Mercurial > dive4elements > river
view flys-artifacts/src/main/java/de/intevation/flys/artifacts/geom/Lines.java @ 979:2306340d7540
Added schema for datacage db
flys-artifacts/trunk@2406 c6561f87-3c4e-4783-a992-168aeb5c3f6f
author | Sascha L. Teichmann <sascha.teichmann@intevation.de> |
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date | Tue, 26 Jul 2011 14:14:55 +0000 |
parents | bd3683453928 |
children | a7def20539fb |
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package de.intevation.flys.geom; import java.util.List; import java.util.ArrayList; import java.awt.geom.Point2D; import java.awt.geom.Line2D; import de.intevation.flys.artifacts.math.Linear; import org.apache.log4j.Logger; public class Lines { private static Logger log = Logger.getLogger(Lines.class); public static final double EPSILON = 1e-4; public static enum Mode { UNDEF, WET, DRY }; protected Lines() { } public static List<Line2D> fillWater(List<Point2D> points, double waterLevel) { boolean debug = log.isDebugEnabled(); if (debug) { log.debug("fillWater"); log.debug("----------------------------"); } List<Line2D> result = new ArrayList(); int N = points.size(); if (N == 0) { return result; } if (N == 1) { Point2D p = points.get(0); // Only generate point if over water if (waterLevel > p.getY()) { result.add(new Line2D.Double( p.getX(), waterLevel, p.getX(), waterLevel)); } return result; } double minX = Double.MAX_VALUE; double minY = Double.MAX_VALUE; double maxX = -Double.MAX_VALUE; double maxY = -Double.MAX_VALUE; // To ensure for sequences of equals x's that // the original index order is preserved. for (Point2D p: points) { double x = p.getX(), y = p.getY(); if (x < minX) minX = x; if (x > maxX) maxX = x; if (y < minY) minY = y; if (y > maxY) maxY = y; } if (minY > waterLevel) { // profile completely over water level log.debug("complete over water"); return result; } if (waterLevel > maxY) { // water floods profile log.debug("complete under water"); result.add(new Line2D.Double(minX, waterLevel, maxX, waterLevel)); return result; } Mode mode = Mode.UNDEF; double startX = minX; for (int i = 1; i < N; ++i) { Point2D p1 = points.get(i-1); Point2D p2 = points.get(i); if (p1.getY() < waterLevel && p2.getY() < waterLevel) { // completely under water if (debug) { log.debug("under water: " + p1 + " " + p2); } if (mode != Mode.WET) { startX = p1.getX(); mode = Mode.WET; } continue; } if (p1.getY() > waterLevel && p2.getY() > waterLevel) { if (debug) { log.debug("over water: " + p1 + " " + p2); } // completely over water if (mode == Mode.WET) { log.debug("over/wet"); result.add(new Line2D.Double( startX, waterLevel, p1.getX(), waterLevel)); } mode = Mode.DRY; continue; } if (Math.abs(p1.getX() - p2.getX()) < EPSILON) { // vertical line switch (mode) { case WET: log.debug("vertical/wet"); mode = Mode.DRY; result.add(new Line2D.Double( startX, waterLevel, p1.getX(), waterLevel)); break; case DRY: log.debug("vertical/dry"); mode = Mode.WET; startX = p2.getX(); break; default: // UNDEF log.debug("vertical/undef"); if (p2.getY() < waterLevel) { mode = Mode.WET; startX = p2.getX(); } else { mode = Mode.DRY; } } continue; } // check if waterlevel directly hits the vertices; boolean p1W = Math.abs(waterLevel - p1.getY()) < EPSILON; boolean p2W = Math.abs(waterLevel - p2.getY()) < EPSILON; if (p1W || p2W) { if (debug) { log.debug("water hits vertex: " + p1 + " " + p2 + " " + mode); } if (p1W && p2W) { // parallel to water -> dry log.debug("water hits both vertices"); if (mode == Mode.WET) { result.add(new Line2D.Double( startX, waterLevel, p1.getX(), waterLevel)); } mode = Mode.DRY; } else if (p1W) { // p1 == waterlevel log.debug("water hits first vertex"); if (p2.getY() > waterLevel) { // --> dry if (mode == Mode.WET) { result.add(new Line2D.Double( startX, waterLevel, p1.getX(), waterLevel)); } mode = Mode.DRY; } else { // --> wet if (mode != Mode.WET) { startX = p1.getX(); mode = Mode.WET; } } } else { // p2 == waterlevel log.debug("water hits second vertex"); if (p1.getY() > waterLevel) { // --> wet if (mode != Mode.WET) { startX = p2.getX(); mode = Mode.WET; } } else { // --> dry if (mode == Mode.WET) { result.add(new Line2D.Double( startX, waterLevel, p2.getX(), waterLevel)); } mode = Mode.DRY; } } if (debug) { log.debug("mode is now: " + mode); } continue; } // intersection case double x = Linear.linear( waterLevel, p1.getY(), p2.getY(), p1.getX(), p2.getX()); if (debug) { log.debug("intersection p1:" + p1); log.debug("intersection p2:" + p2); log.debug("intersection at x: " + x); } switch (mode) { case WET: log.debug("intersect/wet"); mode = Mode.DRY; result.add(new Line2D.Double( startX, waterLevel, x, waterLevel)); break; case DRY: log.debug("intersect/dry"); mode = Mode.WET; startX = x; break; default: // UNDEF log.debug("intersect/undef"); if (p2.getY() > waterLevel) { log.debug("intersect/undef/over"); mode = Mode.DRY; result.add(new Line2D.Double( p1.getX(), waterLevel, x, waterLevel)); } else { mode = Mode.WET; startX = x; } } // switch mode } // for all points p[i] and p[i-1] if (mode == Mode.WET) { result.add(new Line2D.Double( startX, waterLevel, maxX, waterLevel)); } return result; } } // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :