Merge pull request #652 from dreammaster/screen

ALL: Removing code duplication via new managed surface & screen classes

7 files changed, 899 insertions, 0 deletions

diff --git a/graphics/font.cpp b/graphics/font.cpp
index dba48249bc..d709758948 100644
--- a/graphics/font.cpp
+++ b/graphics/font.cpp
@@ -21,6 +21,7 @@
  */
 
 #include "graphics/font.h"
+#include "graphics/managed_surface.h"
 
 #include "common/array.h"
 #include "common/util.h"
@@ -273,6 +274,16 @@ void Font::drawString(Surface *dst, const Common::U32String &str, int x, int y,
 	drawStringImpl(*this, dst, str, x, y, w, color, align, 0);
 }
 
+void Font::drawString(ManagedSurface *dst, const Common::String &str, int x, int y, int w, uint32 color, TextAlign align, int deltax, bool useEllipsis) const {
+	drawString(&dst->_innerSurface, str, x, y, w, color, align, deltax, useEllipsis);
+	dst->addDirtyRect(Common::Rect(x, y, x + w, y + getFontHeight()));
+}
+
+void Font::drawString(ManagedSurface *dst, const Common::U32String &str, int x, int y, int w, uint32 color, TextAlign align) const {
+	drawString(&dst->_innerSurface, str, x, y, w, color, align);
+	dst->addDirtyRect(Common::Rect(x, y, x + w, y + getFontHeight()));
+}
+
 int Font::wordWrapText(const Common::String &str, int maxWidth, Common::Array<Common::String> &lines) const {
 	return wordWrapTextImpl(*this, str, maxWidth, lines);
 }
diff --git a/graphics/font.h b/graphics/font.h
index 35f6792d7f..62e71a8568 100644
--- a/graphics/font.h
+++ b/graphics/font.h
@@ -34,6 +34,7 @@ template<class T> class Array;
 namespace Graphics {
 
 struct Surface;
+class ManagedSurface;
 
 /** Text alignment modes */
 enum TextAlign {
@@ -145,6 +146,8 @@ public:
 	// TODO: Add doxygen comments to this
 	void drawString(Surface *dst, const Common::String &str, int x, int y, int w, uint32 color, TextAlign align = kTextAlignLeft, int deltax = 0, bool useEllipsis = true) const;
 	void drawString(Surface *dst, const Common::U32String &str, int x, int y, int w, uint32 color, TextAlign align = kTextAlignLeft) const;
+	void drawString(ManagedSurface *dst, const Common::String &str, int x, int y, int w, uint32 color, TextAlign align = kTextAlignLeft, int deltax = 0, bool useEllipsis = true) const;
+	void drawString(ManagedSurface *dst, const Common::U32String &str, int x, int y, int w, uint32 color, TextAlign align = kTextAlignLeft) const;
 
 	/**
 	 * Compute and return the width the string str has when rendered using this font.
diff --git a/graphics/managed_surface.cpp b/graphics/managed_surface.cpp
new file mode 100644
index 0000000000..e493ab9f4e
--- /dev/null
+++ b/graphics/managed_surface.cpp
@@ -0,0 +1,260 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "graphics/managed_surface.h"
+#include "common/algorithm.h"
+#include "common/textconsole.h"
+
+namespace Graphics {
+
+const int SCALE_THRESHOLD = 0x100;
+
+ManagedSurface::ManagedSurface() : 
+		w(_innerSurface.w), h(_innerSurface.h), pitch(_innerSurface.pitch), format(_innerSurface.format),
+		_disposeAfterUse(DisposeAfterUse::NO), _owner(nullptr) {
+}
+
+ManagedSurface::ManagedSurface(const ManagedSurface &surf) :
+		w(_innerSurface.w), h(_innerSurface.h), pitch(_innerSurface.pitch), format(_innerSurface.format),
+		_disposeAfterUse(DisposeAfterUse::NO), _owner(nullptr) {
+	*this = surf;
+}
+
+ManagedSurface::ManagedSurface(int width, int height) :
+		w(_innerSurface.w), h(_innerSurface.h), pitch(_innerSurface.pitch), format(_innerSurface.format),
+		_disposeAfterUse(DisposeAfterUse::NO), _owner(nullptr) {
+	create(width, height);
+}
+
+ManagedSurface::ManagedSurface(int width, int height, const Graphics::PixelFormat &pixelFormat) :
+		w(_innerSurface.w), h(_innerSurface.h), pitch(_innerSurface.pitch), format(_innerSurface.format),
+		_disposeAfterUse(DisposeAfterUse::NO), _owner(nullptr) {
+	create(width, height, format);
+}
+
+ManagedSurface::ManagedSurface(ManagedSurface &surf, const Common::Rect &bounds) :
+		w(_innerSurface.w), h(_innerSurface.h), pitch(_innerSurface.pitch), format(_innerSurface.format),
+		_disposeAfterUse(DisposeAfterUse::NO), _owner(nullptr) {
+	create(surf, bounds);
+}
+
+ManagedSurface::~ManagedSurface() {
+	free();
+}
+
+ManagedSurface &ManagedSurface::operator=(const ManagedSurface &surf) {
+	// Free any current surface
+	free();
+
+	if (surf._disposeAfterUse == DisposeAfterUse::YES) {
+		// Create a new surface and copy the pixels from the source surface
+		create(surf.w, surf.h, surf.format);
+		Common::copy((const byte *)surf.getPixels(), (const byte *)surf.getPixels() +
+			surf.w * surf.h * surf.format.bytesPerPixel, (byte *)this->getPixels());
+	} else {
+		// Source isn't managed, so simply copy its fields
+		_owner = surf._owner;
+		_offsetFromOwner = surf._offsetFromOwner;
+		void *srcPixels = (void *)surf._innerSurface.getPixels();
+		_innerSurface.setPixels(srcPixels);
+		_innerSurface.w = surf.w;
+		_innerSurface.h = surf.h;
+		_innerSurface.pitch = surf.pitch;
+		this->format = surf.format;
+	}
+
+	return *this;
+}
+
+void ManagedSurface::setPixels(void *newPixels) {
+	free();
+	_innerSurface.setPixels(newPixels);
+}
+
+void ManagedSurface::create(uint16 width, uint16 height) {
+	create(width, height, PixelFormat::createFormatCLUT8());
+}
+
+void ManagedSurface::create(uint16 width, uint16 height, const PixelFormat &pixelFormat) {
+	free();
+	_innerSurface.create(width, height, pixelFormat);
+
+	_disposeAfterUse = DisposeAfterUse::YES;
+	markAllDirty();
+}
+
+void ManagedSurface::create(ManagedSurface &surf, const Common::Rect &bounds) {
+	free();
+	
+	_offsetFromOwner = Common::Point(bounds.left, bounds.top);
+	_innerSurface.setPixels(surf.getBasePtr(bounds.left, bounds.top));
+	_innerSurface.pitch = surf.pitch;
+	_innerSurface.format = surf.format;
+	_innerSurface.w = bounds.width();
+	_innerSurface.h = bounds.height();
+	_owner = &surf;
+	_disposeAfterUse = DisposeAfterUse::NO;
+}
+
+void ManagedSurface::free() {
+	if (_disposeAfterUse == DisposeAfterUse::YES)
+		_innerSurface.free();
+
+	_disposeAfterUse = DisposeAfterUse::NO;
+	_owner = nullptr;
+	_offsetFromOwner = Common::Point(0, 0);
+}
+
+bool ManagedSurface::clip(Common::Rect &srcBounds, Common::Rect &destBounds) {
+	if (destBounds.left >= this->w || destBounds.top >= this->h ||
+			destBounds.right <= 0 || destBounds.bottom <= 0)
+		return false;
+
+	// Clip the bounds if necessary to fit on-screen
+	if (destBounds.right > this->w) {
+		srcBounds.right -= destBounds.right - this->w;
+		destBounds.right = this->w;
+	}
+
+	if (destBounds.bottom > this->h) {
+		srcBounds.bottom -= destBounds.bottom - this->h;
+		destBounds.bottom = this->h;
+	}
+
+	if (destBounds.top < 0) {
+		srcBounds.top += -destBounds.top;
+		destBounds.top = 0;
+	}
+
+	if (destBounds.left < 0) {
+		srcBounds.left += -destBounds.left;
+		destBounds.left = 0;
+	}
+
+	return true;
+}
+
+void ManagedSurface::blitFrom(const Surface &src) {
+	blitFrom(src, Common::Rect(0, 0, src.w, src.h), Common::Point(0, 0));
+}
+
+void ManagedSurface::blitFrom(const Surface &src, const Common::Point &destPos) {
+	blitFrom(src, Common::Rect(0, 0, src.w, src.h), destPos);
+}
+
+void ManagedSurface::blitFrom(const Surface &src, const Common::Rect &srcRect,
+		const Common::Point &destPos) {
+	Common::Rect srcBounds = srcRect;
+	Common::Rect destBounds(destPos.x, destPos.y, destPos.x + srcRect.width(), 
+		destPos.y + srcRect.height());
+	assert(src.format.bytesPerPixel == format.bytesPerPixel);
+
+	if (!srcRect.isValidRect() || !clip(srcBounds, destBounds))
+		return;
+
+	for (int y = 0; y < srcBounds.height(); ++y) {
+		const byte *srcP = (const byte *)src.getBasePtr(srcBounds.left, srcBounds.top + y);
+		byte *destP = (byte *)getBasePtr(destBounds.left, destBounds.top + y);
+		Common::copy(srcP, srcP + srcBounds.width() * format.bytesPerPixel, destP);
+	}
+
+	addDirtyRect(Common::Rect(0, 0, this->w, this->h));
+}
+
+void ManagedSurface::transBlitFrom(const Surface &src, uint transColor, bool flipped, uint overrideColor) {
+	transBlitFrom(src, Common::Rect(0, 0, src.w, src.h), Common::Rect(0, 0, this->w, this->h),
+		transColor, false, overrideColor);
+}
+
+void ManagedSurface::transBlitFrom(const Surface &src, const Common::Point &destPos,
+		uint transColor, bool flipped, uint overrideColor) {
+	transBlitFrom(src, Common::Rect(0, 0, src.w, src.h), Common::Rect(destPos.x, destPos.y,
+		destPos.x + src.w, destPos.y + src.h), transColor, false, overrideColor);
+}
+
+void ManagedSurface::transBlitFrom(const Surface &src, const Common::Rect &srcRect,
+		const Common::Point &destPos, uint transColor, bool flipped, uint overrideColor) {
+	transBlitFrom(src, srcRect, Common::Rect(destPos.x, destPos.y,
+		destPos.x + src.w, destPos.y + src.h), transColor, false, overrideColor);
+}
+
+template<typename T>
+void transBlit(const Surface &src, const Common::Rect &srcRect, const Surface *dest, const Common::Rect &destRect, uint transColor, bool flipped, uint overrideColor) {
+	int scaleX = SCALE_THRESHOLD * srcRect.width() / destRect.width();
+	int scaleY = SCALE_THRESHOLD * srcRect.height() / destRect.height();
+
+	// Loop through drawing output lines
+	for (int destY = destRect.top, scaleYCtr = 0; destY < destRect.bottom; ++destY, scaleYCtr += scaleY) {
+		if (destY < 0 || destY >= dest->h)
+			continue;
+		const T *srcLine = (const T *)src.getBasePtr(0, scaleYCtr / SCALE_THRESHOLD);
+		T *destLine = (T *)dest->getBasePtr(destRect.left, destY);
+
+		// Loop through drawing the pixels of the row
+		for (int destX = destRect.left, xCtr = 0, scaleXCtr = 0; destX < destRect.right; ++destX, ++xCtr, scaleXCtr += scaleX) {
+			if (destX < 0 || destX >= dest->w)
+				continue;
+
+			T srcVal = srcLine[flipped ? src.w - scaleXCtr / SCALE_THRESHOLD - 1 : scaleXCtr / SCALE_THRESHOLD];
+			if (srcVal != transColor) {
+				destLine[xCtr] = overrideColor ? overrideColor : srcVal;
+			}
+		}
+	}
+}
+
+void ManagedSurface::transBlitFrom(const Surface &src, const Common::Rect &srcRect,
+	const Common::Rect &destRect, uint transColor, bool flipped, uint overrideColor) {
+	if (src.w == 0 || src.h == 0 || destRect.width() == 0 || destRect.height() == 0)
+		return;
+
+	if (format.bytesPerPixel == 1)
+		transBlit<byte>(src, srcRect, &_innerSurface, destRect, transColor, flipped, overrideColor);
+	else if (format.bytesPerPixel == 2)
+		transBlit<uint16>(src, srcRect, &_innerSurface, destRect, transColor, flipped, overrideColor);
+	else if (format.bytesPerPixel == 4)
+		transBlit<uint32>(src, srcRect, &_innerSurface, destRect, transColor, flipped, overrideColor);
+	else
+		error("Surface::transBlitFrom: bytesPerPixel must be 1, 2, or 4");
+
+	// Mark the affected area
+	addDirtyRect(destRect);
+}
+
+void ManagedSurface::markAllDirty() {
+	addDirtyRect(Common::Rect(0, 0, this->w, this->h));
+}
+
+void ManagedSurface::addDirtyRect(const Common::Rect &r) {
+	if (_owner) {
+		Common::Rect bounds = r;
+		bounds.clip(Common::Rect(0, 0, this->w, this->h));
+		bounds.translate(_offsetFromOwner.x, _offsetFromOwner.y);
+		_owner->addDirtyRect(bounds);
+	}
+}
+
+void ManagedSurface::clear(uint color) {
+	fillRect(getBounds(), color);
+}
+
+} // End of namespace Graphics
diff --git a/graphics/managed_surface.h b/graphics/managed_surface.h
new file mode 100644
index 0000000000..bd0632a493
--- /dev/null
+++ b/graphics/managed_surface.h
@@ -0,0 +1,376 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef GRAPHICS_MANAGED_SURFACE_H
+#define GRAPHICS_MANAGED_SURFACE_H
+
+#include "graphics/pixelformat.h"
+#include "graphics/surface.h"
+#include "common/rect.h"
+#include "common/types.h"
+
+namespace Graphics {
+
+class Font;
+
+/**
+ * A derived graphics surface, which handles automatically managing the allocated
+ * surface data block, as well as introducing several new blitting methods
+ */
+class ManagedSurface {
+	friend class Font;
+private:
+	/**
+	 * The Graphics::Surface that the managed surface encapsulates
+	 */
+	Surface _innerSurface;
+
+	/**
+	 * If set, the inner surface will be freed when the surface is recreated,
+	 * as well as when the surface is destroyed
+	 */
+	DisposeAfterUse::Flag _disposeAfterUse;
+
+	/**
+	 * Stores the owning surface if this If this managed surface represents
+	 * a sub-section of another
+	 */
+	ManagedSurface *_owner;
+
+	/**
+	 * For sub-section areas of an owning parent managed surface, this represents
+	 * the offset from the parent's top-left corner this sub-surface starts at
+	 */
+	Common::Point _offsetFromOwner;
+protected:
+	/**
+	 * Clips the given source bounds so the passed destBounds will be entirely on-screen
+	 */
+	bool clip(Common::Rect &srcBounds, Common::Rect &destBounds);
+
+	/**
+	 * Base method that descendent classes can override for recording affected
+	 * dirty areas of the surface
+	 */
+	virtual void addDirtyRect(const Common::Rect &r);
+public:
+	uint16 &w;
+	uint16 &h;
+	uint16 &pitch;
+	PixelFormat &format;
+public:
+	/**
+	 * Create the managed surface
+	 */
+	ManagedSurface();
+
+	/**
+	 * Create a managed surface from another one.
+	 * If the source surface is maintaining it's own surface data, then
+	 * this surface will create it's own surface of the same size and copy
+	 * the contents from the source surface
+	 */
+	ManagedSurface(const ManagedSurface &surf);
+
+	/**
+	 * Create the managed surface
+	 */
+	ManagedSurface(int width, int height);
+	
+	/**
+	 * Create the managed surface
+	 */
+	ManagedSurface(int width, int height, const Graphics::PixelFormat &pixelFormat);
+	
+	/**
+	 * Create the managed surface
+	 */
+	ManagedSurface(ManagedSurface &surf, const Common::Rect &bounds);
+
+	/**
+	 * Destroy the managed surface
+	 */
+	virtual ~ManagedSurface();
+
+	/**
+	 * Implements automatic conversion to a Graphics::Surface by
+	 * simply returning the inner surface. This must be const,
+	 * because we don't want changes being done directly to it,
+	 * since it would bypass dirty rect handling
+	 */
+	operator const Surface &() const { return _innerSurface; }
+	const Surface &rawSurface() const { return _innerSurface; }
+
+	/**
+	 * Reassign one managed surface to another one
+	 * Note that if the source has a managed surface, it will be duplicated
+	 */
+	ManagedSurface &operator=(const ManagedSurface &surf);
+
+	/**
+	 * Returns true if the surface has not yet been allocated
+	 */
+	bool empty() const { return w == 0 || h == 0 || _innerSurface.getPixels() == nullptr; }
+
+	/**
+	 * Returns true if the surface is managing its own pixels
+	 */
+	DisposeAfterUse::Flag disposeAfterUse() const { return _disposeAfterUse; }
+
+	/**
+	 * Return a pointer to the pixel at the specified point.
+	 *
+	 * @param x The x coordinate of the pixel.
+	 * @param y The y coordinate of the pixel.
+	 * @return Pointer to the pixel.
+	 */
+	inline const void *getBasePtr(int x, int y) const {
+		return _innerSurface.getBasePtr(x, y);
+	}
+
+	/**
+	 * Return a pointer to the pixel at the specified point.
+	 *
+	 * @param x The x coordinate of the pixel.
+	 * @param y The y coordinate of the pixel.
+	 * @return Pointer to the pixel.
+	 */
+	inline void *getBasePtr(int x, int y) {
+		return _innerSurface.getBasePtr(x, y);
+	}
+
+	/**
+	 * Get a reference to the pixel data
+	 */
+	inline void *getPixels() { return _innerSurface.getPixels(); }
+	inline const void *getPixels() const { return _innerSurface.getPixels(); }
+
+	/**
+	 * Sets the pixel data.
+	 */
+	virtual void setPixels(void *newPixels);
+
+	/**
+	 * Allocate memory for the pixel data of the surface.
+	 */
+	virtual void create(uint16 width, uint16 height);
+
+	/**
+	 * Allocate memory for the pixel data of the surface.
+	 */
+	virtual void create(uint16 width, uint16 height, const PixelFormat &pixelFormat);
+
+	/**
+	 * Sets up the surface as a sub-section of another passed parent surface. This surface
+	 * will not own the pixels, and any dirty rect notifications will automatically be
+	 * passed to the original parent surface.
+	 * @remarks		Note that this differs from Graphics::Surface::getSubArea, in that that
+	 * method only adds a single initial dirty rect for the whole area, and then none further
+	 */
+	virtual void create(ManagedSurface &surf, const Common::Rect &bounds);
+
+	/**
+	 * Release the memory used by the pixels memory of this surface. This is the
+	 * counterpart to create().
+	 */
+	virtual void free();
+
+	/**
+	 * Clears any pending dirty rects that have been generated for the surface
+	 */
+	virtual void clearDirtyRects() {}
+
+	/**
+	 * When the managed surface is a sub-section of a parent surface, returns the
+	 * the offset in the parent surface that the surface starts at
+	 */
+	const Common::Point getOffsetFromOwner() const { return _offsetFromOwner; }
+
+	/**
+	 * Return a rect giving the bounds of the surface
+	 */
+	const Common::Rect getBounds() const {
+		return Common::Rect(0, 0, this->w, this->h);
+	}
+	
+	/**
+	 * Copies another surface into this one
+	 */
+	void blitFrom(const Surface &src);
+
+	/**
+	 * Copies another surface into this one at a given destination position
+	 */
+	void blitFrom(const Surface &src, const Common::Point &destPos);
+
+	/**
+	 * Copies another surface into this one at a given destination position
+	 */
+	void blitFrom(const Surface &src, const Common::Rect &srcRect,
+		const Common::Point &destPos);
+
+	/**
+	 * Copies another surface into this one ignoring pixels of a designated transparent color
+	 * @param src			Source surface
+	 * @param transColor	Transparency color to ignore copying
+	 * @param flipped		Specifies whether to horizontally flip the image
+	 * @param overrideColor	Optional color to use instead of non-transparent pixels from
+	 *						the source surface
+	 */
+	void transBlitFrom(const Surface &src, uint transColor = 0, bool flipped = false, uint overrideColor = 0);
+
+	/**
+	 * Copies another surface into this one ignoring pixels of a designated transparent color
+	 * @param src			Source surface
+	 * @param destPos		Destination position to draw the surface
+	 * @param transColor	Transparency color to ignore copying
+	 * @param flipped		Specifies whether to horizontally flip the image
+	 * @param overrideColor	Optional color to use instead of non-transparent pixels from
+	 *						the source surface
+	 */
+	void transBlitFrom(const Surface &src, const Common::Point &destPos,
+		uint transColor = 0, bool flipped = false, uint overrideColor = 0);
+
+	/**
+	 * Copies another surface into this one ignoring pixels of a designated transparent color
+	 * @param src			Source surface
+	 * @param srcRect		Sub-section of source surface to draw
+	 * @param destPos		Destination position to draw the surface
+	 * @param transColor	Transparency color to ignore copying
+	 * @param flipped		Specifies whether to horizontally flip the image
+	 * @param overrideColor	Optional color to use instead of non-transparent pixels from
+	 *						the source surface
+	 */
+	void transBlitFrom(const Surface &src, const Common::Rect &srcRect, const Common::Point &destPos,
+		uint transColor = 0, bool flipped = false, uint overrideColor = 0);
+
+	/**
+	 * Copies another surface into this one ignoring pixels of a designated transparent color
+	 * @param src			Source surface
+	 * @param srcRect		Sub-section of source surface to draw
+	 * @param destRect		Destination area to draw the surface in. This can be sized differently
+	 *						then srcRect, allowing for arbitrary scaling of the image
+	 * @param transColor	Transparency color to ignore copying
+	 * @param flipped		Specifies whether to horizontally flip the image
+	 * @param overrideColor	Optional color to use instead of non-transparent pixels from
+	 *						the source surface
+	 */
+	void transBlitFrom(const Surface &src, const Common::Rect &srcRect, const Common::Rect &destRect,
+		uint transColor = 0, bool flipped = false, uint overrideColor = 0);
+
+	/**
+	 * Clear the entire surface
+	 */
+	void clear(uint color = 0);
+
+	/**
+	 * Mark the entire surface as dirty
+	 */
+	void markAllDirty();
+
+	/**
+	 * Copies a bitmap to the Surface internal buffer. The pixel format
+	 * of buffer must match the pixel format of the Surface.
+	 */
+	void copyRectToSurface(const void *buffer, int srcPitch, int destX, int destY, int width, int height) {
+		_innerSurface.copyRectToSurface(buffer, srcPitch, destX, destY, width, height);
+	}
+
+	/**
+	 * Copies a bitmap to the Surface internal buffer. The pixel format
+	 * of buffer must match the pixel format of the Surface.
+	 */
+	void copyRectToSurface(const Graphics::Surface &srcSurface, int destX, int destY, const Common::Rect subRect) {
+		_innerSurface.copyRectToSurface(srcSurface, destX, destY, subRect);
+	}
+
+	/**
+	 * Copy the data from another Surface, reinitializing the
+	 * surface to match the dimensions of the passed surface
+	 */
+	void copyFrom(const ManagedSurface &surf) {
+		clearDirtyRects();
+		_innerSurface.copyFrom(surf._innerSurface);
+	}
+
+	/**
+	 * Draw a line.
+	 */
+	void drawLine(int x0, int y0, int x1, int y1, uint32 color) {
+		_innerSurface.drawLine(x0, y0, x1, y1, color);
+		addDirtyRect(Common::Rect(x0, y0, x1, y1));
+	}
+
+	/**
+	 * Draw a thick line.
+	 */
+	void drawThickLine(int x0, int y0, int x1, int y1, int penX, int penY, uint32 color) {
+		_innerSurface.drawThickLine(x0, y0, x1, y1, penX, penY, color);
+		addDirtyRect(Common::Rect(x0, y0, x1 + penX, y1 + penY));
+	}
+
+	/**
+	 * Draw a horizontal line.
+	 */
+	void hLine(int x, int y, int x2, uint32 color) {
+		_innerSurface.hLine(x, y, x2, color);
+		addDirtyRect(Common::Rect(x, y, x2 + 1, y + 1));
+	}
+
+	/**
+	 * Draw a vertical line.
+	 */
+	void vLine(int x, int y, int y2, uint32 color) {
+		_innerSurface.vLine(x, y, y2, color);
+		addDirtyRect(Common::Rect(x, y, x + 1, y2 + 1));
+	}
+
+	/**
+	 * Fill a rect with a given color.
+	 */
+	void fillRect(Common::Rect r, uint32 color) {
+		_innerSurface.fillRect(r, color);
+		addDirtyRect(r);
+	}
+
+	/**
+	 * Draw a frame around a specified rect.
+	 */
+	void frameRect(const Common::Rect &r, uint32 color) {
+		_innerSurface.frameRect(r, color);
+		addDirtyRect(r);
+	}
+
+	/**
+	 * Returns a sub-area of the screen, but only adds a single initial dirty rect
+	 * for the retrieved area.
+	 */
+	Surface getSubArea(const Common::Rect &area) {
+		addDirtyRect(area);
+		return _innerSurface.getSubArea(area);
+	}
+};
+
+} // End of namespace Graphics
+
+
+#endif
diff --git a/graphics/module.mk b/graphics/module.mk
index b6919cf1ab..90f6a3199c 100644
--- a/graphics/module.mk
+++ b/graphics/module.mk
@@ -12,10 +12,12 @@ MODULE_OBJS := \
 	fonts/ttf.o \
 	fonts/winfont.o \
 	maccursor.o \
+	managed_surface.o \
 	pixelformat.o \
 	primitives.o \
 	scaler.o \
 	scaler/thumbnail_intern.o \
+	screen.o \
 	sjis.o \
 	surface.o \
 	transform_struct.o \
diff --git a/graphics/screen.cpp b/graphics/screen.cpp
new file mode 100644
index 0000000000..4169c98035
--- /dev/null
+++ b/graphics/screen.cpp
@@ -0,0 +1,129 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#include "common/system.h"
+#include "common/algorithm.h"
+#include "graphics/screen.h"
+#include "graphics/palette.h"
+
+namespace Graphics {
+
+Screen::Screen(): ManagedSurface() {
+	create(g_system->getWidth(), g_system->getHeight());
+}
+
+Screen::Screen(int width, int height): ManagedSurface() {
+	create(width, height);
+}
+
+Screen::Screen(int width, int height, PixelFormat pixelFormat): ManagedSurface() {
+	create(width, height, pixelFormat);
+}
+
+void Screen::update() {
+	// Merge the dirty rects
+	mergeDirtyRects();
+
+	// Loop through copying dirty areas to the physical screen
+	Common::List<Common::Rect>::iterator i;
+	for (i = _dirtyRects.begin(); i != _dirtyRects.end(); ++i) {
+		const Common::Rect &r = *i;
+		const byte *srcP = (const byte *)getBasePtr(r.left, r.top);
+		g_system->copyRectToScreen(srcP, pitch, r.left, r.top,
+			r.width(), r.height());
+	}
+
+	// Signal the physical screen to update
+	g_system->updateScreen();
+	_dirtyRects.clear();
+}
+
+
+void Screen::addDirtyRect(const Common::Rect &r) {
+	Common::Rect bounds = r;
+	bounds.clip(getBounds());
+	bounds.translate(getOffsetFromOwner().x, getOffsetFromOwner().y);
+
+	if (bounds.width() > 0 && bounds.height() > 0)
+		_dirtyRects.push_back(bounds);
+}
+
+void Screen::makeAllDirty() {
+	addDirtyRect(Common::Rect(0, 0, this->w, this->h));
+}
+
+void Screen::mergeDirtyRects() {
+	Common::List<Common::Rect>::iterator rOuter, rInner;
+
+	// Process the dirty rect list to find any rects to merge
+	for (rOuter = _dirtyRects.begin(); rOuter != _dirtyRects.end(); ++rOuter) {
+		rInner = rOuter;
+		while (++rInner != _dirtyRects.end()) {
+
+			if ((*rOuter).intersects(*rInner)) {
+				// These two rectangles overlap, so merge them
+				unionRectangle(*rOuter, *rOuter, *rInner);
+
+				// remove the inner rect from the list
+				_dirtyRects.erase(rInner);
+
+				// move back to beginning of list
+				rInner = rOuter;
+			}
+		}
+	}
+}
+
+bool Screen::unionRectangle(Common::Rect &destRect, const Common::Rect &src1, const Common::Rect &src2) {
+	destRect = src1;
+	destRect.extend(src2);
+
+	return !destRect.isEmpty();
+}
+
+void Screen::getPalette(byte palette[PALETTE_SIZE]) {
+	assert(format.bytesPerPixel == 1);
+	g_system->getPaletteManager()->grabPalette(palette, 0, PALETTE_COUNT);
+}
+
+void Screen::getPalette(byte *palette, uint start, uint num) {
+	assert(format.bytesPerPixel == 1);
+	g_system->getPaletteManager()->grabPalette(palette, start, num);
+}
+
+void Screen::setPalette(const byte palette[PALETTE_SIZE]) {
+	assert(format.bytesPerPixel == 1);
+	g_system->getPaletteManager()->setPalette(palette, 0, PALETTE_COUNT);
+}
+
+void Screen::setPalette(const byte *palette, uint start, uint num) {
+	assert(format.bytesPerPixel == 1);
+	g_system->getPaletteManager()->setPalette(palette, start, num);
+}
+
+void Screen::clearPalette() {
+	byte palette[PALETTE_SIZE];
+	Common::fill(&palette[0], &palette[PALETTE_SIZE], 0);
+	setPalette(palette);
+}
+
+} // End of namespace Graphics
diff --git a/graphics/screen.h b/graphics/screen.h
new file mode 100644
index 0000000000..29816120f1
--- /dev/null
+++ b/graphics/screen.h
@@ -0,0 +1,118 @@
+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ */
+
+#ifndef GRAPHICS_SCREEN_H
+#define GRAPHICS_SCREEN_H
+
+#include "graphics/managed_surface.h"
+#include "graphics/pixelformat.h"
+#include "common/list.h"
+#include "common/rect.h"
+
+namespace Graphics {
+
+#define PALETTE_COUNT 256
+#define PALETTE_SIZE (256 * 3)
+
+/**
+ * Implements a specialised surface that represents the screen.
+ * It keeps track of any areas of itself that are updated by drawing
+ * calls, and provides an update that method that blits the affected 
+ * areas to the physical screen
+ */
+class Screen : virtual public ManagedSurface {
+private:
+	/**
+	 * List of affected areas of the screen
+	 */
+	Common::List<Common::Rect> _dirtyRects;
+private:
+	/**
+	* Merges together overlapping dirty areas of the screen
+	*/
+	void mergeDirtyRects();
+
+	/**
+	* Returns the union of two dirty area rectangles
+	*/
+	bool unionRectangle(Common::Rect &destRect, const Common::Rect &src1, const Common::Rect &src2);
+protected:
+	/**
+	 * Adds a rectangle to the list of modified areas of the screen during the
+	 * current frame
+	 */
+	virtual void addDirtyRect(const Common::Rect &r);
+public:
+	Screen();
+	Screen(int width, int height);
+	Screen(int width, int height, PixelFormat pixelFormat);
+
+	/**
+	 * Returns true if there are any pending screen updates (dirty areas)
+	 */
+	bool isDirty() const { return !_dirtyRects.empty(); }
+
+	/**
+	 * Marks the whole screen as dirty. This forces the next call to update 
+	 * to copy the entire screen contents
+	 */
+	void makeAllDirty();
+
+	/**
+	 * Clear the current dirty rects list
+	 */
+	virtual void clearDirtyRects() { _dirtyRects.clear(); }
+
+	/**
+	 * Updates the screen by copying any affected areas to the system
+	 */
+	virtual void update();
+
+	/**
+	 * Return the currently active palette
+	 */
+	void getPalette(byte palette[PALETTE_SIZE]);
+
+	/**
+	 * Return a portion of the currently active palette
+	 */
+	void getPalette(byte *palette, uint start, uint num);
+
+	/**
+	 * Set the palette
+	 */
+	void setPalette(const byte palette[PALETTE_SIZE]);
+
+	/**
+	 * Set a subsection of the palette
+	 */
+	void setPalette(const byte *palette, uint start, uint num);
+
+	/**
+	 * Clears the current palette, setting all entries to black
+	 */
+	void clearPalette();
+};
+
+} // End of namespace Graphics
+
+#endif