sascha@424: package de.intevation.gnv.raster;
sascha@424: 
sascha@779: import de.intevation.gnv.raster.Raster.ValueToIndex;
sascha@779: 
sascha@779: import java.awt.Color;
sascha@779: 
sascha@779: import java.util.Arrays;
sascha@779: 
sascha@779: import org.apache.log4j.Logger;
sascha@779: 
sascha@424: import org.w3c.dom.Document;
sascha@424: import org.w3c.dom.Element;
sascha@424: import org.w3c.dom.NodeList;
sascha@424: 
sascha@424: /**
sascha@801:  * Lookup mechanism to map double values from a list of
sascha@801:  * ranges onto a set of colors and vice versa.
sascha@780:  * @author <a href="mailto:sascha.teichmann@intevation.de">Sascha L. Teichmann</a>
sascha@424:  */
sascha@424: public class Palette
sascha@424: implements   ValueToIndex
sascha@778: {
sascha@801:     private static Logger log = Logger.getLogger(Palette.class);
sascha@447: 
sascha@801:     /**
sascha@801:      * An entry in the lookup table.
sascha@801:      */
sascha@778:     public static final class Entry
sascha@424:     implements                Comparable
sascha@424:     {
sascha@424:         private Entry  left;
sascha@424:         private Entry  right;
sascha@424: 
sascha@424:         private int    index;
sascha@424: 
sascha@483:         private int    externalIndex;
sascha@483: 
sascha@424:         private double from;
sascha@424:         private double to;
sascha@424: 
sascha@424:         private String description;
sascha@424: 
sascha@424:         private Color  color;
sascha@424: 
sascha@801:         /**
sascha@801:          * Default constructor
sascha@801:          */
sascha@424:         public Entry() {
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * Copy constructor
sascha@801:          * @param other The entry to copy.
sascha@801:          */
sascha@435:         public Entry(Entry other) {
sascha@483:             index         = other.index;
sascha@483:             externalIndex = other.externalIndex;
sascha@483:             from          = other.from;
sascha@483:             to            = other.to;
sascha@483:             description   = other.description;
sascha@483:             color         = other.color;
sascha@435:         }
sascha@435: 
sascha@801:         /**
sascha@801:          * Constructor to set the palette index, the exteral index,
sascha@801:          * the value range, the color and the description.
sascha@801:          * @param index The pallette index
sascha@801:          * @param externalIndex The external index
sascha@801:          * @param from Start of the interval
sascha@801:          * @param to End of the interval
sascha@801:          * @param color The color belonging to this interval.
sascha@801:          * @param description The description of this range.
sascha@801:          */
sascha@424:         public Entry(
sascha@778:             int    index,
sascha@483:             int    externalIndex,
sascha@778:             double from,
sascha@778:             double to,
sascha@424:             Color  color,
sascha@424:             String description
sascha@424:         ) {
sascha@483:             this.index         = index;
sascha@483:             this.externalIndex = externalIndex;
sascha@483:             this.from          = from;
sascha@483:             this.to            = to;
sascha@483:             this.color         = color;
sascha@483:             this.description   = description;
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * Compares two entries by the start point of the interval.
sascha@801:          * @param other
sascha@801:          * @return -1 if this start point is before other. +1 if this 
sascha@801:          * start point is after, else 0.
sascha@801:          */
sascha@424:         public int compareTo(Object other) {
sascha@424:             Entry e = (Entry)other;
sascha@424:             if (from < e.from) return -1;
sascha@424:             if (from > e.from) return +1;
sascha@424:             return 0;
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * The starting point of the interval.
sascha@801:          * @return The starting point.
sascha@801:          */
sascha@448:         public double getFrom() {
sascha@448:             return from;
sascha@448:         }
sascha@448: 
sascha@801:         /**
sascha@801:          * The end point of the interval.
sascha@801:          * @return The end point.
sascha@801:          */
sascha@448:         public double getTo() {
sascha@448:             return to;
sascha@448:         }
sascha@448: 
sascha@801:         /**
sascha@801:          * The color of the entry.
sascha@801:          * @return The color.
sascha@801:          */
sascha@449:         public Color getColor() {
sascha@449:             return color;
sascha@449:         }
sascha@449: 
sascha@801:         /**
sascha@801:          * The external index of this entry. Useful to model
sascha@801:          * external joins.
sascha@801:          * @return The external index.
sascha@801:          */
sascha@483:         public int getExternalIndex() {
sascha@483:             return externalIndex;
sascha@483:         }
sascha@483: 
sascha@801:         /**
sascha@801:          * Searches for an entry which has a range that contains
sascha@801:          * the given value.
sascha@801:          * @param value The value to be searched.
sascha@801:          * @return The entry containing the value or null if no such
sascha@801:          * entry exists.
sascha@801:          */
sascha@424:         public Entry locateEntry(double value) {
sascha@424:             Entry current = this;
sascha@424:             while (current != null) {
sascha@424:                 boolean b = value >= current.from;
sascha@424:                 if (b && value <= current.to) {
sascha@424:                     return current;
sascha@424:                 }
sascha@424:                 current = b
sascha@424:                     ? current.right
sascha@424:                     : current.left;
sascha@424:             }
sascha@424:             return null;
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * Returns the palette index for a given value.
sascha@801:          * @param value The value to search.
sascha@801:          * @return The index of the palette entry or -1 if
sascha@801:          * no such entry exists.
sascha@801:          */
sascha@424:         public int locate(double value) {
sascha@424:             Entry entry = locateEntry(value);
sascha@424:             return entry != null
sascha@424:                 ? entry.index
sascha@424:                 : -1;
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * Searches for an interval with a given index.
sascha@801:          * @param index The index to be searched.
sascha@801:          * @return The entry with the given index or null if no
sascha@801:          * such entry exists.
sascha@801:          */
sascha@424:         public Entry findByIndex(int index) {
sascha@424:             Entry current = this;
sascha@424:             while (current != null) {
sascha@424:                 if (current.index == index) {
sascha@424:                     break;
sascha@424:                 }
sascha@424:                 current = index < current.index
sascha@424:                     ? current.left
sascha@424:                     : current.right;
sascha@424:             }
sascha@424:             return current;
sascha@424:         }
sascha@424: 
sascha@801:         /**
sascha@801:          * The description of this entry.
sascha@801:          * @return The description.
sascha@801:          */
sascha@424:         public String getDescription() {
sascha@424:             return description;
sascha@424:         }
sascha@435: 
sascha@801:         /**
sascha@801:          * Determines if the range of this entry has
sascha@801:          * infinitive length.
sascha@801:          * @return true if the range of this entry has infinitive
sascha@801:          * length else false.
sascha@801:          */
sascha@435:         public boolean isInfinity() {
sascha@435:             return from == -Double.MAX_VALUE
sascha@435:               ||   to   ==  Double.MAX_VALUE;
sascha@435:         }
sascha@424:     } // class Entry
sascha@424: 
sascha@801:     /**
sascha@801:      * Internal table of the entrys.
sascha@801:      */
sascha@424:     protected Entry [] entries;
sascha@801:     
sascha@801:     /**
sascha@801:      * Root of the entry tree used to map values to entries.
sascha@801:      */
sascha@424:     protected Entry    lookup;
sascha@801: 
sascha@801:     /**
sascha@801:      * The list of colors used by this palette.
sascha@801:      */
sascha@424:     protected Color [] rgbs;
sascha@424: 
sascha@424:     private Entry buildLookup(Entry [] entries, int lo, int hi) {
sascha@424:         if (lo > hi) {
sascha@424:             return null;
sascha@424:         }
sascha@424:         int mid = (lo + hi)/2;
sascha@424:         Entry entry = entries[mid];
sascha@424:         entry.left  = buildLookup(entries, lo, mid-1);
sascha@424:         entry.right = buildLookup(entries, mid+1, hi);
sascha@424:         return entry;
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Default constructor.
sascha@801:      */
sascha@424:     public Palette() {
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Constructor to create the palette from an XML document.
sascha@801:      * @param document The document with palette information.
sascha@801:      */
sascha@424:     public Palette(Document document) {
sascha@424: 
sascha@424:         NodeList rangeNodes = document.getElementsByTagName("range");
sascha@424: 
sascha@424:         entries = new Entry[rangeNodes.getLength()];
sascha@424:         rgbs    = new Color[entries.length];
sascha@424: 
sascha@424:         for (int i = 0; i < entries.length; ++i) {
sascha@424:             Element rangeElement = (Element)rangeNodes.item(i);
sascha@483:             double from     = doubleValue(rangeElement.getAttribute("from"));
sascha@483:             double to       = doubleValue(rangeElement.getAttribute("to"));
sascha@483:             int    extIndex = intValue(rangeElement.getAttribute("index"), i);
sascha@483:             Color  color    = color(rangeElement.getAttribute("rgb"));
sascha@483:             String desc     = rangeElement.getAttribute("description");
sascha@424:             if (from > to) { double t = from; from = to; to = t; }
sascha@483:             entries[i] = new Entry(i, extIndex, from, to, color, desc);
sascha@424:             rgbs[i] = color;
sascha@424:         }
sascha@424: 
sascha@424:         buildLookup();
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Constructor to split a given palette into a given number of
sascha@801:      * equal sized sub entries. Ranges of infinitive length are not
sascha@801:      * splitted.
sascha@801:      * @param original The source palette.
sascha@801:      * @param N The number of chunks to split single ranges into.
sascha@801:      */
sascha@435:     public Palette(Palette original, int N) {
sascha@435:         if (N < 2)  {
sascha@435:             throw new IllegalArgumentException("N < 2");
sascha@435:         }
sascha@435: 
sascha@435:         Entry [] origEntries = original.entries;
sascha@435: 
sascha@435:         int newSize = 0;
sascha@435:         for (int i = 0; i < origEntries.length; ++i) {
sascha@435:             // cannot split infinity intervals
sascha@435:             newSize += origEntries[i].isInfinity() ? 1 : N;
sascha@435:         }
sascha@435: 
sascha@435:         entries = new Entry[newSize];
sascha@435:         rgbs    = new Color[newSize];
sascha@435: 
sascha@435:         for (int i = 0, j = 0; i < origEntries.length; ++i) {
sascha@435:             Entry origEntry = origEntries[i];
sascha@435:             if (origEntry.isInfinity()) {
sascha@435:                 // infinity intervals are just copied
sascha@435:                 Entry nEntry = new Entry(origEntry);
sascha@435:                 entries[j] = nEntry;
sascha@435:                 rgbs[j]    = nEntry.color;
sascha@435:                 nEntry.index = j++;
sascha@435:             }
sascha@435:             else {
sascha@435:                 // split interval into N parts
sascha@435:                 double from  = origEntry.from;
sascha@435:                 double to    = origEntry.to;
sascha@435:                 double delta = (to - from)/N;
sascha@447: 				for (int k = 0; k < N; ++k) {
sascha@435:                     Entry nEntry = new Entry(origEntry);
sascha@435:                     nEntry.from = from;
sascha@435:                     nEntry.to   = from + delta;
sascha@435:                     from += delta;
sascha@435:                     entries[j] = nEntry;
sascha@435:                     rgbs[j]    = nEntry.color;
sascha@435:                     nEntry.index = j++;
sascha@435:                 }
sascha@435:             } // limited interval
sascha@435:         } // for all original entries
sascha@435: 
sascha@435:         buildLookup();
sascha@435:     }
sascha@435: 
sascha@483:     private static final int intValue(String s, int def) {
sascha@483:         if (s == null || (s = s.trim()).length() == 0) {
sascha@483:             return def;
sascha@483:         }
sascha@483:         try {
sascha@483:             return Integer.parseInt(s);
sascha@483:         }
sascha@483:         catch (NumberFormatException nfe) {
sascha@483:             log.error(nfe.getLocalizedMessage(), nfe);
sascha@483:         }
sascha@483:         return def;
sascha@483:     }
sascha@483: 
sascha@424:     private static final double doubleValue(String s) {
sascha@424:         if (s == null || (s = s.trim()).length() == 0) {
sascha@424:             return 0d;
sascha@424:         }
sascha@424:         if ((s = s.toLowerCase()).startsWith("-inf")) {
sascha@424:             return -Double.MAX_VALUE; // XXX: Not using Double.NEGATIVE_INFINITY!
sascha@424:         }
sascha@424: 
sascha@424:         if (s.startsWith("inf")) {
sascha@424:             return Double.MAX_VALUE; // XXX: Not using Double.NEGATIVE_INFINITY!
sascha@424:         }
sascha@424: 
sascha@424:         return Double.parseDouble(s);
sascha@424:     }
sascha@424: 
sascha@424:     private static final Color color(String s) {
sascha@424:         if (s == null || (s = s.trim()).length() == 0) {
sascha@424:             return null;
sascha@424:         }
sascha@424:         return Color.decode(s);
sascha@424:     }
sascha@424: 
sascha@424: 
sascha@801:     /**
sascha@801:      * Internal method to build the lookup tree.
sascha@801:      */
sascha@424:     protected void buildLookup() {
sascha@424:         Arrays.sort(entries);
sascha@424:         lookup = buildLookup(entries, 0, entries.length-1);
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Creates a new palette which has ranges that are subdivided
sascha@801:      * into a given number of sub ranges each.
sascha@801:      * @param N The number od sub divisions of each range.
sascha@801:      * @return The new created palette.
sascha@801:      */
sascha@435:     public Palette subdivide(int N) {
sascha@435:         return new Palette(this, N);
sascha@435:     }
sascha@435: 
sascha@801:     /**
sascha@801:      * Return the number of entries in this palette.
sascha@801:      * @return The number of entries.
sascha@801:      */
sascha@424:     public int getSize() {
sascha@424:         return rgbs.length;
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Return the color of an entry for a given index.
sascha@801:      * @param index The index.
sascha@801:      * @return The color.
sascha@801:      */
sascha@424:     public Color getColor(int index) {
sascha@424:         return rgbs[index];
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Return the RGB value
sascha@801:      * @param index of an entry for a given index.
sascha@801:      * @return rgb value
sascha@801:      */
sascha@424:     public int indexToRGB(int index) {
sascha@424:         return rgbs[index].getRGB();
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Searches for the index of an entry which contains the
sascha@801:      * given value.
sascha@801:      * @param value The value to be searched.
sascha@801:      * @return The index of the entry or -1 if no entry is found.
sascha@801:      */
sascha@424:     public int toIndex(double value) {
sascha@424:         return lookup.locate(value);
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Searches for the an entry which contains the given value.
sascha@801:      * @param value The value to be searched.
sascha@801:      * @return The entry which contains the value or null if
sascha@801:      * no such entry is found.
sascha@801:      */
sascha@424:     public Entry getEntry(double value) {
sascha@424:         return lookup.locateEntry(value);
sascha@424:     }
sascha@424: 
sascha@801:     /**
sascha@801:      * Searches the entry for a given index.
sascha@801:      * @param index The index of the entry.
sascha@801:      * @return The entry or null if no such entry is found.
sascha@801:      */
sascha@424:     public Entry getEntryByIndex(int index) {
sascha@424:         return lookup.findByIndex(index);
sascha@424:     }
sascha@424: }
sascha@798: // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :