prepare for hexagon display & other models

- display cell as hexagon is Display.mHexagon if set ( not default )
will need a checkbox to set this
- various new models preparation...

java/org/artisanlogiciel/games/maze/model/LineColumnModel.java

@@ -0,0 +1,84 @@
+package org.artisanlogiciel.games.maze.model;
+
+import org.artisanlogiciel.games.maze.Brick;
+import org.artisanlogiciel.games.maze.MovesProvider;
+import org.artisanlogiciel.games.maze.WallsProvider;
+
+public class LineColumnModel
+    implements WallsProvider,
+        MovesProvider
+{
+
+    final BooleanLongSet lines[];
+    final BooleanLongSet columns[];
+
+    public LineColumnModel(int width, int height)
+    {
+        lines = new BooleanLongSet[height];
+        columns = new BooleanLongSet[width];
+    }
+
+    BooleanLongSet getLine(int column)
+    {
+        BooleanLongSet l = lines[column];
+        if ( l == null )
+        {
+            l= new BooleanLongSet(getWidth(),63);
+            lines[column] = l;
+        }
+        return l;
+    }
+
+    BooleanLongSet getColumn(int line)
+    {
+        BooleanLongSet c = columns[line];
+        if ( c == null )
+        {
+            c = new BooleanLongSet(getHeight(),63);
+            columns[line] = c;
+        }
+        return c;
+    }
+
+    @Override
+    public short getWalls(int x, int y) {
+        return (short) (
+                (getLine(y).isSet(x) ? Brick.UP : 0)
+                + (getColumn(x).isSet(y) ? Brick.LEFT : 0)
+                + (getLine(y+1).isSet(x) ? Brick.DOWN : 0)
+                + (getColumn(x+1).isSet(y) ? Brick.RIGHT : 0)
+        );
+    }
+
+    @Override
+    public short getMoves(int x, int y)
+    {
+        // moves are where there is no walls ...
+        return (short) ((~ getWalls(x,y)) & 0x0f);
+    }
+
+    @Override
+    public int getWidth() {
+        return columns.length;
+    }
+
+    @Override
+    public int getHeight() {
+        return lines.length;
+    }
+
+    public void setWalls(int x, int y, short walls)
+    {
+        getLine(y).set(x, (walls & Brick.UP) != 0);
+        getColumn(x).set(y, (walls & Brick.LEFT) != 0);
+        getLine(y+1).set(x, (walls & Brick.DOWN) != 0);
+        getColumn(x+1).set(y, (walls & Brick.RIGHT) != 0);
+    }
+
+    public void setMoves(int x, int y, short moves)
+    {
+        short walls = (short) ~ moves;
+        setWalls(x,y,walls);
+    }
+
+}