BLADERUNNER: Use unsigned 32bit diff for time durations

24 files changed, 363 insertions, 304 deletions

diff --git a/engines/bladerunner/ui/elevator.cpp b/engines/bladerunner/ui/elevator.cpp
index 2f7d7e1dff..a3f795263a 100644
--- a/engines/bladerunner/ui/elevator.cpp
+++ b/engines/bladerunner/ui/elevator.cpp
@@ -244,7 +244,7 @@ void Elevator::reset() {
 	_imagePicker = nullptr;
 	_actorId = -1;
 	_sentenceId = -1;
-	_timeSpeakDescription = 0;
+	_timeSpeakDescriptionStart = 0u;
 	_buttonClicked = false;
 }
 
@@ -283,18 +283,19 @@ void Elevator::buttonFocus(int buttonId) {
 void Elevator::setupDescription(int actorId, int sentenceId) {
 	_actorId = actorId;
 	_sentenceId = sentenceId;
-	_timeSpeakDescription = _vm->_time->current() + 600;
+	_timeSpeakDescriptionStart = _vm->_time->current();
 }
 
 void Elevator::resetDescription() {
 	_actorId = -1;
 	_sentenceId = -1;
-	_timeSpeakDescription = 0;
+	_timeSpeakDescriptionStart = 0u;
 }
 
 void Elevator::tickDescription() {
-	int now = _vm->_time->current();
-	if (_actorId <= 0 || now < _timeSpeakDescription) {
+	uint32 now = _vm->_time->current();
+	// unsigned difference is intentional
+	if (_actorId <= 0 || (now - _timeSpeakDescriptionStart < 600u)) {
 		return;
 	}
 
diff --git a/engines/bladerunner/ui/elevator.h b/engines/bladerunner/ui/elevator.h
index 96724430b0..6ed91ce799 100644
--- a/engines/bladerunner/ui/elevator.h
+++ b/engines/bladerunner/ui/elevator.h
@@ -41,7 +41,7 @@ class Elevator {
 	UIImagePicker         *_imagePicker;
 	int                    _actorId;
 	int                    _sentenceId;
-	int                    _timeSpeakDescription;
+	uint32                 _timeSpeakDescriptionStart;
 
 public:
 	Elevator(BladeRunnerEngine *vm);
diff --git a/engines/bladerunner/ui/end_credits.cpp b/engines/bladerunner/ui/end_credits.cpp
index 08cce2e172..57ea6b3e7c 100644
--- a/engines/bladerunner/ui/end_credits.cpp
+++ b/engines/bladerunner/ui/end_credits.cpp
@@ -109,7 +109,7 @@ void EndCredits::show() {
 		}
 
 		uint32 timeNow = _vm->_time->currentSystem();
-		position += (double)(timeNow - timeLast) * 0.05f;
+		position += (double)(timeNow - timeLast) * 0.05f; // unsigned difference is intentional
 		timeLast = timeNow;
 
 		_vm->_surfaceFront.fillRect(Common::Rect(640, 480), 0);
diff --git a/engines/bladerunner/ui/esper.cpp b/engines/bladerunner/ui/esper.cpp
index 7913362091..3a4e8c9fc4 100644
--- a/engines/bladerunner/ui/esper.cpp
+++ b/engines/bladerunner/ui/esper.cpp
@@ -56,12 +56,12 @@ ESPER::ESPER(BladeRunnerEngine *vm) {
 	_regionSelectedAck  = false;
 	_isDrawingSelection = false;
 
-	_isOpen         = false;
-	_shapeButton    = nullptr;
-	_shapeThumbnail = nullptr;
-	_vqaPlayerMain  = nullptr;
-	_vqaPlayerPhoto = nullptr;
-	_script         = nullptr;
+	_isOpen             = false;
+	_shapeButton        = nullptr;
+	_shapeThumbnail     = nullptr;
+	_vqaPlayerMain      = nullptr;
+	_vqaPlayerPhoto     = nullptr;
+	_script             = nullptr;
 
 	reset();
 
@@ -363,7 +363,7 @@ void ESPER::resetData() {
 	_flash              = false;
 	_isScrolling        = false;
 
-	_timeScrollNext = 0;
+	_timeScrollNextStart = 0u;
 
 	resetPhotos();
 	resetRegions();
@@ -398,7 +398,7 @@ void ESPER::resetViewport() {
 	_zoom           = _zoomVertical;
 	_zoomMin        = _zoom;
 
-	_timeZoomOutNext = 0;
+	_timeZoomOutNextStart = 0u;
 
 	_viewportPositionX = kPhotoWidth  / 2;
 	_viewportPositionY = kPhotoHeight / 2;
@@ -416,20 +416,22 @@ void ESPER::resetSelectionRect() {
 }
 
 void ESPER::resetSelectionBlinking() {
-	_selectionBlinkingCounter  = 0;
-	_selectionBlinkingStyle    = 0;
-	_timeSelectionBlinkingNext = 0;
+	_selectionBlinkingCounter       = 0;
+	_selectionBlinkingStyle         = 0;
+	_timeSelectionBlinkingNextStart = 0u;
 }
 
 void ESPER::resetPhotoZooming() {
 	_zoomStep     = 0;
-	_timeZoomNext = 0;
+	_timeZoomNextDiff  = 0u;
+	_timeZoomNextStart = 0u;
 }
 
 void ESPER::resetPhotoOpening() {
 	_photoOpeningWidth    = _screen.left + 1;
 	_photoOpeningHeight   = _screen.top  + 1;
-	_timePhotoOpeningNext = 0;
+	_timePhotoOpeningNextDiff  = 0u;
+	_timePhotoOpeningNextStart = 0u;
 }
 
 void ESPER::updateViewport() {
@@ -523,11 +525,13 @@ void ESPER::setStatePhoto(EsperPhotoStates state) {
 	_statePhoto = state;
 }
 
-void ESPER::wait(int timeout) {
+void ESPER::wait(uint32 timeout) {
 	if (!_isWaiting) {
 		_isWaiting = true;
-		int timeEnd = timeout + _vm->_time->current();
-		while (_vm->_gameIsRunning && (_vm->_time->current() < timeEnd)) {
+//		int timeEnd = timeout + _vm->_time->current();
+		uint32  timeStart = _vm->_time->current();
+		// unsigned difference is intentional
+		while (_vm->_gameIsRunning && (_vm->_time->current() - timeStart < timeout)) {
 			_vm->gameTick();
 		}
 		_isWaiting = false;
@@ -645,16 +649,17 @@ void ESPER::draw(Graphics::Surface &surface) {
 
 void ESPER::drawPhotoOpening(Graphics::Surface &surface) {
 	bool needMoreZooming = true;
-	int timeNow = _vm->_time->current();
-	if (timeNow >= _timePhotoOpeningNext) {
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timePhotoOpeningNextStart >= _timePhotoOpeningNextDiff) {
 		_photoOpeningWidth  = MIN(_photoOpeningWidth  + 8, _screen.right  - 1);
 		_photoOpeningHeight = MIN(_photoOpeningHeight + 7, _screen.bottom - 1);
 
 		if (_photoOpeningWidth == _screen.right - 1 && _photoOpeningHeight == _screen.bottom - 1) {
 			needMoreZooming = false;
 		}
-
-		_timePhotoOpeningNext = timeNow + 20;
+		_timePhotoOpeningNextDiff  = 20u;
+		_timePhotoOpeningNextStart = timeNow;
 	}
 	copyImageScale(&_surfacePhoto, _viewport, &surface, Common::Rect(_screen.left, _screen.top, _photoOpeningWidth, _photoOpeningHeight));
 
@@ -675,15 +680,16 @@ void ESPER::drawPhotoOpening(Graphics::Surface &surface) {
 bool ESPER::drawSelectionZooming(Graphics::Surface &surface) {
 	bool zooming = false;
 	bool needMoreZooming = true;
-	int timeNow = _vm->_time->current();
-	if (timeNow > _timeSelectionZoomNext) {
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeSelectionZoomNextStart > 150u) {
 		zooming = true;
 		_selection.left   += _selectionDelta.left;
 		_selection.top    += _selectionDelta.top;
 		_selection.right  += _selectionDelta.right;
 		_selection.bottom += _selectionDelta.bottom;
 		++_selectionZoomStep;
-		_timeSelectionZoomNext = timeNow + 150;
+		_timeSelectionZoomNextStart = timeNow;
 		if (_selectionZoomStep > kSelectionZoomSteps) {
 			needMoreZooming = false;
 			_selection.left   = _selectionTarget.left;
@@ -706,9 +712,10 @@ bool ESPER::drawSelectionZooming(Graphics::Surface &surface) {
 
 bool ESPER::drawSelectionBlinking(Graphics::Surface &surface) {
 	bool needMoreBlinking = true;
-	int timeNow = _vm->_time->current();
-	if (timeNow > _timeSelectionBlinkingNext) {
-		_timeSelectionBlinkingNext = timeNow + 100;
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeSelectionBlinkingNextStart > 100u) {
+		_timeSelectionBlinkingNextStart = timeNow;
 		_selectionBlinkingStyle ^= 1;
 		++_selectionBlinkingCounter;
 		if (_selectionBlinkingCounter > 10) {
@@ -724,8 +731,9 @@ bool ESPER::drawSelectionBlinking(Graphics::Surface &surface) {
 }
 
 void ESPER::drawPhotoZooming(Graphics::Surface &surface) {
-	int timeNow = _vm->_time->current();
-	if ((timeNow > _timeZoomNext) && (_zoomStep < _zoomSteps)) {
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if ((timeNow - _timeZoomNextStart > _timeZoomNextDiff) && (_zoomStep < _zoomSteps)) {
 		_flash = true;
 
 		_viewportPositionXCurrent += _viewportPositionXDelta;
@@ -754,7 +762,8 @@ void ESPER::drawPhotoZooming(Graphics::Surface &surface) {
 			_viewportPositionY = _viewportPositionYTarget;
 		}
 		updateViewport();
-		_timeZoomNext = timeNow + 300;
+		_timeZoomNextDiff  = 300u;
+		_timeZoomNextStart = timeNow;
 	}
 
 	if (_zoomDelta >= 0.0f) {
@@ -764,7 +773,8 @@ void ESPER::drawPhotoZooming(Graphics::Surface &surface) {
 	}
 	drawGrid(surface);
 
-	if ((timeNow > _timeZoomNext) && (_zoomStep >= _zoomSteps)) {
+	// unsigned difference is intentional
+	if ((timeNow - _timeZoomNextStart > _timeZoomNextDiff) && (_zoomStep >= _zoomSteps)) {
 		if (_regionSelectedAck) {
 			if (!_regions[_regionSelected].name.empty()) {
 				if (_zoomDelta < 0.0f) {
@@ -772,7 +782,7 @@ void ESPER::drawPhotoZooming(Graphics::Surface &surface) {
 					_zoomDelta = (_zoom * 1.5f - _zoom) / (float)_zoomSteps; // 0.5f * _zoom ???
 				}
 				setStatePhoto(kEsperPhotoStateVideoZooming);
-				_timeZoomNext += 300;
+				_timeZoomNextDiff += 300u;
 			} else {
 				_regionSelectedAck = false;
 				_selection.left   = viewportXToScreenX(_regions[_regionSelected].rectInner.left);
@@ -792,9 +802,10 @@ void ESPER::drawPhotoZooming(Graphics::Surface &surface) {
 }
 
 void ESPER::drawPhotoSharpening(Graphics::Surface &surface) {
-	int timeNow = _vm->_time->current();
+	uint32 timeNow = _vm->_time->current();
 	bool needMoreSharpening = true;
-	if (timeNow >= _timePhotoOpeningNext) {
+	// unsigned difference is intentional
+	if (timeNow - _timePhotoOpeningNextStart >= _timePhotoOpeningNextDiff) {
 		_photoOpeningWidth  = MIN(_photoOpeningWidth  + 8, _screen.right  - 1);
 		_photoOpeningHeight = MIN(_photoOpeningHeight + 7, _screen.bottom - 1);
 
@@ -802,7 +813,8 @@ void ESPER::drawPhotoSharpening(Graphics::Surface &surface) {
 			needMoreSharpening = false;
 		}
 
-		_timePhotoOpeningNext = timeNow + 50;
+		_timePhotoOpeningNextDiff  = 50u;
+		_timePhotoOpeningNextStart = timeNow;
 	}
 
 	if (_regionSelectedAck && !_regions[_regionSelected].name.empty()) {
@@ -833,9 +845,10 @@ void ESPER::drawPhotoSharpening(Graphics::Surface &surface) {
 }
 
 void ESPER::drawPhotoZoomOut(Graphics::Surface &surface) {
-	int timeNow = _vm->_time->current();
-	if (timeNow >= _timeZoomOutNext) {
-		_timeZoomOutNext = timeNow + 300;
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeZoomOutNextStart >= 300u) {
+		_timeZoomOutNextStart = timeNow;
 
 		if (_zoom > _zoomMin) {
 			_zoom /= 1.3f;
@@ -870,14 +883,17 @@ void ESPER::drawVideoZooming(Graphics::Surface &surface) {
 			return;
 		}
 
-		_timeZoomNext = 0;
+		_timeZoomNextDiff  = 0u;
+		_timeZoomNextStart = 0u;
 	}
 
 	bool flash = false;
 	bool advanceFrame = false;
-	int timeNow = _vm->_time->current();
-	if (timeNow > _timeZoomNext) {
-		_timeZoomNext = timeNow + 300;
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeZoomNextStart > _timeZoomNextDiff) {
+		_timeZoomNextDiff  = 300u;
+		_timeZoomNextStart = timeNow;
 		playSound(kSfxBR031_1P, 25);
 		flash = true;
 		advanceFrame = true;
@@ -901,9 +917,11 @@ void ESPER::drawVideoZooming(Graphics::Surface &surface) {
 void ESPER::drawVideoZoomOut(Graphics::Surface &surface) {
 	bool flash = false;
 	bool advanceFrame = false;
-	int timeNow = _vm->_time->current();
-	if (timeNow > _timeZoomNext && _vqaLastFrame > 0) {
-		_timeZoomNext = timeNow + 300;
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeZoomNextStart > _timeZoomNextDiff && _vqaLastFrame > 0) {
+		_timeZoomNextDiff  = 300u;
+		_timeZoomNextStart = timeNow;
 		playSound(kSfxBR031_1P, 25);
 		_vqaPlayerPhoto->seekToFrame(_vqaLastFrame);
 		int nextFrame = _vqaPlayerPhoto->getFrameCount() / 4;
@@ -928,7 +946,8 @@ void ESPER::drawVideoZoomOut(Graphics::Surface &surface) {
 	}
 	copyImageBlit(&_surfaceViewport, Common::Rect(0, 0, 0, 0), &surface, _screen);
 	drawGrid(surface);
-	if (timeNow > _timeZoomNext && _vqaLastFrame <= 0) {
+	// unsigned difference is intentional
+	if (timeNow - _timeZoomNextStart > _timeZoomNextDiff && _vqaLastFrame <= 0) {
 		_vqaPlayerPhoto->close();
 		delete _vqaPlayerPhoto;
 		_vqaPlayerPhoto = nullptr;
@@ -1368,11 +1387,12 @@ void ESPER::tickSound() {
 }
 
 void ESPER::tickScroll() {
-	int timeNow = _vm->_time->current();
-	if (timeNow <= _timeScrollNext) {
+	uint32 timeNow = _vm->_time->current();
+	// unsigned difference is intentional
+	if (timeNow - _timeScrollNextStart <= 300u) {
 		return;
 	}
-	_timeScrollNext = timeNow + 300;
+	_timeScrollNextStart = timeNow;
 
 	if (_scrollingDirection == 0) {
 		scrollUp();
@@ -1610,8 +1630,8 @@ void ESPER::goBack() {
 }
 
 void ESPER::prepareZoom() {
-	_selectionZoomStep     = 0;
-	_timeSelectionZoomNext = 0;
+	_selectionZoomStep          = 0;
+	_timeSelectionZoomNextStart = 0u;
 
 	_selectionTarget = _selection;
 	resetSelectionRect();
diff --git a/engines/bladerunner/ui/esper.h b/engines/bladerunner/ui/esper.h
index 34648a38f4..33954cb34e 100644
--- a/engines/bladerunner/ui/esper.h
+++ b/engines/bladerunner/ui/esper.h
@@ -119,19 +119,20 @@ class ESPER {
 	bool _isMouseDown;
 	int  _mouseOverScroll;
 
-	float _zoomHorizontal;
-	float _zoomVertical;
-	float _zoom;
-	float _zoomMin;
-	float _zoomTarget;
-	float _zoomDelta;
-	float _blur;
-	int   _zoomSteps;
-	int   _zoomStep;
-	int   _timeZoomNext;
-
-	bool _isZoomingOut;
-	int  _timeZoomOutNext;
+	float  _zoomHorizontal;
+	float  _zoomVertical;
+	float  _zoom;
+	float  _zoomMin;
+	float  _zoomTarget;
+	float  _zoomDelta;
+	float  _blur;
+	int    _zoomSteps;
+	int    _zoomStep;
+	uint32 _timeZoomNextDiff;
+	uint32 _timeZoomNextStart;
+
+	bool   _isZoomingOut;
+	uint32 _timeZoomOutNextStart;
 
 	Common::Rect _screen;
 
@@ -159,20 +160,21 @@ class ESPER {
 	int          _selectionCrosshairX;
 	int          _selectionCrosshairY;
 
-	int _selectionBlinkingCounter;
-	int _selectionBlinkingStyle;
-	int _timeSelectionBlinkingNext;
+	int    _selectionBlinkingCounter;
+	int    _selectionBlinkingStyle;
+	uint32 _timeSelectionBlinkingNextStart;
 
-	int _selectionZoomStep;
-	int _timeSelectionZoomNext;
+	int    _selectionZoomStep;
+	uint32 _timeSelectionZoomNextStart;
 
-	int _photoOpeningWidth;
-	int _photoOpeningHeight;
-	int _timePhotoOpeningNext;
+	int    _photoOpeningWidth;
+	int    _photoOpeningHeight;
+	uint32 _timePhotoOpeningNextDiff;
+	uint32 _timePhotoOpeningNextStart;
 
-	bool _isScrolling;
-	int  _scrollingDirection;
-	int  _timeScrollNext;
+	bool   _isScrolling;
+	int    _scrollingDirection;
+	uint32 _timeScrollNextStart;
 
 	int _soundId1;
 	int _volume1;
@@ -218,7 +220,7 @@ private:
 	void setStateMain(EsperMainStates state);
 	void setStatePhoto(EsperPhotoStates state);
 
-	void wait(int timeout);
+	void wait(uint32 timeout);
 	void playSound(int soundId, int volume);
 
 	void draw(Graphics::Surface &surface);
diff --git a/engines/bladerunner/ui/kia.cpp b/engines/bladerunner/ui/kia.cpp
index 666a8bd7ab..7ad73ceea2 100644
--- a/engines/bladerunner/ui/kia.cpp
+++ b/engines/bladerunner/ui/kia.cpp
@@ -227,8 +227,9 @@ void KIA::tick() {
 		return;
 	}
 
-	int timeNow = _vm->_time->currentSystem();
-	int timeDiff = timeNow - _timeLast;
+	uint32 timeNow = _vm->_time->currentSystem();
+	// unsigned difference is intentional
+	uint32 timeDiff = timeNow - _timeLast;
 
 	if (_playerActorDialogueQueueSize == _playerActorDialogueQueuePosition) {
 		_playerActorDialogueState = 0;
@@ -255,22 +256,22 @@ void KIA::tick() {
 		}
 	}
 
-	int timeDiffDiv48 = (timeNow - _playerVqaTimeLast) / 48;
-	if (timeDiffDiv48 > 0) {
+	uint32 timeDiffDiv48 = (timeNow < _playerVqaTimeLast) ? 0u : (timeNow - _playerVqaTimeLast) / 48;
+	if (timeDiffDiv48 > 0u) {
 		_playerVqaTimeLast = timeNow;
 		if (_playerActorDialogueQueueSize == _playerActorDialogueQueuePosition || _playerSliceModelId != -1 || _playerPhotographId != -1 || _playerImage.getPixels() != nullptr) {
 			if (_playerVisualizerState > 0) {
-				_playerVisualizerState = MAX(_playerVisualizerState - timeDiffDiv48, 0);
+				_playerVisualizerState = (_playerVisualizerState < timeDiffDiv48) ? 0u : MAX(_playerVisualizerState - timeDiffDiv48, 0u);
 			}
 		} else {
 			if (_playerVisualizerState < 2) {
-				_playerVisualizerState = MIN(_playerVisualizerState + timeDiffDiv48, 2);
+				_playerVisualizerState = MIN(_playerVisualizerState + timeDiffDiv48, 2u);
 			}
 		}
 
 		if ( _playerSliceModelId != -1 || _playerPhotographId != -1 || _playerImage.getPixels() != nullptr) {
 			if (_playerVqaFrame < 8) {
-				int newVqaFrame  = MIN(timeDiffDiv48 + _playerVqaFrame, 8);
+				int newVqaFrame  = MIN(timeDiffDiv48 + _playerVqaFrame, 8u);
 				if (_playerVqaFrame <= 0 && newVqaFrame > 0) {
 					_vm->_audioPlayer->playAud(_vm->_gameInfo->getSfxTrack(kSfxMECHAN1), 100, 70, 70, 50, 0);
 				}
@@ -278,7 +279,7 @@ void KIA::tick() {
 			}
 		} else {
 			if (_playerVqaFrame > 0) {
-				int newVqaFrame = MAX(_playerVqaFrame - timeDiffDiv48, 0);
+				int newVqaFrame = (_playerVqaFrame < timeDiffDiv48) ? 0 : MAX(_playerVqaFrame - timeDiffDiv48, 0u);
 				if (_playerVqaFrame >= 8 && newVqaFrame < 8) {
 					_vm->_audioPlayer->playAud(_vm->_gameInfo->getSfxTrack(kSfxMECHAN1C), 100, 70, 70, 50, 0);
 				}
diff --git a/engines/bladerunner/ui/kia.h b/engines/bladerunner/ui/kia.h
index 47ea63946d..5c0204b5dd 100644
--- a/engines/bladerunner/ui/kia.h
+++ b/engines/bladerunner/ui/kia.h
@@ -78,16 +78,16 @@ class KIA {
 
 	int _transitionId;
 
-	int                _playerVqaTimeLast;
+	uint32             _playerVqaTimeLast;
 	VQAPlayer         *_playerVqaPlayer;
-	int                _playerVqaFrame;
-	int                _playerVisualizerState;
+	uint32             _playerVqaFrame;
+	uint32             _playerVisualizerState;
 	int                _playerPhotographId;
 	Shape             *_playerPhotograph;
 	int                _playerSliceModelId;
 	float              _playerSliceModelAngle;
 	Graphics::Surface  _playerImage;
-	int                _timeLast;
+	uint32             _timeLast;
 
 	ActorDialogueQueueEntry _playerActorDialogueQueue[kPlayerActorDialogueQueueCapacity];
 	int                     _playerActorDialogueQueuePosition;
diff --git a/engines/bladerunner/ui/kia_section_diagnostic.cpp b/engines/bladerunner/ui/kia_section_diagnostic.cpp
index 41ff43c282..662aef3621 100644
--- a/engines/bladerunner/ui/kia_section_diagnostic.cpp
+++ b/engines/bladerunner/ui/kia_section_diagnostic.cpp
@@ -71,7 +71,7 @@ void KIASectionDiagnostic::close() {
 }
 
 void KIASectionDiagnostic::draw(Graphics::Surface &surface) {
-	int timeNow = _vm->_time->currentSystem();
+	uint32 timeNow = _vm->_time->currentSystem();
 
 	for (int i = 0; i < _text->getCount(); ++i) {
 		int y = kLineHeight * i + 366 - _offset;
@@ -91,7 +91,8 @@ void KIASectionDiagnostic::draw(Graphics::Surface &surface) {
 	}
 
 	// Timing fixed for 60Hz by ScummVM team
-	if (timeNow - _timeLast > 1000 / 60) {
+	// unsigned difference is intentional
+	if (timeNow - _timeLast > (1000u / 60u)) {
 		++_offset;
 		if (_offset > kLineHeight * _text->getCount() + 366) {
 			_offset = 0;
diff --git a/engines/bladerunner/ui/kia_section_diagnostic.h b/engines/bladerunner/ui/kia_section_diagnostic.h
index 0c518f2561..82365575d5 100644
--- a/engines/bladerunner/ui/kia_section_diagnostic.h
+++ b/engines/bladerunner/ui/kia_section_diagnostic.h
@@ -36,7 +36,7 @@ class KIASectionDiagnostic : public KIASectionBase {
 
 	TextResource *_text;
 	int           _offset;
-	int           _timeLast;
+	uint32        _timeLast;
 
 public:
 	KIASectionDiagnostic(BladeRunnerEngine *vm);
diff --git a/engines/bladerunner/ui/kia_section_load.cpp b/engines/bladerunner/ui/kia_section_load.cpp
index 42ace56e0d..41f2e7e18f 100644
--- a/engines/bladerunner/ui/kia_section_load.cpp
+++ b/engines/bladerunner/ui/kia_section_load.cpp
@@ -44,8 +44,8 @@ KIASectionLoad::KIASectionLoad(BladeRunnerEngine *vm) : KIASectionBase(vm) {
 	_scrollBox   = new UIScrollBox(_vm, scrollBoxCallback, this, 1025, 0, true, Common::Rect(155, 158, 461, 346), Common::Rect(506, 160, 506, 350));
 	_uiContainer->add(_scrollBox);
 
-	_timeLast = 0;
-	_timeLeft = 0;
+	_timeLast = 0u;
+	_timeLeft = 0u;
 
 	_hoveredLineId = -1;
 	_displayingLineId = -1;
@@ -86,7 +86,7 @@ void KIASectionLoad::open() {
 
 	_hoveredLineId = -1;
 	_timeLast = _vm->_time->currentSystem();
-	_timeLeft = 800;
+	_timeLeft = 800u;
 }
 
 void KIASectionLoad::close() {
@@ -105,7 +105,7 @@ void KIASectionLoad::draw(Graphics::Surface &surface) {
 
 	if (_hoveredLineId != selectedLineId) {
 		if (selectedLineId >= 0 && selectedLineId < (int)_saveList.size() && _displayingLineId != selectedLineId) {
-			if (_timeLeft == 0) {
+			if (_timeLeft == 0u) {
 				SaveStateDescriptor desc = SaveFileManager::queryMetaInfos(_vm->getTargetName(), selectedLineId);
 				const Graphics::Surface *thumbnail = desc.getThumbnail();
 				if (thumbnail != nullptr) {
@@ -115,7 +115,7 @@ void KIASectionLoad::draw(Graphics::Surface &surface) {
 			}
 		} else {
 			_vm->_kia->playerReset();
-			_timeLeft = 800;
+			_timeLeft = 800u;
 			_displayingLineId = -1;
 		}
 		_hoveredLineId = selectedLineId;
@@ -124,7 +124,7 @@ void KIASectionLoad::draw(Graphics::Surface &surface) {
 	uint32 now = _vm->_time->currentSystem();
 	if (selectedLineId >= 0 && selectedLineId < (int)_saveList.size() && _displayingLineId != selectedLineId) {
 		if (_timeLeft) {
-			uint32 timeDiff = now - _timeLast;
+			uint32 timeDiff = now - _timeLast; // unsigned difference is intentional
 			if (timeDiff >= _timeLeft) {
 				SaveStateDescriptor desc = SaveFileManager::queryMetaInfos(_vm->getTargetName(), _saveList[selectedLineId].getSaveSlot());
 				const Graphics::Surface *thumbnail = desc.getThumbnail();
@@ -133,7 +133,7 @@ void KIASectionLoad::draw(Graphics::Surface &surface) {
 					_displayingLineId = selectedLineId;
 				}
 			} else {
-				_timeLeft -= timeDiff;
+				_timeLeft = (_timeLeft < timeDiff) ? 0u : (_timeLeft - timeDiff);
 			}
 		}
 	}
diff --git a/engines/bladerunner/ui/kia_section_pogo.cpp b/engines/bladerunner/ui/kia_section_pogo.cpp
index c5a325136e..cd0bb27efb 100644
--- a/engines/bladerunner/ui/kia_section_pogo.cpp
+++ b/engines/bladerunner/ui/kia_section_pogo.cpp
@@ -251,9 +251,10 @@ void KIASectionPogo::open() {
 
 void KIASectionPogo::draw(Graphics::Surface &surface) {
 	// Timing fixed for 60Hz by ScummVM team
-	int timeNow = _vm->_time->currentSystem();
+	uint32 timeNow = _vm->_time->currentSystem();
 	bool updateTimeout = false;
-	if (timeNow - _timeLast > 1000 / 60) {
+	// unsigned difference is intentional
+	if (timeNow - _timeLast > (1000u / 60u)) {
 		updateTimeout = true;
 		_timeLast = timeNow;
 	}
diff --git a/engines/bladerunner/ui/kia_section_pogo.h b/engines/bladerunner/ui/kia_section_pogo.h
index 7392cde4cb..85ca29cbc7 100644
--- a/engines/bladerunner/ui/kia_section_pogo.h
+++ b/engines/bladerunner/ui/kia_section_pogo.h
@@ -41,7 +41,7 @@ class KIASectionPogo : public KIASectionBase {
 	int         _lineTimeouts[kLineCount];
 	int         _lineOffsets[kLineCount];
 
-	int         _timeLast;
+	uint32      _timeLast;
 
 public:
 	KIASectionPogo(BladeRunnerEngine *vm);
diff --git a/engines/bladerunner/ui/kia_section_save.cpp b/engines/bladerunner/ui/kia_section_save.cpp
index b0f35b9fda..e4a919040d 100644
--- a/engines/bladerunner/ui/kia_section_save.cpp
+++ b/engines/bladerunner/ui/kia_section_save.cpp
@@ -55,8 +55,8 @@ KIASectionSave::KIASectionSave(BladeRunnerEngine *vm) : KIASectionBase(vm) {
 
 	_buttons = new UIImagePicker(_vm, 3);
 
-	_timeLast = 0;
-	_timeLeft = 0;
+	_timeLast = 0u;
+	_timeLeft = 0u;
 
 	_state = kStateNormal;
 
@@ -130,7 +130,7 @@ void KIASectionSave::open() {
 
 	_hoveredLineId = -1;
 	_timeLast = _vm->_time->currentSystem();
-	_timeLeft = 800;
+	_timeLeft = 800u;
 }
 
 void KIASectionSave::close() {
@@ -185,7 +185,7 @@ void KIASectionSave::draw(Graphics::Surface &surface) {
 
 	if (selectedLineId != _hoveredLineId) {
 		if (selectedLineId >= 0 && selectedLineId < (int)_saveList.size() && _displayingLineId != selectedLineId) {
-			if (_timeLeft == 0) {
+			if (_timeLeft == 0u) {
 				SaveStateDescriptor desc = SaveFileManager::queryMetaInfos(_vm->getTargetName(), selectedLineId);
 				const Graphics::Surface *thumbnail = desc.getThumbnail();
 				if (thumbnail != nullptr) {
@@ -195,7 +195,7 @@ void KIASectionSave::draw(Graphics::Surface &surface) {
 			}
 		} else {
 			_vm->_kia->playerReset();
-			_timeLeft = 800;
+			_timeLeft = 800u;
 			_displayingLineId = -1;
 		}
 		_hoveredLineId = selectedLineId;
@@ -204,7 +204,7 @@ void KIASectionSave::draw(Graphics::Surface &surface) {
 	uint32 now = _vm->_time->currentSystem();
 	if (selectedLineId >= 0 && selectedLineId < (int)_saveList.size() && _displayingLineId != selectedLineId) {
 		if (_timeLeft) {
-			uint32 timeDiff = now - _timeLast;
+			uint32 timeDiff = now - _timeLast; // unsigned difference is intentional
 			if (timeDiff >= _timeLeft) {
 				SaveStateDescriptor desc = SaveFileManager::queryMetaInfos(_vm->getTargetName(), _saveList[selectedLineId].getSaveSlot());
 				const Graphics::Surface *thumbnail = desc.getThumbnail();
@@ -213,7 +213,7 @@ void KIASectionSave::draw(Graphics::Surface &surface) {
 					_displayingLineId = selectedLineId;
 				}
 			} else {
-				_timeLeft -= timeDiff;
+				_timeLeft = (_timeLeft < timeDiff) ? 0u : (_timeLeft - timeDiff);
 			}
 		}
 	}
diff --git a/engines/bladerunner/ui/spinner.cpp b/engines/bladerunner/ui/spinner.cpp
index b6269bbb50..cab2d67dee 100644
--- a/engines/bladerunner/ui/spinner.cpp
+++ b/engines/bladerunner/ui/spinner.cpp
@@ -293,7 +293,7 @@ void Spinner::reset() {
 
 	_actorId = -1;
 	_sentenceId = -1;
-	_timeSpeakDescription = 0;
+	_timeSpeakDescriptionStart = 0u;
 
 	for (int i = 0; i != (int)_shapes.size(); ++i) {
 		delete _shapes[i];
@@ -413,20 +413,21 @@ void Spinner::destinationFocus(int destinationImage) {
 void Spinner::setupDescription(int actorId, int sentenceId) {
 	_actorId = actorId;
 	_sentenceId = sentenceId;
-	_timeSpeakDescription = _vm->_time->current() + 600;
+	_timeSpeakDescriptionStart = _vm->_time->current();
 }
 
 // copied from elevator.cpp code
 void Spinner::resetDescription() {
 	_actorId = -1;
 	_sentenceId = -1;
-	_timeSpeakDescription = 0;
+	_timeSpeakDescriptionStart = 0u;
 }
 
 // copied from elevator.cpp code
 void Spinner::tickDescription() {
-	int now = _vm->_time->current();
-	if (_actorId <= 0 || now < _timeSpeakDescription) {
+	uint32 now = _vm->_time->current();
+	// unsigned difference is intentional
+	if (_actorId <= 0 || (now - _timeSpeakDescriptionStart < 600u)) {
 		return;
 	}
 
diff --git a/engines/bladerunner/ui/spinner.h b/engines/bladerunner/ui/spinner.h
index 50a8be97b6..2fa0dc659c 100644
--- a/engines/bladerunner/ui/spinner.h
+++ b/engines/bladerunner/ui/spinner.h
@@ -54,7 +54,7 @@ class Spinner {
 
 	int                    _actorId;
 	int                    _sentenceId;
-	int                    _timeSpeakDescription;
+	uint32                 _timeSpeakDescriptionStart;
 
 public:
 	Spinner(BladeRunnerEngine *vm);
diff --git a/engines/bladerunner/ui/ui_check_box.cpp b/engines/bladerunner/ui/ui_check_box.cpp
index 76cecd227c..935c53f98a 100644
--- a/engines/bladerunner/ui/ui_check_box.cpp
+++ b/engines/bladerunner/ui/ui_check_box.cpp
@@ -44,9 +44,9 @@ UICheckBox::UICheckBox(BladeRunnerEngine *vm, UIComponentCallback *valueChangedC
 	_style = style;
 
 	if (isChecked) {
-		_frame = 5;
+		_frame = 5u;
 	} else {
-		_frame = 0;
+		_frame = 0u;
 	}
 
 	_timeLast = _vm->_time->currentSystem();
@@ -57,39 +57,41 @@ UICheckBox::UICheckBox(BladeRunnerEngine *vm, UIComponentCallback *valueChangedC
 
 void UICheckBox::draw(Graphics::Surface &surface) {
 	if (_rect.right > _rect.left && _rect.bottom > _rect.top) {
-		int shapeId;
+		uint32 shapeId;
 
-		uint timeNow = _vm->_time->currentSystem();
-		if (timeNow - _timeLast > 67) {
-			int frameDelta = (timeNow - _timeLast) / 67u;
+		uint32 timeNow = _vm->_time->currentSystem();
+		// unsigned difference is intentional
+		if (timeNow - _timeLast > 67u) {
+			// unsigned difference is intentional
+			uint32 frameDelta = (timeNow - _timeLast) / 67u;
 			_timeLast = timeNow;
 
 			if (_isChecked) {
-				_frame = MIN(_frame + frameDelta, 5);
+				_frame = MIN(_frame + frameDelta, 5u);
 			} else {
-				_frame = MAX(_frame - frameDelta, 0);
+				_frame = (_frame < frameDelta) ? 0 : MAX(_frame - frameDelta, 0u);
 			}
 		}
 
 		if (_style) {
 			if (_frame || (_hasFocus && !_isPressed && _isEnabled)) {
-				if (_frame != 5 || (_hasFocus && !_isPressed && _isEnabled)) {
-					shapeId = _frame + 54;
+				if (_frame != 5u || (_hasFocus && !_isPressed && _isEnabled)) {
+					shapeId = _frame + 54u;
 				} else {
-					shapeId = 53;
+					shapeId = 53u;
 				}
 			} else {
-				shapeId = 52;
+				shapeId = 52u;
 			}
 		} else {
 			if (_frame || (_hasFocus && !_isPressed && _isEnabled)) {
-				if (_frame != 5 || (_hasFocus && !_isPressed && _isEnabled)) {
-					shapeId = _frame + 62;
+				if (_frame != 5u || (_hasFocus && !_isPressed && _isEnabled)) {
+					shapeId = _frame + 62u;
 				} else {
-					shapeId = 61;
+					shapeId = 61u;
 				}
 			} else {
-				shapeId = 60;
+				shapeId = 60u;
 			}
 		}
 
diff --git a/engines/bladerunner/ui/ui_check_box.h b/engines/bladerunner/ui/ui_check_box.h
index 01ee555148..9b601ed698 100644
--- a/engines/bladerunner/ui/ui_check_box.h
+++ b/engines/bladerunner/ui/ui_check_box.h
@@ -36,9 +36,9 @@ class UICheckBox : public UIComponent {
 	int                  _style;
 	int                  _isEnabled;
 	Common::Rect         _rect;
-	int                  _frame;
+	uint32               _frame;
 	int                  _isPressed;
-	uint                 _timeLast;
+	uint32               _timeLast;
 	int                  _hasFocus;
 
 public:
diff --git a/engines/bladerunner/ui/ui_image_picker.cpp b/engines/bladerunner/ui/ui_image_picker.cpp
index 0b1a0dd204..e23fd2776e 100644
--- a/engines/bladerunner/ui/ui_image_picker.cpp
+++ b/engines/bladerunner/ui/ui_image_picker.cpp
@@ -167,7 +167,7 @@ void UIImagePicker::activate(UIImagePickerCallback *mouseInCallback,
 	_mouseDownCallback   = mouseDownCallback;
 	_mouseUpCallback     = mouseUpCallback;
 	_callbackData        = callbackData;
-	_hoverStartTimestamp = 0;
+	_hoverStartTimestamp = 0u;
 	_isVisible           = true;
 	_hoveredImageIndex   = -1;
 	_pressedImageIndex   = -1;
@@ -180,7 +180,7 @@ void UIImagePicker::deactivate() {
 	_mouseDownCallback   = nullptr;
 	_mouseUpCallback     = nullptr;
 	_callbackData        = nullptr;
-	_hoverStartTimestamp = 0;
+	_hoverStartTimestamp = 0u;
 	_isVisible           = false;
 	_hoveredImageIndex   = -1;
 	_pressedImageIndex   = -1;
@@ -228,8 +228,8 @@ void UIImagePicker::drawTooltip(Graphics::Surface &surface, int x, int y) {
 		(_hoveredImageIndex == -1) ||
 		(_vm->_mouse->isDisabled()) ||
 		(!_images[_hoveredImageIndex].active) ||
-		(_vm->_time->current() < _hoverStartTimestamp + 1000)
-	) {
+		(_vm->_time->current() - _hoverStartTimestamp < 1000u)
+	) { // unsigned difference is intentional (time difference)
 		return;
 	}
 
@@ -352,7 +352,7 @@ void UIImagePicker::reset() {
 	_isVisible           = false;
 	_hoveredImageIndex   = -1;
 	_pressedImageIndex   = -1;
-	_hoverStartTimestamp = 0;
+	_hoverStartTimestamp = 0u;
 	_isButtonDown        = false;
 	_mouseInCallback     = nullptr;
 	_mouseOutCallback    = nullptr;
diff --git a/engines/bladerunner/ui/ui_image_picker.h b/engines/bladerunner/ui/ui_image_picker.h
index 3d62192454..29d59ba68c 100644
--- a/engines/bladerunner/ui/ui_image_picker.h
+++ b/engines/bladerunner/ui/ui_image_picker.h
@@ -50,12 +50,12 @@ class UIImagePicker {
 
 	BladeRunnerEngine *_vm;
 
-	int _isVisible;
-	int _imageCount;
-	int _hoveredImageIndex;
-	int _pressedImageIndex;
-	int _hoverStartTimestamp;
-	int _isButtonDown;
+	int    _isVisible;
+	int    _imageCount;
+	int    _hoveredImageIndex;
+	int    _pressedImageIndex;
+	uint32 _hoverStartTimestamp;
+	int    _isButtonDown;
 	Common::Array<Image> _images;
 
 	UIImagePickerCallback *_mouseInCallback;
diff --git a/engines/bladerunner/ui/ui_input_box.h b/engines/bladerunner/ui/ui_input_box.h
index ac58a6e4ed..3aa21f2e2f 100644
--- a/engines/bladerunner/ui/ui_input_box.h
+++ b/engines/bladerunner/ui/ui_input_box.h
@@ -42,7 +42,7 @@ class UIInputBox : public UIComponent {
 
 	bool                 _cursorIsVisible;
 
-	int                  _timeLast;
+	uint32               _timeLast;
 
 public:
 	UIInputBox(BladeRunnerEngine *vm, UIComponentCallback *valueChangedCallback, void *callbackData, Common::Rect rect, int maxLength, const Common::String &text);
diff --git a/engines/bladerunner/ui/ui_scroll_box.cpp b/engines/bladerunner/ui/ui_scroll_box.cpp
index 48796a29ba..b24aa89bac 100644
--- a/engines/bladerunner/ui/ui_scroll_box.cpp
+++ b/engines/bladerunner/ui/ui_scroll_box.cpp
@@ -129,7 +129,7 @@ UIScrollBox::UIScrollBox(BladeRunnerEngine *vm, UIScrollBoxCallback *lineSelecte
 		_lines[i] = new Line();
 		_lines[i]->lineData = -1;
 		_lines[i]->flags = 0x00;
-		_lines[i]->checkboxFrame = 5;
+		_lines[i]->checkboxFrame = 5u;
 	}
 
 	_mouseOver = false;
@@ -316,7 +316,7 @@ void UIScrollBox::handleMouseDown(bool alternateButton) {
 	if (!alternateButton) {
 		if (_scrollUpButtonHover) {
 			_scrollUpButtonState = 2;
-			_timeLastScroll = _vm->_time->currentSystem() - 160;
+			_timeLastScroll = _vm->_time->currentSystem() - 160u;
 		} else {
 			_scrollUpButtonState = 1;
 		}
@@ -332,13 +332,13 @@ void UIScrollBox::handleMouseDown(bool alternateButton) {
 		}
 		if (_scrollAreaUpHover) {
 			_scrollAreaUpState = 2;
-			_timeLastScroll = _vm->_time->currentSystem() - 160;
+			_timeLastScroll = _vm->_time->currentSystem() - 160u;
 		} else {
 			_scrollAreaUpState = 1;
 		}
 		if (_scrollAreaDownHover) {
 			_scrollAreaDownState = 2;
-			_timeLastScroll = _vm->_time->currentSystem() - 160;
+			_timeLastScroll = _vm->_time->currentSystem() - 160u;
 		} else {
 			_scrollAreaDownState = 1;
 		}
@@ -380,27 +380,31 @@ int UIScrollBox::getSelectedLineData() {
 }
 
 void UIScrollBox::draw(Graphics::Surface &surface) {
-	int timeNow = _vm->_time->currentSystem();
+	uint32 timeNow = _vm->_time->currentSystem();
 
 	// update scrolling
 	if (_scrollUpButtonState == 2 && _scrollUpButtonHover) {
-		if ((timeNow - _timeLastScroll) > 160) {
+		// unsigned difference is intentional
+		if ((timeNow - _timeLastScroll) > 160u) {
 			scrollUp();
 			_timeLastScroll = timeNow;
 		}
 	} else if (_scrollDownButtonState == 2 && _scrollDownButtonHover) {
-		if ((timeNow - _timeLastScroll) > 160) {
+		// unsigned difference is intentional
+		if ((timeNow - _timeLastScroll) > 160u) {
 			scrollDown();
 			_timeLastScroll = timeNow;
 		}
 	} else if (_scrollAreaUpState == 2 && _scrollAreaUpHover) {
-		if ((timeNow - _timeLastScroll) > 160) {
+		// unsigned difference is intentional
+		if ((timeNow - _timeLastScroll) > 160u) {
 			_firstLineVisible -= _maxLinesVisible - 1;
 			_firstLineVisible = CLIP(_firstLineVisible, 0, _lineCount - _maxLinesVisible);
 			_timeLastScroll = timeNow;
 		}
 	} else if (_scrollAreaDownState == 2 && _scrollAreaDownHover) {
-		if ((timeNow - _timeLastScroll) > 160) {
+		// unsigned difference is intentional
+		if ((timeNow - _timeLastScroll) > 160u) {
 			_firstLineVisible += _maxLinesVisible - 1;
 			_firstLineVisible = CLIP(_firstLineVisible, 0, _lineCount - _maxLinesVisible);
 			_timeLastScroll = timeNow;
@@ -408,24 +412,25 @@ void UIScrollBox::draw(Graphics::Surface &surface) {
 	}
 
 	// update checkboxes
-	int timeDiffCheckBox = timeNow - _timeLastCheckbox;
-	if (timeDiffCheckBox > 67) {
+	// unsigned difference is intentional
+	uint32 timeDiffCheckBox = timeNow - _timeLastCheckbox;
+	if (timeDiffCheckBox > 67u) {
 		_timeLastCheckbox = timeNow;
 		for (int i = 0; i < _lineCount; ++i) {
 			if (_lines[i]->flags & 0x01) { // has checkbox
 				if (_lines[i]->flags & 0x02) { // checkbox checked
-					if (_lines[i]->checkboxFrame < 5) {
-						_lines[i]->checkboxFrame += timeDiffCheckBox / 67;
+					if (_lines[i]->checkboxFrame < 5u) {
+						_lines[i]->checkboxFrame += timeDiffCheckBox / 67u;
 					}
-					if (_lines[i]->checkboxFrame > 5) {
-						_lines[i]->checkboxFrame = 5;
+					if (_lines[i]->checkboxFrame > 5u) {
+						_lines[i]->checkboxFrame = 5u;
 					}
 				} else { // checkbox not checked
-					if (_lines[i]->checkboxFrame > 0) {
-						_lines[i]->checkboxFrame -= timeDiffCheckBox / 67;
+					if (_lines[i]->checkboxFrame > 0u) {
+						_lines[i]->checkboxFrame =  (_lines[i]->checkboxFrame < (timeDiffCheckBox / 67u)) ? 0u : _lines[i]->checkboxFrame - (timeDiffCheckBox / 67u);
 					}
-					if (_lines[i]->checkboxFrame < 0) {
-						_lines[i]->checkboxFrame = 0;
+					if (_lines[i]->checkboxFrame == 0u) { // original was < 0, int
+						_lines[i]->checkboxFrame = 0u;
 					}
 				}
 			}
@@ -434,7 +439,8 @@ void UIScrollBox::draw(Graphics::Surface &surface) {
 
 
 	// update highlight
-	if ((timeNow - _timeLastHighlight) > 67) {
+	// unsigned difference is intentional
+	if ((timeNow - _timeLastHighlight) > 67u) {
 		_timeLastHighlight = timeNow;
 		_highlightFrame = (_highlightFrame + 1) % 8;
 	}
@@ -497,8 +503,8 @@ void UIScrollBox::draw(Graphics::Surface &surface) {
 				int checkboxShapeId = 0;
 				if (_style == 0) {
 					if (_lines[i]->checkboxFrame || v35) {
-						if (_lines[i]->checkboxFrame != 5 || v35) {
-							checkboxShapeId = _lines[i]->checkboxFrame + 62;
+						if (_lines[i]->checkboxFrame != 5u || v35) {
+							checkboxShapeId = _lines[i]->checkboxFrame + 62u;
 						} else {
 							checkboxShapeId = 61;
 						}
@@ -506,8 +512,8 @@ void UIScrollBox::draw(Graphics::Surface &surface) {
 						checkboxShapeId = 60;
 					}
 				} else if (_lines[i]->checkboxFrame || v35) {
-					if (_lines[i]->checkboxFrame != 5 || v35) {
-						checkboxShapeId = _lines[i]->checkboxFrame + 54;
+					if (_lines[i]->checkboxFrame != 5u || v35) {
+						checkboxShapeId = _lines[i]->checkboxFrame + 54u;
 					} else {
 						checkboxShapeId = 53;
 					}
diff --git a/engines/bladerunner/ui/ui_scroll_box.h b/engines/bladerunner/ui/ui_scroll_box.h
index 1cd2913525..2ac0701ee0 100644
--- a/engines/bladerunner/ui/ui_scroll_box.h
+++ b/engines/bladerunner/ui/ui_scroll_box.h
@@ -45,9 +45,9 @@ class UIScrollBox : public UIComponent {
 
 	struct Line {
 		Common::String text;
-		int lineData;
-		int flags;
-		int checkboxFrame;
+		int    lineData;
+		int    flags;
+		uint32 checkboxFrame;
 	};
 
 	int                   _selectedLineState;
@@ -75,9 +75,9 @@ class UIScrollBox : public UIComponent {
 	int                   _style;
 	bool                  _center;
 
-	int                   _timeLastScroll;
-	int                   _timeLastCheckbox;
-	int                   _timeLastHighlight;
+	uint32                _timeLastScroll;
+	uint32                _timeLastCheckbox;
+	uint32                _timeLastHighlight;
 
 	int                   _highlightFrame;
 
diff --git a/engines/bladerunner/ui/vk.cpp b/engines/bladerunner/ui/vk.cpp
index e0b595cedc..1cacf31584 100644
--- a/engines/bladerunner/ui/vk.cpp
+++ b/engines/bladerunner/ui/vk.cpp
@@ -213,7 +213,8 @@ void VK::tick() {
 	_vm->blitToScreen(_vm->_surfaceFront);
 	_vm->_system->delayMillis(10);
 
-	if (_isClosing && _vm->_time->current() >= _timeClose && !_script->isInsideScript()) {
+	// unsigned difference is intentional
+	if (_isClosing && (_vm->_time->current() - _timeCloseStart >= 3000u) && !_script->isInsideScript()) {
 		close();
 		_vm->_mouse->enable();
 		reset();
@@ -265,8 +266,9 @@ void VK::playSpeechLine(int actorId, int sentenceId, float duration) {
 	}
 
 	if (duration > 0.0f && !_vm->_actorSpeakStopIsRequested) {
-		int timeEnd = duration * 1000.0f + _vm->_time->current();
-		while ((timeEnd > _vm->_time->current()) && _vm->_gameIsRunning) {
+		uint32  timeStart = _vm->_time->current();
+		uint32  timeUntil = duration * 1000.0f;
+		while ((_vm->_time->current() - timeStart < timeUntil) && _vm->_gameIsRunning) {
 			_vm->gameTick();
 		}
 	}
@@ -280,13 +282,13 @@ void VK::subjectReacts(int intensity, int humanResponse, int replicantResponse,
 	humanResponse     = CLIP(humanResponse, -20, 20);
 	replicantResponse = CLIP(replicantResponse, -20, 20);
 
-	int timeNow = _vm->_time->current();
-	bool closeVK = false;
+	uint32 timeNow = _vm->_time->current();
+	bool closeVK   = false;
 
 	if (intensity > 0) {
 		_needleValueTarget = 78 * intensity / 100;
 		_needleValueDelta = (_needleValueTarget - _needleValue) / 10;
-		_timeNextNeedleStep = timeNow + 66;
+		_timeNextNeedleStepStart = timeNow;
 	}
 
 	if (humanResponse != 0) {
@@ -309,7 +311,7 @@ void VK::subjectReacts(int intensity, int humanResponse, int replicantResponse,
 
 			if (closeVK == true) {
 				_isClosing = true;
-				_timeClose = timeNow + 3000;
+				_timeCloseStart = timeNow;
 				_vm->_mouse->disable();
 			}
 		}
@@ -340,7 +342,7 @@ void VK::subjectReacts(int intensity, int humanResponse, int replicantResponse,
 
 			if (closeVK == true) {
 				_isClosing = true;
-				_timeClose = timeNow + 3000;
+				_timeCloseStart = timeNow;
 				_vm->_mouse->disable();
 			}
 		}
@@ -368,7 +370,7 @@ void VK::subjectReacts(int intensity, int humanResponse, int replicantResponse,
 
 	if (closeVK == true) {
 		_isClosing = true;
-		_timeClose = timeNow + 3000;
+		_timeCloseStart = timeNow;
 		_vm->_mouse->disable();
 	}
 }
@@ -462,46 +464,49 @@ void VK::reset() {
 	_needleValueTarget       = 0;
 	_needleValueDelta        = 0;
 	_needleValueMax          = 0;
-	_timeNextNeedleStep      = 0;
-	_timeNeedleReturn        = 0;
-	_timeNextNeedleOscillate = 0;
-
-	_humanProbability       = 0;
-	_humanGauge             = 0;
-	_humanGaugeTarget       = 0;
-	_humanGaugeDelta        = 0;
-	_timeNextHumanGaugeStep = 0;
-
-	_replicantProbability       = 0;
-	_replicantGauge             = 0;
-	_replicantGaugeTarget       = 0;
-	_replicantGaugeDelta        = 0;
-	_timeNextReplicantGaugeStep = 0;
+
+	_timeNextNeedleStepStart      = 0u;
+	_timeNeedleReturnStart        = 0u;
+	_timeNextNeedleOscillateStart = 0u;
+
+	_humanProbability                = 0;
+	_humanGauge                      = 0;
+	_humanGaugeTarget                = 0;
+	_humanGaugeDelta                 = 0;
+	_timeNextHumanGaugeStepDiff      = 0u;
+	_timeNextHumanGaugeStepStart     = 0u;
+
+	_replicantProbability            = 0;
+	_replicantGauge                  = 0;
+	_replicantGaugeTarget            = 0;
+	_replicantGaugeDelta             = 0;
+	_timeNextReplicantGaugeStepDiff  = 0u;
+	_timeNextReplicantGaugeStepStart = 0u;
 
 	_anxiety = 0;
 
-	_blinkState          = 0;
-	_timeNextBlink       = 0;
-	_timeNextGaugesBlink = 0;
-
-	_isClosing = false;
-	_timeClose = 0;
-
-	_isAdjusting             = false;
-	_adjustment              = 154;
-	_adjustmentTarget        = 154;
-	_adjustmentDelta         = 0;
-	_timeNextAdjustementStep = 0;
-
-	_eyeLineSelected      = 1;
-	_eyeLineX             = 315;
-	_eyeLineXLast         = 315;
-	_eyeLineY             = 281;
-	_eyeLineYLast         = 281;
-	_eyeLineXDelta        = 8;
-	_eyeLineYDelta        = 8;
-	_timeNextEyeLineStep  = 0;
-	_timeNextEyeLineStart = 0;
+	_blinkState               = 0;
+	_timeNextBlinkStart       = 0u;
+	_timeNextGaugesBlinkStart = 0u;
+
+	_isClosing      = false;
+	_timeCloseStart = 0u;
+
+	_isAdjusting                  = false;
+	_adjustment                   = 154;
+	_adjustmentTarget             = 154;
+	_adjustmentDelta              = 0;
+	_timeNextAdjustementStepStart = 0u;
+
+	_eyeLineSelected           = 1;
+	_eyeLineX                  = 315;
+	_eyeLineXLast              = 315;
+	_eyeLineY                  = 281;
+	_eyeLineYLast              = 281;
+	_eyeLineXDelta             = 8;
+	_eyeLineYDelta             = 8;
+	_timeNextEyeLineStepStart  = 0u;
+	_timeNextEyeLineStart      = 0u;
 
 	_soundTrackId1 = -1;
 	_soundTrackId2 = -1;
@@ -573,14 +578,15 @@ void VK::draw() {
 
 	Graphics::Surface &surface = _vm->_surfaceFront;
 
-	int timeNow = _vm->_time->current();
+	uint32 timeNow = _vm->_time->current();
 
 	if (_isAdjusting && !_testStarted && !_vm->isMouseButtonDown()) {
 		_isAdjusting = false;
 	}
 
 	if (_vqaFrameMain >= 26) {
-		if (_isClosing && timeNow >= _timeNextGaugesBlink) {
+		// unsigned difference is intentional
+		if (_isClosing && timeNow - _timeNextGaugesBlinkStart >= 600u) {
 			if (_blinkState) {
 				_buttons->setImageShapeUp(6, nullptr);
 				_buttons->setImageShapeUp(7, nullptr);
@@ -596,12 +602,13 @@ void VK::draw() {
 				}
 				_blinkState = 1;
 			}
-			_timeNextGaugesBlink = timeNow + 600;
+			_timeNextGaugesBlinkStart = timeNow;
 		}
 
 		_buttons->draw(surface);
 
-		if (_humanGaugeDelta != 0 && timeNow >= _timeNextHumanGaugeStep) {
+		// unsigned difference is intentional
+		if (_humanGaugeDelta != 0 && timeNow - _timeNextHumanGaugeStepStart >= _timeNextHumanGaugeStepDiff) {
 			_humanGauge += _humanGaugeDelta;
 
 			if ((_humanGaugeDelta > 0 && _humanGauge >= _humanGaugeTarget)
@@ -613,17 +620,20 @@ void VK::draw() {
 				if (_humanGaugeTarget != 0) {
 					_humanGaugeTarget = 0;
 					_humanGaugeDelta = -_humanGaugeDelta;
-					_timeNextHumanGaugeStep = timeNow + 500;
+					_timeNextHumanGaugeStepDiff  = 500u;
+					_timeNextHumanGaugeStepStart = timeNow;
 				} else {
 					_humanGaugeDelta = 0;
 				}
 			} else {
-				_timeNextHumanGaugeStep = timeNow + 66;
+				_timeNextHumanGaugeStepDiff  = 66u;
+				_timeNextHumanGaugeStepStart = timeNow;
 			}
 		}
 		drawHumanGauge(surface);
 
-		if (_replicantGaugeDelta != 0 && timeNow >= _timeNextReplicantGaugeStep) {
+		// unsigned difference is intentional
+		if (_replicantGaugeDelta != 0 && timeNow - _timeNextReplicantGaugeStepStart >= _timeNextReplicantGaugeStepDiff) {
 			_replicantGauge += _replicantGaugeDelta;
 
 			if ((_replicantGaugeDelta > 0 && _replicantGauge >= _replicantGaugeTarget)
@@ -635,17 +645,20 @@ void VK::draw() {
 				if (_replicantGaugeTarget != 0) {
 					_replicantGaugeTarget = 0;
 					_replicantGaugeDelta = -_replicantGaugeDelta;
-					_timeNextReplicantGaugeStep = timeNow + 500;
+					_timeNextReplicantGaugeStepDiff  = 500u;
+					_timeNextReplicantGaugeStepStart = timeNow;
 				} else {
 					_replicantGaugeDelta = 0;
 				}
 			} else {
-				_timeNextReplicantGaugeStep = timeNow + 66;
+				_timeNextReplicantGaugeStepDiff  = 66u;
+				_timeNextReplicantGaugeStepStart = timeNow;
 			}
 		}
 		drawReplicantGauge(surface);
 
-		if (!_calibrationStarted && _vqaFrameMain >= 59 && timeNow >= _timeNextBlink) {
+		// unsigned difference is intentional
+		if (!_calibrationStarted && _vqaFrameMain >= 59 && timeNow - _timeNextBlinkStart >= 600u) {
 			if (_blinkState) {
 				_buttons->setImageShapeUp(0, nullptr);
 				_blinkState = false;
@@ -654,10 +667,11 @@ void VK::draw() {
 				_vm->_audioPlayer->playAud(_vm->_gameInfo->getSfxTrack(kSfxVKBEEP1), 50, 0, 0, 50, 0);
 				_blinkState = true;
 			}
-			_timeNextBlink = timeNow + 600;
+			_timeNextBlinkStart = timeNow;
 		}
 
-		if (_adjustmentDelta != 0 && timeNow >= _timeNextAdjustementStep) {
+		// unsigned difference is intentional
+		if (_adjustmentDelta != 0 && timeNow - _timeNextAdjustementStepStart >= 50u) {
 			if (_adjustmentDelta > 0) {
 				_adjustment += 3;
 				if (_adjustment >= _adjustmentTarget) {
@@ -675,7 +689,8 @@ void VK::draw() {
 		}
 		setAdjustmentFromMouse();
 
-		if (_calibrationStarted && !_testStarted && timeNow >= _timeNextBlink) {
+		// unsigned difference is intentional
+		if (_calibrationStarted && !_testStarted && timeNow - _timeNextBlinkStart >= 600u) {
 			if (_blinkState) {
 				_buttons->setImageShapeUp(2, nullptr);
 				_buttons->setImageShapeUp(3, nullptr);
@@ -689,10 +704,11 @@ void VK::draw() {
 
 				_vm->_audioPlayer->playAud(_vm->_gameInfo->getSfxTrack(kSfxVKBEEP2), 33, 0, 0, 50, 0);
 			}
-			_timeNextBlink = timeNow + 600;
+			_timeNextBlinkStart = timeNow;
 		}
 
-		if (_needleValueDelta != 0 && timeNow >= _timeNextNeedleStep) {
+		// unsigned difference is intentional
+		if (_needleValueDelta != 0 && (timeNow - _timeNextNeedleStepStart >= 66u)) {
 			if (_needleValueDelta > 0) {
 				_needleValue += 4;
 				if (_needleValue >= _needleValueTarget) {
@@ -701,13 +717,14 @@ void VK::draw() {
 					_needleValueDelta = -_needleValueDelta;
 					_needleValueTarget = 0;
 
-					_timeNeedleReturn = timeNow + 1800;
+					_timeNeedleReturnStart = timeNow;
 
 					if (!_testStarted) {
 						animateAdjustment(_needleValueMax + 165);
 					}
 				}
-			} else if (timeNow >= _timeNeedleReturn) {
+			} else if (timeNow - _timeNeedleReturnStart >= 1800u) {
+				// unsigned difference is intentional
 				_needleValue -= 4;
 				if (_needleValue <= _needleValueTarget) {
 					_needleValue = _needleValueTarget;
@@ -715,14 +732,15 @@ void VK::draw() {
 				}
 			}
 			_vm->_audioPlayer->playAud(_vm->_gameInfo->getSfxTrack(kSfxBR027_3P), 20, 0, 0, 50, 0);
-			_timeNextNeedleStep = timeNow + 66;
+			_timeNextNeedleStepStart = timeNow;
 		}
 
 		drawNeedle(surface);
 		drawEye(surface);
 		drawEyeCrosshair(surface, timeNow);
-		if (timeNow >= _timeNextNeedleOscillate) {
-			_timeNextNeedleOscillate = timeNow + 66;
+		// unsigned difference is intentional
+		if (timeNow - _timeNextNeedleOscillateStart >= 66u) {
+			_timeNextNeedleOscillateStart = timeNow;
 		}
 		int mouseX, mouseY;
 		_vm->_mouse->getXY(&mouseX, &mouseY);
@@ -734,7 +752,8 @@ void VK::draw() {
 
 void VK::drawNeedle(Graphics::Surface &surface) {
 	int x = _needleValue + 165;
-	if ((_vm->_time->current() >= _timeNextNeedleOscillate) && (x > 165)) {
+	// unsigned difference is intentional
+	if ((_vm->_time->current() - _timeNextNeedleOscillateStart >= 66u) && (x > 165)) {
 		x = CLIP(x + (int)_vm->_rnd.getRandomNumberRng(0, 4) - 2, 165, 245);
 	}
 
@@ -759,7 +778,7 @@ void VK::drawEye(Graphics::Surface &surface) {
 	surface.copyRectToSurface(_surfaceEye, 315, 281, Common::Rect(0, 0, _surfaceEye.w, _surfaceEye.h));
 }
 
-void VK::drawEyeCrosshair(Graphics::Surface &surface, int timeNow) {
+void VK::drawEyeCrosshair(Graphics::Surface &surface, uint32 timeNow) {
 	surface.drawLine(315,                                        _eyeLineY,     486,                                        _eyeLineY,     surface.format.RGBToColor(16, 16, 64));
 	surface.drawLine(315,                                        _eyeLineY - 1, 486,                                        _eyeLineY - 1, surface.format.RGBToColor(16, 16, 64));
 	surface.drawLine(315,                                        _eyeLineY,     _vm->_rnd.getRandomNumberRng(10, 20) + 315, _eyeLineY,     surface.format.RGBToColor(16, 16, 80));
@@ -774,13 +793,15 @@ void VK::drawEyeCrosshair(Graphics::Surface &surface, int timeNow) {
 	surface.drawLine(_eyeLineX - 1, 396 - _vm->_rnd.getRandomNumberRng(10, 20), _eyeLineX - 1, 396,                                        surface.format.RGBToColor(16, 16, 80));
 	surface.drawLine(_eyeLineX - 1, 281,                                        _eyeLineX - 1, _vm->_rnd.getRandomNumberRng(10, 20) + 281, surface.format.RGBToColor(16, 16, 80));
 
-	if (timeNow >= _timeNextEyeLineStart) {
+	// unsigned difference is intentional
+	if (timeNow - _timeNextEyeLineStart >= 1000u) {
 		if (_eyeLineSelected) {
 			if (_eyeLineYLast != _eyeLineY) {
 				surface.drawLine(315, _eyeLineYLast, 486, _eyeLineYLast, surface.format.RGBToColor(16, 16, 32));
 			}
 			_eyeLineYLast = _eyeLineY;
-			if (timeNow >= _timeNextEyeLineStep) {
+			// unsigned difference is intentional
+			if (timeNow - _timeNextEyeLineStepStart >= 50u) {
 				_eyeLineY += _eyeLineYDelta;
 				if (_eyeLineYDelta > 0) {
 					if (_eyeLineY >= 396) {
@@ -791,16 +812,17 @@ void VK::drawEyeCrosshair(Graphics::Surface &surface, int timeNow) {
 					_eyeLineY = 281;
 					_eyeLineYDelta = -_eyeLineYDelta;
 					_eyeLineSelected = 0;
-					_timeNextEyeLineStart = timeNow + 1000;
+					_timeNextEyeLineStart = timeNow;
 				}
-				_timeNextEyeLineStep = timeNow + 50;
+				_timeNextEyeLineStepStart = timeNow;
 			}
 		} else {
 			if (_eyeLineXLast != _eyeLineX) {
 				surface.drawLine(_eyeLineXLast, 281, _eyeLineXLast, 396, surface.format.RGBToColor(16, 16, 32));
 			}
 			_eyeLineXLast = _eyeLineX;
-			if (timeNow >= _timeNextEyeLineStep) {
+			// unsigned difference is intentional
+			if (timeNow - _timeNextEyeLineStepStart >= 50u) {
 				_eyeLineX += _eyeLineXDelta;
 				if ( _eyeLineXDelta > 0) {
 					if (_eyeLineX >= 486) {
@@ -811,9 +833,9 @@ void VK::drawEyeCrosshair(Graphics::Surface &surface, int timeNow) {
 					_eyeLineX = 315;
 					_eyeLineXDelta = -_eyeLineXDelta;
 					_eyeLineSelected = 1;
-					_timeNextEyeLineStart = timeNow + 1000;
+					_timeNextEyeLineStart = timeNow;
 				}
-				_timeNextEyeLineStep = timeNow + 50;
+				_timeNextEyeLineStepStart = timeNow;
 			}
 		}
 	}
@@ -914,7 +936,7 @@ void VK::stopAdjustement() {
 void VK::animateAdjustment(int target) {
 	_adjustmentTarget = MAX(target - 4, 154);
 	_adjustmentDelta = (_adjustmentTarget - _adjustment) / 5;
-	_timeNextAdjustementStep = _vm->_time->current() + 50;
+	_timeNextAdjustementStepStart = _vm->_time->current();
 }
 
 void VK::setAdjustment(int x) {
@@ -1040,7 +1062,7 @@ void VK::askQuestion(int intensity) {
 	) {
 		_isClosing = true;
 		_vm->_mouse->disable();
-		_timeClose = _vm->_time->current() + 3000;
+		_timeCloseStart = _vm->_time->current();
 	}
 }
 
diff --git a/engines/bladerunner/ui/vk.h b/engines/bladerunner/ui/vk.h
index d0b749363d..eeaee1b54d 100644
--- a/engines/bladerunner/ui/vk.h
+++ b/engines/bladerunner/ui/vk.h
@@ -55,13 +55,13 @@ class VK {
 
 	VQAPlayer *_vqaPlayerMain;
 	VQAPlayer *_vqaPlayerEye;
-	int _vqaFrameMain;
+	int  _vqaFrameMain;
 	bool _vqaLoopEnded;
 
 	Graphics::Surface _surfaceEye;
 
 	bool _isOpen;
-	int _actorId;
+	int  _actorId;
 	bool _calibrationStarted;
 	bool _testStarted;
 
@@ -77,50 +77,52 @@ class VK {
 	int _calibrationRatio;
 	int _calibrationCounter;
 
-	int _humanProbability;
-	int _humanGauge;
-	int _humanGaugeTarget;
-	int _humanGaugeDelta;
-	int _timeNextHumanGaugeStep;
-
-	int _replicantProbability;
-	int _replicantGauge;
-	int _replicantGaugeTarget;
-	int _replicantGaugeDelta;
-	int _timeNextReplicantGaugeStep;
-
-	int _anxiety;
-
-	int _needleValue;
-	int _needleValueMax;
-	int _needleValueTarget;
-	int _needleValueDelta;
-	int _timeNextNeedleStep;
-	int _timeNextNeedleOscillate;
-	int _timeNeedleReturn;
-
-	bool _isClosing;
-	int _timeClose;
-
-	int _blinkState;
-	int _timeNextBlink;
-	int _timeNextGaugesBlink;
-
-	bool _isAdjusting;
-	int _adjustment;
-	int _adjustmentTarget;
-	int _adjustmentDelta;
-	int _timeNextAdjustementStep;
-
-	int _eyeLineSelected;
-	int _eyeLineX;
-	int _eyeLineXLast;
-	int _eyeLineY;
-	int _eyeLineYLast;
-	int _eyeLineXDelta;
-	int _eyeLineYDelta;
-	int _timeNextEyeLineStep;
-	int _timeNextEyeLineStart;
+	int    _humanProbability;
+	int    _humanGauge;
+	int    _humanGaugeTarget;
+	int    _humanGaugeDelta;
+	uint32 _timeNextHumanGaugeStepDiff;
+	uint32 _timeNextHumanGaugeStepStart;
+
+	int    _replicantProbability;
+	int    _replicantGauge;
+	int    _replicantGaugeTarget;
+	int    _replicantGaugeDelta;
+	uint32 _timeNextReplicantGaugeStepDiff;
+	uint32 _timeNextReplicantGaugeStepStart;
+
+	int    _anxiety;
+
+	int    _needleValue;
+	int    _needleValueMax;
+	int    _needleValueTarget;
+	int    _needleValueDelta;
+	uint32 _timeNextNeedleStepStart;
+	uint32 _timeNextNeedleOscillateStart;
+	uint32 _timeNeedleReturnStart;
+
+	bool   _isClosing;
+	uint32 _timeCloseStart;
+
+	int    _blinkState;
+	uint32 _timeNextBlinkStart;
+	uint32 _timeNextGaugesBlinkStart;
+
+	bool   _isAdjusting;
+	int    _adjustment;
+	int    _adjustmentTarget;
+	int    _adjustmentDelta;
+	uint32 _timeNextAdjustementStepStart;
+
+	int    _eyeLineSelected;
+	int    _eyeLineX;
+	int    _eyeLineXLast;
+	int    _eyeLineY;
+	int    _eyeLineYLast;
+	int    _eyeLineXDelta;
+	int    _eyeLineYDelta;
+	uint32 _timeNextEyeLineStepStart;
+	uint32 _timeNextEyeLineStart;
 
 public:
 	VK(BladeRunnerEngine *vm);
@@ -154,7 +156,7 @@ private:
 
 	void drawNeedle(Graphics::Surface &surface);
 	void drawEye(Graphics::Surface &surface);
-	void drawEyeCrosshair(Graphics::Surface &surface, int timeNow);
+	void drawEyeCrosshair(Graphics::Surface &surface, uint32 timeNow);
 	void drawMouse(Graphics::Surface &surface);
 	void drawGauge(Graphics::Surface &surface, int value, int x, int y, int width);
 	void drawHumanGauge(Graphics::Surface &surface);