SHERLOCK: Properly restrict scene drawing to scene area

6 files changed, 51 insertions, 40 deletions

diff --git a/engines/sherlock/graphics.cpp b/engines/sherlock/graphics.cpp
index 6e986c839b..6fd046e458 100644
--- a/engines/sherlock/graphics.cpp
+++ b/engines/sherlock/graphics.cpp
@@ -165,14 +165,6 @@ void Surface::fillRect(const Common::Rect &r, byte color) {
 }
 
 /**
- * Return a sub-area of the surface as a new surface object. The surfaces
- * are shared in common, so changes in the sub-surface affects the original.
- */
-Surface Surface::getSubArea(const Common::Rect &r) {
-	return Surface(*this, r);
-}
-
-/**
  * Clips the given source bounds so the passed destBounds will be entirely on-screen
  */
 bool Surface::clip(Common::Rect &srcBounds, Common::Rect &destBounds) {
diff --git a/engines/sherlock/graphics.h b/engines/sherlock/graphics.h
index 85f3ba8c40..80b692130c 100644
--- a/engines/sherlock/graphics.h
+++ b/engines/sherlock/graphics.h
@@ -55,8 +55,6 @@ public:
 
 	void fillRect(int x1, int y1, int x2, int y2, byte color);
 	void fillRect(const Common::Rect &r, byte color);
-
-	Surface getSubArea(const Common::Rect &r);
 };
 
 } // End of namespace Sherlock
diff --git a/engines/sherlock/map.cpp b/engines/sherlock/map.cpp
index 5ff27a9709..f572e3771a 100644
--- a/engines/sherlock/map.cpp
+++ b/engines/sherlock/map.cpp
@@ -442,7 +442,6 @@ void Map::updateMap(bool flushScreen) {
  */
 void Map::walkTheStreets() {
 	People &people = *_vm->_people;
-	Scene &scene = *_vm->_scene;
 	bool reversePath = false;
 	Common::Array<Common::Point> tempPath;
 
diff --git a/engines/sherlock/scene.cpp b/engines/sherlock/scene.cpp
index 1d00e9d23d..50e62b7ba5 100644
--- a/engines/sherlock/scene.cpp
+++ b/engines/sherlock/scene.cpp
@@ -716,10 +716,11 @@ int Scene::toggleObject(const Common::String &name) {
 void Scene::updateBackground() {
 	People &people = *_vm->_people;
 	Screen &screen = *_vm->_screen;
-	Surface surface = screen._backBuffer1.getSubArea(
-		Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCENE_HEIGHT));
 	Sprite &player = people[AL];
 
+	// Restrict drawing window
+	screen.setDisplayBounds(Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCENE_HEIGHT));
+
 	// Update Holmes if he's turned on
 	if (people._holmesOn)
 		player.adjustSprite();
@@ -731,26 +732,26 @@ void Scene::updateBackground() {
 	// Draw all active shapes which are behind the person
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		if (_bgShapes[idx]._type == ACTIVE_BG_SHAPE && _bgShapes[idx]._misc == BEHIND)
-			surface.transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
+			screen._backBuffer->transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
 	}
 
 	// Draw all canimations which are behind the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		if (_canimShapes[idx]._type == ACTIVE_BG_SHAPE && _canimShapes[idx]._misc == BEHIND)
-			surface.transBlitFrom(*_canimShapes[idx]._imageFrame,
+			screen._backBuffer->transBlitFrom(*_canimShapes[idx]._imageFrame,
 				_canimShapes[idx]._position, _canimShapes[idx]._flags & 2);
 	}
 
 	// Draw all active shapes which are normal and behind the person
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		if (_bgShapes[idx]._type == ACTIVE_BG_SHAPE && _bgShapes[idx]._misc == NORMAL_BEHIND)
-			surface.transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
+			screen._backBuffer->transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
 	}
 
 	// Draw all canimations which are normal and behind the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		if (_canimShapes[idx]._type == ACTIVE_BG_SHAPE && _canimShapes[idx]._misc == NORMAL_BEHIND)
-			surface.transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
+			screen._backBuffer->transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
 				_canimShapes[idx]._flags & 2);
 	}
 
@@ -760,7 +761,7 @@ void Scene::updateBackground() {
 			player._sequenceNumber == WALK_UPLEFT || player._sequenceNumber == STOP_UPLEFT ||
 			player._sequenceNumber == WALK_DOWNRIGHT || player._sequenceNumber == STOP_DOWNRIGHT;
 
-		surface.transBlitFrom(*player._imageFrame, Common::Point(player._position.x / 100, 
+		screen._backBuffer->transBlitFrom(*player._imageFrame, Common::Point(player._position.x / 100, 
 			player._position.y / 100 - player.frameHeight()), flipped);
 	}
 
@@ -768,14 +769,14 @@ void Scene::updateBackground() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		if ((_bgShapes[idx]._type == ACTIVE_BG_SHAPE || _bgShapes[idx]._type == STATIC_BG_SHAPE) &&
 				_bgShapes[idx]._misc == NORMAL_FORWARD)
-			surface.transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
+			screen._backBuffer->transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
 	}
 
 	// Draw all static and active canimations that are NORMAL and are in front of the player
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		if ((_canimShapes[idx]._type == ACTIVE_BG_SHAPE || _canimShapes[idx]._type == STATIC_BG_SHAPE) &&
 				_canimShapes[idx]._misc == NORMAL_FORWARD)
-			surface.transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
+			screen._backBuffer->transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
 				_canimShapes[idx]._flags & 2);
 	}
 
@@ -787,14 +788,14 @@ void Scene::updateBackground() {
 
 		if ((_bgShapes[idx]._type == ACTIVE_BG_SHAPE || _bgShapes[idx]._type == STATIC_BG_SHAPE) &&
 				_bgShapes[idx]._misc == FORWARD)
-			surface.transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
+			screen._backBuffer->transBlitFrom(*_bgShapes[idx]._imageFrame, _bgShapes[idx]._position, _bgShapes[idx]._flags & 2);
 	}
 
 	// Draw all static and active canimations that are forward
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		if ((_canimShapes[idx]._type == ACTIVE_BG_SHAPE || _canimShapes[idx]._type == STATIC_BG_SHAPE) &&
 			_canimShapes[idx]._misc == FORWARD)
-			surface.transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
+			screen._backBuffer->transBlitFrom(*_canimShapes[idx]._imageFrame, _canimShapes[idx]._position, 
 				_canimShapes[idx]._flags & 2);
 	}
 }
@@ -1079,8 +1080,8 @@ void Scene::doBgAnim() {
 	Sound &sound = *_vm->_sound;
 	Talk &talk = *_vm->_talk;
 	UserInterface &ui = *_vm->_ui;
-	Surface surface = screen._backBuffer1.getSubArea(Common::Rect(0, 0,
-		SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCENE_HEIGHT));
+
+	screen.setDisplayBounds(Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCENE_HEIGHT));
 	int cursorId = events.getCursor();
 	Common::Point mousePos = events.mousePos();
 
@@ -1150,7 +1151,7 @@ void Scene::doBgAnim() {
 		if (people[AL]._type == CHARACTER)
 			screen.restoreBackground(bounds);
 		else if (people[AL]._type == REMOVE)
-			screen._backBuffer1.blitFrom(screen._backBuffer2, pt, bounds);
+			screen._backBuffer->blitFrom(screen._backBuffer2, pt, bounds);
 
 		for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 			Object &o = _bgShapes[idx];
@@ -1169,7 +1170,7 @@ void Scene::doBgAnim() {
 			Object &o = _bgShapes[idx];
 			if (o._type == NO_SHAPE && ((o._flags & 1) == 0)) {
 				// Restore screen area
-				screen._backBuffer1.blitFrom(screen._backBuffer2, o._position,
+				screen._backBuffer->blitFrom(screen._backBuffer2, o._position,
 					Common::Rect(o._position.x, o._position.y,
 					o._position.x + o._noShapeSize.x, o._position.y + o._noShapeSize.y));
 
@@ -1218,14 +1219,14 @@ void Scene::doBgAnim() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		Object &o = _bgShapes[idx];
 		if (o._type == ACTIVE_BG_SHAPE && o._misc == BEHIND)
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 	}
 	
 	// Draw all canimations which are behind the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		Object &o = _canimShapes[idx];
 		if (o._type == ACTIVE_BG_SHAPE && o._misc == BEHIND) {
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 		}
 	}
 
@@ -1233,14 +1234,14 @@ void Scene::doBgAnim() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		Object &o = _bgShapes[idx];
 		if (o._type == ACTIVE_BG_SHAPE && o._misc == NORMAL_BEHIND)
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 	}
 
 	// Draw all canimations which are NORMAL and behind the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		Object &o = _canimShapes[idx];
 		if (o._type == ACTIVE_BG_SHAPE && o._misc == NORMAL_BEHIND) {
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 		}
 	}
 
@@ -1253,7 +1254,7 @@ void Scene::doBgAnim() {
 		bool flipped = people[AL]._sequenceNumber == WALK_LEFT || people[AL]._sequenceNumber == STOP_LEFT ||
 			people[AL]._sequenceNumber == WALK_UPLEFT || people[AL]._sequenceNumber == STOP_UPLEFT ||
 			people[AL]._sequenceNumber == WALK_DOWNRIGHT || people[AL]._sequenceNumber == STOP_DOWNRIGHT;
-		screen._backBuffer1.transBlitFrom(*people[AL]._imageFrame,
+		screen._backBuffer->transBlitFrom(*people[AL]._imageFrame,
 			Common::Point(tempX, people[AL]._position.y / 100 - people[AL]._imageFrame->_frame.h), flipped);
 	}
 
@@ -1261,14 +1262,14 @@ void Scene::doBgAnim() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		Object &o = _bgShapes[idx];
 		if ((o._type == ACTIVE_BG_SHAPE || o._type == STATIC_BG_SHAPE) && o._misc == NORMAL_FORWARD)
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 	}
 
 	// Draw all static and active canimations that are NORMAL and are in front of the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		Object &o = _canimShapes[idx];
 		if ((o._type == ACTIVE_BG_SHAPE || o._type == STATIC_BG_SHAPE) && o._misc == NORMAL_BEHIND) {
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 		}
 	}
 
@@ -1276,19 +1277,19 @@ void Scene::doBgAnim() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		Object &o = _bgShapes[idx];
 		if ((o._type == ACTIVE_BG_SHAPE || o._type == STATIC_BG_SHAPE) && o._misc == FORWARD)
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 	}
 
 	// Draw any active portrait
 	if (people._portraitLoaded && people._portrait._type == ACTIVE_BG_SHAPE)
-		screen._backBuffer1.transBlitFrom(*people._portrait._imageFrame,
+		screen._backBuffer->transBlitFrom(*people._portrait._imageFrame,
 			people._portrait._position, people._portrait._flags & 2);
 
 	// Draw all static and active canimations that are in front of the person
 	for (uint idx = 0; idx < _canimShapes.size(); ++idx) {
 		Object &o = _canimShapes[idx];
 		if ((o._type == ACTIVE_BG_SHAPE || o._type == STATIC_BG_SHAPE) && o._misc == FORWARD) {
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 		}
 	}
 
@@ -1296,7 +1297,7 @@ void Scene::doBgAnim() {
 	for (uint idx = 0; idx < _bgShapes.size(); ++idx) {
 		Object &o = _bgShapes[idx];
 		if (o._type == NO_SHAPE && (o._flags & 1) == 0)
-			screen._backBuffer1.transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
+			screen._backBuffer->transBlitFrom(*o._imageFrame, o._position, o._flags & 2);
 	}
 
 	// Bring the newly built picture to the screen
diff --git a/engines/sherlock/screen.cpp b/engines/sherlock/screen.cpp
index 3c9a10e4a1..66590c3ada 100644
--- a/engines/sherlock/screen.cpp
+++ b/engines/sherlock/screen.cpp
@@ -39,6 +39,10 @@ Screen::Screen(SherlockEngine *vm) : Surface(SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCR
 	Common::fill(&_cMap[0], &_cMap[PALETTE_SIZE], 0);
 	Common::fill(&_sMap[0], &_sMap[PALETTE_SIZE], 0);
 	setFont(1);
+
+	// Set dummy surface used for restricted scene drawing
+	_sceneSurface.format = Graphics::PixelFormat::createFormatCLUT8();
+	_sceneSurface.pitch = SHERLOCK_SCREEN_WIDTH;
 }
 
 Screen::~Screen() {
@@ -469,15 +473,31 @@ void Screen::makePanel(const Common::Rect &r) {
 	_backBuffer->hLine(r.left + 1, r.bottom - 2, r.right - 1, BUTTON_BOTTOM);
 }
 
+/**
+ * Sets the active back buffer pointer to a restricted sub-area of the first back buffer
+ */
 void Screen::setDisplayBounds(const Common::Rect &r) {
-	// TODO: See if needed
+	assert(r.left == 0 && r.top == 0);
+	_sceneSurface.setPixels(_backBuffer1.getPixels());
+	_sceneSurface.w = r.width();
+	_sceneSurface.h = r.height();
+
+	_backBuffer = &_sceneSurface;
 }
+
+/**
+ * Resets the active buffer pointer to point back to the full first back buffer
+ */
 void Screen::resetDisplayBounds() {
-	setDisplayBounds(Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCREEN_HEIGHT));
+	_backBuffer = &_backBuffer1;
 }
 
+/**
+ * Return the size of the current display window
+ */
 Common::Rect Screen::getDisplayBounds() {
-	return Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCREEN_HEIGHT);
+	return (_backBuffer == &_sceneSurface) ? Common::Rect(0, 0, _sceneSurface.w, _sceneSurface.h) :
+		Common::Rect(0, 0, SHERLOCK_SCREEN_WIDTH, SHERLOCK_SCREEN_HEIGHT);
 }
 
 /**
diff --git a/engines/sherlock/screen.h b/engines/sherlock/screen.h
index a8bdc53b5a..bbfba1c575 100644
--- a/engines/sherlock/screen.h
+++ b/engines/sherlock/screen.h
@@ -65,6 +65,7 @@ private:
 	uint32 _transitionSeed;
 	ImageFile *_font;
 	int _fontHeight;
+	Surface _sceneSurface;
 
 	void mergeDirtyRects();