MADS: Improve background user interface sprite animations

4 files changed, 58 insertions, 54 deletions

diff --git a/engines/mads/msurface.cpp b/engines/mads/msurface.cpp
index 75aad01ee1..2c9d093877 100644
--- a/engines/mads/msurface.cpp
+++ b/engines/mads/msurface.cpp
@@ -418,50 +418,6 @@ void MSurface::copyFrom(MSurface *src, const Common::Point &destPos, int depth,
 	}
 }
 
-void MSurface::mergeFrom(MSurface *src, const Common::Rect &srcBounds, const Common::Point &destPos) {
-	// Validation of the rectangle and position	
-	int destX = destPos.x, destY = destPos.y;
-	if ((destX >= w) || (destY >= h))
-		return;
-
-	Common::Rect copyRect = srcBounds;
-	if (destX < 0) {
-		copyRect.left += -destX;
-		destX = 0;
-	}
-	else if (destX + copyRect.width() > w) {
-		copyRect.right -= destX + copyRect.width() - w;
-	}
-	if (destY < 0) {
-		copyRect.top += -destY;
-		destY = 0;
-	}
-	else if (destY + copyRect.height() > h) {
-		copyRect.bottom -= destY + copyRect.height() - h;
-	}
-
-	if (!copyRect.isValidRect())
-		return;
-
-	// Copy the specified area
-
-	byte *data = src->getData();
-	byte *srcPtr = data + (src->getWidth() * copyRect.top + copyRect.left);
-	byte *destPtr = (byte *)pixels + (destY * getWidth()) + destX;
-
-	for (int rowCtr = 0; rowCtr < copyRect.height(); ++rowCtr) {
-		// Process each line of the area
-		for (int xCtr = 0; xCtr < copyRect.width(); ++xCtr) {
-			// Check for the range used for on-screen text, which should be kept intact
-			if (srcPtr[xCtr] < 8 || srcPtr[xCtr] > 15)
-				destPtr[xCtr] = srcPtr[xCtr];
-		}
-
-		srcPtr += src->getWidth();
-		destPtr += getWidth();
-	}
-}
-
 void MSurface::scrollX(int xAmount) {
 	if (xAmount == 0)
 		return;
diff --git a/engines/mads/msurface.h b/engines/mads/msurface.h
index f590bac2e5..7cf2bbe15b 100644
--- a/engines/mads/msurface.h
+++ b/engines/mads/msurface.h
@@ -188,14 +188,6 @@ public:
 	}
 
 	/**
-	* Merges a sub-section of another surface into the current one.
-	* @param src			Source surface
-	* @param srcBounds		Area to copy/merge from
-	* @param destPos		Destination position to draw in current surface
-	*/
-	void mergeFrom(MSurface *src, const Common::Rect &srcBounds, const Common::Point &destPos);
-
-	/**
 	 * Scroll the screen horizontally by a given amount
 	 * @param xAmount	Horizontal amount
 	 */
diff --git a/engines/mads/user_interface.cpp b/engines/mads/user_interface.cpp
index a5e8a844f9..f775e459b5 100644
--- a/engines/mads/user_interface.cpp
+++ b/engines/mads/user_interface.cpp
@@ -162,10 +162,12 @@ void UISlots::draw(bool updateFlag, bool delFlag) {
 
 					if (flipped) {
 						MSurface *spr = sprite->flipHorizontal();
-						spr->copyTo(&userInterface, slot._position, sprite->getTransparencyIndex());
+						userInterface.mergeFrom(spr, spr->getBounds(), slot._position,
+							sprite->getTransparencyIndex());
 						delete spr;
 					} else {
-						sprite->copyTo(&userInterface, slot._position, sprite->getTransparencyIndex());
+						userInterface.mergeFrom(sprite, sprite->getBounds(), slot._position,
+							sprite->getTransparencyIndex());
 					}
 				}
 			}
@@ -407,6 +409,49 @@ void UserInterface::drawTextElements() {
 	}
 }
 
+void UserInterface::mergeFrom(MSurface *src, const Common::Rect &srcBounds,
+	const Common::Point &destPos, int transparencyIndex) {
+	// Validation of the rectangle and position	
+	int destX = destPos.x, destY = destPos.y;
+	if ((destX >= w) || (destY >= h))
+		return;
+
+	Common::Rect copyRect = srcBounds;
+	if (destX < 0) {
+		copyRect.left += -destX;
+		destX = 0;
+	} else if (destX + copyRect.width() > w) {
+		copyRect.right -= destX + copyRect.width() - w;
+	}
+	if (destY < 0) {
+		copyRect.top += -destY;
+		destY = 0;
+	} else if (destY + copyRect.height() > h) {
+		copyRect.bottom -= destY + copyRect.height() - h;
+	}
+
+	if (!copyRect.isValidRect())
+		return;
+
+	// Copy the specified area
+
+	byte *data = src->getData();
+	byte *srcPtr = data + (src->getWidth() * copyRect.top + copyRect.left);
+	byte *destPtr = (byte *)this->pixels + (destY * getWidth()) + destX;
+
+	for (int rowCtr = 0; rowCtr < copyRect.height(); ++rowCtr) {
+		// Process each line of the area
+		for (int xCtr = 0; xCtr < copyRect.width(); ++xCtr) {
+			// Check for the range used for on-screen text, which should be kept intact
+			if ((destPtr[xCtr] >= 8 && destPtr[xCtr] <= 15) && (int)srcPtr[xCtr] != transparencyIndex)
+				destPtr[xCtr] = srcPtr[xCtr];
+		}
+
+		srcPtr += src->getWidth();
+		destPtr += getWidth();
+	}
+}
+
 void UserInterface::drawActions() {
 	for (int idx = 0; idx < 10; ++idx) {
 		writeVocab(CAT_COMMAND, idx);
diff --git a/engines/mads/user_interface.h b/engines/mads/user_interface.h
index 7541bb8661..a29a0e6de0 100644
--- a/engines/mads/user_interface.h
+++ b/engines/mads/user_interface.h
@@ -229,6 +229,17 @@ public:
 	void drawTextElements();
 
 	/**
+	* Merges a sub-section of another surface into the user interface without
+	* destroying any on-screen text
+	* @param src			Source surface
+	* @param srcBounds		Area to copy/merge from
+	* @param destPos		Destination position to draw in current surface
+	* @param transparencyIndex	Transparency color
+	*/
+	void mergeFrom(MSurface *src, const Common::Rect &srcBounds, const Common::Point &destPos,
+		int transparencyIndex = -1);
+
+	/**
 	 * Loads the animation sprite data for a given inventory object
 	 */
 	void loadInventoryAnim(int objectId);