SCI32: Clean up GfxFrameout

* Rewrap doxygen comments to 80 columns
* Swap public/private sections so public APIs come first
* Clarify comments where easily possible

engines/sci/engine/kgraphics32.cpp

@@ -102,9 +102,9 @@ reg_t kBaseSetter32(EngineState *s, int argc, reg_t *argv) {
 reg_t kSetNowSeen32(EngineState *s, int argc, reg_t *argv) {
 	const bool found = g_sci->_gfxFrameout->kernelSetNowSeen(argv[0]);
 
-	// NOTE: MGDX is assumed to use the older kSetNowSeen since it was
+	// MGDX is assumed to use the older kSetNowSeen since it was released before
-	// released before SQ6, but this has not been verified since it cannot be
+	// SQ6, but this has not been verified since it cannot be disassembled at
-	// disassembled at the moment (Phar Lap Windows-only release)
+	// the moment (Phar Lap Windows-only release)
 	// (See also getNowSeenRect)
 	if (getSciVersion() <= SCI_VERSION_2_1_EARLY ||
 		g_sci->getGameId() == GID_SQ6 ||

engines/sci/graphics/frameout.cpp

@@ -119,9 +119,9 @@ void GfxFrameout::run() {
 	ScreenItem::init();
 	GfxText32::init();
 
-	// NOTE: This happens in SCI::InitPlane in the actual engine,
+	// This plane is created in SCI::InitPlane in SSCI, and is a background fill
-	// and is a background fill plane to ensure hidden planes
+	// plane to ensure "hidden" planes (planes with negative priority) are never
-	// (planes with a priority of -1) are never drawn
+	// drawn
 	Plane *initPlane = new Plane(Common::Rect(_currentBuffer.scriptWidth, _currentBuffer.scriptHeight));
 	initPlane->_priority = 0;
 	_planes.add(initPlane);
@@ -296,8 +296,8 @@ void GfxFrameout::kernelDeletePlane(const reg_t object) {
 	}
 
 	if (plane->_created) {
-		// NOTE: The original engine calls some `AbortPlane` function that
+		// SSCI calls some `AbortPlane` function that just ends up doing this
-		// just ends up doing this anyway so we skip the extra indirection
+		// anyway, so we skip the extra indirection
 		_planes.erase(plane);
 	} else {
 		plane->_created = 0;
@@ -331,8 +331,8 @@ void GfxFrameout::kernelMovePlaneItems(const reg_t object, const int16 deltaX, c
 	for (ScreenItemList::iterator it = plane->_screenItemList.begin(); it != plane->_screenItemList.end(); ++it) {
 		ScreenItem &screenItem = **it;
 
-		// If object is a number, the screen item from the
+		// If object is a number, the screen item from the engine, not a script,
-		// engine, not a script, and should be ignored
+		// and should be ignored
 		if (screenItem._object.isNumber()) {
 			continue;
 		}
@@ -365,14 +365,14 @@ void GfxFrameout::addPlane(Plane *plane) {
 }
 
 void GfxFrameout::updatePlane(Plane &plane) {
-	// NOTE: This assertion comes from SCI engine code.
+	// This assertion comes from SSCI
 	assert(_planes.findByObject(plane._object) == &plane);
 
 	Plane *visiblePlane = _visiblePlanes.findByObject(plane._object);
 	plane.sync(visiblePlane, _screenRect);
-	// NOTE: updateScreenRect was originally called a second time here,
+	// updateScreenRect was called a second time here in SSCI, but it is already
-	// but it is already called at the end of the Plane::Update call
+	// called at the end of the sync call (also in SSCI) so there is no reason
-	// in the original engine anyway.
+	// to do it again
 
 	_planes.sort();
 }
@@ -401,8 +401,8 @@ void GfxFrameout::frameOut(const bool shouldShowBits, const Common::Rect &eraseR
 		robotPlayer.doRobot();
 	}
 
-	// NOTE: The original engine allocated these as static arrays of 100
+	// SSCI allocated these as static arrays of 100 pointers to
-	// pointers to ScreenItemList / RectList
+	// ScreenItemList / RectList
 	ScreenItemListList screenItemLists;
 	EraseListList eraseLists;
 
@@ -459,8 +459,8 @@ void GfxFrameout::palMorphFrameOut(const int8 *styleRanges, PlaneShowStyle *show
 	_showList.add(rect);
 	showBits();
 
-	// NOTE: The original engine allocated these as static arrays of 100
+	// SSCI allocated these as static arrays of 100 pointers to
-	// pointers to ScreenItemList / RectList
+	// ScreenItemList / RectList
 	ScreenItemListList screenItemLists;
 	EraseListList eraseLists;
 
@@ -651,8 +651,7 @@ int splitRectsForRender(Common::Rect &middleRect, const Common::Rect &showRect,
 	return splitCount;
 }
 
-// NOTE: The third rectangle parameter is only ever given a non-empty rect
+// The third rectangle parameter is only ever passed by VMD code
-// by VMD code, via `frameOut`
 void GfxFrameout::calcLists(ScreenItemListList &drawLists, EraseListList &eraseLists, const Common::Rect &eraseRect) {
 	RectList eraseList;
 	Common::Rect outRects[4];
@@ -670,8 +669,8 @@ void GfxFrameout::calcLists(ScreenItemListList &drawLists, EraseListList &eraseL
 		const Plane *outerPlane = _planes[outerPlaneIndex];
 		const Plane *visiblePlane = _visiblePlanes.findByObject(outerPlane->_object);
 
-		// NOTE: SSCI only ever checks for kPlaneTypeTransparent here, even
+		// SSCI only ever checks for kPlaneTypeTransparent here, even though
-		// though kPlaneTypeTransparentPicture is also a transparent plane
+		// kPlaneTypeTransparentPicture is also a transparent plane
 		if (outerPlane->_type == kPlaneTypeTransparent) {
 			foundTransparentPlane = true;
 		}
@@ -741,7 +740,6 @@ void GfxFrameout::calcLists(ScreenItemListList &drawLists, EraseListList &eraseL
 		}
 	}
 
-	// clean up deleted planes
 	if (deletedPlaneCount) {
 		for (int planeIndex = planeCount - 1; planeIndex >= 0; --planeIndex) {
 			Plane *plane = _planes[planeIndex];
@@ -866,7 +864,7 @@ void GfxFrameout::calcLists(ScreenItemListList &drawLists, EraseListList &eraseL
 		}
 	}
 
-	// NOTE: SSCI only looks for kPlaneTypeTransparent, not
+	// SSCI really only looks for kPlaneTypeTransparent, not
 	// kPlaneTypeTransparentPicture
 	if (foundTransparentPlane) {
 		for (PlaneList::size_type planeIndex = 0; planeIndex < planeCount; ++planeIndex) {
@@ -913,8 +911,6 @@ void GfxFrameout::drawScreenItemList(const DrawList &screenItemList) {
 		const DrawItem &drawItem = *screenItemList[i];
 		mergeToShowList(drawItem.rect, _showList, _overdrawThreshold);
 		const ScreenItem &screenItem = *drawItem.screenItem;
-		// TODO: Remove
-//		debug("Drawing item %04x:%04x to %d %d %d %d", PRINT_REG(screenItem._object), PRINT_RECT(drawItem.rect));
 		CelObj &celObj = *screenItem._celObj;
 		celObj.draw(_currentBuffer, screenItem, drawItem.rect, screenItem._mirrorX ^ celObj._mirrorX);
 	}
@@ -986,9 +982,8 @@ void GfxFrameout::showBits() {
 
 	for (RectList::const_iterator rect = _showList.begin(); rect != _showList.end(); ++rect) {
 		Common::Rect rounded(**rect);
-		// NOTE: SCI engine used BR-inclusive rects so used slightly
+		// SSCI uses BR-inclusive rects so has slightly different masking here
-		// different masking here to ensure that the width of rects
+		// to ensure that the width of rects is always even
-		// was always even.
 		rounded.left &= ~1;
 		rounded.right = (rounded.right + 1) & ~1;
 		_cursor->gonnaPaint(rounded);
@@ -998,9 +993,8 @@ void GfxFrameout::showBits() {
 
 	for (RectList::const_iterator rect = _showList.begin(); rect != _showList.end(); ++rect) {
 		Common::Rect rounded(**rect);
-		// NOTE: SCI engine used BR-inclusive rects so used slightly
+		// SSCI uses BR-inclusive rects so has slightly different masking here
-		// different masking here to ensure that the width of rects
+		// to ensure that the width of rects is always even
-		// was always even.
 		rounded.left &= ~1;
 		rounded.right = (rounded.right + 1) & ~1;
 
@@ -1094,9 +1088,9 @@ void GfxFrameout::alterVmap(const Palette &palette1, const Palette &palette2, co
 		int8 styleRangeValue = styleRanges[currentValue];
 		if (styleRangeValue == -1 && styleRangeValue == style) {
 			currentValue = pixels[pixelIndex] = clut[currentValue];
-			// NOTE: In original engine this assignment happens outside of the
+			// In SSCI this assignment happens outside of the condition, but if
-			// condition, but if the branch is not followed the value is just
+			// the branch is not followed the value is just going to be the same
-			// going to be the same as it was before
+			// as it was before, so we do it here instead
 			styleRangeValue = styleRanges[currentValue];
 		}
 
@@ -1110,7 +1104,7 @@ void GfxFrameout::alterVmap(const Palette &palette1, const Palette &palette2, co
 }
 
 void GfxFrameout::updateScreen(const int delta) {
-	// using OSystem::getMillis instead of Sci::getTickCount because these
+	// Using OSystem::getMillis instead of Sci::getTickCount here because these
 	// values need to be monotonically increasing for the duration of the
 	// GfxFrameout object or else the screen will stop updating
 	const uint32 now = g_system->getMillis() * 60 / 1000;
@@ -1199,13 +1193,12 @@ reg_t GfxFrameout::kernelIsOnMe(const reg_t object, const Common::Point &positio
 		return make_reg(0, 0);
 	}
 
-	// NOTE: The original engine passed a copy of the ScreenItem into isOnMe
+	// SSCI passed a copy of the ScreenItem into isOnMe as a hack around the
-	// as a hack around the fact that the screen items in `_visiblePlanes`
+	// fact that the screen items in `_visiblePlanes` did not have their
-	// did not have their `_celObj` pointers cleared when their CelInfo was
+	// `_celObj` pointers cleared when their CelInfo was updated by
-	// updated by `Plane::decrementScreenItemArrayCounts`. We handle this
+	// `Plane::decrementScreenItemArrayCounts`. We handle this this more
-	// this more intelligently by clearing `_celObj` in the copy assignment
+	// intelligently by clearing `_celObj` in the copy assignment operator,
-	// operator, which is only ever called by `decrementScreenItemArrayCounts`
+	// which is only ever called by `decrementScreenItemArrayCounts` anyway.
-	// anyway.
 	return make_reg(0, isOnMe(*screenItem, *plane, position, checkPixel));
 }
 
@@ -1271,9 +1264,9 @@ bool GfxFrameout::getNowSeenRect(const reg_t screenItemObject, Common::Rect &res
 
 	const ScreenItem *screenItem = plane->_screenItemList.findByObject(screenItemObject);
 	if (screenItem == nullptr) {
-		// NOTE: MGDX is assumed to use the older getNowSeenRect since it was
+		// MGDX is assumed to use the older getNowSeenRect since it was released
-		// released before SQ6, but this has not been verified since it cannot
+		// before SQ6, but this has not been verified since it cannot be
-		// be disassembled at the moment (Phar Lap Windows-only release)
+		// disassembled at the moment (Phar Lap Windows-only release)
 		// (See also kSetNowSeen32)
 		if (getSciVersion() <= SCI_VERSION_2_1_EARLY ||
 			g_sci->getGameId() == GID_SQ6 ||

engines/sci/graphics/frameout.h

@@ -37,21 +37,11 @@ class GfxTransitions32;
 struct PlaneShowStyle;
 
 /**
- * Frameout class, kFrameout and relevant functions for SCI32 games.
+ * Frameout class, kFrameOut and relevant functions for SCI32 games.
- * Roughly equivalent to GraphicsMgr in the actual SCI engine.
+ * Roughly equivalent to GraphicsMgr in SSCI.
  */
 class GfxFrameout {
 	friend class GfxTransitions32;
-private:
-	GfxCursor32 *_cursor;
-	GfxPalette32 *_palette;
-	SegManager *_segMan;
-
-	/**
-	 * Determines whether the current game should be rendered in
-	 * high resolution.
-	 */
-	bool gameIsHiRes() const;
 
 public:
 	GfxFrameout(SegManager *segMan, GfxPalette32 *palette, GfxTransitions32 *transitions, GfxCursor32 *cursor);
@@ -62,12 +52,20 @@ public:
 	void clear();
 	void run();
 
+private:
+	GfxCursor32 *_cursor;
+	GfxPalette32 *_palette;
+	GfxTransitions32 *_transitions;
+	SegManager *_segMan;
+
+	/**
+	 * Determines whether the current game should be rendered in high
+	 * resolution.
+	 */
+	bool gameIsHiRes() const;
+
 #pragma mark -
 #pragma mark Screen items
-private:
-	void remapMarkRedraw();
-	bool getNowSeenRect(const reg_t screenItemObject, Common::Rect &result) const;
-
 public:
 	/**
 	 * Adds a screen item.
@@ -100,39 +98,27 @@ public:
 	bool kernelSetNowSeen(const reg_t screenItemObject) const;
 	int16 kernelObjectIntersect(const reg_t object1, const reg_t object2) const;
 
+private:
+	void remapMarkRedraw();
+	bool getNowSeenRect(const reg_t screenItemObject, Common::Rect &result) const;
+
 #pragma mark -
 #pragma mark Planes
-private:
-	/**
-	 * The list of planes (i.e. layers) that have been added
-	 * to the screen.
-	 *
-	 * @note This field is on `GraphicsMgr.screen` in SCI
-	 * engine.
-	 */
-	PlaneList _planes;
-
-	/**
-	 * Updates an existing plane with properties from the
-	 * given VM object.
-	 */
-	void updatePlane(Plane &plane);
-
 public:
 	/**
 	 * Creates and adds a new plane to the plane list. Ownership of the passed
 	 * object is transferred to GfxFrameout.
 	 *
-	 * @note This method is on Screen in SCI engine, but it
+	 * @note This method is on Screen in SSCI, but it is only ever called on
-	 * is only ever called on `GraphicsMgr.screen`.
+	 * `GraphicsMgr.screen`.
 	 */
 	void addPlane(Plane *plane);
 
 	/**
 	 * Deletes a plane within the current plane list.
 	 *
-	 * @note This method is on Screen in SCI engine, but it
+	 * @note This method is on Screen in SSCI, but it is only ever called on
-	 * is only ever called on `GraphicsMgr.screen`.
+	 * `GraphicsMgr.screen`.
 	 */
 	void deletePlane(Plane &plane);
 
@@ -148,6 +134,20 @@ public:
 	void kernelMovePlaneItems(const reg_t object, const int16 deltaX, const int16 deltaY, const bool scrollPics);
 	int16 kernelGetHighPlanePri();
 
+private:
+	/**
+	 * The list of planes (i.e. layers) that will be rendered to the screen on
+	 * the next call to `frameOut`.
+	 *
+	 * @note This field is on `GraphicsMgr.screen` in SSCI.
+	 */
+	PlaneList _planes;
+
+	/**
+	 * Updates an existing plane with properties from the given VM object.
+	 */
+	void updatePlane(Plane &plane);
+
 #pragma mark -
 #pragma mark Pics
 public:
@@ -155,141 +155,6 @@ public:
 
 #pragma mark -
 #pragma mark Rendering
-private:
-	/**
-	 * The last time the hardware screen was updated.
-	 */
-	uint32 _lastScreenUpdateTick;
-
-	GfxTransitions32 *_transitions;
-
-	/**
-	 * State tracker to provide more accurate 60fps
-	 * video throttling.
-	 */
-	uint8 _throttleState;
-
-	/**
-	 * The internal display pixel buffer. During frameOut,
-	 * this buffer is drawn into according to the draw and
-	 * erase rects calculated by `calcLists`, then drawn out
-	 * to the hardware surface according to the `_showList`
-	 * rects (which are also calculated by `calcLists`).
-	 */
-	Buffer _currentBuffer;
-
-	/**
-	 * When true, a change to the remap zone in the palette
-	 * has occurred and screen items with remap data need to
-	 * be redrawn.
-	 */
-	bool _remapOccurred;
-
-	/**
-	 * TODO: Document
-	 * TODO: Depending upon if the engine ever modifies this
-	 * rect, it may be stupid to store it separately instead
-	 * of just getting width/height from GfxScreen.
-	 *
-	 * @note This field is on `GraphicsMgr.screen` in SCI
-	 * engine.
-	 */
-	Common::Rect _screenRect;
-
-	/**
-	 * A list of rectangles, in display coordinates, that
-	 * represent portions of the internal screen buffer that
-	 * should be drawn to the hardware display surface.
-	 *
-	 * @note This field is on `GraphicsMgr.screen` in SCI
-	 * engine.
-	 */
-	RectList _showList;
-
-	/**
-	 * The amount of extra overdraw that is acceptable when
-	 * merging two show list rectangles together into a
-	 * single larger rectangle.
-	 *
-	 * @note This field is on `GraphicsMgr.screen` in SCI
-	 * engine.
-	 */
-	int _overdrawThreshold;
-
-	/**
-	 * A list of planes that are currently drawn to the
-	 * hardware display surface. Used to calculate
-	 * differences in plane properties between the last
-	 * frame and current frame.
-	 *
-	 * @note This field is on `GraphicsMgr.visibleScreen` in
-	 * SCI engine.
-	 */
-	PlaneList _visiblePlanes;
-
-	/**
-	 * Calculates the location and dimensions of dirty rects
-	 * over the entire screen for rendering the next frame.
-	 * The draw and erase lists in `drawLists` and
-	 * `eraseLists` each represent one plane on the screen.
-	 * The optional `eraseRect` argument allows a specific
-	 * area of the screen to be erased.
-	 */
-	void calcLists(ScreenItemListList &drawLists, EraseListList &eraseLists, const Common::Rect &eraseRect = Common::Rect());
-
-	/**
-	 * Erases the areas in the given erase list from the
-	 * visible screen buffer by filling them with the color
-	 * from the corresponding plane. This is an optimisation
-	 * for colored-type planes only; other plane types have
-	 * to be redrawn from pixel data.
-	 */
-	void drawEraseList(const RectList &eraseList, const Plane &plane);
-
-	/**
-	 * Draws all screen items from the given draw list to
-	 * the visible screen buffer.
-	 */
-	void drawScreenItemList(const DrawList &screenItemList);
-
-	/**
-	 * Adds a new rectangle to the list of regions to write
-	 * out to the hardware. The provided rect may be merged
-	 * into an existing rectangle to reduce the number of
-	 * blit operations.
-	 */
-	void mergeToShowList(const Common::Rect &drawRect, RectList &showList, const int overdrawThreshold);
-
-	/**
-	 * Sends all dirty rects from the internal frame buffer to the backend,
-	 * then updates the hardware screen.
-	 */
-	void showBits();
-
-	/**
-	 * Validates whether the given palette index in the
-	 * style range should copy a color from the next
-	 * palette to the source palette during a palette
-	 * morph operation.
-	 */
-	inline bool validZeroStyle(const uint8 style, const int i) const {
-		if (style != 0) {
-			return false;
-		}
-
-		// TODO: Cannot check Shivers or MGDX until those executables can be
-		// unwrapped
-		switch (g_sci->getGameId()) {
-		case GID_KQ7:
-		case GID_PHANTASMAGORIA:
-		case GID_SQ6:
-			return (i > 71 && i < 104);
-			break;
-		default:
-			return true;
-		}
-	}
-
 public:
 	/**
 	 * Updates the hardware screen, no more than once per tick.
@@ -316,9 +181,9 @@ public:
 	bool _throttleKernelFrameOut;
 
 	/**
-	 * Whether palMorphFrameOut should be used instead of
+	 * Whether `palMorphFrameOut` should be used instead of `frameOut` for
-	 * frameOut for rendering. Used by kMorphOn to
+	 * rendering. Used by `kMorphOn` to explicitly enable `palMorphFrameOut` for
-	 * explicitly enable palMorphFrameOut for one frame.
+	 * one frame.
 	 */
 	bool _palMorphIsOn;
 
@@ -329,16 +194,14 @@ public:
 	void kernelFrameOut(const bool showBits);
 
 	/**
-	 * Throttles the engine as necessary to maintain
+	 * Throttles the engine as necessary to maintain 60fps output.
-	 * 60fps output.
 	 */
 	void throttle();
 
 	/**
-	 * Updates the internal screen buffer for the next
+	 * Updates the internal screen buffer for the next frame. If
-	 * frame. If `shouldShowBits` is true, also sends the
+	 * `shouldShowBits` is true, also sends the buffer to hardware. If
-	 * buffer to hardware. If `eraseRect` is non-empty,
+	 * `eraseRect` is non-empty, it is added to the erase list for this frame.
-	 * it is added to the erase list for this frame.
 	 */
 	void frameOut(const bool shouldShowBits, const Common::Rect &eraseRect = Common::Rect());
 
@@ -361,19 +224,18 @@ public:
 #endif
 
 	/**
-	 * Modifies the raw pixel data for the next frame with
+	 * Modifies the raw pixel data for the next frame with new palette indexes
-	 * new palette indexes based on matched style ranges.
+	 * based on matched style ranges.
 	 */
 	void alterVmap(const Palette &palette1, const Palette &palette2, const int8 style, const int8 *const styleRanges);
 
-	// NOTE: This function is used within ScreenItem subsystem and assigned
+	// This function is used within ScreenItem subsystem and assigned to various
-	// to various booleanish fields that seem to represent the state of the
+	// booleanish fields that seem to represent the state of the screen item
-	// screen item (created, updated, deleted). In GK1/DOS, Phant1/m68k,
+	// (created, updated, deleted). In GK1/DOS, Phant1/m68k, SQ6/DOS, SQ6/Win,
-	// SQ6/DOS, SQ6/Win, and Phant2/Win, this function simply returns 1. If
+	// and Phant2/Win, this function simply returns 1. If you know of any
-	// you know of any game/environment where this function returns some
+	// game/environment where this function returns some value other than 1, or
-	// value other than 1, or if you used to work at Sierra and can explain
+	// if you used to work at Sierra and can explain why this is a thing (and if
-	// why this is a thing (and if anyone needs to care about it), please
+	// anyone needs to care about it), please open a ticket!!
-	// open a ticket!!
 	inline int getScreenCount() const {
 		return 1;
 	};
@@ -383,8 +245,128 @@ public:
 	 */
 	void shakeScreen(const int16 numShakes, const ShakeDirection direction);
 
+private:
+	/**
+	 * The last time the hardware screen was updated.
+	 */
+	uint32 _lastScreenUpdateTick;
+
+	/**
+	 * State tracker to provide more accurate 60fps video throttling.
+	 */
+	uint8 _throttleState;
+
+	/**
+	 * The internal display pixel buffer. During `frameOut`, this buffer is
+	 * drawn into according to the draw and erase rects calculated by
+	 * `calcLists`, then drawn out to the hardware surface according to the
+	 * `_showList` rects (which are also calculated by `calcLists`).
+	 */
+	Buffer _currentBuffer;
+
+	/**
+	 * When true, a change to the remap zone in the palette has occurred and
+	 * screen items with remap data need to be redrawn.
+	 */
+	bool _remapOccurred;
+
+	/**
+	 * The dimensions of the output buffer, in display coordinates.
+	 *
+	 * @note This field is on `GraphicsMgr.screen` in SSCI.
+	 */
+	Common::Rect _screenRect;
+
+	/**
+	 * A list of rectangles, in screen coordinates, that represent portions of
+	 * the internal screen buffer that are dirty and should be drawn to the
+	 * hardware display surface.
+	 *
+	 * @note This field is on `GraphicsMgr.screen` in SSCI.
+	 */
+	RectList _showList;
+
+	/**
+	 * The amount of extra overdraw that is acceptable when merging two show
+	 * list rectangles together into a single larger rectangle.
+	 *
+	 * @note This field is on `GraphicsMgr.screen` in SSCI.
+	 */
+	int _overdrawThreshold;
+
+	/**
+	 * The list of planes that are currently drawn to the hardware display
+	 * surface. Used to calculate differences in plane properties between the
+	 * last frame and current frame.
+	 *
+	 * @note This field is on `GraphicsMgr.visibleScreen` in SSCI.
+	 */
+	PlaneList _visiblePlanes;
+
+	/**
+	 * Calculates the location and dimensions of dirty rects over the entire
+	 * screen for rendering the next frame. The draw and erase lists in
+	 * `drawLists` and `eraseLists` each represent one plane on the screen.
+	 * The optional `eraseRect` argument allows a specific area of the screen to
+	 * be explicitly erased.
+	 */
+	void calcLists(ScreenItemListList &drawLists, EraseListList &eraseLists, const Common::Rect &eraseRect = Common::Rect());
+
+	/**
+	 * Erases the areas in the given erase list from the visible screen buffer
+	 * by filling them with the color from the corresponding plane. This is an
+	 * optimisation for colored-type planes only; other plane types have to be
+	 * redrawn from pixel data.
+	 */
+	void drawEraseList(const RectList &eraseList, const Plane &plane);
+
+	/**
+	 * Draws all screen items from the given draw list to the visible screen
+	 * buffer.
+	 */
+	void drawScreenItemList(const DrawList &screenItemList);
+
+	/**
+	 * Adds a new rectangle to the list of regions to write out to the hardware.
+	 * The provided rect may be merged into an existing rectangle to reduce the
+	 * number of blit operations.
+	 */
+	void mergeToShowList(const Common::Rect &drawRect, RectList &showList, const int overdrawThreshold);
+
+	/**
+	 * Sends all dirty rects from the internal frame buffer to the backend, then
+	 * updates the hardware screen.
+	 */
+	void showBits();
+
+	/**
+	 * Validates whether the given palette index in the style range should copy
+	 * a color from the next palette to the source palette during a palette
+	 * morph operation.
+	 */
+	inline bool validZeroStyle(const uint8 style, const int i) const {
+		if (style != 0) {
+			return false;
+		}
+
+		// TODO: Cannot check Shivers or MGDX until those executables can be
+		// unwrapped
+		switch (g_sci->getGameId()) {
+		case GID_KQ7:
+		case GID_PHANTASMAGORIA:
+		case GID_SQ6:
+			return (i > 71 && i < 104);
+			break;
+		default:
+			return true;
+		}
+	}
+
 #pragma mark -
 #pragma mark Mouse cursor
+public:
+	reg_t kernelIsOnMe(const reg_t object, const Common::Point &position, const bool checkPixel) const;
+
 private:
 	void updateMousePositionForRendering() const {
 		// In SSCI, mouse events were received via hardware interrupt, so the
@@ -398,14 +380,11 @@ private:
 	}
 
 	/**
-	 * Determines whether or not the point given by
+	 * Determines whether or not the point given by `position` is inside of the
-	 * `position` is inside of the given screen item.
+	 * given screen item.
 	 */
 	bool isOnMe(const ScreenItem &screenItem, const Plane &plane, const Common::Point &position, const bool checkPixel) const;
 
-public:
-	reg_t kernelIsOnMe(const reg_t object, const Common::Point &position, const bool checkPixel) const;
-
 #pragma mark -
 #pragma mark Debugging
 public: