: List<Line2D> result = new ArrayList();
sascha@933:
sascha@933: int N = points.size();
sascha@933:
sascha@933: if (N == 0) {
felix@2674: return new ListWithArea(result, 0d);
sascha@933: }
sascha@933:
sascha@933: if (N == 1) {
sascha@933: Point2D p = points.get(0);
felix@2673: // Only generate point if over profile
sascha@933: if (waterLevel > p.getY()) {
sascha@933: result.add(new Line2D.Double(
sascha@934: p.getX(), waterLevel,
sascha@934: p.getX(), waterLevel));
sascha@933: }
felix@2679: // TODO continue calculating area.
felix@2674: return new ListWithArea(result, 0d);
sascha@933: }
sascha@933:
sascha@933: double minX = Double.MAX_VALUE;
sascha@933: double minY = Double.MAX_VALUE;
sascha@933: double maxX = -Double.MAX_VALUE;
sascha@933: double maxY = -Double.MAX_VALUE;
sascha@933:
sascha@933: // To ensure for sequences of equals x's that
sascha@933: // the original index order is preserved.
sascha@938: for (Point2D p: points) {
sascha@933: double x = p.getX(), y = p.getY();
sascha@933: if (x < minX) minX = x;
sascha@933: if (x > maxX) maxX = x;
sascha@933: if (y < minY) minY = y;
sascha@933: if (y > maxY) maxY = y;
sascha@933: }
sascha@933:
sascha@933: if (minY > waterLevel) { // profile completely over water level
sascha@938: log.debug("complete over water");
felix@2674: return new ListWithArea(result, 0d);
sascha@933: }
sascha@933:
sascha@933: if (waterLevel > maxY) { // water floods profile
sascha@938: log.debug("complete under water");
sascha@933: result.add(new Line2D.Double(minX, waterLevel, maxX, waterLevel));
felix@2674: return new ListWithArea(result, 0d);
sascha@933: }
sascha@933:
felix@2673: // Water is sometimes above, sometimes under profile.
sascha@933: Mode mode = Mode.UNDEF;
sascha@933:
sascha@938: double startX = minX;
sascha@933:
felix@2673: double area = 0d;
felix@2673: // Walking along the profile.
sascha@933: for (int i = 1; i < N; ++i) {
sascha@938: Point2D p1 = points.get(i-1);
sascha@938: Point2D p2 = points.get(i);
sascha@933:
sascha@938: if (p1.getY() < waterLevel && p2.getY() < waterLevel) {
sascha@933: // completely under water
sascha@938: if (debug) {
sascha@938: log.debug("under water: " + p1 + " " + p2);
sascha@938: }
sascha@938: if (mode != Mode.WET) {
sascha@938: startX = p1.getX();
sascha@938: mode = Mode.WET;
sascha@938: }
felix@2673: area += area(p1, p2,
felix@2673: new Point2D.Double(p2.getX(), waterLevel),
felix@2673: new Point2D.Double(p1.getX(), waterLevel));
sascha@933: continue;
sascha@933: }
sascha@933:
felix@2673: // TODO trigger area calculation
sascha@938: if (p1.getY() > waterLevel && p2.getY() > waterLevel) {
sascha@938: if (debug) {
sascha@938: log.debug("over water: " + p1 + " " + p2);
sascha@938: }
sascha@933: // completely over water
sascha@933: if (mode == Mode.WET) {
sascha@938: log.debug("over/wet");
sascha@933: result.add(new Line2D.Double(
sascha@933: startX, waterLevel,
sascha@933: p1.getX(), waterLevel));
sascha@933: }
sascha@933: mode = Mode.DRY;
sascha@933: continue;
sascha@933: }
sascha@933:
felix@2673: // TODO trigger area calculation
sascha@933: if (Math.abs(p1.getX() - p2.getX()) < EPSILON) {
sascha@933: // vertical line
sascha@933: switch (mode) {
sascha@933: case WET:
sascha@938: log.debug("vertical/wet");
sascha@933: mode = Mode.DRY;
sascha@933: result.add(new Line2D.Double(
sascha@933: startX, waterLevel,
sascha@933: p1.getX(), waterLevel));
sascha@933: break;
sascha@933: case DRY:
sascha@938: log.debug("vertical/dry");
sascha@933: mode = Mode.WET;
sascha@933: startX = p2.getX();
sascha@933: break;
sascha@933: default: // UNDEF
sascha@938: log.debug("vertical/undef");
sascha@933: if (p2.getY() < waterLevel) {
sascha@933: mode = Mode.WET;
sascha@933: startX = p2.getX();
sascha@933: }
sascha@933: else {
sascha@933: mode = Mode.DRY;
sascha@933: }
sascha@933: }
sascha@933: continue;
sascha@933: }
sascha@933:
sascha@938: // check if waterlevel directly hits the vertices;
sascha@938:
sascha@938: boolean p1W = Math.abs(waterLevel - p1.getY()) < EPSILON;
sascha@938: boolean p2W = Math.abs(waterLevel - p2.getY()) < EPSILON;
sascha@938:
felix@2673: // TODO trigger area calculation
sascha@938: if (p1W || p2W) {
sascha@938: if (debug) {
sascha@938: log.debug("water hits vertex: " + p1 + " " + p2 + " " + mode);
sascha@938: }
sascha@938: if (p1W && p2W) { // parallel to water -> dry
sascha@938: log.debug("water hits both vertices");
sascha@938: if (mode == Mode.WET) {
sascha@938: result.add(new Line2D.Double(
sascha@938: startX, waterLevel,
sascha@938: p1.getX(), waterLevel));
sascha@938: }
sascha@938: mode = Mode.DRY;
sascha@938: }
sascha@938: else if (p1W) { // p1 == waterlevel
sascha@938: log.debug("water hits first vertex");
sascha@938: if (p2.getY() > waterLevel) { // --> dry
sascha@938: if (mode == Mode.WET) {
sascha@938: result.add(new Line2D.Double(
sascha@938: startX, waterLevel,
sascha@938: p1.getX(), waterLevel));
sascha@938: }
sascha@938: mode = Mode.DRY;
sascha@938: }
sascha@938: else { // --> wet
sascha@938: if (mode != Mode.WET) {
sascha@938: startX = p1.getX();
sascha@938: mode = Mode.WET;
sascha@938: }
felix@2687: area += area(p1, p2,
felix@2687: new Point2D.Double(p2.getX(), waterLevel),
felix@2687: new Point2D.Double(p2.getX(), waterLevel));
sascha@938: }
sascha@938: }
sascha@938: else { // p2 == waterlevel
sascha@938: log.debug("water hits second vertex");
sascha@938: if (p1.getY() > waterLevel) { // --> wet
sascha@938: if (mode != Mode.WET) {
sascha@938: startX = p2.getX();
sascha@938: mode = Mode.WET;
sascha@938: }
sascha@938: }
sascha@938: else { // --> dry
sascha@938: if (mode == Mode.WET) {
sascha@938: result.add(new Line2D.Double(
sascha@938: startX, waterLevel,
sascha@938: p2.getX(), waterLevel));
sascha@938: }
sascha@938: mode = Mode.DRY;
felix@2687: area += area(p1, p2,
felix@2687: new Point2D.Double(p1.getX(), waterLevel),
felix@2687: new Point2D.Double(p1.getX(), waterLevel));
sascha@938: }
sascha@938: }
sascha@938: if (debug) {
sascha@938: log.debug("mode is now: " + mode);
sascha@938: }
sascha@938: continue;
sascha@938: }
sascha@938:
felix@2673: // TODO trigger area calculation
sascha@933: // intersection case
sascha@933: double x = Linear.linear(
sascha@933: waterLevel,
sascha@938: p1.getY(), p2.getY(),
sascha@938: p1.getX(), p2.getX());
sascha@938:
sascha@938: if (debug) {
sascha@938: log.debug("intersection p1:" + p1);
sascha@938: log.debug("intersection p2:" + p2);
sascha@938: log.debug("intersection at x: " + x);
sascha@938: }
sascha@933:
felix@2687: // Add area of that part of intersection that is 'wet'.
felix@2687: if (p1.getY() > waterLevel) {
felix@2687: area += area(new Point2D.Double(x, waterLevel),
felix@2687: p2,
felix@2687: new Point2D.Double(p2.getX(), waterLevel),
felix@2687: new Point2D.Double(x, waterLevel));
felix@2687: }
felix@2687: else {
felix@2687: area += area(new Point2D.Double(x, waterLevel),
felix@2687: p1,
felix@2687: new Point2D.Double(p1.getX(), waterLevel),
felix@2687: new Point2D.Double(x, waterLevel));
felix@2687: }
felix@2687:
sascha@933: switch (mode) {
sascha@933: case WET:
sascha@938: log.debug("intersect/wet");
sascha@933: mode = Mode.DRY;
sascha@933: result.add(new Line2D.Double(
sascha@933: startX, waterLevel,
sascha@933: x, waterLevel));
sascha@933: break;
sascha@933:
sascha@933: case DRY:
sascha@938: log.debug("intersect/dry");
sascha@933: mode = Mode.WET;
sascha@933: startX = x;
sascha@933: break;
sascha@933:
sascha@933: default: // UNDEF
sascha@938: log.debug("intersect/undef");
sascha@933: if (p2.getY() > waterLevel) {
sascha@938: log.debug("intersect/undef/over");
sascha@933: mode = Mode.DRY;
sascha@933: result.add(new Line2D.Double(
sascha@933: p1.getX(), waterLevel,
sascha@933: x, waterLevel));
sascha@933: }
sascha@933: else {
sascha@933: mode = Mode.WET;
sascha@933: startX = x;
sascha@933: }
sascha@933: } // switch mode
sascha@934: } // for all points p[i] and p[i-1]
sascha@933:
sascha@933: if (mode == Mode.WET) {
sascha@933: result.add(new Line2D.Double(
sascha@933: startX, waterLevel,
sascha@933: maxX, waterLevel));
sascha@933: }
sascha@933:
felix@2674: return new ListWithArea(result, area);
sascha@933: }
sascha@1651:
felix@2652:
felix@2652: /**
felix@2652: * Class holding points that form lines and the calculated length.
felix@2652: */
felix@2652: public static class LineData {
felix@2652: public double [][] points;
felix@2652: public double width;
felix@2673: public double area;
felix@2673: public LineData(double[][] points, double width, double area) {
felix@2652: this.points = points;
felix@2652: this.width = width;
felix@2673: this.area = area;
felix@2652: }
felix@2652: }
felix@2652:
felix@2652:
felix@2681: /** Return length of a single line. */
felix@2681: public static double lineLength(Line2D line) {
felix@2681: double xDiff = line.getX1() - line.getX2();
felix@2681: double yDiff = line.getY1() - line.getY2();
felix@2681: return Math.sqrt(xDiff*xDiff + yDiff*yDiff);
felix@2681: }
felix@2681:
felix@2681:
felix@2681: /**
felix@2681: * @param points the riverbed.
felix@2681: */
felix@2652: public static LineData createWaterLines(
sascha@1651: List<Point2D> points,
sascha@1651: double waterlevel
sascha@1651: ) {
felix@2674: ListWithArea listAndArea = fillWater(points, waterlevel);
felix@2674: List<Line2D> lines = listAndArea.lines;
sascha@1651:
sascha@1651: TDoubleArrayList lxs = new TDoubleArrayList();
sascha@1651: TDoubleArrayList lys = new TDoubleArrayList();
felix@2652: double linesLength = 0.0f;
sascha@1651:
sascha@1651: for (Iterator<Line2D> iter = lines.iterator(); iter.hasNext();) {
felix@2652: Line2D line = iter.next();
felix@2652: Point2D p1 = line.getP1();
felix@2652: Point2D p2 = line.getP2();
sascha@1651: lxs.add(p1.getX());
sascha@1651: lys.add(p1.getY());
sascha@1651: lxs.add(p2.getX());
sascha@1651: lys.add(p2.getY());
felix@2652:
felix@2652: // Length calculation.
felix@2681: linesLength += lineLength(line);
felix@2652:
sascha@1651: if (iter.hasNext()) {
sascha@1651: lxs.add(Double.NaN);
sascha@1651: lys.add(Double.NaN);
sascha@1651: }
sascha@1651: }
sascha@1651:
felix@2652: return new LineData(
felix@2652: new double [][] { lxs.toNativeArray(), lys.toNativeArray() },
felix@2674: linesLength, listAndArea.area
felix@2652: );
sascha@1651: }
sascha@933: }
sascha@933: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :