dive4elements/gnv-client: gnv-artifacts/src/main/java/de/intevation/gnv/raster/Vectorizer.java comparison

comparison gnv-artifacts/src/main/java/de/intevation/gnv/raster/Vectorizer.java @ 657:af3f56758f59

merged gnv-artifacts/0.5

author	Thomas Arendsen Hein <thomas@intevation.de>
date	Fri, 28 Sep 2012 12:13:53 +0200
parents	92b7ccbf6163
children	9a828e5a2390

comparison

equal deleted inserted replaced

-:5f5f273c8566
+:af3f56758f59
+package de.intevation.gnv.raster;
+import java.util.BitSet;
+import java.util.List;
+import java.util.ArrayList;
+import gnu.trove.TIntStack;
+import gnu.trove.TIntObjectHashMap;
+import org.apache.log4j.Logger;
+/**
+* @author Sascha L. Teichmann (sascha.teichmann@intevation.de)
+*/
+public class Vectorizer
+{
+private static Logger log = Logger.getLogger(Vectorizer.class);
+public interface RingsHandler {
+void handleRings(
+List<Edge> rings,
+int        value,
+int        width,
+int        height);
+} // interface RingsHandler
+public static final class Edge {
+public Edge prev;
+public Edge next;
+public int a;
+public int b;
+public Edge() {
+}
+public Edge(int a, int b) {
+this.a = a;
+this.b = b;
+}
+public Edge(Edge other) {
+a = other.a;
+b = other.b;
+}
+public void chain(Edge other, int found) {
+if (found == a) {
+other.next = this;
+prev = other;
+return;
+}
+if (found == b) {
+next = other;
+other.prev = this;
+return;
+}
+throw new IllegalStateException("cannot chain");
+}
+public boolean isComplete() {
+Edge current = this;
+do {
+if (current.prev == null || current.next == null) {
+return false;
+}
+current = current.next;
+}
+while (current != this);
+return true;
+}
+public int length() {
+int length = 0;
+Edge current = this;
+do { ++length; }
+while ((current = current.next) != null && current != this);
+return length;
+}
+		public Edge head() {
+			Edge current = this;
+			while (current.prev != null) {
+				current = current.prev;
+			}
+			return current;
+		}
+public int hashCode() {
+return (a << 16) | b;
+}
+public boolean equals(Object other) {
+Edge e = (Edge)other;
+return a == e.a && b == e.b;
+}
+} // class Edge
+protected static Edge simplify(Edge edge, int width) {
+Edge e1 = edge, start = edge;
+int length = edge.length();
+if (length < 2) {
+return e1;
+}
+Edge e2 = edge.next;
+int count = 0;
+do {
+int e1x = e1.a % width;
+int e1y = e1.a / width;
+int e2x = e1.b % width;
+int e2y = e1.b / width;
+int e3x = e2.b % width;
+int e3y = e2.b / width;
+if ((e1x == e2x && e2x == e3x && e1x == e3x)
+||  (e1y == e2y && e2y == e3y && e1y == e3y)) {
+e1.b = e2.b;
+Edge removed = e1.next;
+e1.next = e2.next;
+if (e1.next != null) {
+e1.next.prev = e1;
+}
+e2 = e1.next;
+count = 0;
+--length;
+if (removed == start) {
+start = e1;
+}
+}
+else {
+e1 = e1.next;
+e2 = e2.next;
+++count;
+}
+}
+while (length > 1 && e2 != null && count < length + 2);
+return start;
+}
+protected int []            raster;
+protected int               width;
+protected TIntObjectHashMap openEdges;
+protected List<Edge>        rings;
+protected boolean           simplify;
+public Vectorizer() {
+this(true);
+}
+public Vectorizer(boolean simplify) {
+openEdges     = new TIntObjectHashMap();
+rings         = new ArrayList<Edge>();
+this.simplify = simplify;
+}
+public Vectorizer(int [] raster, int width) {
+this(true, raster, width);
+}
+public Vectorizer(boolean simplify, int [] raster, int width) {
+this(simplify);
+this.raster = raster;
+this.width  = width;
+}
+public static final int tl(int i, int w) {
+int x = i % w;
+int y = i / w;
+return x + (w + 1)*y;
+}
+public static final int tr(int i, int w) {
+return tl(i, w) + 1;
+}
+public static final int bl(int i, int w) {
+return tl(i, w) + w + 1;
+}
+public static final int br(int i, int w) {
+return bl(i, w) + 1;
+}
+protected void resetRegion() {
+openEdges.clear();
+rings.clear();
+}
+protected void emit(Edge edge) {
+Edge otherA = (Edge)openEdges.remove(edge.a);
+if (otherA != null) {
+otherA.chain(edge, edge.a);
+}
+Edge otherB = (Edge)openEdges.remove(edge.b);
+if (otherB != null) {
+otherB.chain(edge, edge.b);
+}
+if (edge.isComplete()) {
+rings.add(simplify ? simplify(edge, width + 1) : edge);
+}
+else {
+if (otherA == null) {
+openEdges.put(edge.a, edge);
+}
+if (otherB == null) {
+openEdges.put(edge.b, edge);
+}
+}
+}
+public int process(RingsHandler handler) {
+BitSet visited = new BitSet(raster.length);
+TIntStack stack = new TIntStack();
+int regions = 0;
+int height = raster.length / width;
+for (int i = 0; i < raster.length; ++i) {
+if (visited.get(i)) {
+continue;
+}
+++regions;
+int currentValue = raster[i];
+visited.set(i);
+int current = i;
+visited.set(current);
+for (;;) {
+int tl = tl(current, width);
+int tr = tr(current, width);
+int bl = bl(current, width);
+int br = br(current, width);
+int t = current - width;
+if (t < 0) {
+emit(new Edge(tr, tl));
+}
+else {
+if (raster[t] != currentValue) {
+emit(new Edge(tr, tl));
+}
+else {
+if (!visited.get(t)) {
+visited.set(t);
+stack.push(t);
+}
+}
+}
+int b = current + width;
+if (b >= raster.length) {
+emit(new Edge(bl, br));
+}
+else {
+if (raster[b] != currentValue) {
+emit(new Edge(bl, br));
+}
+else {
+if (!visited.get(b)) {
+visited.set(b);
+stack.push(b);
+}
+}
+}
+int x = current % width;
+if (x == 0) {
+emit(new Edge(tl, bl));
+}
+else {
+int l = current - 1;
+if (raster[l] != currentValue) {
+emit(new Edge(tl, bl));
+}
+else {
+if (!visited.get(l)) {
+visited.set(l);
+stack.push(l);
+}
+}
+}
+if (x == width - 1) {
+emit(new Edge(br, tr));
+}
+else {
+int r = current + 1;
+if (raster[r] != currentValue) {
+emit(new Edge(br, tr));
+}
+else {
+if (!visited.get(r)) {
+visited.set(r);
+stack.push(r);
+}
+}
+}
+if (stack.size() == 0) {
+break;
+}
+current = stack.pop();
+}
+handler.handleRings(
+rings,
+currentValue,
+width + 1,
+height + 1);
+resetRegion();
+}
+return regions;
+}
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8:

Mercurial > dive4elements > gnv-client

comparison gnv-artifacts/src/main/java/de/intevation/gnv/raster/Vectorizer.java @ 657:af3f56758f59