1 files changed, 40 insertions, 0 deletions
diff --git a/backends/dc/display.cpp b/backends/dc/display.cpp
index 97c7f2aed5..317f33a0fa 100644
--- a/backends/dc/display.cpp
+++ b/backends/dc/display.cpp
@@ -132,6 +132,46 @@ void OSystem_Dreamcast::copy_rect(const byte *buf, int pitch, int x, int y,
   } while (--h);
 }
 
+void OSystem_Dreamcast::move_screen(int dx, int dy, int height) {
+
+	if ((dx == 0) && (dy == 0))
+		return;
+
+	if (dx == 0) {
+		// vertical movement
+		if (dy > 0) {
+			// move down
+			// copy from bottom to top
+			for (int y = height - 1; y >= dy; y--)
+				copy_rect(screen + SCREEN_W * (y - dy), SCREEN_W, 0, y, SCREEN_W, 1);
+		} else {
+			// move up
+			// copy from top to bottom
+			for (int y = 0; y < height + dx; y++)
+				copy_rect(screen + SCREEN_W * (y - dy), SCREEN_W, 0, y, SCREEN_W, 1);
+		}
+	} else if (dy == 0) {
+		// horizontal movement
+		if (dx > 0) {
+			// move right
+			// copy from right to left
+			for (int x = SCREEN_W - 1; x >= dx; x--)
+				copy_rect(screen + x - dx, SCREEN_W, x, 0, 1, height);
+		} else {
+			// move left
+			// copy from left to right
+			for (int x = 0; x < SCREEN_W; x++)
+				copy_rect(screen + x - dx, SCREEN_W, x, 0, 1, height);
+		}
+	} else {
+		// free movement
+		// not neccessary for now
+	}
+
+
+}
+
+
 bool OSystem_Dreamcast::show_mouse(bool visible)
 {	
   bool last = _ms_visible;