2 files changed, 296 insertions, 5 deletions

diff --git a/engines/pegasus/graphics.cpp b/engines/pegasus/graphics.cpp
index 28aafdb04f..cec8595362 100644
--- a/engines/pegasus/graphics.cpp
+++ b/engines/pegasus/graphics.cpp
@@ -4,6 +4,9 @@
  * are too numerous to list here. Please refer to the COPYRIGHT
  * file distributed with this source distribution.
  *
+ * Additional copyright for this file:
+ * Copyright (C) 1995-1997 Presto Studios, Inc.
+ *
  * 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
@@ -19,7 +22,7 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  *
  */
- 
+
 #include "pegasus/graphics.h"
 
 #include "common/endian.h"
@@ -28,17 +31,149 @@
 #include "engines/util.h"
 
 namespace Pegasus {
-	
+
+DisplayElement::DisplayElement(const tDisplayElementID id) : IDObject(id) {
+	_elementIsDisplaying = false;
+	_elementIsVisible = false;
+	_elementOrder = 0;
+	_triggeredElement = this;
+	_nextElement = 0;
+}
+
+DisplayElement::~DisplayElement() {
+	if (isDisplaying())
+		((PegasusEngine *)g_engine)->_gfx->removeDisplayElement(this);
+}
+
+void DisplayElement::setDisplayOrder(const tDisplayOrder order) {
+	if (_elementOrder != order) {
+		_elementOrder = order;
+		if (isDisplaying()) {
+			((PegasusEngine *)g_engine)->_gfx->removeDisplayElement(this);
+			((PegasusEngine *)g_engine)->_gfx->addDisplayElement(this);
+			triggerRedraw();
+		}
+	}
+}
+
+void DisplayElement::startDisplaying() {
+	if (!isDisplaying()) {
+		((PegasusEngine *)g_engine)->_gfx->addDisplayElement(this);
+		triggerRedraw();
+	}
+}
+
+void DisplayElement::stopDisplaying() {
+	if (isDisplaying()) {
+		triggerRedraw();
+		((PegasusEngine *)g_engine)->_gfx->removeDisplayElement(this);
+	}
+}
+
+void DisplayElement::setBounds(const tCoordType left, const tCoordType top, const tCoordType right, const tCoordType bottom) {
+	_bounds = Common::Rect(left, top, right, bottom);
+}
+
+void DisplayElement::getBounds(Common::Rect &r) const {
+	r = _bounds;
+}
+
+void DisplayElement::sizeElement(const tCoordType h, const tCoordType v) {
+	_bounds.right = _bounds.left + h;
+	_bounds.bottom = _bounds.top + v;
+}
+
+void DisplayElement::moveElementTo(const tCoordType h, const tCoordType v) {
+	_bounds.moveTo(h, v);
+}
+
+void DisplayElement::moveElement(const tCoordType dh, const tCoordType dv) {
+	_bounds.translate(dh, dv);
+}
+
+void DisplayElement::getLocation(tCoordType &h, tCoordType &v) const {
+	h = _bounds.left;
+	v = _bounds.top;
+}
+
+void DisplayElement::centerElementAt(const tCoordType h, const tCoordType v) {
+	_bounds.moveTo(h - (_bounds.width() / 2), v - (_bounds.height() / 2));
+}
+
+void DisplayElement::getCenter(tCoordType &h, tCoordType &v) const {
+	h = (_bounds.left + _bounds.right) / 2;
+	v = (_bounds.top + _bounds.bottom) / 2;
+}
+
+void DisplayElement::setBounds(const Common::Rect &r) {
+	if (r != _bounds) {
+		triggerRedraw();
+		_bounds = r;
+		triggerRedraw();
+	}
+}
+
+void DisplayElement::hide() {
+	if (_elementIsVisible) {
+		triggerRedraw();
+		_elementIsVisible = false;
+	}
+}
+
+void DisplayElement::show() {
+	if (!_elementIsVisible) {
+		_elementIsVisible = true;
+		triggerRedraw();
+	}
+}
+
+//	Only invalidates this element's bounding rectangle if all these conditions are true:
+//	--	The triggered element is this element.
+//	--	The element is displaying on the display list.
+//	--	The element is visible.
+//	--	The element is part of the active layer OR is one of the reserved items.
+void DisplayElement::triggerRedraw() {
+	GraphicsManager *gfx = ((PegasusEngine *)g_engine)->_gfx;
+
+	if (_triggeredElement == this) {
+		if (validToDraw(gfx->getBackOfActiveLayer(), gfx->getFrontOfActiveLayer()))
+			gfx->invalRect(_bounds);
+	} else {
+		_triggeredElement->triggerRedraw();
+	}
+}
+
+void DisplayElement::setTriggeredElement(DisplayElement *element) {
+	if (element)
+		_triggeredElement = element;
+	else
+		_triggeredElement = this;
+}
+
+bool DisplayElement::validToDraw(tDisplayOrder backLayer, tDisplayOrder frontLayer) {
+	return	isDisplaying() && _elementIsVisible &&
+			(getObjectID() <= kHighestReservedElementID ||
+			(getDisplayOrder() >= backLayer &&
+			getDisplayOrder() <= frontLayer));
+}
+
 GraphicsManager::GraphicsManager(PegasusEngine *vm) : _vm(vm) {
 	initGraphics(640, 480, true, NULL);
-	
+
+	// Old
 	_pictDecoder = new Graphics::PictDecoder(_vm->_system->getScreenFormat());
 
 	for (int i = 0; i < kImageCacheSize; i++)
 		_cache[i].surface = 0;
+
+	// New
+	_backLayer = kMinAvailableOrder;
+	_frontLayer = kMaxAvailableOrder;
+	_firstDisplayElement = _lastDisplayElement = 0;
 }
 	
 GraphicsManager::~GraphicsManager() {
+	// Old
 	delete _pictDecoder;
 
 	for (int i = 0; i < kImageCacheSize; i++) {
@@ -168,5 +303,99 @@ int GraphicsManager::getImageSlot(const Common::String &filename) {
 	_cache[slot].lastUsed = _vm->_system->getMillis();
 	return slot;
 }
+
+void GraphicsManager::invalRect(const Common::Rect &rect) {
+	// We're using a simpler algorithm for dirty rect handling than the original
+	// The original was way too overcomplicated for what we need here now.
+
+	if (_dirtyRect.width() == 0 || _dirtyRect.height() == 0) {
+		// We have no dirty rect, so this is now our dirty rect
+		_dirtyRect = rect;
+	} else {
+		// Expand our dirty rect to include rect
+		_dirtyRect.left = MIN<int>(_dirtyRect.left, rect.left);
+		_dirtyRect.top = MIN<int>(_dirtyRect.top, rect.top);
+		_dirtyRect.right = MAX<int>(_dirtyRect.right, rect.right);
+		_dirtyRect.bottom = MAX<int>(_dirtyRect.bottom, rect.bottom);
+	}
+}
+
+void GraphicsManager::addDisplayElement(DisplayElement *newElement) {
+	newElement->_elementOrder = CLIP<int>(newElement->_elementOrder, kMinAvailableOrder, kMaxAvailableOrder);
+
+	if (_firstDisplayElement) {
+		DisplayElement *runner = _firstDisplayElement;
+		DisplayElement *lastRunner = 0;
+
+		// Search for first element whose display order is greater than
+		// the new element's and add the new element just before it.
+		while (runner) {
+			if (newElement->_elementOrder < runner->_elementOrder) {
+				if (lastRunner) {
+					lastRunner->_nextElement = newElement;
+					newElement->_nextElement = runner;
+				} else {
+					newElement->_nextElement = _firstDisplayElement;
+					_firstDisplayElement = newElement;
+				}
+				break;
+			}
+			lastRunner = runner;
+			runner = runner->_nextElement;
+		}
+
+		// If got here and runner == NULL, we ran through the whole list without
+		// inserting, so add at the end.
+		if (!runner) {
+			_lastDisplayElement->_nextElement = newElement;
+			_lastDisplayElement = newElement;
+		}
+	} else {
+		_firstDisplayElement = newElement;
+		_lastDisplayElement = newElement;
+	}
+
+	newElement->_elementIsDisplaying = true;
+}
+
+void GraphicsManager::removeDisplayElement(DisplayElement *oldElement) {
+	if (!_firstDisplayElement)
+		return;
+
+	if (oldElement == _firstDisplayElement) {
+		if (oldElement == _lastDisplayElement) {
+			_firstDisplayElement = 0;
+			_lastDisplayElement = 0;
+		} else {
+			_firstDisplayElement = oldElement->_nextElement;
+		}
+
+		invalRect(oldElement->_bounds);
+	} else {
+		// Scan list for element.
+		// If we get here, we know that the list has at least one item, and it
+		// is not the first item, so we can skip it.
+		DisplayElement *runner = _firstDisplayElement->_nextElement;
+		DisplayElement *lastRunner = _firstDisplayElement;
+
+		while (runner) {
+			if (runner == oldElement) {
+				lastRunner->_nextElement = runner->_nextElement;
+
+				if (oldElement == _lastDisplayElement)
+					_lastDisplayElement = lastRunner;
+
+				invalRect(oldElement->_bounds);
+				break;
+			}
+
+			lastRunner = runner;
+			runner = runner->_nextElement;
+		}
+	}
+
+	oldElement->_nextElement = 0;
+	oldElement->_elementIsDisplaying = false;
+}
 	
 } // End of namespace Pegasus
diff --git a/engines/pegasus/graphics.h b/engines/pegasus/graphics.h
index 41353735b1..6778adb323 100644
--- a/engines/pegasus/graphics.h
+++ b/engines/pegasus/graphics.h
@@ -4,6 +4,9 @@
  * are too numerous to list here. Please refer to the COPYRIGHT
  * file distributed with this source distribution.
  *
+ * Additional copyright for this file:
+ * Copyright (C) 1995-1997 Presto Studios, Inc.
+ *
  * 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
@@ -30,9 +33,55 @@
 #include "graphics/surface.h"
 
 #include "pegasus/pegasus.h"
+#include "pegasus/util.h"
 
 namespace Pegasus {
 
+class DisplayElement : public IDObject {
+friend class GraphicsManager;
+public:
+	DisplayElement(const tDisplayElementID);
+	virtual ~DisplayElement();
+	
+	void setDisplayOrder(const tDisplayOrder);
+	tDisplayOrder getDisplayOrder() const { return _elementOrder; }
+	
+	bool validToDraw(tDisplayOrder, tDisplayOrder);
+	
+	virtual void draw(const Common::Rect&) {}
+	bool isDisplaying() { return _elementIsDisplaying; }
+	virtual void startDisplaying();
+	virtual void stopDisplaying();
+	
+	virtual void show();
+	virtual void hide();
+	bool isVisible() { return _elementIsVisible; }
+	
+	// triggerRedraw only triggers a draw if the element is displaying and visible.
+	void triggerRedraw();
+	void setTriggeredElement(DisplayElement *);
+	
+	virtual void setBounds(const tCoordType, const tCoordType, const tCoordType, const tCoordType);
+	virtual void setBounds(const Common::Rect&);
+	virtual void getBounds(Common::Rect&) const;
+	virtual void sizeElement(const tCoordType, const tCoordType);
+	virtual void moveElementTo(const tCoordType, const tCoordType);
+	virtual void moveElement(const tCoordType, const tCoordType);
+	virtual void getLocation(tCoordType&, tCoordType&) const;
+	virtual void getCenter(tCoordType&, tCoordType&) const;
+	virtual void centerElementAt(const tCoordType, const tCoordType);
+
+protected:
+	Common::Rect _bounds;
+	bool _elementIsVisible;
+	DisplayElement *_triggeredElement;
+
+	// Used only by PegasusEngine
+	bool _elementIsDisplaying;
+	tDisplayOrder _elementOrder;
+	DisplayElement *_nextElement;
+};
+
 enum {
 	kImageCacheSize = 10
 };
@@ -50,17 +99,30 @@ public:
 	GraphicsManager(PegasusEngine *vm);
 	~GraphicsManager();
 
+	// Older "temporary" API
 	void drawPict(Common::String filename, int x, int y, bool updateScreen = true);
 	void drawPictTransparent(Common::String filename, int x, int y, uint32 transparency, bool updateScreen = true);
 	uint32 getColor(byte r, byte g, byte b);
-	
+
+	// Newer "to-be-used" API
+	void addDisplayElement(DisplayElement *element);
+	void removeDisplayElement(DisplayElement *element);
+	void invalRect(const Common::Rect &rect);
+	tDisplayOrder getBackOfActiveLayer() const { return _backLayer; }
+	tDisplayOrder getFrontOfActiveLayer() const { return _frontLayer; }
 private:		
 	PegasusEngine *_vm;
-	Graphics::PictDecoder *_pictDecoder;
 
+	// Older "temporary" API
+	Graphics::PictDecoder *_pictDecoder;
 	Graphics::Surface *decodeImage(const Common::String &filename);
 	ImageCache _cache[kImageCacheSize];
 	int getImageSlot(const Common::String &filename);
+
+	// Newer "to-be-used" API
+	Common::Rect _dirtyRect;
+	tDisplayOrder _backLayer, _frontLayer;
+	DisplayElement *_firstDisplayElement, *_lastDisplayElement;
 };
 
 } // End of namespace Pegasus