SCI32: Add transparent pic plane type

It is not clear if this is ever actually used by game scripts,
though.

3 files changed, 47 insertions, 20 deletions

diff --git a/engines/sci/graphics/frameout.cpp b/engines/sci/graphics/frameout.cpp
index 62a77da5ef..fd37020896 100644
--- a/engines/sci/graphics/frameout.cpp
+++ b/engines/sci/graphics/frameout.cpp
@@ -700,6 +700,8 @@ 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
+		// though kPlaneTypeTransparentPicture is also a transparent plane
 		if (outerPlane->_type == kPlaneTypeTransparent) {
 			foundTransparentPlane = true;
 		}
@@ -890,6 +892,8 @@ void GfxFrameout::calcLists(ScreenItemListList &drawLists, EraseListList &eraseL
 		}
 	}
 
+	// NOTE: SSCI only looks for kPlaneTypeTransparent, not
+	// kPlaneTypeTransparentPicture
 	if (foundTransparentPlane) {
 		for (PlaneList::size_type planeIndex = 0; planeIndex < planeCount; ++planeIndex) {
 			for (PlaneList::size_type i = planeIndex + 1; i < planeCount; ++i) {
diff --git a/engines/sci/graphics/plane32.cpp b/engines/sci/graphics/plane32.cpp
index 021ac523b8..175875c414 100644
--- a/engines/sci/graphics/plane32.cpp
+++ b/engines/sci/graphics/plane32.cpp
@@ -163,11 +163,15 @@ void Plane::printDebugInfo(Console *con) const {
 void Plane::addPicInternal(const GuiResourceId pictureId, const Common::Point *position, const bool mirrorX) {
 
 	uint16 celCount = 1000;
+	bool transparent = true;
 	for (uint16 celNo = 0; celNo < celCount; ++celNo) {
 		CelObjPic *celObj = new CelObjPic(pictureId, celNo);
 		if (celCount == 1000) {
 			celCount = celObj->_celCount;
 		}
+		if (!celObj->_transparent) {
+			transparent = false;
+		}
 
 		ScreenItem *screenItem = new ScreenItem(_object, celObj->_info);
 		screenItem->_pictureId = pictureId;
@@ -184,6 +188,7 @@ void Plane::addPicInternal(const GuiResourceId pictureId, const Common::Point *p
 		delete screenItem->_celObj;
 		screenItem->_celObj = celObj;
 	}
+	_type = transparent ? kPlaneTypeTransparentPicture : kPlaneTypePicture;
 }
 
 void Plane::addPic(const GuiResourceId pictureId, const Common::Point &position, const bool mirrorX) {
@@ -196,7 +201,7 @@ void Plane::addPic(const GuiResourceId pictureId, const Common::Point &position,
 void Plane::changePic() {
 	_pictureChanged = false;
 
-	if (_type != kPlaneTypePicture) {
+	if (_type != kPlaneTypePicture && _type != kPlaneTypeTransparentPicture) {
 		return;
 	}
 
@@ -245,7 +250,10 @@ void Plane::breakDrawListByPlanes(DrawList &drawList, const PlaneList &planeList
 
 	for (DrawList::size_type i = 0; i < drawList.size(); ++i) {
 		for (PlaneList::size_type j = nextPlaneIndex; j < planeCount; ++j) {
-			if (planeList[j]->_type != kPlaneTypeTransparent) {
+			if (
+				planeList[j]->_type != kPlaneTypeTransparent &&
+				planeList[j]->_type != kPlaneTypeTransparentPicture
+			) {
 				Common::Rect outRects[4];
 				int splitCount = splitRects(drawList[i]->rect, planeList[j]->_screenRect, outRects);
 				if (splitCount != -1) {
@@ -268,7 +276,10 @@ void Plane::breakEraseListByPlanes(RectList &eraseList, const PlaneList &planeLi
 
 	for (RectList::size_type i = 0; i < eraseList.size(); ++i) {
 		for (PlaneList::size_type j = nextPlaneIndex; j < planeCount; ++j) {
-			if (planeList[j]->_type != kPlaneTypeTransparent) {
+			if (
+				planeList[j]->_type != kPlaneTypeTransparent &&
+				planeList[j]->_type != kPlaneTypeTransparentPicture
+			) {
 				Common::Rect outRects[4];
 				int splitCount = splitRects(*eraseList[i], planeList[j]->_screenRect, outRects);
 				if (splitCount != -1) {
@@ -555,7 +566,7 @@ void Plane::decrementScreenItemArrayCounts(Plane *visiblePlane, const bool force
 void Plane::filterDownEraseRects(DrawList &drawList, RectList &eraseList, RectList &higherEraseList) const {
 	const RectList::size_type higherEraseCount = higherEraseList.size();
 
-	if (_type == kPlaneTypeTransparent) {
+	if (_type == kPlaneTypeTransparent || _type == kPlaneTypeTransparentPicture) {
 		for (RectList::size_type i = 0; i < higherEraseCount; ++i) {
 			const Common::Rect &r = *higherEraseList[i];
 			const ScreenItemList::size_type screenItemCount = _screenItemList.size();
@@ -727,14 +738,24 @@ void Plane::redrawAll(Plane *visiblePlane, const PlaneList &planeList, DrawList
 }
 
 void Plane::setType() {
-	if (_pictureId == kPlanePicOpaque) {
-		_type = kPlaneTypeOpaque;
-	} else if (_pictureId == kPlanePicTransparent) {
-		_type = kPlaneTypeTransparent;
-	} else if (_pictureId == kPlanePicColored) {
+	switch (_pictureId) {
+	case kPlanePicColored:
 		_type = kPlaneTypeColored;
-	} else {
-		_type = kPlaneTypePicture;
+		break;
+	case kPlanePicTransparent:
+		_type = kPlaneTypeTransparent;
+		break;
+	case kPlanePicOpaque:
+		_type = kPlaneTypeOpaque;
+		break;
+	case kPlanePicTransparentPicture:
+		_type = kPlaneTypeTransparentPicture;
+		break;
+	default:
+		if (_type != kPlaneTypeTransparentPicture) {
+			_type = kPlaneTypePicture;
+		}
+		break;
 	}
 }
 
diff --git a/engines/sci/graphics/plane32.h b/engines/sci/graphics/plane32.h
index 20cff40814..acd535e75a 100644
--- a/engines/sci/graphics/plane32.h
+++ b/engines/sci/graphics/plane32.h
@@ -32,19 +32,21 @@
 
 namespace Sci {
 enum PlaneType {
-	kPlaneTypeColored     = 0,
-	kPlaneTypePicture     = 1,
-	kPlaneTypeTransparent = 2,
-	kPlaneTypeOpaque      = 3
+	kPlaneTypeColored            = 0,
+	kPlaneTypePicture            = 1,
+	kPlaneTypeTransparent        = 2,
+	kPlaneTypeOpaque             = 3,
+	kPlaneTypeTransparentPicture = 4
 };
 
 enum PlanePictureCodes {
-	// NOTE: Any value at or below 65532 means the plane
+	// NOTE: Any value at or below 65531 means the plane
 	// is a kPlaneTypePicture.
-	kPlanePic            = 65532,
-	kPlanePicOpaque      = 65533,
-	kPlanePicTransparent = 65534,
-	kPlanePicColored     = 65535
+	kPlanePic                   = 65531,
+	kPlanePicTransparentPicture = 65532,
+	kPlanePicOpaque             = 65533,
+	kPlanePicTransparent        = 65534,
+	kPlanePicColored            = 65535
 };
 
 #pragma mark -