Revert "MOHAWK: Revert the screen cache since it has a huge performance hit, and is not needed as is."

This reverts commit 291bea1858c12b8557aeb46e6f57dc701293c956.

svn-id: r54624

2 files changed, 10 insertions, 2 deletions

diff --git a/engines/mohawk/graphics.cpp b/engines/mohawk/graphics.cpp
index ee1ffb26f1..5732c96d0d 100644
--- a/engines/mohawk/graphics.cpp
+++ b/engines/mohawk/graphics.cpp
@@ -138,6 +138,9 @@ MystGraphics::MystGraphics(MohawkEngine_Myst* vm) : GraphicsManager(), _vm(vm) {
 
 	_pictureFile.entries = NULL;
 
+	// Initialize our buffer
+	_mainScreen = new Graphics::Surface();
+	_mainScreen->create(_vm->_system->getWidth(), _vm->_system->getHeight(), _pixelFormat.bytesPerPixel);
 	_dirtyScreen = false;
 }
 
@@ -146,6 +149,9 @@ MystGraphics::~MystGraphics() {
 	delete _jpegDecoder;
 	delete _pictDecoder;
 	delete[] _pictureFile.entries;
+
+	_mainScreen->free();
+	delete _mainScreen;
 }
 
 static const char* picFileNames[] = {
@@ -267,9 +273,9 @@ 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);
 
 	// Mark the screen as dirty
 	_dirtyScreen = true;
@@ -282,6 +288,7 @@ void MystGraphics::copyImageToScreen(uint16 image, Common::Rect 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;
 	}
diff --git a/engines/mohawk/graphics.h b/engines/mohawk/graphics.h
index 75ffe12987..6942aba4f4 100644
--- a/engines/mohawk/graphics.h
+++ b/engines/mohawk/graphics.h
@@ -130,6 +130,7 @@ private:
 		Common::File picFile;
 	} _pictureFile;
 
+	Graphics::Surface *_mainScreen;
 	bool _dirtyScreen;
 	Graphics::PixelFormat _pixelFormat;
 };