[gnome-2048] Calculate score on the fly.

[Arnaud B. <arnaudb src gnome org>]

commit 20440d93beb56e8bcf182de22aceabdfaa9db7de
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Wed Feb 6 15:05:10 2019 +0100

    Calculate score on the fly.
    
    At least when loading or undoing.

 src/application.vala |  2 +-
 src/game.vala        | 40 +++++++---------------------------------
 src/grid.vala        | 25 +++++++++++++++++++++++++
 3 files changed, 33 insertions(+), 34 deletions(-)
---
diff --git a/src/application.vala b/src/application.vala
index b59e81d..d0f3fd0 100644
--- a/src/application.vala
+++ b/src/application.vala
@@ -168,7 +168,7 @@ private class Application : Gtk.Application
     private void _init_game ()
     {
         _game = new Game (ref _settings);
-        _game.notify["score"].connect ((s, p) => {
+        _game.notify ["score"].connect ((s, p) => {
                 _score.label = _game.score.to_string ();
             });
         _game.finished.connect ((s) => {
diff --git a/src/game.vala b/src/game.vala
index 4cc0706..b9e52ab 100644
--- a/src/game.vala
+++ b/src/game.vala
@@ -99,7 +99,7 @@ private class Game : Object
     * * others
     \*/
 
-    internal uint score { internal get; private set; default = 0; }
+    internal long score { internal get; private set; default = 0; }
 
     internal void new_game (ref GLib.Settings settings)
     {
@@ -132,11 +132,7 @@ private class Game : Object
 
     internal void save_game ()
     {
-        string contents = "";
-
-        contents += _grid.save ();
-        contents += _score.to_string () + "\n";
-
+        string contents = _grid.save ();
         try {
             DirUtils.create_with_parents (Path.get_dirname (_saved_path), 0775);
             FileUtils.set_contents (_saved_path, contents);
@@ -161,16 +157,7 @@ private class Game : Object
             return false;
         }
 
-        string [] lines = contents.split ("\n");
-        string last_line = lines [lines.length - 1];    // not UNIX?
-        if (last_line == "")
-            last_line = lines [lines.length - 2];
-        uint64 score_64;
-        if (!uint64.try_parse (last_line, out score_64))
-            return false;
-        if (score_64 > (uint64) uint.MAX)
-            return false;
-        score = (uint) score_64;
+        score = _grid.get_score ();
 
         if (_background_init_done)
             _clear_background ();
@@ -524,17 +511,16 @@ private class Game : Object
             _dim_tile (((!) e).from);
         }
 
-        uint delta_score = 0;
+        long delta_score = 0;   // do not notify["score"] multiple times
         foreach (Tile? e in _to_show)
         {
             if (e == null)
                 assert_not_reached ();
             _create_tile ((!) e);
             _show_tile (((!) e).pos);
-            delta_score += (uint) Math.pow (2, ((!) e).val);
+            delta_score += (long) Math.pow (2, ((!) e).val);
         }
         score += delta_score;
-        _store_score_update (delta_score);
 
         _create_random_tile ();
     }
@@ -662,8 +648,7 @@ private class Game : Object
 
     private bool _allow_undo = false;
     private uint _undo_stack_max_size;
-    private Gee.LinkedList<Grid> _undo_stack       = new Gee.LinkedList<Grid> ();
-    private Gee.LinkedList<uint> _undo_score_stack = new Gee.LinkedList<uint> ();
+    private Gee.LinkedList<Grid> _undo_stack = new Gee.LinkedList<Grid> ();
 
     internal void undo ()
         requires (_allow_undo == true)
@@ -674,7 +659,7 @@ private class Game : Object
         _clear_foreground ();
         _grid = _undo_stack.poll_head ();
         _restore_foreground (false);
-        score -= _undo_score_stack.poll_head ();
+        score = _grid.get_score ();
 
         if (_undo_stack.size == 0)
             undo_disabled ();
@@ -696,7 +681,6 @@ private class Game : Object
     private void _clear_history ()
     {
         _undo_stack.clear ();
-        _undo_score_stack.clear ();
     }
 
     private void _store_movement (Grid clone)
@@ -710,14 +694,4 @@ private class Game : Object
         if (_undo_stack.size == 1)
             undo_enabled ();
     }
-
-    private void _store_score_update (uint delta_score)
-    {
-        if (!_allow_undo)
-            return;
-
-        if (_undo_score_stack.size >= _undo_stack_max_size)
-            _undo_score_stack.poll_tail ();
-        _undo_score_stack.offer_head (delta_score);
-    }
 }
diff --git a/src/grid.vala b/src/grid.vala
index 44602a7..ad38e14 100644
--- a/src/grid.vala
+++ b/src/grid.vala
@@ -430,6 +430,29 @@ private class Grid : Object
                 grid [i, j] = 0;
     }
 
+    internal long get_score ()
+    {
+        return _get_score (ref _grid);
+    }
+    private static long _get_score (ref uint8 [,] grid)
+    {
+        long score = 0;
+
+        uint rows = grid.length [0];
+        uint cols = grid.length [1];
+
+        for (uint i = 0; i < rows; i++)
+            for (uint j = 0; j < cols; j++)
+                score += _calculate_score_value (grid [i, j]);
+        return score;
+    }
+    private static inline long _calculate_score_value (uint8 tile_value)
+    {
+        if (tile_value < 2)
+            return 0;
+        return (long) (Math.pow (2, tile_value) * (tile_value - 1));
+    }
+
     /*\
     * * getting values
     \*/
@@ -460,6 +483,8 @@ private class Grid : Object
     {
         string ret_string = @"$_rows $_cols\n";
         _convert_to_string (ref _grid, ref ret_string);
+        ret_string += _get_score (ref _grid).to_string ();  // historical, not
+        ret_string += "\n";                                // used when loading
         return ret_string;
     }