Next step in transaction implementation. Now it postpones all calls.

NOTE: This breaks most ports, and they will not pass assertions. If you will
fix it (by moving violating OSystem calls to go() method), I'll be grateful.
If you don't bother to fix it, there is a workaround. Just comment out
beginGFXTransaction() and endGFXTransaction() in backends/sdl/graphics.cpp.
This will tunr it off and will use default transaction-less implementation.

svn-id: r15870

3 files changed, 150 insertions, 15 deletions

diff --git a/backends/sdl/graphics.cpp b/backends/sdl/graphics.cpp
index ed4a3cbd1e..ea16da6694 100644
--- a/backends/sdl/graphics.cpp
+++ b/backends/sdl/graphics.cpp
@@ -49,12 +49,55 @@ int OSystem_SDL::getDefaultGraphicsMode() const {
 	return GFX_DOUBLESIZE;
 }
 
+void OSystem_SDL::beginGFXTransaction(void) {
+	assert (_transactionMode == kTransactionNone);
+
+	_transactionMode = kTransactionActive;
+
+	_transactionDetails.modeChanged = false;
+	_transactionDetails.wChanged = false;
+	_transactionDetails.hChanged = false;
+	_transactionDetails.arChanged = false;
+	_transactionDetails.fsChanged = false;
+}
+
+void OSystem_SDL::endGFXTransaction(void) {
+	assert (_transactionMode == kTransactionActive);
+
+	_transactionMode = kTransactionCommit;
+	if (_transactionDetails.modeChanged) {
+		setGraphicsMode(_transactionDetails.mode);
+	}
+	if (_transactionDetails.wChanged || _transactionDetails.hChanged) {
+		initSize(_transactionDetails.w, _transactionDetails.h);
+	}
+	if (_transactionDetails.arChanged) {
+		setAspectRatioCorrection(_transactionDetails.ar);
+	}
+	if (_transactionDetails.fsChanged) {
+		setFullscreenMode(_transactionDetails.fs);
+	}
+	_transactionMode = kTransactionNone;
+}
+
 bool OSystem_SDL::setGraphicsMode(int mode) {
 	Common::StackLock lock(_graphicsMutex);
 
 	int newScaleFactor = 1;
 	ScalerProc *newScalerProc;
 
+	switch (_transactionMode) {
+	case kTransactionActive:
+		_transactionDetails.mode = mode;
+		_transactionDetails.modeChanged = true;
+		return true;
+		break;
+	case kTransactionCommit:
+		break;
+	default:
+		break;
+	} 
+
 	switch(mode) {
 	case GFX_NORMAL:
 		newScaleFactor = 1;
@@ -143,10 +186,25 @@ bool OSystem_SDL::setGraphicsMode(int mode) {
 }
 
 int OSystem_SDL::getGraphicsMode() const {
+	assert (_transactionMode == kTransactionNone);
 	return _mode;
 }
 
 void OSystem_SDL::initSize(uint w, uint h) {
+	switch (_transactionMode) {
+	case kTransactionActive:
+		_transactionDetails.w = w;
+		_transactionDetails.wChanged = true;
+		_transactionDetails.h = h;
+		_transactionDetails.hChanged = true;
+		return;
+		break;
+	case kTransactionCommit:
+		break;
+	default:
+		break;
+	} 
+
 	// Avoid redundant res changes
 	if ((int)w == _screenWidth && (int)h == _screenHeight)
 		return;
@@ -316,6 +374,8 @@ void OSystem_SDL::hotswap_gfx_mode() {
 }
 
 void OSystem_SDL::updateScreen() {
+	assert (_transactionMode == kTransactionNone);
+
 	Common::StackLock lock(_graphicsMutex);	// Lock the mutex until this function ends
 
 	internUpdateScreen();
@@ -485,6 +545,18 @@ bool OSystem_SDL::save_screenshot(const char *filename) {
 }
 
 void OSystem_SDL::setFullscreenMode(bool enable) {
+	switch (_transactionMode) {
+	case kTransactionActive:
+		_transactionDetails.fs = enable;
+		_transactionDetails.fsChanged = true;
+		return;
+		break;
+	case kTransactionCommit:
+		break;
+	default:
+		break;
+	} 
+
 	Common::StackLock lock(_graphicsMutex);
 
 	if (_full_screen != enable) {
@@ -514,7 +586,37 @@ void OSystem_SDL::setFullscreenMode(bool enable) {
 	}
 }
 
+void OSystem_SDL::setAspectRatioCorrection(bool enable) {
+	switch (_transactionMode) {
+	case kTransactionActive:
+		_transactionDetails.ar = enable;
+		_transactionDetails.arChanged = true;
+		return;
+		break;
+	case kTransactionCommit:
+		break;
+	default:
+		break;
+	} 
+
+	if (_screenHeight == 200 && _adjustAspectRatio != enable) {
+		Common::StackLock lock(_graphicsMutex);
+
+		//assert(_hwscreen != 0);
+		_adjustAspectRatio ^= true;
+		hotswap_gfx_mode();
+			
+		// Blit everything to the screen
+		internUpdateScreen();
+			
+		// Make sure that an EVENT_SCREEN_CHANGED gets sent later
+		_modeChanged = true;
+	}
+}
+
 void OSystem_SDL::clearScreen() {
+	assert (_transactionMode == kTransactionNone);
+
 	// Try to lock the screen surface
 	if (SDL_LockSurface(_screen) == -1)
 		error("SDL_LockSurface failed: %s", SDL_GetError());
@@ -529,6 +631,8 @@ void OSystem_SDL::clearScreen() {
 }
 
 void OSystem_SDL::copyRectToScreen(const byte *src, int pitch, int x, int y, int w, int h) {
+	assert (_transactionMode == kTransactionNone);
+
 	if (_screen == NULL)
 		return;
 
@@ -746,6 +850,8 @@ void OSystem_SDL::setPalette(const byte *colors, uint start, uint num) {
 }
 
 void OSystem_SDL::setShakePos(int shake_pos) {
+	assert (_transactionMode == kTransactionNone);
+
 	_newShakePos = shake_pos;
 }
 
@@ -755,6 +861,8 @@ void OSystem_SDL::setShakePos(int shake_pos) {
 #pragma mark -
 
 void OSystem_SDL::showOverlay() {
+	assert (_transactionMode == kTransactionNone);
+
 	// hide the mouse
 	undraw_mouse();
 
@@ -763,6 +871,8 @@ void OSystem_SDL::showOverlay() {
 }
 
 void OSystem_SDL::hideOverlay() {
+	assert (_transactionMode == kTransactionNone);
+
 	// hide the mouse
 	undraw_mouse();
 
@@ -771,6 +881,8 @@ void OSystem_SDL::hideOverlay() {
 }
 
 void OSystem_SDL::clearOverlay() {
+	assert (_transactionMode == kTransactionNone);
+
 	if (!_overlayVisible)
 		return;
 	
@@ -792,6 +904,8 @@ void OSystem_SDL::clearOverlay() {
 }
 
 void OSystem_SDL::grabOverlay(OverlayColor *buf, int pitch) {
+	assert (_transactionMode == kTransactionNone);
+
 	if (!_overlayVisible)
 		return;
 
@@ -816,6 +930,8 @@ void OSystem_SDL::grabOverlay(OverlayColor *buf, int pitch) {
 }
 
 void OSystem_SDL::copyRectToOverlay(const OverlayColor *buf, int pitch, int x, int y, int w, int h) {
+	assert (_transactionMode == kTransactionNone);
+
 	if (!_overlayVisible)
 		return;
 
@@ -946,6 +1062,8 @@ void OSystem_SDL::toggleMouseGrab() {
 }
 
 void OSystem_SDL::draw_mouse() {
+	assert (_transactionMode == kTransactionNone);
+
 	if (_mouseDrawn || !_mouseVisible)
 		return;
 
@@ -1034,6 +1152,8 @@ void OSystem_SDL::draw_mouse() {
 }
 
 void OSystem_SDL::undraw_mouse() {
+	assert (_transactionMode == kTransactionNone);
+
 	if (!_mouseDrawn)
 		return;
 	_mouseDrawn = false;
@@ -1103,7 +1223,8 @@ void OSystem_SDL::undraw_mouse() {
 
 #ifdef USE_OSD
 void OSystem_SDL::displayMessageOnOSD(const char *msg) {
-	
+	assert (_transactionMode == kTransactionNone);
+
 	uint i;
 	
 	// Lock the OSD surface for drawing
diff --git a/backends/sdl/sdl-common.h b/backends/sdl/sdl-common.h
index 646c9a262e..2175d70590 100644
--- a/backends/sdl/sdl-common.h
+++ b/backends/sdl/sdl-common.h
@@ -53,6 +53,9 @@ public:
 	OSystem_SDL();
 	virtual ~OSystem_SDL();
 
+	void beginGFXTransaction(void);
+	void endGFXTransaction(void);
+
 	// Set the size of the video bitmap.
 	// Typically, 320x200
 	void initSize(uint w, uint h);
@@ -195,11 +198,31 @@ protected:
 		DF_UPDATE_EXPAND_1_PIXEL	= 1 << 1
 	};
 
+	enum {
+		kTransactionNone = 0,
+		kTransactionCommit = 1,
+		kTransactionActive = 2
+	};
+
+	struct transactionDetails {
+		int mode;
+		bool modeChanged;
+		int w;
+		bool wChanged;
+		int h;
+		bool hChanged;
+		bool fs;
+		bool fsChanged;
+		bool ar;
+		bool arChanged;
+	} _transactionDetails;
+
 	bool _forceFull; // Force full redraw on next updateScreen
 	ScalerProc *_scalerProc;
 	int _scalerType;
 	int _scaleFactor;
 	int _mode;
+	int _transactionMode;
 	bool _full_screen;
 	uint32 _mode_flags;
 	bool _modeChanged;
@@ -281,6 +304,7 @@ protected:
 	virtual void hotswap_gfx_mode();
 	
 	void setFullscreenMode(bool enable);
+	void setAspectRatioCorrection(bool enable);
 
 	bool save_screenshot(const char *filename);
 	
diff --git a/backends/sdl/sdl.cpp b/backends/sdl/sdl.cpp
index 7883d292f5..80d9d62dfa 100644
--- a/backends/sdl/sdl.cpp
+++ b/backends/sdl/sdl.cpp
@@ -104,7 +104,7 @@ OSystem_SDL::OSystem_SDL()
 	_mouseHotspotX(0), _mouseHotspotY(0),
 	_currentShakePos(0), _newShakePos(0),
 	_paletteDirtyStart(0), _paletteDirtyEnd(0),
-	_graphicsMutex(0) {
+	_graphicsMutex(0), _transactionMode(kTransactionNone) {
 
 	// allocate palette storage
 	_currentPalette = (SDL_Color *)calloc(sizeof(SDL_Color), 256);
@@ -160,19 +160,7 @@ void OSystem_SDL::setFeatureState(Feature f, bool enable) {
 		setFullscreenMode(enable);
 		break;
 	case kFeatureAspectRatioCorrection:
-		if (_screenHeight == 200 && _adjustAspectRatio != enable) {
-			Common::StackLock lock(_graphicsMutex);
-
-			//assert(_hwscreen != 0);
-			_adjustAspectRatio ^= true;
-			hotswap_gfx_mode();
-			
-			// Blit everything to the screen
-			internUpdateScreen();
-			
-			// Make sure that an EVENT_SCREEN_CHANGED gets sent later
-			_modeChanged = true;
-		}
+		setAspectRatioCorrection(enable);
 		break;
 	case kFeatureAutoComputeDirtyRects:
 		if (enable)
@@ -186,6 +174,8 @@ void OSystem_SDL::setFeatureState(Feature f, bool enable) {
 }
 
 bool OSystem_SDL::getFeatureState(Feature f) {
+	assert (_transactionMode != kTransactionNone);
+
 	switch (f) {
 	case kFeatureFullscreenMode:
 		return _full_screen;