Reduce code duplication (#233)

* Use ConvertGridNoToCenterCellXY instead of CenterX & CenterY

* Add direction utility function

We have a lot of places in the code that calculate direction based on center cell coordinates, but lack a utility function for it similar to other direction methods.

* Use utility function for calculating direction

* Use ConvertGridNoToCenterCellXY

* Use utility function for direction

* Use ConvertGridNoToCenterCellXY instead of CenterX & CenterY

* Use ConvertGridNoToCenterCellXY instead of CenterX & CenterY

* Remove CenterX & CenterY functions

Use ConvertGridNoToCenterCellXY instead

* Remove CenterX & CenterY calls from UB configuration

* Address review feedback

* Remove duplicate function

ConvertGridNoToCenterCellXY and ConvertMapPosToWorldTileCenter do the exact same thing

* Use PythSpacesAway instead of GetRangeFromGridNoDiff

Both functions calculate the same thing

* Remove GetRangeFromGridNoDiff

* Remove calls to abs()

The values end up being squared anyways making these unnecessary

Tactical/Air Raid.cpp

@@ -352,9 +352,8 @@ INT32 PickRandomLocationAtMinSpacesAway( INT32 sGridNo, INT16 sMinValue, INT16 s
 
 	DebugMsg(TOPIC_JA2,DBG_LEVEL_3,"PickRandomLocationAtMinSpacesAway");
 
-	sX = CenterX( sGridNo );
-	sY = CenterY( sGridNo );
-	
+	ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+
 	while(TileIsOutOfBounds(sNewGridNo))
 	{
 		sNewX = sX + sMinValue + (INT16)Random( sRandomVar );
@@ -596,8 +595,7 @@ void BeginBombing( )
 	sGridNo = PickRandomLocationAtMinSpacesAway( gsDiveTargetLocation , 300, 200 );
 
 	// Save X, y:
-	gsDiveX = CenterX( sGridNo );
-	gsDiveY = CenterY( sGridNo );
+	ConvertGridNoToCenterCellXY(sGridNo, &gsDiveX, &gsDiveY);
 
 	RESETTIMECOUNTER( giTimerAirRaidUpdate, RAID_DELAY );
 
@@ -657,8 +655,7 @@ void BeginDive( )
 	sGridNo = PickRandomLocationAtMinSpacesAway( gsDiveTargetLocation, 300, 200 );
 
 	// Save X, y:
-	gsDiveX = CenterX( sGridNo );
-	gsDiveY = CenterY( sGridNo );
+	ConvertGridNoToCenterCellXY(sGridNo, &gsDiveX, &gsDiveY);
 
 	RESETTIMECOUNTER( giTimerAirRaidUpdate, RAID_DELAY );
 	giNumTurnsSinceDiveStarted = 0;
@@ -760,8 +757,7 @@ void DoDive(	)
 
 			DebugMsg(TOPIC_JA2,DBG_LEVEL_3,"DoDive: move towards target");
 			// Move Towards target....
-			sTargetX = CenterX( gsDiveTargetLocation );
-			sTargetY = CenterY( gsDiveTargetLocation );
+			ConvertGridNoToCenterCellXY(gsDiveTargetLocation, &sTargetX, &sTargetY);
 
 			// Determine deltas
 			dDeltaX = (FLOAT)( sTargetX - gsDiveX );
@@ -886,7 +882,7 @@ void DoBombing(	)
 	INT16		sRange;
 	INT32		sGridNo, sOldGridNo, sBombGridNo;
 
-	INT16		sTargetX, sTargetY;
+	INT16		sTargetX, sTargetY, sBombX, sBombY;
 	UINT16	usItem;
 	INT16		sStrafeX, sStrafeY;
 	FLOAT		dDeltaX, dDeltaY, dAngle, dDeltaXPos, dDeltaYPos;
@@ -933,8 +929,7 @@ void DoBombing(	)
 			RESETTIMECOUNTER( giTimerAirRaidUpdate, RAID_DELAY );
 
 			// Move Towards target....
-			sTargetX = CenterX( gsDiveTargetLocation );
-			sTargetY = CenterY( gsDiveTargetLocation );
+			ConvertGridNoToCenterCellXY(gsDiveTargetLocation, &sTargetX, &sTargetY);
 
 			// Determine deltas
 			dDeltaX = (FLOAT)( sTargetX - gsDiveX );
@@ -1002,7 +997,8 @@ void DoBombing(	)
 						}
 
 						// Drop bombs...
-						InternalIgniteExplosion( NOBODY, CenterX( sBombGridNo ), CenterY( sBombGridNo ), 0, sBombGridNo, usItem, fLocate , (UINT8)IsRoofPresentAtGridNo( sBombGridNo ) );
+						ConvertGridNoToCenterCellXY(sBombGridNo, &sBombX, &sBombY);
+						InternalIgniteExplosion( NOBODY, sBombX, sBombY, 0, sBombGridNo, usItem, fLocate , (UINT8)IsRoofPresentAtGridNo( sBombGridNo ) );
 
 					}
 

Tactical/Handle Items.cpp

@@ -2187,7 +2187,7 @@ void HandleSoldierThrowItem( SOLDIERTYPE *pSoldier, INT32 sGridNo )
 					pSoldier->usPendingAnimation = LOB_ITEM;
 			}
 			// Draw item depending on distance from buddy
-			else if ( GetRangeFromGridNoDiff( sGridNo, pSoldier->sGridNo ) < MIN_LOB_RANGE )
+			else if (PythSpacesAway( sGridNo, pSoldier->sGridNo ) < MIN_LOB_RANGE )
 			{
 				//ddd maybe need to add check for throwing item class - grenade
 				if( (pSoldier->pThrowParams->ubActionCode == THROW_ARM_ITEM) && 
@@ -5919,8 +5919,7 @@ void SetOffBoobyTrap( ITEM_POOL * pItemPool )
 	if ( pItemPool )
 	{
 		INT16 sX, sY;
-		sX = CenterX( pItemPool->sGridNo );
-		sY = CenterY( pItemPool->sGridNo );
+		ConvertGridNoToCenterCellXY(pItemPool->sGridNo, &sX, &sY);
 		IgniteExplosion( NOBODY, sX, sY, (INT16) (gpWorldLevelData[pItemPool->sGridNo].sHeight + pItemPool->bRenderZHeightAboveLevel), pItemPool->sGridNo, MINI_GRENADE, 0 );
 		RemoveItemFromPool( pItemPool->sGridNo, pItemPool->iItemIndex, pItemPool->ubLevel );
 	}

Tactical/Handle UI.cpp

@@ -5619,7 +5619,7 @@ UINT32 UIHandleTOnTerrain( UI_EVENT *pUIEvent )
 		sTargetGridNo = MercPtrs[ ubTargID ]->sGridNo;
 	}
 
-	uiRange = GetRangeFromGridNoDiff( pSoldier->sGridNo, sTargetGridNo );
+	uiRange = PythSpacesAway( pSoldier->sGridNo, sTargetGridNo );
 
 
 	if ( uiRange <= NPC_TALK_RADIUS )
@@ -6610,7 +6610,7 @@ BOOLEAN HandleTalkInit(	)
 			}
 
 			// Check distance
-			uiRange = GetRangeFromGridNoDiff( pSoldier->sGridNo, usMapPos );
+			uiRange = PythSpacesAway( pSoldier->sGridNo, usMapPos );
 
 			// Double check path
 			if ( GetCivType( pTSoldier ) != CIV_TYPE_NA )

Tactical/Interface Dialogue.cpp

@@ -1827,7 +1827,7 @@ void HandleNPCDoAction( UINT8 ubTargetNPC, UINT16 usActionCode, UINT8 ubQuoteNum
 	EXITGRID								ExitGrid;
 	INT32 iRandom = 0;
 	UINT8										ubMineIndex;
-
+	INT16 sX, sY, sX2, sY2;
 
 	pSoldier2 = NULL;
 	//ScreenMsg( FONT_MCOLOR_LTYELLOW, MSG_INTERFACE, L"Handling %s, action %d at %ld", gMercProfiles[ ubTargetNPC ].zNickname, usActionCode, GetJA2Clock() );
@@ -1840,7 +1840,9 @@ void HandleNPCDoAction( UINT8 ubTargetNPC, UINT16 usActionCode, UINT8 ubQuoteNum
 		if (pSoldier && pSoldier2)
 		{
 			// see if we are facing this person
-			ubDesiredMercDir = atan8(CenterX(pSoldier->sGridNo),CenterY(pSoldier->sGridNo),CenterX(pSoldier2->sGridNo),CenterY(pSoldier2->sGridNo));
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+			ConvertGridNoToCenterCellXY(pSoldier2->sGridNo, &sX2, &sY2);
+			ubDesiredMercDir = atan8(sX, sY, sX2, sY2);
 			// if not already facing in that direction,
 			if (pSoldier->ubDirection != ubDesiredMercDir)
 			{
@@ -2317,7 +2319,9 @@ void HandleNPCDoAction( UINT8 ubTargetNPC, UINT16 usActionCode, UINT8 ubQuoteNum
 					if (!TileIsOutOfBounds(sGridNo))
 					{
 						// see if we are facing this person
-						ubDesiredMercDir = atan8(CenterX(pSoldier->sGridNo),CenterY(pSoldier->sGridNo),CenterX(sGridNo),CenterY(sGridNo));
+						ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+						ConvertGridNoToCenterCellXY(sGridNo, &sX2, &sY2);
+						ubDesiredMercDir = atan8(sX, sY, sX2, sY2);
 						// if not already facing in that direction,
 						if (pSoldier->ubDirection != ubDesiredMercDir)
 						{
@@ -5632,7 +5636,9 @@ void HandleRaulBlowingHimselfUp()
 
 		//blow himself up with, hmmm, lets say TNT.  :)
 		usItem = HAND_GRENADE;
-		IgniteExplosion( RAUL_UB, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, usItem, pSoldier->pathing.bLevel );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+		IgniteExplosion( RAUL_UB, sX, sY, 0, pSoldier->sGridNo, usItem, pSoldier->pathing.bLevel );
 
 		SetJa25GeneralFlag( JA_GF__RAUL_BLOW_HIMSELF_UP );
 	}

Tactical/Interface Items.cpp

@@ -9570,7 +9570,7 @@ BOOLEAN HandleItemPointerClick( INT32 usMapPos )
 BOOLEAN ItemCursorInLobRange( INT32 usMapPos )
 {
 	// Draw item depending on distance from buddy
-	if ( GetRangeFromGridNoDiff( usMapPos, gpItemPointerSoldier->sGridNo ) > MIN_LOB_RANGE )
+	if (PythSpacesAway( usMapPos, gpItemPointerSoldier->sGridNo ) > MIN_LOB_RANGE )
 	{
 		return( FALSE );
 	}

Tactical/Interface.cpp

@@ -2478,14 +2478,16 @@ BOOLEAN DrawCTHIndicator()
 
 	//////////////////////////////////
 	// Calculate Aperture
-
+	INT16 sX, sY;
 	// Calculate the center point of the shooter, in world coordinates.
-	FLOAT dStartX = (FLOAT) CenterX( gCTHDisplay.iShooterGridNo );
-	FLOAT dStartY = (FLOAT) CenterY( gCTHDisplay.iShooterGridNo );
+	ConvertGridNoToCenterCellXY(gCTHDisplay.iShooterGridNo, &sX, &sY);
+	FLOAT dStartX = (FLOAT) sX;
+	FLOAT dStartY = (FLOAT) sY;
 
 	// Calculate the center point of the target, in world coordinates.
-	FLOAT dEndX = (FLOAT) CenterX( gCTHDisplay.iTargetGridNo );
-	FLOAT dEndY = (FLOAT) CenterY( gCTHDisplay.iTargetGridNo );
+	ConvertGridNoToCenterCellXY(gCTHDisplay.iTargetGridNo, &sX, &sY);
+	FLOAT dEndX = (FLOAT) sX;
+	FLOAT dEndY = (FLOAT) sY;
 
 	// Calculate a delta: the difference between the shooter and target.
 	FLOAT dDeltaX = dEndX - dStartX;
@@ -6647,4 +6649,4 @@ INT16 GetBackgroundValue( UINT8 usProfile, UINT16 aNr )
 	}
 
 	return 0;
-}
+}

Tactical/Items.cpp

@@ -9262,13 +9262,16 @@ void CheckEquipmentForDamage( SOLDIERTYPE *pSoldier, INT32 iDamage )
 		if (fBlowsUp)
 		{
 			// blow it up!
+			INT16 sX, sY;
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+
 			if ( gTacticalStatus.ubAttackBusyCount )
 			{
-				IgniteExplosion( pSoldier->ubAttackerID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, pSoldier->inv[ bSlot ].usItem, pSoldier->pathing.bLevel, pSoldier->ubDirection, &pSoldier->inv[ bSlot ] );
+				IgniteExplosion( pSoldier->ubAttackerID, sX, sY, 0, pSoldier->sGridNo, pSoldier->inv[ bSlot ].usItem, pSoldier->pathing.bLevel, pSoldier->ubDirection, &pSoldier->inv[ bSlot ] );
 			}
 			else
 			{
-				IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, pSoldier->inv[ bSlot ].usItem, pSoldier->pathing.bLevel, pSoldier->ubDirection, &pSoldier->inv[ bSlot ] );
+				IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, pSoldier->inv[ bSlot ].usItem, pSoldier->pathing.bLevel, pSoldier->ubDirection, &pSoldier->inv[ bSlot ] );
 			}
 
 			//ADB when something in a stack blows up the whole stack goes, so no need to worry about number of items
@@ -9333,7 +9336,9 @@ BOOLEAN DamageItemOnGround( OBJECTTYPE * pObject, INT32 sGridNo, INT8 bLevel, IN
 	if ( fBlowsUp )
 	{
 		// OK, Ignite this explosion!
-		IgniteExplosion( ubOwner, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, pObject->usItem, bLevel, DIRECTION_IRRELEVANT, pObject );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+		IgniteExplosion( ubOwner, sX, sY, 0, sGridNo, pObject->usItem, bLevel, DIRECTION_IRRELEVANT, pObject );
 
 		// SANDRO - merc records
 		if ( (pObject->fFlags & OBJECT_ARMED_BOMB) && ((*pObject)[0]->data.misc.ubBombOwner > 1) )

Tactical/Keys.cpp

@@ -669,7 +669,9 @@ void HandleDoorTrap( SOLDIERTYPE * pSoldier, DOOR * pDoor )
 	{
 		case EXPLOSION:
 			// cause damage as a regular hand grenade
-			IgniteExplosion( NOBODY, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 25, pSoldier->sGridNo, HAND_GRENADE, 0 );
+			INT16 sX, sY;
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+			IgniteExplosion( NOBODY, sX, sY, 25, pSoldier->sGridNo, HAND_GRENADE, 0 );
 			break;
 
  		case SIREN:
@@ -760,8 +762,7 @@ BOOLEAN AttemptToBlowUpLock(SOLDIERTYPE * pSoldier, DOOR * pDoor)
 		sGridNo = pDoor->sGridNo;
 
 		// Get sX, sy;
-		sX = CenterX(sGridNo);
-		sY = CenterY(sGridNo);
+		ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
 
 		// Get Z position, based on orientation....
 		sZ = 20;

Tactical/LOS.cpp

@@ -2380,12 +2380,15 @@ INT32 SoldierToSoldierLineOfSightTest( SOLDIERTYPE * pStartSoldier, SOLDIERTYPE
 		UINT8  ubNumberOfTiles = pBase->pDBStructureRef->pDBStructure->ubNumberOfTiles;
 
 		INT32 sStructGridNo;
+		INT16 sX, sY, sX2, sY2;
+		ConvertGridNoToCenterCellXY(pStartSoldier->sGridNo, &sX, &sY);
 
 		// loop through all tiles
 		for (UINT8 ubLoop = BASE_TILE; ubLoop < ubNumberOfTiles; ubLoop++)
 		{
 			sStructGridNo = AddPosRelToBase(pBase->sGridNo, ppTile[ubLoop]);
-			if( LineOfSightTest( (FLOAT) CenterX( pStartSoldier->sGridNo ), (FLOAT) CenterY( pStartSoldier->sGridNo ), dStartZPos, (FLOAT) CenterX( sStructGridNo ), (FLOAT) CenterY( sStructGridNo ), dEndZPos, iTileSightLimit, bAware, fSmell, NULL, adjustForSight, cthCalc ) )
+			ConvertGridNoToCenterCellXY(sStructGridNo, &sX2, &sY2);
+			if( LineOfSightTest( (FLOAT) sX, (FLOAT) sY, dStartZPos, (FLOAT) sX2, (FLOAT) sY2, dEndZPos, iTileSightLimit, bAware, fSmell, NULL, adjustForSight, cthCalc ) )
 			{
 				return( TRUE );
 			}
@@ -2393,14 +2396,18 @@ INT32 SoldierToSoldierLineOfSightTest( SOLDIERTYPE * pStartSoldier, SOLDIERTYPE
 		return( FALSE );
 	}
 
-	return( LineOfSightTest( (FLOAT) CenterX( pStartSoldier->sGridNo ), (FLOAT) CenterY( pStartSoldier->sGridNo ), dStartZPos, (FLOAT) CenterX( pEndSoldier->sGridNo ), (FLOAT) CenterY( pEndSoldier->sGridNo ), dEndZPos, iTileSightLimit, bAware, fSmell, NULL, adjustForSight, cthCalc ) );
+	INT16 sX, sY, sX2, sY2;
+	ConvertGridNoToCenterCellXY(pStartSoldier->sGridNo, &sX, &sY);
+	ConvertGridNoToCenterCellXY(pEndSoldier->sGridNo, &sX2, &sY2);
+
+	return( LineOfSightTest( (FLOAT) sX, (FLOAT) sY, dStartZPos, (FLOAT) sX2, (FLOAT) sY2, dEndZPos, iTileSightLimit, bAware, fSmell, NULL, adjustForSight, cthCalc ) );
 	}
 
 INT32 SoldierToLocationWindowTest( SOLDIERTYPE * pStartSoldier, INT32 sEndGridNo )
 {
 	// figure out if there is a SINGLE window between the looker and target
 	FLOAT			dStartZPos, dEndZPos;
-	INT16			sXPos, sYPos;
+	INT16			sX, sY, sX2, sY2;
 	INT32			sWindowGridNo = NOWHERE;
 	INT32			iRet;
 
@@ -2413,24 +2420,23 @@ INT32 SoldierToLocationWindowTest( SOLDIERTYPE * pStartSoldier, INT32 sEndGridNo
 	dStartZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[pStartSoldier->sGridNo].sHeight );
 	dEndZPos = dStartZPos;
 
-	ConvertGridNoToXY( sEndGridNo, &sXPos, &sYPos );
-	sXPos = sXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-	sYPos = sYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
+	ConvertGridNoToCenterCellXY(pStartSoldier->sGridNo, &sX, &sY);
+	ConvertGridNoToCenterCellXY(sEndGridNo, &sX2, &sY2);
 
 	//ADB changed from 255 to 511 to handle new LOS test
 	// We don't want to consider distance limits here so pass in tile sight limit of 255( + 256)
 	// and consider trees as little as possible
-	iRet = LineOfSightTest( (FLOAT) CenterX( pStartSoldier->sGridNo ), (FLOAT) CenterY( pStartSoldier->sGridNo ), dStartZPos, (FLOAT) sXPos, (FLOAT) sYPos, dEndZPos, 511, TRUE, FALSE, &sWindowGridNo );
+	iRet = LineOfSightTest( (FLOAT) sX, (FLOAT) sY, dStartZPos, (FLOAT) sX2, (FLOAT) sY2, dEndZPos, 511, TRUE, FALSE, &sWindowGridNo );
 
 	return( sWindowGridNo );
 }
 
 INT32 SoldierTo3DLocationLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32 sGridNo, INT8 bLevel, INT8 bCubeLevel, INT8 bAware, int iTileSightLimit, bool adjustForSight )
 {
-	FLOAT						dStartZPos, dEndZPos;
-	INT16						sXPos, sYPos;
-	UINT8						ubTargetID;
-	BOOLEAN					fOk;
+	FLOAT dStartZPos, dEndZPos;
+	INT16 sX, sY, sX2, sY2;
+	UINT8 ubTargetID;
+	BOOLEAN fOk;
 
 	CHECKF( pStartSoldier );
 
@@ -2457,9 +2463,6 @@ INT32 SoldierTo3DLocationLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32 sGr
 		dEndZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[ sGridNo ].sHeight );
 	}
 
-	ConvertGridNoToXY( sGridNo, &sXPos, &sYPos );
-	sXPos = sXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-	sYPos = sYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
 
 	if (iTileSightLimit == CALC_FROM_ALL_DIRS || iTileSightLimit == CALC_FROM_WANTED_DIR) {
 		iTileSightLimit = pStartSoldier->GetMaxDistanceVisible( sGridNo, bLevel, iTileSightLimit );
@@ -2468,14 +2471,17 @@ INT32 SoldierTo3DLocationLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32 sGr
 		iTileSightLimit = 255 + pStartSoldier->GetMaxDistanceVisible( sGridNo, bLevel, CALC_FROM_ALL_DIRS );
 	}
 
-	return( LineOfSightTest( (FLOAT) CenterX( pStartSoldier->sGridNo ), (FLOAT) CenterY( pStartSoldier->sGridNo ), dStartZPos, (FLOAT) sXPos, (FLOAT) sYPos, dEndZPos, iTileSightLimit, bAware, HasThermalOptics( pStartSoldier), NULL, adjustForSight ) );
+	ConvertGridNoToCenterCellXY(pStartSoldier->sGridNo, &sX, &sY);
+	ConvertGridNoToCenterCellXY(sGridNo, &sX2, &sY2);
+
+	return( LineOfSightTest( (FLOAT) sX, (FLOAT) sY, dStartZPos, (FLOAT) sX2, (FLOAT) sY2, dEndZPos, iTileSightLimit, bAware, HasThermalOptics( pStartSoldier), NULL, adjustForSight ) );
 }
 
 INT32 SoldierToVirtualSoldierLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32 sGridNo, INT8 bLevel, INT8 bStance, INT8 bAware, int iTileSightLimit )
 {
-	FLOAT						dStartZPos, dEndZPos;
-	INT16						sXPos, sYPos;
-	BOOLEAN					fOk;
+	FLOAT dStartZPos, dEndZPos;
+	INT16 endXPos, endYPos, startXPos, startYPos;
+	BOOLEAN fOk;
 
 	CHECKF( pStartSoldier );
 
@@ -2504,10 +2510,6 @@ INT32 SoldierToVirtualSoldierLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32
 	}
 
 
-	ConvertGridNoToXY( sGridNo, &sXPos, &sYPos );
-	sXPos = sXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-	sYPos = sYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
-
 	if (iTileSightLimit == CALC_FROM_ALL_DIRS || iTileSightLimit == CALC_FROM_WANTED_DIR) {
 		iTileSightLimit = pStartSoldier->GetMaxDistanceVisible( sGridNo, bLevel, iTileSightLimit );
 	}
@@ -2515,13 +2517,15 @@ INT32 SoldierToVirtualSoldierLineOfSightTest( SOLDIERTYPE * pStartSoldier, INT32
 		iTileSightLimit = 255 + pStartSoldier->GetMaxDistanceVisible( sGridNo, bLevel, CALC_FROM_ALL_DIRS );
 	}
 
-	return( LineOfSightTest( (FLOAT) CenterX( pStartSoldier->sGridNo ), (FLOAT) CenterY( pStartSoldier->sGridNo ), dStartZPos, (FLOAT) sXPos, (FLOAT) sYPos, dEndZPos, iTileSightLimit, bAware, HasThermalOptics( pStartSoldier), NULL, false ) );
+	ConvertGridNoToCenterCellXY(pStartSoldier->sGridNo, &startXPos, &startYPos);
+	ConvertGridNoToCenterCellXY(sGridNo, &endXPos, &endYPos);
+	return(LineOfSightTest((FLOAT)startXPos, (FLOAT)startYPos, dStartZPos, (FLOAT)endXPos, (FLOAT)endYPos, dEndZPos, iTileSightLimit, bAware, HasThermalOptics(pStartSoldier), NULL, false));
 }
 
 INT32 LocationToLocationLineOfSightTest( INT32 sStartGridNo, INT8 bStartLevel, INT32 sEndGridNo, INT8 bEndLevel, INT8 bAware, int iTileSightLimit, FLOAT dStartPos, FLOAT dEndPos )
 {
-	FLOAT						dStartZPos, dEndZPos;
-	INT16						sStartXPos, sStartYPos, sEndXPos, sEndYPos;
+	FLOAT dStartZPos, dEndZPos;
+	INT16 sStartXPos, sStartYPos, sEndXPos, sEndYPos;
 
 	// Bob: prevent access violation 
 	if (sStartGridNo < 0) { 
@@ -2544,19 +2548,11 @@ INT32 LocationToLocationLineOfSightTest( INT32 sStartGridNo, INT8 bStartLevel, I
 	// add in ground height
 	dStartZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[ sStartGridNo ].sHeight );
 
-	ConvertGridNoToXY( sStartGridNo, &sStartXPos, &sStartYPos );
-	sStartXPos = sStartXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-	sStartYPos = sStartYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
-
 	// sevenfm: use height argument
 	dEndZPos = dEndPos + bEndLevel * HEIGHT_UNITS;
 	// add in ground height
 	dEndZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[ sEndGridNo ].sHeight );
 
-	ConvertGridNoToXY( sEndGridNo, &sEndXPos, &sEndYPos );
-	sEndXPos = sEndXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-	sEndYPos = sEndYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
-
 	if (iTileSightLimit == CALC_FROM_ALL_DIRS || iTileSightLimit == CALC_FROM_WANTED_DIR)
 	{
 		iTileSightLimit = MaxNormalDistanceVisible();
@@ -2565,6 +2561,10 @@ INT32 LocationToLocationLineOfSightTest( INT32 sStartGridNo, INT8 bStartLevel, I
 	{
 		iTileSightLimit = 255 + MaxNormalDistanceVisible();
 	}
+
+	ConvertGridNoToCenterCellXY(sStartGridNo, &sStartXPos, &sStartYPos);
+	ConvertGridNoToCenterCellXY(sEndGridNo, &sEndXPos, &sEndYPos);
+
 	return( LineOfSightTest( (FLOAT)sStartXPos, (FLOAT)sStartYPos, dStartZPos, (FLOAT) sEndXPos, (FLOAT) sEndYPos, dEndZPos, iTileSightLimit, bAware, FALSE, NULL ) );
 }
 
@@ -2931,20 +2931,24 @@ BOOLEAN BulletHitMerc( BULLET * pBullet, STRUCTURE * pStructure, BOOLEAN fIntend
 						
 							// Flugente: we measure the distance of the bullet's location to the location of the soldier, and to the 2 gridnos his head and leg occupy
 							// From this we can decide what body part was hit
-							FLOAT bodycenterX = (FLOAT)CenterX( pTarget->sGridNo );
-							FLOAT bodycenterY = (FLOAT)CenterY( pTarget->sGridNo );
+							INT16 sX, sY;
+							ConvertGridNoToCenterCellXY(pTarget->sGridNo, &sX, &sY);
+							FLOAT bodycenterX = (FLOAT) sX;
+							FLOAT bodycenterY = (FLOAT) sY;
 
 							FLOAT difftobodycenter = sqrt( (bodycenterX - x) * (bodycenterX - x) + (bodycenterY - y) * (bodycenterY - y) );
 
 							INT32 viewdirectiongridno = NewGridNo( pTarget->sGridNo, DirectionInc( pTarget->ubDirection ) );
-							FLOAT nextgridnocenterX = (FLOAT)CenterX( viewdirectiongridno );
-							FLOAT nextgridnocenterY = (FLOAT)CenterY( viewdirectiongridno );
+							ConvertGridNoToCenterCellXY(viewdirectiongridno, &sX, &sY);
+							FLOAT nextgridnocenterX = (FLOAT) sX;
+							FLOAT nextgridnocenterY = (FLOAT) sY;
 
 							FLOAT difftonextgridno = sqrt( (nextgridnocenterX - x) * (nextgridnocenterX - x) + (nextgridnocenterY - y) * (nextgridnocenterY - y) );
 
 							INT32 oppositeviewdirectiongridno = NewGridNo( pTarget->sGridNo, DirectionInc( gOppositeDirection[pTarget->ubDirection] ) );
-							FLOAT oppositenextgridnocenterX = (FLOAT)CenterX( oppositeviewdirectiongridno );
-							FLOAT oppositenextgridnocenterY = (FLOAT)CenterY( oppositeviewdirectiongridno );
+							ConvertGridNoToCenterCellXY(oppositeviewdirectiongridno, &sX, &sY);
+							FLOAT oppositenextgridnocenterX = (FLOAT) sX;
+							FLOAT oppositenextgridnocenterY = (FLOAT) sY;
 
 							FLOAT difftooppositenextgridno = sqrt( (oppositenextgridnocenterX - x) * (oppositenextgridnocenterX - x) + (oppositenextgridnocenterY - y) * (oppositenextgridnocenterY - y) );
 
@@ -4319,8 +4323,9 @@ UINT8 CalcChanceToGetThrough( BULLET * pBullet )
 
 UINT8 SoldierToSoldierChanceToGetThrough( SOLDIERTYPE * pStartSoldier, SOLDIERTYPE * pEndSoldier )
 {
-	FLOAT			dEndZPos;
-	BOOLEAN		fOk;
+	INT16 sX, sY;
+	FLOAT dEndZPos;
+	BOOLEAN fOk;
 
 	if (pStartSoldier == pEndSoldier)
 	{
@@ -4337,15 +4342,18 @@ UINT8 SoldierToSoldierChanceToGetThrough( SOLDIERTYPE * pStartSoldier, SOLDIERTY
 	// set startsoldier's target ID ... need an ID stored in case this
 	// is the AI calculating cover to a location where he might not be any more
 	pStartSoldier->ubCTGTTargetID = pEndSoldier->ubID;
-	return( ChanceToGetThrough( pStartSoldier, (FLOAT) CenterX( pEndSoldier->sGridNo ), (FLOAT) CenterY( pEndSoldier->sGridNo ), dEndZPos ) );
+
+	ConvertGridNoToCenterCellXY(pEndSoldier->sGridNo, &sX, &sY);
+	return( ChanceToGetThrough( pStartSoldier, (FLOAT) sX, (FLOAT) sY, dEndZPos ) );
 }
 
 UINT8 SoldierToSoldierBodyPartChanceToGetThrough( SOLDIERTYPE * pStartSoldier, SOLDIERTYPE * pEndSoldier, UINT8 ubAimLocation )
 {
 	// does like StS-CTGT but with a particular body part in mind
-	FLOAT			dEndZPos;
-	BOOLEAN		fOk;
-	UINT8			ubPosType;
+	INT16 sX, sY;
+	FLOAT dEndZPos;
+	BOOLEAN fOk;
+	UINT8 ubPosType;
 
 	if (pStartSoldier == pEndSoldier)
 	{
@@ -4378,7 +4386,8 @@ UINT8 SoldierToSoldierBodyPartChanceToGetThrough( SOLDIERTYPE * pStartSoldier, S
 	// set startsoldier's target ID ... need an ID stored in case this
 	// is the AI calculating cover to a location where he might not be any more
 	pStartSoldier->ubCTGTTargetID = pEndSoldier->ubID;
-	return( ChanceToGetThrough( pStartSoldier, (FLOAT) CenterX( pEndSoldier->sGridNo ), (FLOAT) CenterY( pEndSoldier->sGridNo ), dEndZPos ) );
+	ConvertGridNoToCenterCellXY(pEndSoldier->sGridNo, &sX, &sY);
+	return( ChanceToGetThrough( pStartSoldier, (FLOAT) sX, (FLOAT) sY, dEndZPos ) );
 }
 
 UINT8 SoldierToLocationChanceToGetThrough( SOLDIERTYPE * pStartSoldier, INT32 sGridNo, INT8 bLevel, INT8 bCubeLevel, UINT8 ubTargetID )
@@ -4423,9 +4432,7 @@ UINT8 SoldierToLocationChanceToGetThrough( SOLDIERTYPE * pStartSoldier, INT32 sG
 		}
 
 		dEndZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[sGridNo].sHeight );
-		ConvertGridNoToXY( sGridNo, &sXPos, &sYPos );
-		sXPos = sXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-		sYPos = sYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
+		ConvertGridNoToCenterCellXY(sGridNo, &sXPos, &sYPos);
 
 		// set startsoldier's target ID ... need an ID stored in case this
 		// is the AI calculating cover to a location where he might not be any more
@@ -4437,6 +4444,7 @@ UINT8 SoldierToLocationChanceToGetThrough( SOLDIERTYPE * pStartSoldier, INT32 sG
 UINT8 AISoldierToSoldierChanceToGetThrough( SOLDIERTYPE * pStartSoldier, SOLDIERTYPE * pEndSoldier )
 {
 	// Like a standard CTGT algorithm BUT fakes the start soldier at standing height
+	INT16 sX, sY;
 	FLOAT			dEndZPos;
 	BOOLEAN		fOk;
 	UINT8			ubChance;
@@ -4460,7 +4468,8 @@ UINT8 AISoldierToSoldierChanceToGetThrough( SOLDIERTYPE * pStartSoldier, SOLDIER
 	// is the AI calculating cover to a location where he might not be any more
 	pStartSoldier->ubCTGTTargetID = NOBODY;
 
-	ubChance = ChanceToGetThrough( pStartSoldier, (FLOAT) CenterX( pEndSoldier->sGridNo ), (FLOAT) CenterY( pEndSoldier->sGridNo ), dEndZPos );
+	ConvertGridNoToCenterCellXY(pEndSoldier->sGridNo, &sX, &sY);
+	ubChance = ChanceToGetThrough( pStartSoldier, (FLOAT) sX, (FLOAT) sY, dEndZPos );
 	pStartSoldier->usAnimState = usTrueState;
 	return( ubChance );
 }
@@ -4510,9 +4519,7 @@ UINT8 AISoldierToLocationChanceToGetThrough( SOLDIERTYPE * pStartSoldier, INT32
 		}
 
 		dEndZPos += CONVERT_PIXELS_TO_HEIGHTUNITS( gpWorldLevelData[sGridNo].sHeight );
-		ConvertGridNoToXY( sGridNo, &sXPos, &sYPos );
-		sXPos = sXPos * CELL_X_SIZE + (CELL_X_SIZE / 2);
-		sYPos = sYPos * CELL_Y_SIZE + (CELL_Y_SIZE / 2);
+		ConvertGridNoToCenterCellXY(sGridNo, &sXPos, &sYPos);
 
 		// set startsoldier's target ID ... need an ID stored in case this
 		// is the AI calculating cover to a location where he might not be any more
@@ -4788,6 +4795,7 @@ INT8 FireBulletGivenTargetNCTH( SOLDIERTYPE * pFirer, FLOAT dEndX, FLOAT dEndY,
 	UINT8		ubSpreadIndex = 0;
 	UINT16	usBulletFlags = 0;
 	int n=0;
+	INT16 sXPos, sYPos;
 
 	OBJECTTYPE* pObjAttHand = pFirer->GetUsedWeapon( &(pFirer->inv[pFirer->ubAttackingHand]) );
 
@@ -4799,8 +4807,9 @@ INT8 FireBulletGivenTargetNCTH( SOLDIERTYPE * pFirer, FLOAT dEndX, FLOAT dEndY,
 
 	CalculateSoldierZPos( pFirer, FIRING_POS, &dStartZ );
 
-	dStartX = (FLOAT) CenterX( pFirer->sGridNo );
-	dStartY = (FLOAT) CenterY( pFirer->sGridNo );
+	ConvertGridNoToCenterCellXY(pFirer->sGridNo, &sXPos, &sYPos);
+	dStartX = (FLOAT) sXPos;
+	dStartY = (FLOAT) sYPos;
 
 	dDeltaX = dEndX - dStartX;
 	dDeltaY = dEndY - dStartY;
@@ -5279,6 +5288,7 @@ INT8 FireBulletGivenTarget( SOLDIERTYPE * pFirer, FLOAT dEndX, FLOAT dEndY, FLOA
 	UINT8		ubSpreadIndex = 0;
 	UINT16	usBulletFlags = 0;
 	int n=0;
+	INT16 sXPos, sYPos;
 
 	OBJECTTYPE* pObjAttHand = pFirer->GetUsedWeapon( &(pFirer->inv[pFirer->ubAttackingHand]) );
 
@@ -5290,8 +5300,9 @@ INT8 FireBulletGivenTarget( SOLDIERTYPE * pFirer, FLOAT dEndX, FLOAT dEndY, FLOA
 
 	CalculateSoldierZPos( pFirer, FIRING_POS, &dStartZ );
 
-	dStartX = (FLOAT) CenterX( pFirer->sGridNo );
-	dStartY = (FLOAT) CenterY( pFirer->sGridNo );
+	ConvertGridNoToCenterCellXY(pFirer->sGridNo, &sXPos, &sYPos);
+	dStartX = (FLOAT) sXPos;
+	dStartY = (FLOAT) sYPos;
 
 	dDeltaX = dEndX - dStartX;
 	dDeltaY = dEndY - dStartY;
@@ -5954,6 +5965,7 @@ INT8 FireBulletGivenTargetTrapOnly( SOLDIERTYPE* pThrower, OBJECTTYPE* pObj, INT
 	UINT8		ubSpreadIndex = 0;
 	UINT16	usBulletFlags = 0;
 	int n=0;
+	INT16 sXPos, sYPos;
 
 	UINT16 usItem = pObj->usItem;
 	UINT8 ammotype = ( *pObj )[0]->data.gun.ubGunAmmoType;
@@ -5962,8 +5974,9 @@ INT8 FireBulletGivenTargetTrapOnly( SOLDIERTYPE* pThrower, OBJECTTYPE* pObj, INT
 	if ( AmmoTypes[ammotype].numberOfBullets > 1 )
 		fBuckshot = TRUE;
 		
-	dStartX = (FLOAT) CenterX( gridno );
-	dStartY = (FLOAT) CenterY( gridno );
+	ConvertGridNoToCenterCellXY(gridno, &sXPos, &sYPos);
+	dStartX = (FLOAT) sXPos;
+	dStartY = (FLOAT) sYPos;
 
 	dDeltaX = dEndX - dStartX;
 	dDeltaY = dEndY - dStartY;
@@ -6541,13 +6554,15 @@ INT8 FireBulletGivenTarget_NoObjectNoSoldier( UINT16 usItem, UINT8 ammotype, UIN
 	UINT8		ubSpreadIndex = 0;
 	UINT16	usBulletFlags = 0;
 	int n = 0;
-	
+	INT16 sXPos, sYPos;
+
 	BOOLEAN fBuckshot = FALSE;
 	if ( AmmoTypes[ammotype].numberOfBullets > 1 )
 		fBuckshot = TRUE;
 
-	dStartX = (FLOAT)CenterX( gridno );
-	dStartY = (FLOAT)CenterY( gridno );
+	ConvertGridNoToCenterCellXY(gridno, &sXPos, &sYPos);
+	dStartX = (FLOAT)sXPos;
+	dStartY = (FLOAT)sYPos;
 
 	dDeltaX = dEndX - dStartX;
 	dDeltaY = dEndY - dStartY;
@@ -8537,8 +8552,10 @@ void AdjustTargetCenterPoint( SOLDIERTYPE *pShooter, INT32 iTargetGridNo, FLOAT
 	CalculateSoldierZPos( pShooter, FIRING_POS, &dStartZ );
 
 	// Locate absolute center X,Y of the shooter
-	dStartX = (FLOAT) CenterX( pShooter->sGridNo );
-	dStartY = (FLOAT) CenterY( pShooter->sGridNo );
+	INT16 sXPos, sYPos;
+	ConvertGridNoToCenterCellXY(pShooter->sGridNo, &sXPos, &sYPos);
+	dStartX = (FLOAT) sXPos;
+	dStartY = (FLOAT) sYPos;
 
 	////////////////////////////////////////////////////////////////////////////
 	// Calculate difference (Delta) between start and end point of bullet flight
@@ -9157,8 +9174,10 @@ void CalcTargetMovementOffset( SOLDIERTYPE *pShooter, SOLDIERTYPE *pTarget, OBJE
 	{
 		// HEADROCK HAM 4: Hopefully the right spot for this: This soldier has no "old" coordinates, so just set them
 		// to wherever he/she is currently standing.
-		pTarget->sOldXPos = CenterX( pTarget->sGridNo );
-		pTarget->sOldYPos = CenterY( pTarget->sGridNo );
+		INT16 sXPos, sYPos;
+		ConvertGridNoToCenterCellXY(pTarget->sGridNo, &sXPos, &sYPos);
+		pTarget->sOldXPos = sXPos;
+		pTarget->sOldYPos = sYPos;
 		// Since movement is now nonexistent, break the formula here without adjusting coordinates.
 		return;
 	}

Tactical/Rotting Corpses.cpp

@@ -561,8 +561,7 @@ INT32	AddRottingCorpse( ROTTING_CORPSE_DEFINITION *pCorpseDef )
 	}
 	else
 	{
-		AniParams.sX = CenterX(pCorpse->def.sGridNo);
-		AniParams.sY = CenterY(pCorpse->def.sGridNo);
+		ConvertGridNoToCenterCellXY(pCorpse->def.sGridNo, &AniParams.sX, &AniParams.sY);
 	}
 		
 	AniParams.sZ									= (INT16)pCorpse->def.sHeightAdjustment;
@@ -1588,8 +1587,7 @@ void VaporizeCorpse( INT32 sGridNo, INT8 asLevel, UINT16 usStructureID )
 		AniParams.sDelay = (INT16)( 80 );
 		AniParams.sStartFrame = 0;
 		AniParams.uiFlags = ANITILE_CACHEDTILE | ANITILE_FORWARD;
-		AniParams.sX = CenterX( sBaseGridNo );
-		AniParams.sY = CenterY( sBaseGridNo );
+		ConvertGridNoToCenterCellXY(sBaseGridNo, &AniParams.sX, &AniParams.sY);
 		AniParams.sZ = (INT16)pCorpse->def.sHeightAdjustment;
 
 		strcpy( AniParams.zCachedFile, "TILECACHE\\GEN_BLOW.STI" );
@@ -2284,10 +2282,12 @@ BOOLEAN AddCorpseFromObject(OBJECTTYPE* pObj, INT32 sGridNo, INT8 bLevel )
 		Corpse.ubBodyType = REGMALE;
 	}
 
+	INT16 sX, sY;
+	ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+
 	Corpse.sGridNo = sGridNo;
-	
-	Corpse.dXPos = CenterX(Corpse.sGridNo);
-	Corpse.dYPos = CenterY(Corpse.sGridNo);
+	Corpse.dXPos = sX;
+	Corpse.dYPos = sY;
 
 	Corpse.sHeightAdjustment = 0;
 

Tactical/ShopKeeper Interface.cpp

@@ -776,7 +776,7 @@ BOOLEAN EnterShopKeeperInterface()
 	else
 		pShopkeeper = FindSoldierByProfileID( armsDealerInfo[gbSelectedArmsDealerID].ubShopKeeperID, FALSE );
 
-	if ( GetRangeFromGridNoDiff( pSoldier->sGridNo, pShopkeeper->sGridNo ) > NPC_TALK_RADIUS )
+	if (PythSpacesAway( pSoldier->sGridNo, pShopkeeper->sGridNo ) > NPC_TALK_RADIUS )
 	{
 		//so now we know we are too far away to trade, so instead of just quitting,
 		//either post a message or run to the guy like HandleTalkInit does
@@ -6668,7 +6668,7 @@ BOOLEAN CanMercInteractWithSelectedShopkeeper( SOLDIERTYPE *pSoldier )
 		if ( SoldierTo3DLocationLineOfSightTest( pSoldier, sDestGridNo, bDestLevel, 3, TRUE, CALC_FROM_ALL_DIRS ) )
 		{
 			// Get range to shopkeeper
-			uiRange = GetRangeFromGridNoDiff( pSoldier->sGridNo, sDestGridNo );
+			uiRange = PythSpacesAway( pSoldier->sGridNo, sDestGridNo );
 
 			// and is close enough to talk to the shopkeeper (use this define INSTEAD of PASSING_ITEM_DISTANCE_OKLIFE!)
 			if ( uiRange <= NPC_TALK_RADIUS )

Tactical/Soldier Add.cpp

@@ -1367,11 +1367,9 @@ void InternalSoldierInSectorSleep( SOLDIERTYPE *pSoldier, INT32 sGridNo, BOOLEAN
 	usAnim = STANDING;
 	}
 
-	// OK, look for sutable placement....
+	// OK, look for suitable placement....
 	sGoodGridNo = FindGridNoFromSweetSpotWithStructData( pSoldier, usAnim, sGridNo, 5, &ubNewDirection, FALSE );
-
-	sWorldX = CenterX( sGoodGridNo );
-	sWorldY = CenterY( sGoodGridNo );
+	ConvertGridNoToCenterCellXY(sGoodGridNo, &sWorldX, &sWorldY);
 
 	pSoldier->EVENT_SetSoldierPosition( sWorldX, sWorldY );
 
@@ -1408,11 +1406,9 @@ void SoldierInSectorIncompaciated( SOLDIERTYPE *pSoldier, INT32 sGridNo )
 		return;
 	}
 
-	// OK, look for sutable placement....
+	// OK, look for suitable placement....
 	sGoodGridNo = FindGridNoFromSweetSpotWithStructData( pSoldier, STAND_FALLFORWARD_STOP, sGridNo, 5, &ubNewDirection, FALSE );
-
-	sWorldX = CenterX( sGoodGridNo );
-	sWorldY = CenterY( sGoodGridNo );
+	ConvertGridNoToCenterCellXY(sGoodGridNo, &sWorldX, &sWorldY);
 
 	pSoldier->EVENT_SetSoldierPosition( sWorldX, sWorldY );
 
@@ -1444,11 +1440,9 @@ void SoldierInSectorPatient( SOLDIERTYPE *pSoldier, INT32 sGridNo )
 		return;
 	}
 
-	// OK, look for sutable placement....
+	// OK, look for suitable placement....
 	sGoodGridNo = FindGridNoFromSweetSpotWithStructData( pSoldier, BEING_PATIENT, sGridNo, 5, &ubNewDirection, FALSE );
-
-	sWorldX = CenterX( sGoodGridNo );
-	sWorldY = CenterY( sGoodGridNo );
+	ConvertGridNoToCenterCellXY(sGoodGridNo, &sWorldX, &sWorldY);
 
 	pSoldier->EVENT_SetSoldierPosition( sWorldX, sWorldY );
 
@@ -1479,11 +1473,9 @@ void SoldierInSectorDoctor( SOLDIERTYPE *pSoldier, INT32 sGridNo )
 		return;
 	}
 
-	// OK, look for sutable placement....
+	// OK, look for suitable placement....
 	sGoodGridNo = FindGridNoFromSweetSpotWithStructData( pSoldier, BEING_DOCTOR, sGridNo, 5, &ubNewDirection, FALSE );
-
-	sWorldX = CenterX( sGoodGridNo );
-	sWorldY = CenterY( sGoodGridNo );
+	ConvertGridNoToCenterCellXY(sGoodGridNo, &sWorldX, &sWorldY);
 
 	pSoldier->EVENT_SetSoldierPosition( sWorldX, sWorldY );
 
@@ -1514,11 +1506,9 @@ void SoldierInSectorRepair( SOLDIERTYPE *pSoldier, INT32 sGridNo )
 		return;
 	}
 
-	// OK, look for sutable placement....
+	// OK, look for suitable placement....
 	sGoodGridNo = FindGridNoFromSweetSpotWithStructData( pSoldier, BEING_REPAIRMAN, sGridNo, 5, &ubNewDirection, FALSE );
-
-	sWorldX = CenterX( sGoodGridNo );
-	sWorldY = CenterY( sGoodGridNo );
+	ConvertGridNoToCenterCellXY(sGoodGridNo, &sWorldX, &sWorldY);
 
 	pSoldier->EVENT_SetSoldierPosition( sWorldX, sWorldY );
 
@@ -1550,8 +1540,7 @@ void AddSoldierToSectorGridNo( SOLDIERTYPE *pSoldier, INT32 sGridNo, UINT8 ubDir
 	DebugMsg(TOPIC_JA2,DBG_LEVEL_3,String("AddSoldierToSectorGridNo"));
 
 	// Add merc to gridno
-	sWorldX = CenterX( sGridNo );
-	sWorldY = CenterY( sGridNo );
+	ConvertGridNoToCenterCellXY(sGridNo, &sWorldX, &sWorldY);
 
 	// Set reserved location!
 	pSoldier->sReservedMovementGridNo = NOWHERE;

Tactical/Soldier Ani.cpp

@@ -280,7 +280,7 @@ BOOLEAN AdjustToNextAnimationFrame( SOLDIERTYPE *pSoldier )
 					INT16		sXPos, sYPos;
 
 					//sNewGridNo = NewGridNo( pSoldier->sGridNo, (UINT16)DirectionInc( pSoldier->ubDirection ) );
-					ConvertMapPosToWorldTileCenter( pSoldier->sTempNewGridNo, &sXPos, &sYPos );
+					ConvertGridNoToCenterCellXY( pSoldier->sTempNewGridNo, &sXPos, &sYPos );
 					pSoldier->EVENT_SetSoldierPosition( (FLOAT)sXPos, (FLOAT)sYPos );
 				}
 
@@ -717,8 +717,7 @@ BOOLEAN AdjustToNextAnimationFrame( SOLDIERTYPE *pSoldier )
 
 				// CODE: End Hop Fence
 				// MOVE TO FORCASTED GRIDNO
-				sX = CenterX( pSoldier->sForcastGridno );
-				sY = CenterY( pSoldier->sForcastGridno );
+				ConvertGridNoToCenterCellXY(pSoldier->sForcastGridno, &sX, &sY);
 
 				pSoldier->EVENT_InternalSetSoldierPosition( (FLOAT) sX, (FLOAT) sY, FALSE, FALSE, FALSE );
 				pSoldier->EVENT_SetSoldierDirection(	gTwoCDirection[ pSoldier->ubDirection ] );

Tactical/Soldier Control.cpp

@@ -5041,8 +5041,10 @@ void SOLDIERTYPE::EVENT_FireSoldierWeapon( INT32 sTargetGridNo )
 						}
 						else if (!TileIsOutOfBounds(sTargetGridNo) && !GridNoOnScreen(sTargetGridNo))
 						{
-							INT16 sNewCenterWorldX = CenterX(sTargetGridNo);
-							INT16 sNewCenterWorldY = CenterY(sTargetGridNo);
+							INT16 sNewCenterWorldX;
+							INT16 sNewCenterWorldY;
+							ConvertGridNoToCenterCellXY(sTargetGridNo, &sNewCenterWorldX, &sNewCenterWorldY);
+
 							SetRenderCenter(sNewCenterWorldX, sNewCenterWorldY);
 
 							// Plot new path!
@@ -7359,7 +7361,7 @@ void SOLDIERTYPE::EVENT_InternalSetSoldierDestination( UINT16	usNewDirection, BO
 	// Get dest gridno, convert to center coords
 	sNewGridNo = NewGridNo( this->sGridNo, DirectionInc( (UINT8)usNewDirection ) );
 
-	ConvertMapPosToWorldTileCenter( sNewGridNo, &sXPos, &sYPos );
+	ConvertGridNoToCenterCellXY( sNewGridNo, &sXPos, &sYPos );
 
 	// Save new dest gridno, x, y
 	this->pathing.sDestination = sNewGridNo;
@@ -11544,7 +11546,7 @@ void SOLDIERTYPE::MoveMerc( FLOAT dMovementChange, FLOAT dAngle, BOOLEAN fCheckR
 				{
 					INT16 this_base_x = 0;
 					INT16 this_base_y = 0;
-					ConvertMapPosToWorldTileCenter( this->sGridNo, &this_base_x, &this_base_y );
+					ConvertGridNoToCenterCellXY( this->sGridNo, &this_base_x, &this_base_y );
 
 					dx = this->dXPos - this_base_x;
 					dy = this->dYPos - this_base_y;
@@ -11552,7 +11554,7 @@ void SOLDIERTYPE::MoveMerc( FLOAT dMovementChange, FLOAT dAngle, BOOLEAN fCheckR
 
 				INT16 base_x = 0;
 				INT16 base_y = 0;
-				ConvertMapPosToWorldTileCenter( gridnotouse, &base_x, &base_y );
+				ConvertGridNoToCenterCellXY( gridnotouse, &base_x, &base_y );
 
 				pSoldier->EVENT_InternalSetSoldierPosition( base_x + dx, base_y + dy, FALSE, FALSE, FALSE );
 			}
@@ -11586,27 +11588,33 @@ void SOLDIERTYPE::MoveMerc( FLOAT dMovementChange, FLOAT dAngle, BOOLEAN fCheckR
 				// adjust both gridno and x,y coordinates
 				if (sOldGridNo != this->sGridNo)
 				{
-					CorpseDef.sGridNo	= sOldGridNo;
-					CorpseDef.dXPos		= CenterX(CorpseDef.sGridNo);
-					CorpseDef.dYPos		= CenterY(CorpseDef.sGridNo);
+					INT16 sX, sY;
+					ConvertGridNoToCenterCellXY(sOldGridNo, &sX, &sY);
+
+					CorpseDef.sGridNo = sOldGridNo;
+					CorpseDef.dXPos = sX;
+					CorpseDef.dYPos	= sY;
 				}
 				else
 				{
 					// move corpse a bit
 					INT16 this_base_x = 0;
 					INT16 this_base_y = 0;
-					ConvertMapPosToWorldTileCenter(this->sGridNo, &this_base_x, &this_base_y);
+					ConvertGridNoToCenterCellXY(this->sGridNo, &this_base_x, &this_base_y);
 
 					FLOAT dx = this->dXPos - this_base_x;
 					FLOAT dy = this->dYPos - this_base_y;
 						
 					INT16 base_x = 0;
 					INT16 base_y = 0;
-					ConvertMapPosToWorldTileCenter(pCorpse->def.sGridNo, &base_x, &base_y);
+					ConvertGridNoToCenterCellXY(pCorpse->def.sGridNo, &base_x, &base_y);
+
+					INT16 sX, sY;
+					ConvertGridNoToCenterCellXY(pCorpse->def.sGridNo, &sX, &sY);
 
 					CorpseDef.sGridNo	= pCorpse->def.sGridNo;
-					CorpseDef.dXPos		= CenterX(CorpseDef.sGridNo) + dx;
-					CorpseDef.dYPos		= CenterY(CorpseDef.sGridNo) + dy;
+					CorpseDef.dXPos		= sX + dx;
+					CorpseDef.dYPos		= sY + dy;
 				}
 
 				CorpseDef.usFlags		|= ROTTING_CORPSE_USE_XY_PROVIDED;
@@ -11768,6 +11776,17 @@ UINT8 GetDirectionFromXY( INT16 sXPos, INT16 sYPos, SOLDIERTYPE *pSoldier )
 	return(atan8( sXPos2, sYPos2, sXPos, sYPos ));
 }
 
+INT16 GetDirectionFromCenterCellXYGridNo(INT32 EndGridNo, INT32 StartGridNo)
+{
+	INT16 sXPos2, sYPos2;
+	INT16 sXPos, sYPos;
+
+	ConvertGridNoToCenterCellXY(StartGridNo, &sXPos, &sYPos);
+	ConvertGridNoToCenterCellXY(EndGridNo, &sXPos2, &sYPos2);
+
+	return(atan8(sXPos2, sYPos2, sXPos, sYPos));
+}
+
 
 //#if 0
 UINT8 atan8( INT16 sXPos, INT16 sYPos, INT16 sXPos2, INT16 sYPos2 )
@@ -12261,8 +12280,7 @@ void SOLDIERTYPE::ReviveSoldier( void )
 		this->BeginSoldierGetup( );
 
 		// Makesure center of tile
-		sX = CenterX( this->sGridNo );
-		sY = CenterY( this->sGridNo );
+		ConvertGridNoToCenterCellXY(this->sGridNo, &sX, &sY);
 
 		this->EVENT_SetSoldierPosition( (FLOAT)sX, (FLOAT)sY );
 
@@ -13962,8 +13980,7 @@ void SOLDIERTYPE::EVENT_StopMerc( INT32 sGridNo, INT8 bDirection )
 
 	// MOVE GUY TO GRIDNO--- SHOULD BE THE SAME UNLESS IN MULTIPLAYER
 	// Makesure center of tile
-	sX = CenterX( sGridNo );
-	sY = CenterY( sGridNo );
+	ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
 
 	//Cancel pending events
 	if ( !this->flags.fDelayedMovement )
@@ -15862,7 +15879,7 @@ BOOLEAN		SOLDIERTYPE::SeemsLegit( UINT8 ubObserverID )
 	}
 
 	UINT8 covertlevel = NUM_SKILL_TRAITS( this, COVERT_NT );	// our level in covert operations
-	INT32 distance = GetRangeFromGridNoDiff( this->sGridNo, pSoldier->sGridNo );
+	INT32 distance = PythSpacesAway( this->sGridNo, pSoldier->sGridNo );
 
 	// if we are closer than this, our cover will always break if we do not have the skill
 	// if we have the skill, our cover will blow if we dress up as a soldier, but not if we are dressed like a civilian
@@ -20865,7 +20882,7 @@ void	SOLDIERTYPE::CancelDrag()
 		{
 			INT16 base_x = 0;
 			INT16 base_y = 0;
-			ConvertMapPosToWorldTileCenter(pSoldier->sGridNo, &base_x, &base_y);
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &base_x, &base_y);
 
 			pSoldier->EVENT_InternalSetSoldierPosition(base_x, base_y, FALSE, FALSE, FALSE);
 		}
@@ -23199,7 +23216,7 @@ BOOLEAN SOLDIERTYPE::PlayerSoldierStartTalking( UINT8 ubTargetID, BOOLEAN fValid
 			return(FALSE);
 		}
 
-		uiRange = GetRangeFromGridNoDiff( this->sGridNo, pTSoldier->sGridNo );
+		uiRange = PythSpacesAway( this->sGridNo, pTSoldier->sGridNo );
 
 		if ( uiRange > (NPC_TALK_RADIUS * 2) )
 		{

Tactical/Soldier Control.h

@@ -2204,7 +2204,8 @@ BOOLEAN GetDirectionChangeAmount( INT32 sGridNo, SOLDIERTYPE *pSoldier, UINT8 ui
 UINT8 GetDirectionFromGridNo( INT32 sGridNo, SOLDIERTYPE *pSoldier );
 UINT8 atan8( INT16 sXPos, INT16 sYPos, INT16 sXPos2, INT16 sYPos2 );
 UINT8 atan8FromAngle( DOUBLE dAngle );
-INT16 GetDirectionToGridNoFromGridNo( INT32 sGridNoDest, INT32 sGridNoSrc );
+INT16 GetDirectionToGridNoFromGridNo(INT32 sGridNoDest, INT32 sGridNoSrc);
+INT16 GetDirectionFromCenterCellXYGridNo(INT32 EndGridNo, INT32 StartGridNo);
 // This function is now obsolete.	Call ReduceAttackBusyCount instead.
 // void ReleaseSoldiersAttacker( SOLDIERTYPE *pSoldier );
 

Tactical/Soldier Find.cpp

@@ -814,8 +814,7 @@ BOOLEAN SoldierLocationRelativeToScreen( INT32 sGridNo, UINT16 usReasonID, INT8
 
 	*puiScrollFlags = 0;
 
-	sX = CenterX( sGridNo );
-	sY = CenterY( sGridNo );
+	ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
 
 	// Get screen coordinates for current position of soldier
 	GetWorldXYAbsoluteScreenXY( (INT16)(sX/CELL_X_SIZE), (INT16)(sY/CELL_Y_SIZE), &sWorldX, &sWorldY);
@@ -954,25 +953,28 @@ BOOLEAN FindRelativeSoldierPosition( SOLDIERTYPE *pSoldier, UINT16 *usFlags, INT
 					// Then, depending on whether this is the gridno we are looking at, this will be head or legs
 					if ( gGameExternalOptions.fAllowTargetHeadAndLegIfProne )
 					{
-						INT16 sWorldX, sWorldY;
+						INT16 sWorldX, sWorldY, sX, sY;
 						GetMouseWorldCoords( &sWorldX, &sWorldY );
 
 						// Flugente: we measure the distance of the bullet's location to the location of the soldier, and to the 2 gridnos his head and leg occupy
 						// From this we can decide what body part was hit
-						FLOAT bodycenterX = (FLOAT)CenterX( pSoldier->sGridNo );
-						FLOAT bodycenterY = (FLOAT)CenterY( pSoldier->sGridNo );
+						ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+						FLOAT bodycenterX = (FLOAT) sX;
+						FLOAT bodycenterY = (FLOAT) sY;
 
 						FLOAT difftobodycenter = sqrt( (bodycenterX - sWorldX) * (bodycenterX - sWorldX) + (bodycenterY - sWorldY) * (bodycenterY - sWorldY) );
 						
 						INT32 viewdirectiongridno = NewGridNo( pSoldier->sGridNo, DirectionInc( pSoldier->ubDirection ) );
-						FLOAT nextgridnocenterX = (FLOAT)CenterX( viewdirectiongridno );
-						FLOAT nextgridnocenterY = (FLOAT)CenterY( viewdirectiongridno );
+						ConvertGridNoToCenterCellXY(viewdirectiongridno, &sX, &sY);
+						FLOAT nextgridnocenterX = (FLOAT) sX;
+						FLOAT nextgridnocenterY = (FLOAT) sY;
 
 						FLOAT difftonextgridno = sqrt( (nextgridnocenterX - sWorldX) * (nextgridnocenterX - sWorldX) + (nextgridnocenterY - sWorldY) * (nextgridnocenterY - sWorldY) );
 						
 						INT32 oppositeviewdirectiongridno = NewGridNo( pSoldier->sGridNo, DirectionInc( gOppositeDirection[pSoldier->ubDirection] ) );
-						FLOAT oppositenextgridnocenterX = (FLOAT)CenterX( oppositeviewdirectiongridno );
-						FLOAT oppositenextgridnocenterY = (FLOAT)CenterY( oppositeviewdirectiongridno );
+						ConvertGridNoToCenterCellXY(oppositeviewdirectiongridno, &sX, &sY);
+						FLOAT oppositenextgridnocenterX = (FLOAT) sX;
+						FLOAT oppositenextgridnocenterY = (FLOAT) sY;
 
 						FLOAT difftooppositenextgridno = sqrt( (oppositenextgridnocenterX - sWorldX) * (oppositenextgridnocenterX - sWorldX) + (oppositenextgridnocenterY - sWorldY) * (oppositenextgridnocenterY - sWorldY) );
 
@@ -1030,13 +1032,15 @@ UINT8 QuickFindSoldier( INT32 sGridNo )
 
 void GetGridNoScreenPos( INT32 sGridNo, UINT8 ubLevel, INT16 *psScreenX, INT16 *psScreenY )
 {
-		INT16 sScreenX, sScreenY;
+		INT16 sScreenX, sScreenY, sX, sY;
 		FLOAT dOffsetX, dOffsetY;
 		FLOAT dTempX_S, dTempY_S;
 
+		ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+
 		// Get 'TRUE' merc position
-		dOffsetX = (FLOAT)( CenterX( sGridNo ) - gsRenderCenterX );
-		dOffsetY = (FLOAT)( CenterY( sGridNo ) - gsRenderCenterY );
+		dOffsetX = (FLOAT)( sX - gsRenderCenterX );
+		dOffsetY = (FLOAT)( sY - gsRenderCenterY );
 
 		// OK, DONT'T ASK... CONVERSION TO PROPER Y NEEDS THIS...
 		dOffsetX -= CELL_Y_SIZE;

Tactical/Soldier Tile.cpp

@@ -738,8 +738,7 @@ BOOLEAN TeleportSoldier( SOLDIERTYPE *pSoldier, INT32 sGridNo, BOOLEAN fForce )
 	if ( NewOKDestination( pSoldier, sGridNo, TRUE, 0 ) || fForce )
 	{
 		// TELEPORT TO THIS LOCATION!
-		sX = CenterX( sGridNo );
-		sY = CenterY( sGridNo );
+		ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
 		pSoldier->EVENT_SetSoldierPosition( (FLOAT) sX, (FLOAT) sY );
 
 		pSoldier->pathing.sFinalDestination = sGridNo;

Tactical/Tactical Save.cpp

@@ -1878,8 +1878,10 @@ BOOLEAN LoadRottingCorpsesFromTempCorpseFile( INT16 sMapX, INT16 sMapY, INT8 bMa
 			def.sGridNo = gMapInformation.sWestGridNo;
 		}
 		//Recalculate the dx,dy info
-		def.dXPos = CenterX( def.sGridNo );
-		def.dYPos = CenterY( def.sGridNo );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(def.sGridNo, &sX, &sY);
+		def.dXPos = sX;
+		def.dYPos = sY;
 		// If not from loading a save....
 		if( !(gTacticalStatus.uiFlags & LOADING_SAVED_GAME ) )
 		{
@@ -2737,15 +2739,14 @@ BOOLEAN AddDeadSoldierToUnLoadedSector( INT16 sMapX, INT16 sMapY, UINT8 bMapZ, S
 	memset( &Corpse, 0, sizeof( ROTTING_CORPSE_DEFINITION ) );
 
 	// Setup some values!
-	Corpse.ubBodyType							= pSoldier->ubBodyType;
-	Corpse.sGridNo								= sGridNo;
+	ConvertGridNoToCenterCellXY(sGridNo, &sXPos, &sYPos);
 
-	ConvertGridNoToXY( sGridNo, &sXPos, &sYPos );
-
-	Corpse.dXPos									= (FLOAT)( CenterX( sXPos ) );
-	Corpse.dYPos									= (FLOAT)( CenterY( sYPos ) );
-	Corpse.sHeightAdjustment			= pSoldier->sHeightAdjustment;
-	Corpse.bVisible								=	TRUE;
+	Corpse.ubBodyType			= pSoldier->ubBodyType;
+	Corpse.sGridNo				= sGridNo;
+	Corpse.dXPos				= (FLOAT)( sXPos );
+	Corpse.dYPos				= (FLOAT)( sYPos );
+	Corpse.sHeightAdjustment	= pSoldier->sHeightAdjustment;
+	Corpse.bVisible				=	TRUE;
 
 	SET_PALETTEREP_ID ( Corpse.HeadPal,		pSoldier->HeadPal );
 	SET_PALETTEREP_ID ( Corpse.VestPal,		pSoldier->VestPal );

Tactical/UI Cursors.cpp

@@ -676,8 +676,12 @@ UINT8 HandleActivatedTargetCursor( SOLDIERTYPE *pSoldier, INT32 usMapPos, BOOLEA
 						gCTHDisplay.iTargetGridNo = usMapPos;
 						
 						// Calculate distance to target
-						FLOAT dDeltaX = (FLOAT)(CenterX( pSoldier->sGridNo ) - CenterX( usMapPos ));
-						FLOAT dDeltaY = (FLOAT)(CenterY( pSoldier->sGridNo ) - CenterY( usMapPos ));
+						INT16 sX, sY, sXMap, sYMap;
+						ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+						ConvertGridNoToCenterCellXY(usMapPos, &sXMap, &sYMap);
+
+						FLOAT dDeltaX = (FLOAT)( sX - sXMap );
+						FLOAT dDeltaY = (FLOAT)( sY - sYMap );
 						FLOAT d2DDistance = sqrt((dDeltaX*dDeltaX)+(dDeltaY*dDeltaY));
 
 						CalcMagFactorSimple( pSoldier, d2DDistance, pSoldier->aiData.bShownAimTime, usMapPos );
@@ -782,8 +786,12 @@ UINT8 HandleActivatedTargetCursor( SOLDIERTYPE *pSoldier, INT32 usMapPos, BOOLEA
 						gbCtHBurstCount = 0;
 
 						// Calculate distance to target
-						FLOAT dDeltaX = (FLOAT)(CenterX( pSoldier->sGridNo ) - CenterX( usMapPos ));
-						FLOAT dDeltaY = (FLOAT)(CenterY( pSoldier->sGridNo ) - CenterY( usMapPos ));
+						INT16 sX, sY, sXMap, sYMap;
+						ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+						ConvertGridNoToCenterCellXY(usMapPos, &sXMap, &sYMap);
+
+						FLOAT dDeltaX = (FLOAT)(sX - sXMap);
+						FLOAT dDeltaY = (FLOAT)(sY - sYMap);
 						FLOAT d2DDistance = sqrt((dDeltaX*dDeltaX)+(dDeltaY*dDeltaY));
 
 						CalcMagFactorSimple( pSoldier, d2DDistance, pSoldier->aiData.bShownAimTime, usMapPos );
@@ -884,8 +892,12 @@ UINT8 HandleActivatedTargetCursor( SOLDIERTYPE *pSoldier, INT32 usMapPos, BOOLEA
 					gCTHDisplay.iTargetGridNo = usMapPos;
 
 					// Calculate distance to target
-					FLOAT dDeltaX = (FLOAT)(CenterX( pSoldier->sGridNo ) - CenterX( usMapPos ));
-					FLOAT dDeltaY = (FLOAT)(CenterY( pSoldier->sGridNo ) - CenterY( usMapPos ));
+					INT16 sX, sY, sXMap, sYMap;
+					ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+					ConvertGridNoToCenterCellXY(usMapPos, &sXMap, &sYMap);
+
+					FLOAT dDeltaX = (FLOAT)(sX - sXMap);
+					FLOAT dDeltaY = (FLOAT)(sY - sYMap);
 					FLOAT d2DDistance = sqrt((dDeltaX*dDeltaX)+(dDeltaY*dDeltaY));
 
 					CalcMagFactorSimple( pSoldier, d2DDistance, pSoldier->aiData.bShownAimTime, usMapPos );

Tactical/Vehicles.cpp

@@ -1787,7 +1787,9 @@ BOOLEAN ExitVehicle( SOLDIERTYPE *pSoldier )
 		pSoldier->aiData.bOppList[ pVehicle->ubID ] = 1;
 
 		// Add to sector....
-		pSoldier->EVENT_SetSoldierPosition( CenterX( sGridNo ), CenterY( sGridNo ) );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+		pSoldier->EVENT_SetSoldierPosition( sX, sY );
 
 		// anv: since now they can shoot it's important to set passenger to proper stance
 		// namely, back to standing, because we set them to crouching when entering
@@ -2064,7 +2066,9 @@ void HandleCriticalHitForVehicleInLocation( UINT8 ubID, INT16 sDmg, INT32 sGridN
 		pVehicleList[ ubID ].fDestroyed	= TRUE;
 
 		// Explode vehicle...
-		IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, GREAT_BIG_EXPLOSION, 0 );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+		IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, GREAT_BIG_EXPLOSION, 0 );
 
 		if ( pSoldier != NULL )
 		{

Tactical/Weapons.cpp

@@ -1714,7 +1714,7 @@ void GetTargetWorldPositions( SOLDIERTYPE *pSoldier, INT32 sTargetGridNo, FLOAT
 	FLOAT								dTargetZ;
 	SOLDIERTYPE*						pTargetSoldier = NULL;
 	INT8								bStructHeight;
-	INT16								sXMapPos, sYMapPos;
+	INT16								sXMapPos, sYMapPos, sX, sY;
 	UINT32							uiRoll;
 	INT8								bTargetCubeLevel = 0;
 	INT8								bTargetLevel = 0;
@@ -1731,8 +1731,9 @@ void GetTargetWorldPositions( SOLDIERTYPE *pSoldier, INT32 sTargetGridNo, FLOAT
 	{
 		// SAVE OPP ID
 		pSoldier->ubOppNum = pTargetSoldier->ubID;
-		dTargetX = (FLOAT) CenterX( pTargetSoldier->sGridNo );
-		dTargetY = (FLOAT) CenterY( pTargetSoldier->sGridNo );
+		ConvertGridNoToCenterCellXY(pTargetSoldier->sGridNo, &sX, &sY);
+		dTargetX = (FLOAT) sX;
+		dTargetY = (FLOAT) sY;
 		if (pSoldier->bAimShotLocation == AIM_SHOT_RANDOM)
 		{
 			uiRoll = PreRandom( 100 );
@@ -1773,9 +1774,11 @@ void GetTargetWorldPositions( SOLDIERTYPE *pSoldier, INT32 sTargetGridNo, FLOAT
 					if ( gGameExternalOptions.fAllowTargetHeadAndLegIfProne && gAnimControl[pTargetSoldier->usAnimState].ubHeight == ANIM_PRONE )
 					{
 						INT32 viewdirectiongridno = NewGridNo( pTargetSoldier->sGridNo, DirectionInc( pTargetSoldier->ubDirection ) );
+						INT16 sX, sY;
+						ConvertGridNoToCenterCellXY(viewdirectiongridno, &sX, &sY);
 
-						dTargetX = (0.3f * dTargetX + 0.7f * (FLOAT)CenterX( viewdirectiongridno )) / 1.0f;
-						dTargetY = (0.3f * dTargetY + 0.7f * (FLOAT)CenterY( viewdirectiongridno )) / 1.0f;
+						dTargetX = (0.3f * dTargetX + 0.7f * (FLOAT)sX) / 1.0f;
+						dTargetY = (0.3f * dTargetY + 0.7f * (FLOAT)sY) / 1.0f;
 					}
 				}
 				break;
@@ -1789,9 +1792,11 @@ void GetTargetWorldPositions( SOLDIERTYPE *pSoldier, INT32 sTargetGridNo, FLOAT
 					if ( gGameExternalOptions.fAllowTargetHeadAndLegIfProne && gAnimControl[pTargetSoldier->usAnimState].ubHeight == ANIM_PRONE )
 					{
 						INT32 viewdirectiongridno = NewGridNo( pTargetSoldier->sGridNo, DirectionInc( gOppositeDirection[pTargetSoldier->ubDirection] ) );
+						INT16 sX, sY;
+						ConvertGridNoToCenterCellXY(viewdirectiongridno, &sX, &sY);
 
-						dTargetX = (0.3f * dTargetX + 0.7f * (FLOAT)CenterX( viewdirectiongridno )) / 1.0f;
-						dTargetY = (0.3f * dTargetY + 0.7f * (FLOAT)CenterY( viewdirectiongridno )) / 1.0f;
+						dTargetX = (0.3f * dTargetX + 0.7f * (FLOAT)sX) / 1.0f;
+						dTargetY = (0.3f * dTargetY + 0.7f * (FLOAT)sY) / 1.0f;
 					}
 				}
 				break;
@@ -2718,11 +2723,14 @@ BOOLEAN UseGunNCTH( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 	{
 		if ( WillExplosiveWeaponFail( pSoldier, pObjHand ) )
 		{
+			INT16 sX, sY;
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+
 			if ( Item[usUBItem].singleshotrocketlauncher  )
 			{
 				CreateItem( Item[usItemNum].discardedlauncheritem , (*pObjHand)[0]->data.objectStatus, pObjHand );
 				
-				// Flugente: why would we keep a piece of scrap in our ahnds in the first place? just drop it to the ground
+				// Flugente: why would we keep a piece of scrap in our hands in the first place? just drop it to the ground
 				AddItemToPool( pSoldier->sGridNo, pObjHand, 1, pSoldier->pathing.bLevel, 0, -1 );
 
 				// Delete object
@@ -2730,20 +2738,21 @@ BOOLEAN UseGunNCTH( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 
 				DirtyMercPanelInterface( pSoldier, DIRTYLEVEL2 );
 
+
 				if ( Item[usUBItem].usBuddyItem != 0 && Item[Item[usUBItem].usBuddyItem].usItemClass & IC_EXPLOSV )
 				{
-					IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, Item[usUBItem].usBuddyItem, pSoldier->pathing.bLevel );
+					IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, Item[usUBItem].usBuddyItem, pSoldier->pathing.bLevel );
 				}
 				else
 				{
-					IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
+					IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
 				}
 			}
 			else
 			{
 				DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String("StructureHit: RPG7 item: %d, Ammo: %d", usUBItem , (*pObjHand)[0]->data.gun.usGunAmmoItem ) );
 
-				IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, (*pObjHand)[0]->data.gun.usGunAmmoItem, pSoldier->pathing.bLevel );
+				IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, (*pObjHand)[0]->data.gun.usGunAmmoItem, pSoldier->pathing.bLevel );
 				pSoldier->inv[pSoldier->ubAttackingHand ][0]->data.gun.usGunAmmoItem = NONE;
 			}
 		  // Reduce again for attack end 'cause it has been incremented for a normal attack
@@ -2893,8 +2902,8 @@ BOOLEAN UseGunNCTH( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 		{
 			sTempGridNo = NewGridNo(sTempGridNo, DirectionInc(pSoldier->ubDirection));
 		}
-		INT16 sX = CenterX(sTempGridNo);
-		INT16 sY = CenterY(sTempGridNo);
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(sTempGridNo, &sX, &sY);
 
 		AniParams.sGridNo = pSoldier->sGridNo;
 		AniParams.ubLevelID = ANI_TOPMOST_LEVEL;
@@ -3643,6 +3652,9 @@ BOOLEAN UseGun( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 	{
 		if ( WillExplosiveWeaponFail( pSoldier, pObjUsed ) )
 		{
+			INT16 sX, sY;
+			ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+
 			if ( Item[usUBItem].singleshotrocketlauncher  )
 			{
 				CreateItem( Item[usUBItem].discardedlauncheritem , (*pObjUsed)[0]->data.objectStatus, pObjUsed );
@@ -3655,20 +3667,21 @@ BOOLEAN UseGun( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 
 				DirtyMercPanelInterface( pSoldier, DIRTYLEVEL2 );
 
+
 				if ( Item[usUBItem].usBuddyItem != 0 && Item[Item[usUBItem].usBuddyItem].usItemClass & IC_EXPLOSV )
 				{
-					IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
+					IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
 				}
 				else
 				{
-					IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
+					IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, C1, pSoldier->pathing.bLevel );
 				}
 			}
 			else
 			{
 				DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String("StructureHit: RPG7 item: %d, Ammo: %d", usUBItem , (*pObjUsed)[0]->data.gun.usGunAmmoItem ) );
 
-				IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, (*pObjUsed)[0]->data.gun.usGunAmmoItem, pSoldier->pathing.bLevel );
+				IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, (*pObjUsed)[0]->data.gun.usGunAmmoItem, pSoldier->pathing.bLevel );
 			
 				OBJECTTYPE * pLaunchable = FindLaunchableAttachment( pObjUsed, usUBItem );
 				if(pLaunchable)
@@ -3708,8 +3721,8 @@ BOOLEAN UseGun( SOLDIERTYPE *pSoldier , INT32 sTargetGridNo )
 		{
 			sTempGridNo = NewGridNo(sTempGridNo, DirectionInc(pSoldier->ubDirection));
 		}
-		INT16 sX = CenterX(sTempGridNo);
-		INT16 sY = CenterY(sTempGridNo);
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(sTempGridNo, &sX, &sY);
 
 		AniParams.sGridNo = pSoldier->sGridNo;
 		AniParams.ubLevelID = ANI_TOPMOST_LEVEL;
@@ -5167,7 +5180,9 @@ BOOLEAN UseLauncher( SOLDIERTYPE *pSoldier, INT32 sTargetGridNo )
 
 		// So we still should have ABC > 0
 		// Begin explosion due to failure...
-		IgniteExplosion( pSoldier->ubID, CenterX( pSoldier->sGridNo ), CenterY( pSoldier->sGridNo ), 0, pSoldier->sGridNo, Launchable.usItem, pSoldier->pathing.bLevel );
+		INT16 sX, sY;
+		ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+		IgniteExplosion( pSoldier->ubID, sX, sY, 0, pSoldier->sGridNo, Launchable.usItem, pSoldier->pathing.bLevel );
 
 		// Reduce again for attack end 'cause it has been incremented for a normal attack
 		// Nope, not anymore.
@@ -5676,15 +5691,18 @@ void StructureHit( INT32 iBullet, UINT16 usWeaponIndex, INT16 bWeaponStatus, UIN
 			// HEADROCK HAM 5: Fragments fired by such weapons should not explode. 
 			if ( pBullet->fFragment == false)
 			{
+				INT16 sX, sY;
+				ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+
 				if ( Item[usWeaponIndex].singleshotrocketlauncher )
 				{
 					if ( Item[usWeaponIndex].usBuddyItem != 0 && Item[Item[usWeaponIndex].usBuddyItem].usItemClass & IC_EXPLOSV )
 					{
-						IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, Item[usWeaponIndex].usBuddyItem, bLevel, usDirection );
+						IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, Item[usWeaponIndex].usBuddyItem, bLevel, usDirection );
 					}
 					else
 					{
-						IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, C1, bLevel, usDirection );
+						IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, C1, bLevel, usDirection );
 					}
 				}
 				// changed too to use 2 flag to determine
@@ -5692,7 +5710,7 @@ void StructureHit( INT32 iBullet, UINT16 usWeaponIndex, INT16 bWeaponStatus, UIN
 					//there shouldn't be a way to enter here with an UnderBarrel weapon, so retaining original code :JMich
 				{
 					DebugMsg( TOPIC_JA2, DBG_LEVEL_3, String("StructureHit: RPG7 item: %d, Ammo: %d",pAttacker->inv[HANDPOS].usItem , pAttacker->inv[HANDPOS][0]->data.gun.usGunAmmoItem ) );
-					IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, pAttacker->inv[pAttacker->ubAttackingHand][0]->data.gun.usGunAmmoItem, bLevel, usDirection );
+					IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, pAttacker->inv[pAttacker->ubAttackingHand][0]->data.gun.usGunAmmoItem, bLevel, usDirection );
 					
 					//This is just to make multishot launchers work in semi auto. It's not really a permanent solution because it still doesn't allow autofire, but it will do for now.
 					OBJECTTYPE * pLaunchable = FindLaunchableAttachment( &(pAttacker->inv[pAttacker->ubAttackingHand ]), pAttacker->inv[pAttacker->ubAttackingHand ].usItem );
@@ -5708,7 +5726,7 @@ void StructureHit( INT32 iBullet, UINT16 usWeaponIndex, INT16 bWeaponStatus, UIN
 				else if ( AmmoTypes[(*pObj)[0]->data.gun.ubGunAmmoType].explosionSize > 1)
 				{
 					// re-routed the Highexplosive value to define exposion type
-					IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, AmmoTypes[(*pObj)[0]->data.gun.ubGunAmmoType].highExplosive, bLevel, usDirection );
+					IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, AmmoTypes[(*pObj)[0]->data.gun.ubGunAmmoType].highExplosive, bLevel, usDirection );
 					// pSoldier->inv[pSoldier->ubAttackingHand ][0]->data.gun.usGunAmmoItem = NONE;
 				}
 			}
@@ -5726,7 +5744,9 @@ void StructureHit( INT32 iBullet, UINT16 usWeaponIndex, INT16 bWeaponStatus, UIN
 			//FreeUpAttacker( ubAttackerID );
 
 			// HEADROCK HAM 5 TODO: Tank shell!!
-			IgniteExplosion( ubAttackerID, CenterX( sGridNo ), CenterY( sGridNo ), 0, sGridNo, TANK_SHELL, bLevel, usDirection );
+			INT16 sX, sY;
+			ConvertGridNoToCenterCellXY(sGridNo, &sX, &sY);
+			IgniteExplosion( ubAttackerID, sX, sY, 0, sGridNo, TANK_SHELL, bLevel, usDirection );
 			//FreeUpAttacker( (UINT8) ubAttackerID );
 
 			// Moved here to keep ABC >0 as long as possible
@@ -6250,7 +6270,7 @@ UINT32 CalcNewChanceToHitGun(SOLDIERTYPE *pSoldier, INT32 sGridNo, INT16 ubAimTi
 	// Basic defines
 	SOLDIERTYPE * pTarget;
 	INT32 iRange, iSightRange; //, minRange;
-
+	INT16 sX, sY, sX2, sY2;
 	UINT16	usInHand;
 	OBJECTTYPE * pInHand;
 	INT16	sDistVis, sDistVisNoScope;
@@ -6270,8 +6290,11 @@ UINT32 CalcNewChanceToHitGun(SOLDIERTYPE *pSoldier, INT32 sGridNo, INT16 ubAimTi
 
 	// calculate actual range (in units, 10 units = 1 tile)
 	iRange = GetRangeInCellCoordsFromGridNoDiff( pSoldier->sGridNo, sGridNo );
-	FLOAT dDeltaX = (FLOAT)(CenterX( pSoldier->sGridNo ) - CenterX( sGridNo ));
-	FLOAT dDeltaY = (FLOAT)(CenterY( pSoldier->sGridNo ) - CenterY( sGridNo ));
+
+	ConvertGridNoToCenterCellXY(pSoldier->sGridNo, &sX, &sY);
+	ConvertGridNoToCenterCellXY(sGridNo, &sX2, &sY2);
+	FLOAT dDeltaX = (FLOAT)( sX - sX2 );
+	FLOAT dDeltaY = (FLOAT)( sY - sY2 );
 	FLOAT d2DDistance = sqrt((dDeltaX*dDeltaX)+(dDeltaY*dDeltaY));
 
 	// Find a target in the tile

Tactical/opplist.cpp

@@ -6130,10 +6130,8 @@ void ProcessNoise(UINT8 ubNoiseMaker, INT32 sGridNo, INT8 bLevel, UINT8 ubTerrTy
 			{
 				// ALL RIGHT!	Passed all the tests, this listener hears this noise!!!
 				HearNoise(pSoldier,ubSource,sGridNo,bLevel,ubEffVolume,ubNoiseType, (UINT8 *)&bSeen);
-
 				bHeard = TRUE;
-
-				ubNoiseDir = atan8(CenterX(pSoldier->sGridNo),CenterY(pSoldier->sGridNo),CenterX(sGridNo),CenterY(sGridNo));
+				ubNoiseDir = GetDirectionFromCenterCellXYGridNo(pSoldier->sGridNo, sGridNo);
 
 				// check the 'noise heard & reported' bit for that soldier & direction
 				if ( ubNoiseType != NOISE_MOVEMENT || bTeam != OUR_TEAM || (pSoldier->aiData.bInterruptDuelPts != NO_INTERRUPT) || !(pSoldier->ubMovementNoiseHeard & (1 << ubNoiseDir) ) )
@@ -6441,8 +6439,7 @@ void HearNoise(SOLDIERTYPE *pSoldier, UINT8 ubNoiseMaker, INT32 sGridNo, INT8 bL
 	// ignore muzzle flashes when turning head to see noise
 	if ( ubNoiseType == NOISE_GUNFIRE && ubNoiseMaker != NOBODY && MercPtrs[ ubNoiseMaker ]->flags.fMuzzleFlash )
 	{
-		sNoiseX = CenterX(sGridNo);
-		sNoiseY = CenterY(sGridNo);
+		ConvertGridNoToCenterCellXY(sGridNo, &sNoiseX, &sNoiseY);
 		bDirection = atan8(pSoldier->sX,pSoldier->sY,sNoiseX,sNoiseY);
 		if ( pSoldier->ubDirection != bDirection && pSoldier->ubDirection != gOneCDirection[ bDirection ] && pSoldier->ubDirection != gOneCCDirection[ bDirection ] )
 		{
@@ -6463,8 +6460,7 @@ void HearNoise(SOLDIERTYPE *pSoldier, UINT8 ubNoiseMaker, INT32 sGridNo, INT8 bL
 	if (PythSpacesAway(pSoldier->sGridNo,sGridNo) <= sDistVisible )
 	{
 		// just use the XXadjustedXX center of the gridno
-		sNoiseX = CenterX(sGridNo);
-		sNoiseY = CenterY(sGridNo);
+		ConvertGridNoToCenterCellXY(sGridNo, &sNoiseX, &sNoiseY);
 
 		if (pSoldier->ubDirection != atan8(pSoldier->sX,pSoldier->sY,sNoiseX,sNoiseY))
 		{