Board : implements distance for Hex and Square boards

6 files changed, 88 insertions, 1 deletions

diff --git a/TODO.md b/TODO.md
index c6ae8c7..7f56bb2 100644
--- a/TODO.md
+++ b/TODO.md
@@ -2,10 +2,15 @@
  - UI widgets
     - list
     - scrollbale vert/horiz
+
  - Algos
-    - Distance
     - Adjacents
     - Line Of Sight
     - Reachable Tiles ::: BFS
     - Shortest Path ::: A*
+
+ - TriangleMap
+    - Distance
+
  - CircleMap
+    - everything
diff --git a/core/src/ch/asynk/gdx/boardgame/boards/Board.java b/core/src/ch/asynk/gdx/boardgame/boards/Board.java
index 1037842..4043849 100644
--- a/core/src/ch/asynk/gdx/boardgame/boards/Board.java
+++ b/core/src/ch/asynk/gdx/boardgame/boards/Board.java
@@ -7,4 +7,12 @@ public interface Board
     public int[] getAngles();
     public void centerOf(int x, int y, Vector2 v);
     public void toBoard(float x, float y, Vector2 v);
+    public float distance(int x0, int y0, int x1, int y1, Geometry geometry);
+
+    enum Geometry
+    {
+        EUCLIDEAN,
+        TAXICAB,
+        TCHEBYCHEV
+    }
 }
diff --git a/core/src/ch/asynk/gdx/boardgame/boards/HexBoard.java b/core/src/ch/asynk/gdx/boardgame/boards/HexBoard.java
index c78fb77..6a409ad 100644
--- a/core/src/ch/asynk/gdx/boardgame/boards/HexBoard.java
+++ b/core/src/ch/asynk/gdx/boardgame/boards/HexBoard.java
@@ -144,4 +144,38 @@ public class HexBoard implements Board
 
         v.set(col, row);
     }
+
+    @Override public float distance(int x0, int y0, int x1, int y1, Geometry geometry)
+    {
+        if (geometry == Board.Geometry.EUCLIDEAN) {
+            int dx = (x1 - x0);
+            int dy = (y1 - y0);
+
+            if (dx == 0) {
+                return  Math.abs(dy);
+            }
+            else if (dy == 0 || dx == dy) {
+                return  Math.abs(dx);
+            }
+            float fdx = dx - dy / 2f;
+            float fdy = dy * 0.86602f;
+            return (float)Math.sqrt((fdx * fdx) + (fdy * fdy));
+        } else {
+            int dx = Math.abs(x1 - x0);
+            int dy = Math.abs(y1 - y0);
+            int dz = Math.abs((x0 - y0) - (x1 - y1));
+
+            if (dx > dy) {
+                if (dx > dz)
+                    return dx;
+                else
+                    return dz;
+            } else {
+                if (dy > dz)
+                    return dy;
+                else
+                    return dz;
+            }
+        }
+    }
 }
diff --git a/core/src/ch/asynk/gdx/boardgame/boards/SquareBoard.java b/core/src/ch/asynk/gdx/boardgame/boards/SquareBoard.java
index 665d1ca..5a7d2b8 100644
--- a/core/src/ch/asynk/gdx/boardgame/boards/SquareBoard.java
+++ b/core/src/ch/asynk/gdx/boardgame/boards/SquareBoard.java
@@ -42,4 +42,20 @@ public class SquareBoard implements Board
 
         v.set(col, row);
     }
+
+    @Override public float distance(int x0, int y0, int x1, int y1, Geometry geometry)
+    {
+        int dx = Math.abs(x1 - x0);
+        int dy = Math.abs(y1 - y0);
+
+        switch (geometry) {
+            case EUCLIDEAN:
+                return (float)Math.sqrt((dx * dx) + (dy * dy));
+            case TAXICAB:
+                return dx + dy;
+            case TCHEBYCHEV:
+                return (dx > dy ? dx : dy);
+        }
+        return -1;
+    }
 }
diff --git a/core/src/ch/asynk/gdx/boardgame/boards/TriangleBoard.java b/core/src/ch/asynk/gdx/boardgame/boards/TriangleBoard.java
index 1fbd034..4be04f3 100644
--- a/core/src/ch/asynk/gdx/boardgame/boards/TriangleBoard.java
+++ b/core/src/ch/asynk/gdx/boardgame/boards/TriangleBoard.java
@@ -116,4 +116,20 @@ public class TriangleBoard implements Board
 
         v.set(col, row);
     }
+
+    @Override public float distance(int x0, int y0, int x1, int y1, Geometry geometry)
+    {
+        int dx = Math.abs(x1 - x0);
+        int dy = Math.abs(y1 - y0);
+
+        switch (geometry) {
+            case EUCLIDEAN:
+                return 0; // FIXME
+            case TAXICAB:
+                return dx + dy; // move should only be allowed through the 3 sides not through de vertices
+            case TCHEBYCHEV:
+                return dx + dy;
+        }
+        return -1;
+    }
 }
diff --git a/test/src/ch/asynk/gdx/boardgame/test/BoardScreen.java b/test/src/ch/asynk/gdx/boardgame/test/BoardScreen.java
index 613fe57..85b57c9 100644
--- a/test/src/ch/asynk/gdx/boardgame/test/BoardScreen.java
+++ b/test/src/ch/asynk/gdx/boardgame/test/BoardScreen.java
@@ -21,6 +21,7 @@ public class BoardScreen extends AbstractScreen
     {
         private final Assets assets;
         private final Piece panzer;
+        private final Vector2 pos;
         private final Vector2 v;
         public Texture map;
         public Board board;
@@ -33,6 +34,7 @@ public class BoardScreen extends AbstractScreen
         public MyBoard(final Assets assets)
         {
             this.assets = assets;
+            this.pos = new Vector2();
             this.v = new Vector2();
             this.panzer = new Piece(assets.getTexture(assets.PANZER));
         }
@@ -45,6 +47,7 @@ public class BoardScreen extends AbstractScreen
 
         public void reset()
         {
+            pos.set(0, 0);
             board.centerOf(0, 0, v);
             panzer.centerOn(v.x, v.y);
             panzer.setRotation(Orientation.DEFAULT.r());
@@ -54,6 +57,11 @@ public class BoardScreen extends AbstractScreen
         {
             board.toBoard(x, y, v);
             GdxBoardTest.debug("BoardScreen", String.format("touchDown [%d;%d] => [%d;%d]", (int)x, (int)y, (int)v.x, (int)v.y));
+            float d0 = board.distance((int)pos.x, (int)pos.y, (int)v.x, (int)v.y, Board.Geometry.TCHEBYCHEV);
+            float d1 = board.distance((int)pos.x, (int)pos.y, (int)v.x, (int)v.y, Board.Geometry.TAXICAB);
+            float d2 = board.distance((int)pos.x, (int)pos.y, (int)v.x, (int)v.y, Board.Geometry.EUCLIDEAN);
+            GdxBoardTest.debug("BoardScreen", String.format("     from [%d;%d] => %d :: %d :: %f", (int)pos.x, (int)pos.y, (int)d0, (int)d1, d2));
+            pos.set(v);
             board.centerOf((int)v.x, (int)v.y, v);
             panzer.centerOn(v.x, v.y);
             panzer.setRotation(Orientation.fromR(panzer.getRotation()).left().r());