MADS: Implement screen shaking

4 files changed, 34 insertions, 11 deletions

diff --git a/engines/mads/game.cpp b/engines/mads/game.cpp
index ac77aec4ae..3f424711f7 100644
--- a/engines/mads/game.cpp
+++ b/engines/mads/game.cpp
@@ -495,6 +495,7 @@ void Game::loadGame(int slotNumber) {
 	_scene._currentSceneId = -2;
 	_sectionNumber = _scene._nextSceneId / 100;
 	_scene._frameStartTime = _vm->_events->getFrameCounter();
+	_vm->_screen._shakeCountdown = -1;
 
 	// Default the selected inventory item to the first one, if the player has any
 	_scene._userInterface._selectedInvIndex = _objects._inventoryList.size() > 0 ? 0 : -1;
diff --git a/engines/mads/nebular/nebular_scenes3.cpp b/engines/mads/nebular/nebular_scenes3.cpp
index ddff434ca0..11eb2f85e0 100644
--- a/engines/mads/nebular/nebular_scenes3.cpp
+++ b/engines/mads/nebular/nebular_scenes3.cpp
@@ -2800,7 +2800,7 @@ void Scene318::step() {
 
 		if (_internCounter >= 3600) {
 			_vm->_sound->command(59);
-			warning("TODO: shake_countdown = 20;");
+			_vm->_screen._shakeCountdown = 20;
 			_internWalkingFl = true;
 		}
 	}
@@ -3270,22 +3270,22 @@ void Scene319::step() {
 
 		if (_animMode == 2) {
 			if (_animFrame == 13)
-				warning("TODO: shake_countdown = 40;");
+				_vm->_screen._shakeCountdown = 40;
 
 			if (_animFrame == 16)
-				warning("TODO: shake_countdown = 1;");
+				_vm->_screen._shakeCountdown = 1;
 		}
 
 		if (_animMode == 3) {
 			if (_animFrame == 11)
-				warning("TODO: shake_countdown = 60;");
+				_vm->_screen._shakeCountdown = 60;
 
 			if (_animFrame == 18)
-				warning("TODO: shake_countdown = 1;");
+				_vm->_screen._shakeCountdown = 1;
 		}
 
 		if ((_animMode == 4) && (_animFrame == 16))
-			warning("TODO: shake_countdown = 80;");
+			_vm->_screen._shakeCountdown = 80;
 
 		if ((nextFrame >= 0) && (nextFrame != _scene->_activeAnimation->getCurrentFrame())) {
 			_scene->_activeAnimation->setCurrentFrame(nextFrame);
@@ -3308,7 +3308,7 @@ void Scene319::step() {
 
 		_animFrame = _scene->_activeAnimation->getCurrentFrame();
 		_slacheTalkingFl = true;
-		warning("TODO: shake_countdown = 1;");
+		_vm->_screen._shakeCountdown = 1;
 
 		for (int i = 0; i <= 1; i++) {
 			int oldIdx = _globals._sequenceIndexes[i];
@@ -3325,7 +3325,7 @@ void Scene319::step() {
 		_vm->_palette->setColorValues(0, 0, 0);
 		_vm->_palette->fadeOut(_vm->_palette->_mainPalette, nullptr, 18, 228,
 			248, 0, 1, 16);
-		warning("TODO: shake_countdown = 1;");
+		_vm->_screen._shakeCountdown = 1;
 		_scene->_reloadSceneFlag = true;
 		break;
 
@@ -3706,7 +3706,7 @@ void Scene320::step() {
 
 			case 417:
 			case 457:
-				warning("TODO: shake_countdown = 40;");
+				_vm->_screen._shakeCountdown = 40;
 				_vm->_sound->command(59);
 				break;
 
diff --git a/engines/mads/screen.cpp b/engines/mads/screen.cpp
index ae129995ac..dacd20a348 100644
--- a/engines/mads/screen.cpp
+++ b/engines/mads/screen.cpp
@@ -545,6 +545,8 @@ void ScreenObjects::synchronize(Common::Serializer &s) {
 /*------------------------------------------------------------------------*/
 
 ScreenSurface::ScreenSurface() {
+	_shakeCountdown = -1;
+	_random = 0x4D2;
 }
 
 void ScreenSurface::init() {
@@ -553,7 +555,7 @@ void ScreenSurface::init() {
 
 void ScreenSurface::copyRectToScreen(const Common::Point &destPos,
 		const Common::Rect &bounds) {
-	byte *buf = getBasePtr(destPos.x, destPos.y);
+	const byte *buf = getBasePtr(destPos.x, destPos.y);
 
 	if (bounds.width() != 0 && bounds.height() != 0)
 		g_system->copyRectToScreen(buf, this->pitch, bounds.left, bounds.top,
@@ -564,8 +566,25 @@ void ScreenSurface::copyRectToScreen(const Common::Rect &bounds) {
 	copyRectToScreen(Common::Point(bounds.left, bounds.top), bounds);
 }
 
-
 void ScreenSurface::updateScreen() {
+	if (_shakeCountdown >= 0) {
+		_random = _random * 5 + 1;
+		int offset = (_random >> 8) & 3;
+		if (_shakeCountdown-- <= 0)
+			offset = 0;
+
+		// Copy the screen with the left hand hide side of the screen of a given
+		// offset width shown at the very right. The offset changes to give 
+		// an effect of shaking the screen
+		offset *= 4;
+		const byte *buf = getBasePtr(offset, 0);
+		g_system->copyRectToScreen(buf, this->pitch, 0, 0,
+			this->pitch - offset, this->h);
+		if (offset > 0)
+			g_system->copyRectToScreen(this->pixels, this->pitch, 
+				this->pitch - offset, 0, offset, this->h);
+	}
+
 	g_system->updateScreen();
 }
 
diff --git a/engines/mads/screen.h b/engines/mads/screen.h
index 0e678d87a0..b81fddd87a 100644
--- a/engines/mads/screen.h
+++ b/engines/mads/screen.h
@@ -197,8 +197,11 @@ public:
 };
 
 class ScreenSurface : public MSurface {
+private:
+	uint16 _random;
 public:
 	Common::Point _offset;
+	int _shakeCountdown;
 public:
 	/**
 	 * Constructor