Compensate small lags in Util::waitEndFrame(), so that the CD audio intro sequences in Gob1 and Gob2 CD hopefully won't de-sync so easily

svn-id: r38702

5 files changed, 27 insertions, 13 deletions

diff --git a/engines/gob/global.cpp b/engines/gob/global.cpp
index acca5564dd..8283552f2c 100644
--- a/engines/gob/global.cpp
+++ b/engines/gob/global.cpp
@@ -41,9 +41,6 @@ Global::Global(GobEngine *vm) : _vm(vm) {
 	_fakeVideoMode = 0;
 	_oldMode = 3;
 
-	_frameWaitTime = 0;
-	_startFrameTime = 0;
-
 	_soundFlags = 0;
 
 	_language = 0x8000;
diff --git a/engines/gob/global.h b/engines/gob/global.h
index 32651cf15d..5c63f2b68a 100644
--- a/engines/gob/global.h
+++ b/engines/gob/global.h
@@ -78,9 +78,6 @@ public:
 	int16 _fakeVideoMode;
 	int16 _oldMode;
 
-	int16 _frameWaitTime;
-	int32 _startFrameTime;
-
 	uint16 _soundFlags;
 
 	uint16 _language;
diff --git a/engines/gob/gob.cpp b/engines/gob/gob.cpp
index ced85357a3..dc11d29f55 100644
--- a/engines/gob/gob.cpp
+++ b/engines/gob/gob.cpp
@@ -265,6 +265,7 @@ void GobEngine::pauseEngineIntern(bool pause) {
 		uint32 duration = _system->getMillis() - _pauseStart;
 
 		_vm->_vidPlayer->notifyPaused(duration);
+		_vm->_util->notifyPaused(duration);
 
 		_vm->_game->_startTimeKey += duration;
 		_vm->_draw->_cursorTimeKey += duration;
diff --git a/engines/gob/util.cpp b/engines/gob/util.cpp
index 58430f0d41..2916caa340 100644
--- a/engines/gob/util.cpp
+++ b/engines/gob/util.cpp
@@ -43,6 +43,9 @@ Util::Util(GobEngine *vm) : _vm(vm) {
 	_keyBufferTail = 0;
 	_fastMode = 0;
 	_frameRate = 12;
+	_frameWaitTime = 0;
+	_startFrameTime = 0;
+	_frameWaitLag = 0;
 }
 
 uint32 Util::getTimeKey(void) {
@@ -63,6 +66,10 @@ void Util::beep(int16 freq) {
 	_vm->_sound->speakerOn(freq, 50);
 }
 
+void Util::notifyPaused(uint32 duration) {
+	_startFrameTime += duration;
+}
+
 void Util::delay(uint16 msecs) {
 	g_system->delayMillis(msecs / _vm->_global->_speedFactor);
 }
@@ -309,8 +316,8 @@ void Util::setFrameRate(int16 rate) {
 		rate = 1;
 
 	_frameRate = rate;
-	_vm->_global->_frameWaitTime = 1000 / rate;
-	_vm->_global->_startFrameTime = getTimeKey();
+	_frameWaitTime = 1000 / rate;
+	_startFrameTime = getTimeKey();
 }
 
 void Util::waitEndFrame() {
@@ -318,16 +325,23 @@ void Util::waitEndFrame() {
 
 	_vm->_video->waitRetrace();
 
-	time = getTimeKey() - _vm->_global->_startFrameTime;
+	time = getTimeKey() - _startFrameTime;
 	if ((time > 1000) || (time < 0)) {
-		_vm->_global->_startFrameTime = getTimeKey();
+		_startFrameTime = getTimeKey();
 		return;
 	}
 
-	if ((_vm->_global->_frameWaitTime - time) > 0)
-		delay(_vm->_global->_frameWaitTime - time);
+	int32 waitTime = _frameWaitTime - _frameWaitLag;
+	int32 toWait = waitTime - time;
+
+	if (toWait > 0)
+		delay(toWait);
+
+	int32 now = getTimeKey();
+
+	_frameWaitLag = (now - _startFrameTime) - waitTime;
 
-	_vm->_global->_startFrameTime = getTimeKey();
+	_startFrameTime = now;
 }
 
 void Util::setScrollOffset(int16 x, int16 y) {
diff --git a/engines/gob/util.h b/engines/gob/util.h
index 926338e271..19b11801bc 100644
--- a/engines/gob/util.h
+++ b/engines/gob/util.h
@@ -54,6 +54,8 @@ public:
 	int16 getRandom(int16 max);
 	void beep(int16 freq);
 
+	void notifyPaused(uint32 duration);
+
 	void delay(uint16 msecs);
 	void longDelay(uint16 msecs);
 
@@ -99,6 +101,9 @@ protected:
 	uint8 _fastMode;
 
 	int16 _frameRate;
+	int16 _frameWaitTime;
+	uint32 _startFrameTime;
+	int32 _frameWaitLag;
 
 	GobEngine *_vm;