Fixed recent regression (too many blast texts) in The Dig's end credits and

made the text scroll off the screen instead of just vanishing at the top.
(The latter also applies to Full Throttle's end credits.)

svn-id: r8402

4 files changed, 24 insertions, 9 deletions

diff --git a/scumm/charset.cpp b/scumm/charset.cpp
index b895043d25..c27d2a8c4a 100644
--- a/scumm/charset.cpp
+++ b/scumm/charset.cpp
@@ -597,7 +597,7 @@ void CharsetRendererClassic::printChar(int chr) {
 
 	_vm->checkRange(_vm->_maxCharsets - 1, 1, _curId, "Printing with bad charset %d");
 	
-	if ((vs = _vm->findVirtScreen(_top)) == NULL)
+	if ((vs = _vm->findVirtScreen(_top)) == NULL && (vs = _vm->findVirtScreen(_top + getFontHeight())) == NULL)
 		return;
 
 	if (chr == '@')
@@ -671,8 +671,6 @@ void CharsetRendererClassic::printChar(int chr) {
 		_str.top = _top;
 
 	int drawTop = _top - vs->topline;
-	if (drawTop < 0)
-		drawTop = 0;
 
 	_vm->updateDirtyRect(vs->number, _left, _left + width, drawTop, drawTop + height + offsY, 0);
 
@@ -740,7 +738,7 @@ void CharsetRendererClassic::drawBitsN(VirtScreen *vs, byte *dst, const byte *sr
 		for (x = 0; x < width; x++) {
 			color = (bits >> (8 - bpp)) & 0xFF;
 			
-			if (color) {
+			if (color && y + drawTop >= 0) {
 				*dst = _vm->_charsetColorMap[color];
 				if (useMask) {
 					mask[maskpos] |= maskmask;
@@ -778,7 +776,7 @@ void CharsetRendererCommon::drawBits1(VirtScreen *vs, byte *dst, const byte *src
 		for (x = 0; x < width; x++) {
 			if ((x % 8) == 0)
 				bits = *src++;
-			if (bits & revBitMask[x % 8]) {
+			if ((bits & revBitMask[x % 8]) && y + drawTop >= 0) {
 				if (_dropShadow) {
 					*(dst + 1) = 0;
 					*(dst + _vm->_screenWidth) = 0;
diff --git a/scumm/gfx.cpp b/scumm/gfx.cpp
index f70322b16c..c7655ac517 100644
--- a/scumm/gfx.cpp
+++ b/scumm/gfx.cpp
@@ -803,10 +803,10 @@ void Scumm::restoreBG(ScummVM::Rect rect, byte backColor) {
 	byte *backbuff, *bgbak;
 	bool lightsOn;
 
-	if (rect.left >= rect.right || rect.top >= rect.bottom)
-		return;
 	if (rect.top < 0)
 		rect.top = 0;
+	if (rect.left >= rect.right || rect.top >= rect.bottom)
+		return;
 
 	if ((vs = findVirtScreen(rect.top)) == NULL)
 		return;
diff --git a/scumm/scumm.h b/scumm/scumm.h
index aa7ce4e26a..33003414d4 100644
--- a/scumm/scumm.h
+++ b/scumm/scumm.h
@@ -919,7 +919,7 @@ protected:
 	BlastObject _blastObjectQueue[128];
 
 	int _blastTextQueuePos;
-	BlastText _blastTextQueue[32];	// FIXME - how many blast texts can there be at once?
+	BlastText _blastTextQueue[35];	// FIXME - how many blast texts can there be at once? The Dig needs 33 for its end credits.
 
 	void enqueueText(const byte *text, int x, int y, byte color, byte charset, bool center);
 	void drawBlastTexts();
diff --git a/scumm/string.cpp b/scumm/string.cpp
index 8f21d2d49e..aab1d45147 100644
--- a/scumm/string.cpp
+++ b/scumm/string.cpp
@@ -690,8 +690,25 @@ void Scumm::initCharset(int charsetno) {
 }
 
 void Scumm::enqueueText(const byte *text, int x, int y, byte color, byte charset, bool center) {
+	// The Dig will keep enqueueing texts long after they've scrolled off
+	// the screen, eventually overflowing the blast text queue if left
+	// unchecked.
+
+	if (y < 0) {
+		byte old_charset;
+		int font_height;
+
+		old_charset = _charset->getCurID();
+		_charset->setCurID(charset);
+		font_height = _charset->getFontHeight();
+		_charset->setCurID(old_charset);
+
+		if (y <= -font_height)
+			return;
+	}
+
 	BlastText &bt = _blastTextQueue[_blastTextQueuePos++];
-	assert(_blastTextQueuePos <= 32);
+	assert(_blastTextQueuePos <= ARRAYSIZE(_blastTextQueue));
 	
 	strcpy((char *)bt.text, (const char *)text);
 	bt.xpos = x;