From ceb4e23edaec3c39f2ac28c55ba6a0e8c0938bdc Mon Sep 17 00:00:00 2001
From: Per Inge Mathisen <per@wz2100.net>
Date: Thu, 28 Aug 2008 19:55:09 +0000
Subject: [PATCH] patch #1096: Improve speed of fireOnLocation, and use it to
 fix AI bug

git-svn-id: svn+ssh://svn.gna.org/svn/warzone/trunk@5883 4a71c877-e1ca-e34f-864e-861f7616d084
---
 src/effects.c     | 43 ++++++++++++++++++++++++++++---------------
 src/map.h         |  1 +
 src/scriptfuncs.c |  2 +-
 3 files changed, 30 insertions(+), 16 deletions(-)

diff --git a/src/effects.c b/src/effects.c
index c8295c64b..dcf197d44 100644
--- a/src/effects.c
+++ b/src/effects.c
@@ -261,6 +261,18 @@ static void positionEffect(EFFECT *psEffect)
 
 static void killEffect(EFFECT *e)
 {
+	if (e->group == EFFECT_FIRE)
+	{
+		const int posX = map_coord(e->position.x);
+		const int posY = map_coord(e->position.z);
+		MAPTILE *psTile = mapTile(posX, posY);
+
+		ASSERT(psTile, "Fire effect on non-existing tile (%d, %d)", posX, posY);
+		if (psTile)
+		{
+			psTile->tileInfoBits &= ~BITS_ON_FIRE;	// clear fire bit
+		}
+	}
 	effectStatus[e-asEffectsList] = ES_INACTIVE;
 	e->control = (UBYTE) 0;
 }
@@ -2326,6 +2338,15 @@ void	effectSetupConstruction(EFFECT *psEffect)
 // ----------------------------------------------------------------------------------------
 void	effectSetupFire(EFFECT *psEffect)
 {
+	const int posX = map_coord(psEffect->position.x);
+	const int posY = map_coord(psEffect->position.z);
+	MAPTILE *psTile = mapTile(posX, posY);
+
+	ASSERT(psTile, "Cannot place a fire effect %d, %d - outside map!", posX, posY);
+	if (psTile)
+	{
+		psTile->tileInfoBits |= BITS_ON_FIRE;
+	}
 	psEffect->frameDelay = 300;	   // needs to be investigated...
 	psEffect->radius = auxVar;	// needs to be investigated
 	psEffect->lifeSpan = (UWORD)auxVarSec;
@@ -2709,26 +2730,18 @@ UDWORD	i;
 
 
 // -----------------------------------------------------------------------------------
+/// Check if tile contained within the given world coordinates is burning.
 bool fireOnLocation(unsigned int x, unsigned int y)
 {
-	unsigned int i;
+	const int posX = map_coord(x);
+	const int posY = map_coord(y);
+	MAPTILE *psTile = mapTile(posX, posY);
 
-	for(i = 0; i < MAX_EFFECTS; ++i)
+	ASSERT(psTile, "Checking fire on tile outside the map (%d, %d)", posX, posY);
+	if (psTile)
 	{
-	 	if (effectStatus[i] == ES_ACTIVE
-	 	 && asEffectsList[i].group == EFFECT_FIRE)
-		{
-			const unsigned int posX = asEffectsList[i].position.x;
-			const unsigned int posY = asEffectsList[i].position.z;
-
-			if (posX == x
-			 && posY == y)
-			{
-				return true;
-			}
-		}
+		return (psTile->tileInfoBits & BITS_ON_FIRE);
 	}
-
 	return false;
 }
 
diff --git a/src/map.h b/src/map.h
index e393d4be1..da9f31068 100644
--- a/src/map.h
+++ b/src/map.h
@@ -73,6 +73,7 @@ static inline unsigned short TileNumber_texture(unsigned short tilenumber)
 
 #define BITS_NOTBLOCKING 0x01 // units can drive on this even if there is a structure or feature on it
 #define BITS_FPATHBLOCK	0x10		// bit set temporarily by find path to mark a blocking tile
+#define BITS_ON_FIRE	0x20		// cache whether tile is burning
 #define BITS_GATEWAY	0x40		// bit set to show a gateway on the tile
 #define BITS_TALLSTRUCTURE 0x80		// bit set to show a tall structure which camera needs to avoid.
 
diff --git a/src/scriptfuncs.c b/src/scriptfuncs.c
index 42f428271..73f1a5149 100644
--- a/src/scriptfuncs.c
+++ b/src/scriptfuncs.c
@@ -1777,7 +1777,7 @@ BOOL scrGetFeatureB(void)
 		if(	( psCurrEnumFeature[bucket]->psStats->subType == psFeatureStatToFind[bucket]->subType)
 			&&( psCurrEnumFeature[bucket]->visible[playerToEnum[bucket]]	!= 0)
 			&&!TileHasStructure(mapTile(map_coord(psCurrEnumFeature[bucket]->pos.x), map_coord(psCurrEnumFeature[bucket]->pos.y)))
-			 /*&&!fireOnLocation(psCurrEnumFeature[bucket]->pos.x,psCurrEnumFeature[bucket]->pos.y )*/		// not burning.
+			&&!fireOnLocation(psCurrEnumFeature[bucket]->pos.x,psCurrEnumFeature[bucket]->pos.y )		// not burning.
 			)
 		{
 			scrFunctionResult.v.oval = psCurrEnumFeature[bucket];