LAB: Use a local buffer for moving tiles in the tile puzzle

This fixes the crash when a tile is moved

5 files changed, 21 insertions, 15 deletions

diff --git a/engines/lab/dispman.cpp b/engines/lab/dispman.cpp
index df42f173ef..199c9e04c8 100644
--- a/engines/lab/dispman.cpp
+++ b/engines/lab/dispman.cpp
@@ -53,7 +53,6 @@ DisplayMan::DisplayMan(LabEngine *vm) : _vm(vm) {
 	_curBitmap = nullptr;
 	_displayBuffer = nullptr;
 	_currentDisplayBuffer = nullptr;
-	_tempScrollData = nullptr;
 	FadePalette = nullptr;
 
 	_screenWidth = 0;
diff --git a/engines/lab/dispman.h b/engines/lab/dispman.h
index 5ce4923ec4..dbeeefc1c1 100644
--- a/engines/lab/dispman.h
+++ b/engines/lab/dispman.h
@@ -66,7 +66,6 @@ private:
 	byte _curapen;
 	byte *_curBitmap;
 	byte _curvgapal[256 * 3];
-	byte *_tempScrollData;
 
 public:
 	DisplayMan(LabEngine *lab);
@@ -141,8 +140,8 @@ public:
 	void setPalette(void *cmap, uint16 numcolors);
 	void overlayRect(uint16 pencolor, uint16 x1, uint16 y1, uint16 x2, uint16 y2);
 	byte *getCurrentDrawingBuffer();
-	void scrollDisplayX(int16 dx, uint16 x1, uint16 y1, uint16 x2, uint16 y2);
-	void scrollDisplayY(int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2);
+	void scrollDisplayX(int16 dx, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer);
+	void scrollDisplayY(int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer);
 	void fade(bool fadein, uint16 res);
 	void closeFont(TextFont *tf);
 	uint16 textLength(TextFont *tf, const char *text, uint16 numchars);
diff --git a/engines/lab/lab.h b/engines/lab/lab.h
index a1a5bb0617..ac27c94d93 100644
--- a/engines/lab/lab.h
+++ b/engines/lab/lab.h
@@ -219,7 +219,7 @@ private:
 	void showTile(const char *filename, bool showsolution);
 	void doTileScroll(uint16 col, uint16 row, uint16 scrolltype);
 	void changeCombination(uint16 number);
-	void scrollRaster(int16 dx, int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2);
+	void scrollRaster(int16 dx, int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer);
 	void doCombination();
 	void showCombination(const char *filename);
 	void initTilePuzzle();
diff --git a/engines/lab/tilepuzzle.cpp b/engines/lab/tilepuzzle.cpp
index db3027765b..652c633c61 100644
--- a/engines/lab/tilepuzzle.cpp
+++ b/engines/lab/tilepuzzle.cpp
@@ -281,19 +281,23 @@ void LabEngine::doTileScroll(uint16 col, uint16 row, uint16 scrolltype) {
 	uint16 x1 = _utils->vgaScaleX(100) + (col * _utils->vgaScaleX(30)) + dx;
 	uint16 y1 = _utils->vgaScaleY(25) + (row * _utils->vgaScaleY(25)) + dy;
 
+	byte *buffer = new byte[_tiles[1]->_width * _tiles[1]->_height * 2L];
+
 	for (uint16 i = 0; i < last; i++) {
 		waitTOF();
-		scrollRaster(dX, dY, x1, y1, x1 + _utils->vgaScaleX(28) + sx, y1 + _utils->vgaScaleY(23) + sy);
+		scrollRaster(dX, dY, x1, y1, x1 + _utils->vgaScaleX(28) + sx, y1 + _utils->vgaScaleY(23) + sy, buffer);
 		x1 += dX;
 		y1 += dY;
 	}
+
+	delete[] buffer;
 }
 
 /**
  * Changes the combination number of one of the slots
  */
 void LabEngine::changeCombination(uint16 number) {
-	static const int solution[6] = { 0, 4, 0, 8, 7, 2 };
+	const int solution[6] = { 0, 4, 0, 8, 7, 2 };
 
 	Image display;
 	uint16 combnum;
@@ -310,6 +314,8 @@ void LabEngine::changeCombination(uint16 number) {
 	display._width     = _graphics->_screenWidth;
 	display._height    = _graphics->_screenHeight;
 
+	byte *buffer = new byte[_tiles[1]->_width * _tiles[1]->_height * 2L];
+
 	for (uint16 i = 1; i <= (_numberImages[combnum]->_height / 2); i++) {
 		if (_isHiRes) {
 			if (i & 1)
@@ -318,10 +324,12 @@ void LabEngine::changeCombination(uint16 number) {
 			waitTOF();
 
 		display._imageData = _graphics->getCurrentDrawingBuffer();
-		_graphics->scrollDisplayY(2, _utils->vgaScaleX(COMBINATION_X[number]), _utils->vgaScaleY(65), _utils->vgaScaleX(COMBINATION_X[number]) + (_numberImages[combnum])->_width - 1, _utils->vgaScaleY(65) + (_numberImages[combnum])->_height);
+		_graphics->scrollDisplayY(2, _utils->vgaScaleX(COMBINATION_X[number]), _utils->vgaScaleY(65), _utils->vgaScaleX(COMBINATION_X[number]) + (_numberImages[combnum])->_width - 1, _utils->vgaScaleY(65) + (_numberImages[combnum])->_height, buffer);
 		_numberImages[combnum]->blitBitmap(0, (_numberImages[combnum])->_height - (2 * i), &(display), _utils->vgaScaleX(COMBINATION_X[number]), _utils->vgaScaleY(65), (_numberImages[combnum])->_width, 2, false);
 	}
 
+	delete[] buffer;
+
 	for (uint16 i = 0; i < 6; i++)
 		unlocked &= (_combination[i] == solution[i]);
 
@@ -331,12 +339,12 @@ void LabEngine::changeCombination(uint16 number) {
 		_conditions->exclElement(COMBINATIONUNLOCKED);
 }
 
-void LabEngine::scrollRaster(int16 dx, int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2) {
+void LabEngine::scrollRaster(int16 dx, int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer) {
 	if (dx)
-		_graphics->scrollDisplayX(dx, x1, y1, x2, y2);
+		_graphics->scrollDisplayX(dx, x1, y1, x2, y2, buffer);
 
 	if (dy)
-		_graphics->scrollDisplayY(dy, x1, y1, x2, y2);
+		_graphics->scrollDisplayY(dy, x1, y1, x2, y2, buffer);
 }
 
 /**
diff --git a/engines/lab/transitions.cpp b/engines/lab/transitions.cpp
index b2f07fc60b..7c0b99dc53 100644
--- a/engines/lab/transitions.cpp
+++ b/engines/lab/transitions.cpp
@@ -387,10 +387,10 @@ void DisplayMan::blackAllScreen() {
  * The _tempScrollData variable must be initialized to some memory, or this
  * function will fail.
  */
-void DisplayMan::scrollDisplayX(int16 dx, uint16 x1, uint16 y1, uint16 x2, uint16 y2) {
+void DisplayMan::scrollDisplayX(int16 dx, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer) {
 	Image im;
 
-	im._imageData = _tempScrollData;
+	im._imageData = buffer;
 
 	if (x1 > x2)
 		SWAP<uint16>(x1, x2);
@@ -411,10 +411,10 @@ void DisplayMan::scrollDisplayX(int16 dx, uint16 x1, uint16 y1, uint16 x2, uint1
 /**
  * Scrolls the display in the y direction by blitting.
  */
-void DisplayMan::scrollDisplayY(int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2) {
+void DisplayMan::scrollDisplayY(int16 dy, uint16 x1, uint16 y1, uint16 x2, uint16 y2, byte *buffer) {
 	Image im;
 
-	im._imageData = _tempScrollData;
+	im._imageData = buffer;
 
 	if (x1 > x2)
 		SWAP<uint16>(x1, x2);