--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/backend/src/main/java/org/dive4elements/river/model/Range.java	Thu Apr 25 15:23:37 2013 +0200
@@ -0,0 +1,173 @@
+package org.dive4elements.river.model;
+
+import java.io.Serializable;
+
+import java.math.BigDecimal;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+import javax.persistence.GeneratedValue;
+import javax.persistence.Column;
+import javax.persistence.SequenceGenerator;
+import javax.persistence.GenerationType;
+import javax.persistence.JoinColumn;
+import javax.persistence.OneToOne;
+
+@Entity
+@Table(name = "ranges")
+public class Range
+implements   Serializable
+{
+    public static final double EPSILON = 1e-5;
+    private Integer    id;
+    private BigDecimal a;
+    private BigDecimal b;
+
+    private River      river;
+
+    public Range() {
+    }
+
+    public Range(double a, double b, River river) {
+        this(new BigDecimal(a), new BigDecimal(b), river);
+    }
+
+    public Range(BigDecimal a, BigDecimal b, River river) {
+        this.a     = a;
+        this.b     = b;
+        this.river = river;
+    }
+
+    @Id
+    @SequenceGenerator(
+        name           = "SEQUENCE_RANGES_ID_SEQ",
+        sequenceName   = "RANGES_ID_SEQ",
+        allocationSize = 1)
+    @GeneratedValue(
+        strategy  = GenerationType.SEQUENCE,
+        generator = "SEQUENCE_RANGES_ID_SEQ")
+    @Column(name = "id")
+    public Integer getId() {
+        return id;
+    }
+
+    public void setId(Integer id) {
+        this.id = id;
+    }
+
+    @Column(name = "a") // FIXME: type mapping needed?
+    public BigDecimal getA() {
+        return a;
+    }
+
+    public void setA(BigDecimal a) {
+        this.a = a;
+    }
+
+    @Column(name = "b") // FIXME: type mapping needed?
+    public BigDecimal getB() {
+        return b;
+    }
+
+    public void setB(BigDecimal b) {
+        this.b = b;
+    }
+
+    public boolean containsTolerant(double x) {
+            return containsTolerant(x, EPSILON);
+    }
+
+    public boolean containsTolerant(double x, double tolerance) {
+        BigDecimal b = this.b != null ? this.b : a;
+        double av = a.doubleValue();
+        double bv = b.doubleValue();
+        if (av > bv) {
+            double t = av;
+            av = bv;
+            bv = t;
+        }
+        return x+tolerance >= av && x-tolerance <= bv;
+    }
+
+    public boolean contains(double x) {
+        BigDecimal b = this.b != null ? this.b : a;
+        double av = a.doubleValue();
+        double bv = b.doubleValue();
+        if (av > bv) {
+            double t = av;
+            av = bv;
+            bv = t;
+        }
+        return x >= av && x <= bv;
+    }
+
+    @OneToOne
+    @JoinColumn(name = "river_id")
+    public River getRiver() {
+        return river;
+    }
+
+    public void setRiver(River river) {
+        this.river = river;
+    }
+
+    public int code() {
+        int code = 0;
+        if (a != null) code  = 1;
+        if (b != null) code |= 2;
+        return code;
+    }
+
+    public boolean intersects(BigDecimal c) {
+        return !(a.compareTo(c) > 0 || b.compareTo(c) < 0);
+    }
+
+    public boolean intersects(Range other) {
+
+        int code  = code();
+        int ocode = other.code();
+
+        if (code == 0 || ocode == 0) {
+            return false;
+        }
+
+        switch (code) {
+            case 1: // has a
+                switch (ocode) {
+                    case 1: // has a
+                        return a.compareTo(other.a) == 0;
+                    case 2: // has b
+                        return a.compareTo(other.b) == 0;
+                    case 3: // has range
+                        return other.intersects(a);
+                }
+                break;
+            case 2: // has b
+                switch (ocode) {
+                    case 1: // has a
+                        return b.compareTo(other.a) == 0;
+                    case 2: // has b
+                        return b.compareTo(other.b) == 0;
+                    case 3: // has range
+                        return other.intersects(b);
+                }
+                break;
+            case 3: // has range
+                switch (ocode) {
+                    case 1: // has a
+                        return intersects(other.a);
+                    case 2: // has b
+                        return intersects(other.b);
+                    case 3: // has range
+                        return !(other.b.compareTo(a) < 0
+                               ||other.a.compareTo(b) > 0);
+                }
+                break;
+
+        }
+
+        return false;
+    }
+}
+// vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :