MOHAWK: Cache the Myst screen buffer

This is needed for use with sliders. The screen is now updated fewer times as well.

svn-id: r54300

5 files changed, 61 insertions, 13 deletions

diff --git a/engines/mohawk/graphics.cpp b/engines/mohawk/graphics.cpp
index e4f9a009fd..e0dce6369a 100644
--- a/engines/mohawk/graphics.cpp
+++ b/engines/mohawk/graphics.cpp
@@ -86,6 +86,11 @@ MystGraphics::MystGraphics(MohawkEngine_Myst* vm) : _vm(vm) {
 	}
 
 	_pictureFile.entries = NULL;
+
+	// Initialize our buffer
+	_mainScreen = new Graphics::Surface();
+	_mainScreen->create(_vm->_system->getWidth(), _vm->_system->getHeight(), _pixelFormat.bytesPerPixel);
+	_dirtyScreen = false;
 }
 
 MystGraphics::~MystGraphics() {
@@ -93,6 +98,9 @@ MystGraphics::~MystGraphics() {
 	delete _jpegDecoder;
 	delete _pictDecoder;
 	delete[] _pictureFile.entries;
+
+	_mainScreen->free();
+	delete _mainScreen;
 }
 
 static const char* picFileNames[] = {
@@ -144,7 +152,6 @@ void MystGraphics::copyImageSectionToScreen(uint16 image, Common::Rect src, Comm
 
 	Graphics::Surface *surface = NULL;
 
-
 	// Myst ME uses JPEG/PICT images instead of compressed Windows Bitmaps for room images,
 	// though there are a few weird ones that use that format. For further nonsense with images,
 	// the Macintosh version stores images in external "picture files." We check them before
@@ -210,19 +217,30 @@ void MystGraphics::copyImageSectionToScreen(uint16 image, Common::Rect src, Comm
 		// Convert from bitmap coordinates to surface coordinates
 		uint16 top = surface->h - src.top - height;
 
-		_vm->_system->copyRectToScreen((byte *)surface->getBasePtr(src.left, top), surface->pitch, dest.left, dest.top, width, height);
+		for (uint16 i = 0; i < height; i++)
+			memcpy(_mainScreen->getBasePtr(dest.left, i + dest.top), surface->getBasePtr(src.left, top + i), width * surface->bytesPerPixel);
+
 		surface->free();
 		delete surface;
-	}
 
-	// FIXME: Remove this and update only at certain points
-	_vm->_system->updateScreen();
+		// Mark the screen as dirty
+		_dirtyScreen = true;
+	}
 }
 
 void MystGraphics::copyImageToScreen(uint16 image, Common::Rect dest) {
 	copyImageSectionToScreen(image, Common::Rect(0, 0, 544, 333), dest);
 }
 
+void MystGraphics::updateScreen() {
+	if (_dirtyScreen) {
+		// Only copy the buffer to the screen if it's dirty
+		_vm->_system->copyRectToScreen((byte *)_mainScreen->pixels, _mainScreen->pitch, 0, 0, _mainScreen->w, _mainScreen->h);
+		_vm->_system->updateScreen();
+		_dirtyScreen = false;
+	}
+}
+
 void MystGraphics::showCursor(void) {
 	CursorMan.showMouse(true);
 	_vm->_needsUpdate = true;
diff --git a/engines/mohawk/graphics.h b/engines/mohawk/graphics.h
index 9419aad277..e44bba213b 100644
--- a/engines/mohawk/graphics.h
+++ b/engines/mohawk/graphics.h
@@ -101,6 +101,7 @@ public:
 	void showCursor();
 	void hideCursor();
 	void changeCursor(uint16);
+	void updateScreen();
 
 	void drawRect(Common::Rect rect, bool active);
 private:
@@ -108,7 +109,6 @@ private:
 	MystBitmap *_bmpDecoder;
 	Graphics::PictDecoder *_pictDecoder;
 	Graphics::JPEGDecoder *_jpegDecoder;
-	Graphics::PixelFormat _pixelFormat;
 
 	struct PictureFile {
 		uint32 pictureCount;
@@ -123,6 +123,10 @@ private:
 
 		Common::File picFile;
 	} _pictureFile;
+
+	Graphics::Surface *_mainScreen;
+	bool _dirtyScreen;
+	Graphics::PixelFormat _pixelFormat;
 };
 
 struct SFXERecord {
diff --git a/engines/mohawk/myst.cpp b/engines/mohawk/myst.cpp
index 39c460edd5..bed917165c 100644
--- a/engines/mohawk/myst.cpp
+++ b/engines/mohawk/myst.cpp
@@ -299,9 +299,7 @@ Common::Error MohawkEngine_Myst::run() {
 					_resources[_curResource]->handleMouseUp();
 				}
 
-				for (uint16 i = 0; i < _resources.size(); i++)
-					if (_resources[i]->isEnabled())
-						_resources[i]->drawDataToScreen();
+				drawResourceImages();
 				break;
 			case Common::EVENT_LBUTTONDOWN:
 				if (_curResource >= 0) {
@@ -450,6 +448,9 @@ void MohawkEngine_Myst::changeToCard(uint16 card) {
 		error("Unknown sound action %d", soundAction);
 	}
 
+	// Update the images of each area too
+	drawResourceImages();
+
 	// TODO: Handle Script Resources
 
 	// Run the entrance script (if present)
@@ -739,6 +740,8 @@ void MohawkEngine_Myst::runInitScript() {
 	for (uint16 i = 0; i < scriptCount; i++)
 		delete[] scripts[i].values;
 	delete[] scripts;
+
+	_gfx->updateScreen();
 }
 
 void MohawkEngine_Myst::runExitScript() {
@@ -792,6 +795,8 @@ void MohawkEngine_Myst::runExitScript() {
 	for (uint16 i = 0; i < scriptCount; i++)
 		delete[] scripts[i].values;
 	delete[] scripts;
+
+	_gfx->updateScreen();
 }
 
 void MohawkEngine_Myst::loadHelp(uint16 id) {
@@ -930,6 +935,15 @@ void MohawkEngine_Myst::setResourceEnabled(uint16 resourceId, bool enable) {
 		warning("Attempt to change unknown resource enable state");
 }
 
+void MohawkEngine_Myst::drawResourceImages() {
+	for (uint16 i = 0; i < _resources.size(); i++)
+		if (_resources[i]->isEnabled())
+			_resources[i]->drawDataToScreen();
+
+	// Make sure the screen is updated
+	_gfx->updateScreen();
+}
+
 static MystResource *loadResource(MohawkEngine_Myst *vm, Common::SeekableReadStream *rlstStream, MystResource *parent) {
 	uint16 type = rlstStream->readUint16LE();
 
@@ -1605,6 +1619,7 @@ void MystResourceType12::handleAnimation() {
 	// TODO: Probably not final version. Variable/Type 11 Controlled?
 	if (_doAnimation) {
 		_vm->_gfx->copyImageToScreen(_currentFrame++, _frameRect);
+		_vm->_gfx->updateScreen();
 		if ((_currentFrame - _firstFrame) >= _numFrames)
 			_doAnimation = false;
 	}
diff --git a/engines/mohawk/myst.h b/engines/mohawk/myst.h
index a66456e1c8..29f26704f9 100644
--- a/engines/mohawk/myst.h
+++ b/engines/mohawk/myst.h
@@ -413,6 +413,7 @@ private:
 	void drawResourceRects();
 	void checkCurrentResource();
 	int16 _curResource;
+	void drawResourceImages();
 
 	uint16 _cursorHintCount;
 	MystCursorHint *_cursorHints;
diff --git a/engines/mohawk/myst_scripts.cpp b/engines/mohawk/myst_scripts.cpp
index e397d30df3..a4b493eab4 100644
--- a/engines/mohawk/myst_scripts.cpp
+++ b/engines/mohawk/myst_scripts.cpp
@@ -381,9 +381,10 @@ void MystScriptParser::opcode_4(uint16 op, uint16 var, uint16 argc, uint16 *argv
 		// the general case, rather than this image blit...
 		uint16 var_value = _vm->_varStore->getVar(var);
 		if (var_value < _vm->_view.scriptResCount) {
-			if (_vm->_view.scriptResources[var_value].type == 1) // TODO: Add Symbols for Types
+			if (_vm->_view.scriptResources[var_value].type == 1) { // TODO: Add Symbols for Types
 				_vm->_gfx->copyImageToScreen(_vm->_view.scriptResources[var_value].id, Common::Rect(0, 0, 544, 333));
-			else
+				_vm->_gfx->updateScreen();
+			} else
 				warning("Opcode %d: Script Resource %d Type Not Image", op, var_value);
 		} else
 			warning("Opcode %d: var %d value %d outside Script Resource Range %d", op, var, var_value, _vm->_view.scriptResCount);
@@ -952,7 +953,7 @@ void MystScriptParser::opcode_35(uint16 op, uint16 var, uint16 argc, uint16 *arg
 		debugC(kDebugScript, "\tdelay: %d", delay);
 
 		_vm->_gfx->copyImageToScreen(imageId, Common::Rect(0, 0, 544, 333));
-		_vm->_system->updateScreen();
+		_vm->_gfx->updateScreen();
 		_vm->_system->delayMillis(delay * 100);
 		_vm->changeToCard(cardId);
 	} else
@@ -1685,6 +1686,7 @@ void MystScriptParser::opcode_104(uint16 op, uint16 var, uint16 argc, uint16 *ar
 			// TODO: Need to load the image ids from Script Resources structure of VIEW
 			for (uint16 imageId = 3595; imageId <= 3601; imageId++) {
 				_vm->_gfx->copyImageToScreen(imageId, rect);
+				_vm->_gfx->updateScreen();
 				_vm->_system->delayMillis(50);
 			}
 
@@ -2515,6 +2517,7 @@ void MystScriptParser::opcode_122(uint16 op, uint16 var, uint16 argc, uint16 *ar
 			// TODO: Need to load the image ids from Script Resources structure of VIEW
 			for (uint16 imageId = 3601; imageId >= 3595; imageId--) {
 				_vm->_gfx->copyImageToScreen(imageId, rect);
+				_vm->_gfx->updateScreen();
 				_vm->_system->delayMillis(50);
 			}
 
@@ -3142,8 +3145,10 @@ void MystScriptParser::opcode_200_run() {
 			else
 				rect = Common::Rect(0, 0, 544, 333);
 
-			if (curImageIndex != lastImageIndex)
+			if (curImageIndex != lastImageIndex) {
 				_vm->_gfx->copyImageToScreen(g_opcode200Parameters.imageBaseId + curImageIndex, rect);
+				_vm->_gfx->updateScreen();
+			}
 
 			// TODO: Comparison with original engine shows that this simple solution
 			//       may not be the correct one and the choice of which sound
@@ -3165,6 +3170,7 @@ void MystScriptParser::opcode_200_run() {
 
 				// Note: The modulus by 6 is because the 6th image is the one at imageBaseId
 				_vm->_gfx->copyImageToScreen(g_opcode200Parameters.imageBaseId + curImageIndex % 6, Common::Rect(0, 0, 544, 333));
+				_vm->_gfx->updateScreen();
 
 				_vm->_varStore->setVar(g_opcode200Parameters.var, curImageIndex + 1);
 				g_opcode200Parameters.lastCardTime = _vm->_system->getMillis();
@@ -3379,6 +3385,7 @@ void MystScriptParser::opcode_201(uint16 op, uint16 var, uint16 argc, uint16 *ar
 	case kIntroStack:
 		_vm->_system->delayMillis(4 * 1000);
 		_vm->_gfx->copyImageToScreen(4, Common::Rect(0, 0, 544, 333));
+		_vm->_gfx->updateScreen();
 		// TODO : Wait until video ends, then change to card 5
 		break;
 	case kSeleniticStack:
@@ -4327,6 +4334,8 @@ void MystScriptParser::opcode_211_run(void) {
 			lastGridState[i] = gridState[i];
 		}
 
+		_vm->_gfx->updateScreen();
+
 		// Var 23 contains boolean for whether pattern matches correct book pattern i.e. Pattern 158
 		if (gridState[0] == 0xc3 && gridState[1] == 0x6b && gridState[2] == 0xa3 &&
 		    gridState[3] == 0x93 && gridState[4] == 0xcc && gridState[5] == 0xfa)
@@ -4656,6 +4665,7 @@ void MystScriptParser::opcode_298(uint16 op, uint16 var, uint16 argc, uint16 *ar
 		_vm->_system->delayMillis(20 * 1000);
 		for (uint16 imageId = 3001; imageId <= 3012; imageId++) {
 			_vm->_gfx->copyImageToScreen(imageId, Common::Rect(0, 0, 544, 333));
+			_vm->_gfx->updateScreen();
 			_vm->_system->delayMillis(5 * 1000);
 		}
 		break;