LAB: Refactor readPictToMem()

This fixes crashes in the teleporter and the journal, and plugs several
memory leaks

5 files changed, 46 insertions, 74 deletions

diff --git a/engines/lab/anim.cpp b/engines/lab/anim.cpp
index 936c49223c..20d1473c67 100644
--- a/engines/lab/anim.cpp
+++ b/engines/lab/anim.cpp
@@ -82,13 +82,13 @@ void Anim::diffNextFrame(bool onlyDiffData) {
 		// Already done.
 		return;
 
-	if (_vm->_graphics->_dispBitMap->_drawOnScreen) {
-		_vm->_graphics->_dispBitMap->_planes[0] = _vm->_graphics->getCurrentDrawingBuffer();
-		_vm->_graphics->_dispBitMap->_planes[1] = _vm->_graphics->_dispBitMap->_planes[0] + 0x10000;
-		_vm->_graphics->_dispBitMap->_planes[2] = _vm->_graphics->_dispBitMap->_planes[1] + 0x10000;
-		_vm->_graphics->_dispBitMap->_planes[3] = _vm->_graphics->_dispBitMap->_planes[2] + 0x10000;
-		_vm->_graphics->_dispBitMap->_planes[4] = _vm->_graphics->_dispBitMap->_planes[3] + 0x10000;
-	}
+	if (_vm->_graphics->_dispBitMap->_drawOnScreen)
+		_vm->_graphics->_dispBitMap->_planes[0] = _vm->_graphics->getCurrentDrawingBuffer();	
+
+	_vm->_graphics->_dispBitMap->_planes[1] = _vm->_graphics->_dispBitMap->_planes[0] + 0x10000;
+	_vm->_graphics->_dispBitMap->_planes[2] = _vm->_graphics->_dispBitMap->_planes[1] + 0x10000;
+	_vm->_graphics->_dispBitMap->_planes[3] = _vm->_graphics->_dispBitMap->_planes[2] + 0x10000;
+	_vm->_graphics->_dispBitMap->_planes[4] = _vm->_graphics->_dispBitMap->_planes[3] + 0x10000;
 
 	_vm->_event->mouseHide();
 
diff --git a/engines/lab/dispman.cpp b/engines/lab/dispman.cpp
index ba2cfc846b..df35f9f29d 100644
--- a/engines/lab/dispman.cpp
+++ b/engines/lab/dispman.cpp
@@ -80,9 +80,9 @@ void DisplayMan::loadPict(const char *filename) {
 }
 
 /**
- * Reads in a picture into the dest bitmap.
+ * Reads in a picture into the display bitmap.
  */
-void DisplayMan::readPict(const char *filename, bool playOnce, bool onlyDiffData) {
+void DisplayMan::readPict(const char *filename, bool playOnce, bool onlyDiffData, byte *memoryBuffer, uint16 maxHeight) {
 	_vm->_anim->stopDiff();
 
 	loadPict(filename);
@@ -92,40 +92,15 @@ void DisplayMan::readPict(const char *filename, bool playOnce, bool onlyDiffData
 	if (!_vm->_music->_doNotFilestopSoundEffect)
 		_vm->_music->stopSoundEffect();
 
-	_dispBitMap->_bytesPerRow = _screenWidth;
-	_dispBitMap->_rows        = _screenHeight;
-	_dispBitMap->_drawOnScreen = true;
+	_dispBitMap->_bytesPerRow  = _screenWidth;
+	_dispBitMap->_rows         = (maxHeight > 0) ? maxHeight : _screenHeight;
+	_dispBitMap->_drawOnScreen = (memoryBuffer == nullptr);
+	if (memoryBuffer)
+		_dispBitMap->_planes[0] = memoryBuffer;
 
 	_vm->_anim->readDiff(_curBitmap, playOnce, onlyDiffData);
 }
 
-/**
- * Reads in a picture into buffer memory.
- */
-byte *DisplayMan::readPictToMem(const char *filename, uint16 width, uint16 height) {
-	_vm->_anim->stopDiff();
-
-	loadPict(filename);
-
-	_vm->_music->updateMusic();
-
-	if (!_vm->_music->_doNotFilestopSoundEffect)
-		_vm->_music->stopSoundEffect();
-
-	_dispBitMap->_bytesPerRow = width;
-	_dispBitMap->_rows = height;
-	_dispBitMap->_drawOnScreen = false;
-	_dispBitMap->_planes[0] = _curBitmap;
-	_dispBitMap->_planes[1] = _dispBitMap->_planes[0] + 0x10000;
-	_dispBitMap->_planes[2] = _dispBitMap->_planes[1] + 0x10000;
-	_dispBitMap->_planes[3] = _dispBitMap->_planes[2] + 0x10000;
-	_dispBitMap->_planes[4] = _dispBitMap->_planes[3] + 0x10000;
-
-	_vm->_anim->readDiff(_curBitmap, true);
-
-	return _curBitmap;
-}
-
 void DisplayMan::freePict() {
 	delete _curBitmap;
 	_curBitmap = NULL;
diff --git a/engines/lab/dispman.h b/engines/lab/dispman.h
index 5938198b87..ad506c4cdf 100644
--- a/engines/lab/dispman.h
+++ b/engines/lab/dispman.h
@@ -73,9 +73,8 @@ public:
 	virtual ~DisplayMan();
 
 	void loadPict(const char *filename);
-	void readPict(const char *filename, bool playOnce, bool onlyDiffData = false);
+	void readPict(const char *filename, bool playOnce, bool onlyDiffData = false, byte *memoryBuffer = nullptr, uint16 maxHeight = 0);
 	void freePict();
-	byte *readPictToMem(const char *filename, uint16 x, uint16 y);
 	void doScrollBlack();
 	void copyPage(uint16 width, uint16 height, uint16 nheight, uint16 startline, byte *mem);
 	void doScrollWipe(char *filename);
diff --git a/engines/lab/special.cpp b/engines/lab/special.cpp
index f0b8152a34..6289cf2583 100644
--- a/engines/lab/special.cpp
+++ b/engines/lab/special.cpp
@@ -51,7 +51,7 @@ static char *journaltext, *journaltexttitle;
 static uint16 JPage = 0;
 static bool lastpage = false;
 static Image JBackImage, ScreenImage;
-static bool GotBackImage = false;
+static byte *_blankJournal;
 static uint16 monitorPage;
 static const char *TextFileName;
 
@@ -67,16 +67,11 @@ Image *MonButton;
 #define NOCLEAN     152
 
 
-static byte *loadBackPict(const char *fileName, bool tomem) {
-	byte *res = nullptr;
-
+static void loadBackPict(const char *fileName) {
 	g_lab->_graphics->FadePalette = hipal;
-	g_lab->_anim->_noPalChange = true;
 
-	if (tomem)
-		res = g_lab->_graphics->readPictToMem(fileName, g_lab->_graphics->_screenWidth, g_lab->_graphics->_screenHeight);
-	else
-		g_lab->_graphics->readPict(fileName, true);
+	g_lab->_anim->_noPalChange = true;
+	g_lab->_graphics->readPict(fileName, true);
 
 	for (uint16 i = 0; i < 16; i++) {
 		hipal[i] = ((g_lab->_anim->_diffPalette[i * 3] >> 2) << 8) +
@@ -85,8 +80,6 @@ static byte *loadBackPict(const char *fileName, bool tomem) {
 	}
 
 	g_lab->_anim->_noPalChange = false;
-
-	return res;
 }
 
 /**
@@ -184,12 +177,21 @@ void LabEngine::loadJournalData() {
 
 	Common::File *journalFile = _resource->openDataFile("P:JImage");
 	Utils *utils = _utils;
-
 	_journalGadgetList.push_back(createButton( 80, utils->vgaScaleY(162) + utils->svgaCord(1), 0, VKEY_LTARROW, new Image(journalFile), new Image(journalFile)));	// back
-	_journalGadgetList.push_back(createButton(144, utils->vgaScaleY(164) - utils->svgaCord(1), 1, VKEY_RTARROW, new Image(journalFile), new Image(journalFile)));	// foward
 	_journalGadgetList.push_back(createButton(194, utils->vgaScaleY(162) + utils->svgaCord(1), 2,            0, new Image(journalFile), new Image(journalFile)));	// cancel
-
+	_journalGadgetList.push_back(createButton(144, utils->vgaScaleY(164) - utils->svgaCord(1), 1, VKEY_RTARROW, new Image(journalFile), new Image(journalFile)));	// forward
 	delete journalFile;
+
+	_anim->_noPalChange = true;
+	JBackImage._imageData = new byte[_graphics->_screenWidth * _graphics->_screenHeight];
+	_graphics->readPict("P:Journal.pic", true, false, JBackImage._imageData);
+	_anim->_noPalChange = false;
+
+	// Keep a copy of the blank journal
+	_blankJournal = new byte[_graphics->_screenWidth * _graphics->_screenHeight];
+	memcpy(_blankJournal, JBackImage._imageData, _graphics->_screenWidth * _graphics->_screenHeight);
+
+	ScreenImage._imageData = _graphics->getCurrentDrawingBuffer();
 }
 
 /**
@@ -256,15 +258,11 @@ static void turnPage(bool fromLeft) {
  */
 void LabEngine::drawJournal(uint16 wipenum, bool needFade) {
 	_event->mouseHide();
-
 	_music->updateMusic();
-
-	if (!GotBackImage)
-		JBackImage._imageData = loadBackPict("P:Journal.pic", true);
-
 	drawJournalText();
 
-	ScreenImage._imageData = _graphics->getCurrentDrawingBuffer();
+	// TODO: This is only called to set the palette correctly. Refactor, if possible
+	loadBackPict("P:Journal.pic");
 
 	if (wipenum == 0)
 		JBackImage.blitBitmap(0, 0, &ScreenImage, 0, 0, _graphics->_screenWidth, _graphics->_screenHeight, false);
@@ -272,7 +270,7 @@ void LabEngine::drawJournal(uint16 wipenum, bool needFade) {
 		turnPage((bool)(wipenum == 1));
 
 	Gadget *backGadget = _event->getGadget(0);
-	Gadget *forwardGadget = _event->getGadget(1);
+	Gadget *forwardGadget = _event->getGadget(2);
 
 	if (JPage == 0)
 		disableGadget(backGadget, 15);
@@ -284,18 +282,14 @@ void LabEngine::drawJournal(uint16 wipenum, bool needFade) {
 	else
 		enableGadget(forwardGadget);
 
-
 	if (needFade)
 		_graphics->fade(true, 0);
 
-	_anim->_noPalChange = true;
-	JBackImage._imageData = _graphics->readPictToMem("P:Journal.pic", _graphics->_screenWidth, _graphics->_screenHeight);
-	GotBackImage = true;
+	// Reset the journal background, so that all the text that has been blitted on it is erased
+	memcpy(JBackImage._imageData, _blankJournal, _graphics->_screenWidth * _graphics->_screenHeight);
 
 	eatMessages();
 	_event->mouseShow();
-
-	_anim->_noPalChange = false;
 }
 
 /**
@@ -343,7 +337,6 @@ void LabEngine::doJournal() {
 	_graphics->blackAllScreen();
 
 	lastpage    = false;
-	GotBackImage = false;
 
 	JBackImage._width = _graphics->_screenWidth;
 	JBackImage._height = _graphics->_screenHeight;
@@ -355,15 +348,16 @@ void LabEngine::doJournal() {
 	_music->updateMusic();
 	loadJournalData();
 
-	drawJournal(0, true);
-
 	_event->attachGadgetList(&_journalGadgetList);
+	drawJournal(0, true);
 	_event->mouseShow();
 	processJournal();
 	_event->attachGadgetList(NULL);
 	_graphics->fade(false, 0);
 	_event->mouseHide();
 
+	delete[] _blankJournal;
+	delete[] JBackImage._imageData;
 	freeButtonList(&_journalGadgetList);
 	_graphics->closeFont(journalFont);
 
@@ -556,7 +550,7 @@ void LabEngine::doMonitor(char *background, char *textfile, bool isinteractive,
 	delete buttonFile;
 
 	ntext = _resource->getText(textfile);
-	loadBackPict(background, false);
+	loadBackPict(background);
 	drawMonText(ntext, monitorFont, x1, y1, x2, y2, isinteractive);
 	_event->mouseShow();
 	_graphics->fade(true, 0);
diff --git a/engines/lab/transitions.cpp b/engines/lab/transitions.cpp
index d70da5c548..5f0f419d62 100644
--- a/engines/lab/transitions.cpp
+++ b/engines/lab/transitions.cpp
@@ -283,12 +283,14 @@ void DisplayMan::doTransWipe(CloseDataPtr *closePtrList, char *filename) {
 	else
 		_vm->_curFileName = _vm->getPictName(closePtrList);
 
-	byte *BitMapMem = readPictToMem(_vm->_curFileName, _screenWidth, lastY + 5);
+	byte *bitMapBuffer = new byte[_screenWidth * (lastY + 5)];
+	readPict(_vm->_curFileName, true, false, bitMapBuffer, lastY + 5);
+
 	setPalette(_vm->_anim->_diffPalette, 256);
 
 	imSource._width = _screenWidth;
 	imSource._height = lastY;
-	imSource._imageData = BitMapMem;
+	imSource._imageData = bitMapBuffer;
 
 	imDest._width = _screenWidth;
 	imDest._height = _screenHeight;
@@ -319,6 +321,8 @@ void DisplayMan::doTransWipe(CloseDataPtr *closePtrList, char *filename) {
 			}	// while
 		}	// for i
 	}	// for j
+
+	delete[] bitMapBuffer;
 }
 
 /**