Utility function for distance to stones and GTP command to show distance

git-svn-id: svn://svn.code.sf.net/p/fuego/code/trunk@2003 2e953b5c-c64d-0410-be54-f773e93e544c

go/GoGtpEngine.cpp

@@ -18,6 +18,7 @@
 #include "GoBoardRestorer.h"
 #include "GoEyeUtil.h"
 #include "GoGtpCommandUtil.h"
+#include "GoInfluence.h"
 #include "GoModBoard.h"
 #include "GoNodeUtil.h"
 #include "GoPlayer.h"
@@ -111,6 +112,7 @@ GoGtpEngine::GoGtpEngine(int fixedBoardSize, const char* programPath,
     Register("get_komi", &GoGtpEngine::CmdGetKomi, this);
     Register("gg-undo", &GoGtpEngine::CmdGGUndo, this);
     Register("go_board", &GoGtpEngine::CmdBoard, this);
+    Register("go_distance", &GoGtpEngine::CmdDistance, this);
     Register("go_param", &GoGtpEngine::CmdParam, this);
     Register("go_param_rules", &GoGtpEngine::CmdParamRules, this);
     Register("go_player_board", &GoGtpEngine::CmdPlayerBoard, this);
@@ -336,6 +338,7 @@ void GoGtpEngine::CmdAnalyzeCommands(GtpCommand& cmd)
         "sboard/Go Point Numbers/go_point_numbers\n"
         "none/Go Rules/go_rules %s\n"
         "plist/All Legal/all_legal %c\n"
+        "sboard/Go Distance/go_distance %c\n"
         "string/ShowBoard/showboard\n"
         "string/CpuTime/cputime\n"
         "string/Get Komi/get_komi\n"
@@ -403,6 +406,16 @@ void GoGtpEngine::CmdClock(GtpCommand& cmd)
     cmd << '\n' << m_game.Time();
 }
 
+void GoGtpEngine::CmdDistance(GtpCommand& cmd)
+{
+    cmd.CheckNuArg(1);
+    SgBlackWhite color = GoGtpCommandUtil::BlackWhiteArg(cmd, 0);
+    SgPointArray<int> distance;
+    GoInfluence::FindDistanceToStones(Board(), color, distance);
+    cmd << '\n' << SgWritePointArray<int>(distance, Board().Size());
+}
+
+
 /** Compute final score.
     Computes score only if GoRules::CaptureDead() == true.
     Otherwise it returns an error. Override this function for players that

go/GoGtpEngine.h

@@ -85,6 +85,7 @@ class GoGtpEngine
     virtual void CmdBoardSize(GtpCommand&);
     virtual void CmdClearBoard(GtpCommand&);
     virtual void CmdClock(GtpCommand&);
+    virtual void CmdDistance(GtpCommand& cmd);
     virtual void CmdFinalScore(GtpCommand&);
     virtual void CmdFixedHandicap(GtpCommand&);
     virtual void CmdGameOver(GtpCommand&);

go/GoInfluence.cpp

@@ -6,7 +6,9 @@
 #include "SgSystem.h"
 #include "GoInfluence.h"
 
+#include <vector>
 #include "SgNbIterator.h"
+#include "SgPointset.h"
 
 //----------------------------------------------------------------------------
 namespace {
@@ -31,11 +33,65 @@ void Spread(const GoBoard& bd, SgPoint p, const SgPointSet& stopPts,
 } // namespace
 //----------------------------------------------------------------------------
 
+void GoInfluence::ComputeInfluence(const GoBoard& bd,
+                                   const SgBWSet& stopPts,
+                                   SgBWArray<SgPointArray<int> >* influence)
+{
+    const int MAX_INFLUENCE = 64;
+    for (SgBWIterator cit; cit; ++cit)
+    {
+        SgBlackWhite color = *cit;
+        ((*influence)[color]).Fill(0);
+        for (GoBoard::Iterator it(bd); it; ++it)
+        {
+            SgPoint p(*it);
+            if (bd.IsColor(p, color))
+                Spread(bd, p, stopPts[color], MAX_INFLUENCE, 
+                       (*influence)[color]);
+        }
+    }
+}
+
+void GoInfluence::FindDistanceToStones(const GoBoard& bd,
+                                       SgBlackWhite color,
+                                       SgPointArray<int>& distance)
+{
+    for (GoBoard::Iterator it(bd); it; ++it)
+        distance[*it] = DISTANCE_INFINITE;
+
+    std::vector<SgPoint> queue;
+    SgMarker marker;
+    for (SgSetIterator it(bd.All(color)); it; ++it)
+    {
+        queue.push_back(*it);
+        marker.Include(*it);
+    }
+
+    int d = 0;
+    while (! queue.empty())
+    {
+        std::vector<SgPoint> next;
+        for(std::vector<int>::const_iterator it = queue.begin(); it != queue.end(); ++it)
+        {
+            const SgPoint p = *it;
+            distance[p] = d;
+            for (GoNbIterator it2(bd, p); it2; ++it2)
+            {
+                const SgPoint nb = *it2;
+                if (marker.NewMark(nb) && bd.IsEmpty(nb))
+                    next.push_back(nb);
+            }
+        }
+        ++d;
+        queue.swap(next);
+    }
+}
+
 void GoInfluence::FindInfluence(const GoBoard& board,
-                    int nuExpand,
-                    int nuShrink,
-                    SgBWSet* influence)
-{   
+                                int nuExpand,
+                                int nuShrink,
+                                SgBWSet* influence)
+{
     SgBWSet result = SgBWSet(board.All(SG_BLACK), board.All(SG_WHITE));
     SgBWSet next;
     const int size = board.Size();
@@ -68,25 +124,3 @@ int GoInfluence::Influence(const GoBoard& board,
     FindInfluence(board, nuExpand, nuShrink, &result);
     return result[color].Size();
 }
-
-
-void GoInfluence::ComputeInfluence(const GoBoard& bd,
-                      const SgBWSet& stopPts,
-                      SgBWArray<SgPointArray<int> >* influence)
-{
-    const int MAX_INFLUENCE = 64;
-    for (SgBWIterator cit; cit; ++cit)
-    {
-        SgBlackWhite color = *cit;
-        ((*influence)[color]).Fill(0);
-        for (GoBoard::Iterator it(bd); it; ++it)
-        {
-            SgPoint p(*it);
-            if (bd.IsColor(p, color))
-                Spread(bd, p, stopPts[color], MAX_INFLUENCE, 
-                       (*influence)[color]);
-        }
-    }
-}
-
-

go/GoInfluence.h

@@ -13,6 +13,14 @@
 
 namespace GoInfluence {
 
+const int DISTANCE_INFINITE = 99;
+
+/** Find Manhattan distance to nearest stone of color. Does not
+    go through opponent stones. Set distance to DISTANCE_INFINITE if no stone
+    is reachable. */
+void FindDistanceToStones(const GoBoard& board, SgBlackWhite color,
+                          SgPointArray<int>& distance);
+
 /** Compute influence by nuExpand expansions followed by nuShrink
     contractions.
     Starts from the player's stones.

go/test/GoInfluenceTest.cpp

@@ -0,0 +1,63 @@
+//----------------------------------------------------------------------------
+/** @file GoInfluenceTest.cpp
+ Unit tests for GoInfluence. */
+//----------------------------------------------------------------------------
+
+#include "SgSystem.h"
+
+#include <boost/test/auto_unit_test.hpp>
+#include "GoInfluence.h"
+
+#include "GoSetupUtil.h"
+
+using SgPointUtil::Pt;
+
+//----------------------------------------------------------------------------
+
+namespace {
+
+    //----------------------------------------------------------------------------
+
+    BOOST_AUTO_TEST_CASE(GoInfluenceTest_Distance_Black)
+    {
+        std::string s(". . . .\n"
+                      ". . . .\n"
+                      ". . X .\n"
+                      ". . . .\n");
+        int boardSize;
+        GoSetup setup = GoSetupUtil::CreateSetupFromString(s, boardSize);
+        GoBoard bd(boardSize, setup);
+        SgPointArray<int> distance;
+        GoInfluence::FindDistanceToStones(bd, SG_BLACK, distance);
+        BOOST_CHECK_EQUAL(distance[Pt(3, 2)], 0);
+        BOOST_CHECK_EQUAL(distance[Pt(2, 2)], 1);
+        BOOST_CHECK_EQUAL(distance[Pt(3, 1)], 1);
+        BOOST_CHECK_EQUAL(distance[Pt(3, 3)], 1);
+        BOOST_CHECK_EQUAL(distance[Pt(1, 3)], 3);
+        BOOST_CHECK_EQUAL(distance[Pt(1, 4)], 4);
+        BOOST_CHECK_EQUAL(distance[Pt(4, 3)], 2);
+   }
+
+    BOOST_AUTO_TEST_CASE(GoInfluenceTest_Distance_White)
+    {
+        std::string s(". . . .\n"
+                      ". . . .\n"
+                      ". . . .\n"
+                      ". . . O\n");
+        int boardSize;
+        GoSetup setup = GoSetupUtil::CreateSetupFromString(s, boardSize);
+        GoBoard bd(boardSize, setup);
+        SgPointArray<int> distance;
+        GoInfluence::FindDistanceToStones(bd, SG_WHITE, distance);
+        BOOST_CHECK_EQUAL(distance[Pt(4, 1)], 0);
+        BOOST_CHECK_EQUAL(distance[Pt(4, 2)], 1);
+        BOOST_CHECK_EQUAL(distance[Pt(3, 1)], 1);
+        BOOST_CHECK_EQUAL(distance[Pt(3, 2)], 2);
+        BOOST_CHECK_EQUAL(distance[Pt(1, 3)], 5);
+        BOOST_CHECK_EQUAL(distance[Pt(1, 4)], 6);
+        BOOST_CHECK_EQUAL(distance[Pt(4, 3)], 2);
+    }
+
+    //----------------------------------------------------------------------------
+
+} // namespace