Fix spell rendering

Source/engine.cpp

@@ -187,10 +187,9 @@ void CelDecodeHdrOnly(BYTE *pBuff, BYTE *pCelBuff, int nCel, int nWidth, int Cel
 	CelDrawDatOnly(pBuff, pRLEBytes + nDataStart, nDataSize, nWidth);
 }
 
-void CelDecDatLightOnly(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth)
+void CelDecDatLightOnly(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth, BYTE *tbl)
 {
 	int w;
-	BYTE *tbl;
 
 	/// ASSERT: assert(pDecodeTo != NULL);
 	if (!pDecodeTo)
@@ -205,7 +204,8 @@ void CelDecDatLightOnly(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWi
 
 	src = pRLEBytes;
 	dst = pDecodeTo;
-	tbl = &pLightTbl[light_table_index * 256];
+	if (!tbl)
+		tbl = &pLightTbl[light_table_index * 256];
 	w = nWidth;
 
 	for (; src != &pRLEBytes[nDataSize]; dst -= BUFFER_WIDTH + w) {

Source/engine.h

@@ -16,7 +16,7 @@ void CelDecodeOnly(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
 void CelDecDatOnly(BYTE *pBuff, BYTE *pCelBuff, int nCel, int nWidth);
 void CelDrawHdrOnly(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, int CelSkip, int CelCap);
 void CelDecodeHdrOnly(BYTE *pBuff, BYTE *pCelBuff, int nCel, int nWidth, int CelSkip, int CelCap);
-void CelDecDatLightOnly(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth);
+void CelDecDatLightOnly(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth, BYTE *tbl = NULL);
 void CelDecDatLightTrans(BYTE *pDecodeTo, BYTE *pRLEBytes, int nDataSize, int nWidth);
 void CelDecodeLightOnly(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth);
 void CelDecodeHdrLightOnly(int sx, int sy, BYTE *pCelBuff, int nCel, int nWidth, int CelSkip, int CelCap);