5 files changed, 16 insertions, 20 deletions

diff --git a/engines/lab/anim.cpp b/engines/lab/anim.cpp
index 4927b25eae..fef1edfa4c 100644
--- a/engines/lab/anim.cpp
+++ b/engines/lab/anim.cpp
@@ -37,7 +37,6 @@ Anim::Anim(LabEngine *vm) : _vm(vm) {
 	_header = 0;
 	_curBit = 0;
 	_numChunks = 1;
-	_isBM = false;
 	_headerdata._width = 0;
 	_headerdata._height = 0;
 	_headerdata._fps = 0;
@@ -78,7 +77,7 @@ void Anim::readBlock(void *Buffer, uint32 Size, byte **File) {
 	(*File) += Size;
 }
 
-void Anim::diffNextFrame() {
+void Anim::diffNextFrame(bool onlyDiffData) {
 	if (_header == 65535)  /* Already done. */
 		return;
 
@@ -96,7 +95,7 @@ void Anim::diffNextFrame() {
 		if (_curBit >= _numChunks) {
 			_vm->_event->mouseShow();
 
-			if (!_isBM) {
+			if (!onlyDiffData) {
 				if (_headerdata._fps) {
 					_vm->waitForTime(_waitSec, _waitMicros);
 					_vm->addCurTime(0L, _delayMicros, &_waitSec, &_waitMicros);
@@ -110,7 +109,7 @@ void Anim::diffNextFrame() {
 				_donePal = true;
 			}
 
-			if (_isPal && !_noPalChange && !_isBM && !_donePal) {
+			if (_isPal && !_noPalChange && !onlyDiffData && !_donePal) {
 				_vm->_graphics->setPalette(_diffPalette, 256);
 				_isPal = false;
 			}
@@ -147,7 +146,7 @@ void Anim::diffNextFrame() {
 		case 10L:
 			_rawDiffBM._planes[_curBit] = _diffFile;
 
-			if (_isBM)
+			if (onlyDiffData)
 				_diffFile += _size;
 			else {
 				readBlock(DrawBitMap->_planes[_curBit], _size, &_diffFile);
@@ -246,7 +245,7 @@ void Anim::diffNextFrame() {
 /**
  * A separate task launched by readDiff.  Plays the DIFF.
  */
-void Anim::playDiff(byte *buffer) {
+void Anim::playDiff(byte *buffer, bool onlyDiffData) {
 	_waitSec = 0L;
 	_waitMicros = 0L;
 	_delayMicros = 0L;
@@ -325,9 +324,9 @@ void Anim::playDiff(byte *buffer) {
 
 	if (_playOnce) {
 		while (_header != 65535)
-			diffNextFrame();
+			diffNextFrame(onlyDiffData);
 	} else
-		diffNextFrame();
+		diffNextFrame(onlyDiffData);
 }
 
 /**
@@ -354,9 +353,9 @@ void Anim::stopDiffEnd() {
 /**
  * Reads in a DIFF file.
  */
-bool Anim::readDiff(byte *buffer, bool playOnce) {
+bool Anim::readDiff(byte *buffer, bool playOnce, bool onlyDiffData) {
 	_playOnce = playOnce;
-	playDiff(buffer);
+	playDiff(buffer, onlyDiffData);
 	return true;
 }
 
diff --git a/engines/lab/anim.h b/engines/lab/anim.h
index 121edea20e..82732f063f 100644
--- a/engines/lab/anim.h
+++ b/engines/lab/anim.h
@@ -86,21 +86,20 @@ private:
 	BitMap *DrawBitMap;
 
 	void readBlock(void *Buffer, uint32 Size, byte **File);
-	void playDiff(byte *buffer);
+	void playDiff(byte *buffer, bool onlyDiffData = false);
 
 public:
 	Anim(LabEngine *vm);
 
 	DIFFHeader _headerdata;
 	char _diffPalette[256 * 3];
-	bool _isBM;          /* Just fill in the RawDIFFBM structure */
 	bool _waitForEffect; /* Wait for each sound effect to finish before continuing. */
 	bool _doBlack;       /* Black the screen before new picture  */
 	bool _noPalChange;   /* Don't change the palette.            */
 	BitMap _rawDiffBM;
 
-	bool readDiff(byte *buffer, bool playOnce);
-	void diffNextFrame();
+	bool readDiff(byte *buffer, bool playOnce, bool onlyDiffData = false);
+	void diffNextFrame(bool onlyDiffData = false);
 	void stopDiff();
 	void stopDiffEnd();
 };
diff --git a/engines/lab/graphics.cpp b/engines/lab/graphics.cpp
index 926dc7ce6d..0d4501ea52 100644
--- a/engines/lab/graphics.cpp
+++ b/engines/lab/graphics.cpp
@@ -77,7 +77,7 @@ void DisplayMan::loadPict(const char *filename) {
 /**
  * Reads in a picture into the dest bitmap.
  */
-void DisplayMan::readPict(const char *filename, bool playOnce) {
+void DisplayMan::readPict(const char *filename, bool playOnce, bool onlyDiffData) {
 	_vm->_anim->stopDiff();
 
 	loadPict(filename);
@@ -91,7 +91,7 @@ void DisplayMan::readPict(const char *filename, bool playOnce) {
 	_dispBitMap._rows        = _screenHeight;
 	_dispBitMap._flags       = BITMAPF_VIDEO;
 
-	_vm->_anim->readDiff(_curBitmap, playOnce);
+	_vm->_anim->readDiff(_curBitmap, playOnce, onlyDiffData);
 }
 
 /**
diff --git a/engines/lab/graphics.h b/engines/lab/graphics.h
index 9c25295343..8798718529 100644
--- a/engines/lab/graphics.h
+++ b/engines/lab/graphics.h
@@ -75,7 +75,7 @@ public:
 	virtual ~DisplayMan();
 
 	void loadPict(const char *filename);
-	void readPict(const char *filename, bool playOnce);
+	void readPict(const char *filename, bool playOnce, bool onlyDiffData = false);
 	void freePict();
 	byte *readPictToMem(const char *filename, uint16 x, uint16 y);
 	void doScrollBlack();
diff --git a/engines/lab/transitions.cpp b/engines/lab/transitions.cpp
index 6f90718eda..c611266020 100644
--- a/engines/lab/transitions.cpp
+++ b/engines/lab/transitions.cpp
@@ -147,10 +147,8 @@ void DisplayMan::doScrollWipe(char *filename) {
 		_vm->waitTOF();
 	}
 
-	_vm->_anim->_isBM = true;
-	readPict(filename, true);
+	readPict(filename, true, true);
 	setPalette(_vm->_anim->_diffPalette, 256);
-	_vm->_anim->_isBM = false;
 	byte *mem = _vm->_anim->_rawDiffBM._planes[0];
 
 	_vm->_music->updateMusic();