1 files changed, 76 insertions, 0 deletions

diff --git a/ws2015/eip/blaetter/07/H7-1C/de/lmu/tcs/Hexagon.java b/ws2015/eip/blaetter/07/H7-1C/de/lmu/tcs/Hexagon.java
new file mode 100644
index 0000000..12f1031
--- /dev/null
+++ b/ws2015/eip/blaetter/07/H7-1C/de/lmu/tcs/Hexagon.java
@@ -0,0 +1,76 @@
+package de.lmu.tcs;
+
+import java.awt.*;
+
+class Hexagon {
+    private final Point center;
+    private final int sideLength;
+
+    public Hexagon(Point center2, int sideLength2)
+    {
+        this.center = center2;
+        this.sideLength = sideLength2;
+    }
+
+    public Point[] vertices()
+    {
+        Point vertex = new Point((int) (Math.sqrt(3) * ((double) sideLength) / 2), sideLength / 2);
+        Point[] relative = { new Point(0, sideLength)
+                             , vertex
+                             , mirrory(vertex)
+                             , new Point(0, -1 * sideLength)
+                             , mirrorx(mirrory(vertex))
+                             , mirrorx(vertex)
+        };
+
+        for (Point r : relative)
+            r.translate(center.x, center.y);
+
+        return relative;
+    }
+
+    private static Point mirrorx(Point r)
+    {
+        return new Point(r.x * -1, r.y);
+    }
+
+    private static Point mirrory(Point r)
+    {
+        return new Point(r.x, r.y * -1);
+    }
+
+    public int height()
+    {
+        return 2 * sideLength;
+    }
+
+    public int width()
+    {
+        return (int) (Math.sqrt(3) * (double) sideLength);
+    }   
+
+    public boolean contains(Point r)
+    { // clever maths is clever (and very hexagon-specific)
+        int rx = Math.abs(r.x - center.x);
+        int ry = Math.abs(r.y - center.y);
+
+        if (rx > width() / 2 || ry > height())
+            return false;
+        return width() * height() - height() * rx - height() * ry >= 0;
+    }
+
+    public Rectangle boundingBox()
+    {
+        Point uL = new Point(center);
+        uL.translate(-1 * width() / 2, -1 * height() / 2);
+        return new Rectangle(uL, new Dimension(width(), height()));
+    }
+
+    public Polygon asPolygon()
+    {
+        Polygon ret = new Polygon();
+        for (Point r : vertices())
+            ret.addPoint(r.x, r.y);
+        return ret;
+    }
+}