SHERLOCK: RT: Implement makeBGArea for converting to greyscale

2 files changed, 17 insertions, 0 deletions

diff --git a/engines/sherlock/tattoo/tattoo_user_interface.cpp b/engines/sherlock/tattoo/tattoo_user_interface.cpp
index 771c22c46e..84ebfe7837 100644
--- a/engines/sherlock/tattoo/tattoo_user_interface.cpp
+++ b/engines/sherlock/tattoo/tattoo_user_interface.cpp
@@ -863,6 +863,18 @@ void TattooUserInterface::drawMaskArea(bool mode) {
 	}
 }
 
+void TattooUserInterface::makeBGArea(const Common::Rect &r) {
+	Screen &screen = *_vm->_screen;
+
+	for (int yp = r.top; yp < r.bottom; ++yp) {
+		byte *ptr = screen._backBuffer1.getBasePtr(r.left, yp);
+
+		for (int xp = r.left; xp < r.right; ++xp, ++ptr)
+			*ptr = _lookupTable[*ptr];
+	}
+}
+
+
 } // End of namespace Tattoo
 
 } // End of namespace Sherlock
diff --git a/engines/sherlock/tattoo/tattoo_user_interface.h b/engines/sherlock/tattoo/tattoo_user_interface.h
index 6eeae2dfd9..27039d9e4b 100644
--- a/engines/sherlock/tattoo/tattoo_user_interface.h
+++ b/engines/sherlock/tattoo/tattoo_user_interface.h
@@ -208,6 +208,11 @@ public:
 	void doBgAnimEraseBackground();
 
 	void drawMaskArea(bool mode);
+
+	/**
+	 * Translate a given area of the back buffer to greyscale shading
+	 */
+	void makeBGArea(const Common::Rect &r);
 public:
 	/**
 	 * Resets the user interface