From 7a5a8ea11998209db6c9a3184633b3ad4ca9b7cf Mon Sep 17 00:00:00 2001
From: H.G. Muller <h.g.muller@hccnet.nl>
Date: Sun, 8 May 2011 13:02:52 +0200
Subject: [PATCH] Allow changing MultiPV setting from Engine-Output window

In analyze mode a header line is printed in the first engine-output
pane, which can be right-clicked to increase or decrease the number of
PVs. (Only with engines that support the MultiPV option.)
---
 backend.c      |   25 ++++++++++++++++++++++---
 backend.h      |    1 +
 engineoutput.c |   12 +++++++++---
 3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/backend.c b/backend.c
index a2c554f..fa46773 100644
--- a/backend.c
+++ b/backend.c
@@ -5315,22 +5315,41 @@ fprintf(debugFP,"parsePV: %d %c%c%c%c yy='%s'\nPV = '%s'\n", valid, fromX+AAA, f
   DrawPosition(TRUE, boards[currentMove]);
 }
 
+int
+MultiPV(ChessProgramState *cps)
+{	// check if engine supports MultiPV, and if so, return the nmber of the option that sets it
+	int i;
+	for(i=0; i<cps->nrOptions; i++)
+	    if(!strcmp(cps->option[i].name, "MultiPV") && cps->option[i].type == Spin)
+		return i;
+	return -1;
+}
+
 Boolean
 LoadMultiPV(int x, int y, char *buf, int index, int *start, int *end)
 {
-	int startPV;
-	char *p;
+	int startPV, multi, lineStart, origIndex = index;
+	char *p, buf2[MSG_SIZ];
 
 	if(index < 0 || index >= strlen(buf)) return FALSE; // sanity
 	lastX = x; lastY = y;
 	while(index > 0 && buf[index-1] != '\n') index--; // beginning of line
-	startPV = index;
+	lineStart = startPV = index;
 	while(buf[index] != '\n') if(buf[index++] == '\t') startPV = index;
 	if(index == startPV && (p = StrCaseStr(buf+index, "PV="))) startPV = p - buf + 3;
 	index = startPV;
 	do{ while(buf[index] && buf[index] != '\n') index++;
 	} while(buf[index] == '\n' && buf[index+1] == '\\' && buf[index+2] == ' ' && index++); // join kibitzed PV continuation line
 	buf[index] = 0;
+	if(lineStart == 0 && gameMode == AnalyzeMode && (multi = MultiPV(&first)) >= 0) {
+		int n = first.option[multi].value;
+		if(origIndex < 10) { if(n>1) n--; } else if(origIndex > index - 6) n++;
+		snprintf(buf2, MSG_SIZ, "option MultiPV=%d\n", n);
+		if(first.option[multi].value != n) SendToProgram(buf2, &first);
+		first.option[multi].value = n;
+		*start = *end = 0;
+		return TRUE;
+	}
 	ParsePV(buf+startPV, FALSE, !shiftKey);
 	*start = startPV; *end = index-1;
 	return TRUE;
diff --git a/backend.h b/backend.h
index 8e499dd..ebcc74f 100644
--- a/backend.h
+++ b/backend.h
@@ -417,5 +417,6 @@ extern int errorExitStatus;
 void SettingsPopUp P((ChessProgramState *cps)); // [HGM] really in front-end, but CPS not known in frontend.h
 int WaitForEngine P((ChessProgramState *cps, DelayedEventCallback x));
 void Load P((ChessProgramState *cps, int n));
+int MultiPV P((ChessProgramState *cps));
 
 #endif /* _BACKEND */
diff --git a/engineoutput.c b/engineoutput.c
index f37b9c2..12081f5 100644
--- a/engineoutput.c
+++ b/engineoutput.c
@@ -70,6 +70,7 @@ static int  lastDepth[2] = { -1, -1 };
 static int  lastForwardMostMove[2] = { -1, -1 };
 static int  engineState[2] = { -1, -1 };
 static char lastLine[2][MSG_SIZ];
+static char header[MSG_SIZ];
 
 #define MAX_VAR 400
 static int scores[MAX_VAR], textEnd[MAX_VAR], curDepth[2], nrVariations[2];
@@ -111,8 +112,7 @@ void SetProgramStats( FrontEndProgramStats * stats ) // now directly called by b
 {
     EngineOutputData ed;
     int clearMemo = FALSE;
-    int which;
-    int depth;
+    int which, depth, multi;
 
     if( stats == 0 ) {
         SetEngineState( 0, STATE_IDLE, "" );
@@ -171,6 +171,12 @@ void SetProgramStats( FrontEndProgramStats * stats ) // now directly called by b
 
     if( clearMemo ) {
         DoClearMemo(which); nrVariations[which] = 0;
+        header[0] = NULLCHAR;
+        if(gameMode == AnalyzeMode && (multi = MultiPV(&first)) >= 0) {
+            snprintf(header, MSG_SIZ, "\t\t\t\tfewer / Multi-PV setting = %d / more\n",
+                                       first.option[multi].value);
+            InsertIntoMemo( which, header, 0);
+        } else
         if(appData.ponderNextMove && lastLine[which][0]) {
             InsertIntoMemo( which, lastLine[which], 0 );
             InsertIntoMemo( which, "\n", 0 );
@@ -345,7 +351,7 @@ static int InsertionPoint( int len, EngineOutputData * ed )
 		scores[n] = newScore;
 	}
 	nrVariations[n] += 2;
-      return offs;
+      return offs + (gameMode == AnalyzeMode)*strlen(header);
 }
 
 
-- 
1.7.0.4