MOHAWK: Implement fading for Myst Demo

5 files changed, 55 insertions, 9 deletions

diff --git a/engines/mohawk/graphics.cpp b/engines/mohawk/graphics.cpp
index 35c9d478d8..c4326d175f 100644
--- a/engines/mohawk/graphics.cpp
+++ b/engines/mohawk/graphics.cpp
@@ -672,12 +672,50 @@ void MystGraphics::simulatePreviousDrawDelay(const Common::Rect &dest) {
 	_nextAllowedDrawTime = time + _constantDrawDelay + dest.height() * dest.width() / _proportionalDrawDelay;
 }
 
+void MystGraphics::copyBackBufferToScreenWithSaturation(int16 saturation) {
+	Graphics::Surface *screen = _vm->_system->lockScreen();
+
+	for (uint16 y = 0; y < _viewport.height(); y++)
+		for (uint16 x = 0; x < _viewport.width(); x++) {
+			uint32 color;
+			uint8 r, g, b;
+
+			if (_pixelFormat.bytesPerPixel == 2)
+				color = *(const uint16 *)_backBuffer->getBasePtr(x, y);
+			else
+				color = *(const uint32 *)_backBuffer->getBasePtr(x, y);
+
+			_pixelFormat.colorToRGB(color, r, g, b);
+
+			r = CLIP<int16>((int16)r - saturation, 0, 255);
+			g = CLIP<int16>((int16)g - saturation, 0, 255);
+			b = CLIP<int16>((int16)b - saturation, 0, 255);
+
+			color = _pixelFormat.RGBToColor(r, g, b);
+
+			if (_pixelFormat.bytesPerPixel == 2) {
+				uint16 *dst = (uint16 *)screen->getBasePtr(x, y);
+				*dst = color;
+			} else {
+				uint32 *dst = (uint32 *)screen->getBasePtr(x, y);
+				*dst = color;
+			}
+		}
+
+	_vm->_system->unlockScreen();
+	_vm->_system->updateScreen();
+}
+
 void MystGraphics::fadeToBlack() {
-	// TODO: Implement
+	for (int16 i = 0; i < 256; i += 32) {
+		copyBackBufferToScreenWithSaturation(i);
+	}
 }
 
 void MystGraphics::fadeFromBlack() {
-	// TODO: Implement
+	for (int16 i = 256; i >= 0; i -= 32) {
+		copyBackBufferToScreenWithSaturation(i);
+	}
 }
 
 #endif // ENABLE_MYST
diff --git a/engines/mohawk/graphics.h b/engines/mohawk/graphics.h
index 96357bbff1..463608a2aa 100644
--- a/engines/mohawk/graphics.h
+++ b/engines/mohawk/graphics.h
@@ -136,6 +136,7 @@ protected:
 	MohawkSurface *decodeImage(uint16 id);
 	MohawkEngine *getVM() { return (MohawkEngine *)_vm; }
 	void simulatePreviousDrawDelay(const Common::Rect &dest);
+	void copyBackBufferToScreenWithSaturation(int16 saturation);
 
 private:
 	MohawkEngine_Myst *_vm;
diff --git a/engines/mohawk/myst_stacks/demo.cpp b/engines/mohawk/myst_stacks/demo.cpp
index c9e806655e..fbad7dc384 100644
--- a/engines/mohawk/myst_stacks/demo.cpp
+++ b/engines/mohawk/myst_stacks/demo.cpp
@@ -84,7 +84,10 @@ void Demo::o_stopIntro(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 
 void Demo::o_fadeFromBlack(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 	debugC(kDebugScript, "Opcode %d: Fade from black", op);
-	_vm->_gfx->fadeFromBlack();
+
+	// FIXME: This glitches when enabled. The backbuffer is drawn to screen,
+	// and then the fading occurs, causing the background to appear for one frame.
+	// _vm->_gfx->fadeFromBlack();
 }
 
 void Demo::o_fadeToBlack(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
@@ -101,14 +104,14 @@ void Demo::returnToMenu_run() {
 	switch (_returnToMenuStep){
 	case 0:
 		_vm->_gfx->fadeToBlack();
-		_vm->changeToCard(2003, true);
+		_vm->changeToCard(2003, false);
 		_vm->_gfx->fadeFromBlack();
 
 		_returnToMenuStep++;
 		break;
 	case 1:
 		_vm->_gfx->fadeToBlack();
-		_vm->changeToCard(2001, true);
+		_vm->changeToCard(2001, false);
 		_vm->_gfx->fadeFromBlack();
 		_vm->_cursor->showCursor();
 
diff --git a/engines/mohawk/myst_stacks/preview.cpp b/engines/mohawk/myst_stacks/preview.cpp
index 1b72c85d96..31e22bb8c5 100644
--- a/engines/mohawk/myst_stacks/preview.cpp
+++ b/engines/mohawk/myst_stacks/preview.cpp
@@ -85,7 +85,10 @@ void Preview::o_fadeToBlack(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 
 void Preview::o_fadeFromBlack(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 	debugC(kDebugScript, "Opcode %d: Fade from black", op);
-	_vm->_gfx->fadeFromBlack();
+
+	// FIXME: This glitches when enabled. The backbuffer is drawn to screen,
+	// and then the fading occurs, causing the background to appear for one frame.
+	// _vm->_gfx->fadeFromBlack();
 }
 
 void Preview::o_stayHere(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
@@ -99,6 +102,7 @@ void Preview::o_stayHere(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 void Preview::o_speechStop(uint16 op, uint16 var, uint16 argc, uint16 *argv) {
 	debugC(kDebugScript, "Opcode %d: Speech stop", op);
 
+	_vm->_sound->stopSound(3001);
 	_speechRunning = false;
 	_globals.currentAge = 2;
 }
@@ -143,7 +147,7 @@ void Preview::speech_run() {
 	case 2: // Go to Myst
 		if (_currentCue >= 2) {
 			_vm->_gfx->fadeToBlack();
-			_vm->changeToCard(3002, true);
+			_vm->changeToCard(3002, false);
 			_vm->_gfx->fadeFromBlack();
 
 			_speechStep++;
@@ -186,7 +190,7 @@ void Preview::speech_run() {
 			break;
 
 		_vm->_gfx->fadeToBlack();
-		_vm->changeToCard(3005, true);
+		_vm->changeToCard(3005, false);
 		_vm->_gfx->fadeFromBlack();
 		_speechNextTime = time + 1000;
 		_speechStep++;
diff --git a/engines/mohawk/myst_stacks/slides.cpp b/engines/mohawk/myst_stacks/slides.cpp
index 943cb90071..794793e49c 100644
--- a/engines/mohawk/myst_stacks/slides.cpp
+++ b/engines/mohawk/myst_stacks/slides.cpp
@@ -63,7 +63,7 @@ void Slides::runPersistentScripts() {
 		// Used on Cards...
 		if (_vm->_system->getMillis() > _nextCardTime) {
 			_vm->_gfx->fadeToBlack();
-			_vm->changeToCard(_nextCardID, true);
+			_vm->changeToCard(_nextCardID, false);
 			_vm->_gfx->fadeFromBlack();
 		}
 	}