X-Git-Url: https://git.artsoft.org/?p=rocksndiamonds.git;a=blobdiff_plain;f=src%2Fgame.c;h=0b52048d657b6e2243a4ebb8bb2830e4fb2caef6;hp=bb6e6ede2b2d259978b05380fef26368630f6027;hb=80e176e969192ac90d74ef83b4ab22dc0fe21b7a;hpb=dff0e0c8702770fe23992f07964ebe9ed54e9f7c

diff --git a/src/game.c b/src/game.c
index bb6e6ede..0b52048d 100644
--- a/src/game.c
+++ b/src/game.c
@@ -10565,8 +10565,32 @@ static boolean AllPlayersInVisibleScreen()
 
 void ScrollLevel(int dx, int dy)
 {
+  int i, x, y;
+
+  /* only horizontal XOR vertical scroll direction allowed */
+  if ((dx == 0 && dy == 0) || (dx != 0 && dy != 0))
+    return;
+
+#if 1
+  int xsize = (BX2 - BX1 + 1);
+  int ysize = (BY2 - BY1 + 1);
+  int start = (dx != 0 ? (dx == -1 ? BX1 : BX2) : (dy == -1 ? BY1 : BY2));
+  int end   = (dx != 0 ? (dx == -1 ? BX2 : BX1) : (dy == -1 ? BY2 : BY1));
+  int step  = (start < end ? +1 : -1);
+
+  for (i = start; i != end; i += step)
+  {
+    BlitBitmap(drawto_field, drawto_field,
+	       FX + TILEX * (dx != 0 ? i + step : 0),
+	       FY + TILEY * (dy != 0 ? i + step : 0),
+	       TILEX * (dx != 0 ? 1 : xsize),
+	       TILEY * (dy != 0 ? 1 : ysize),
+	       FX + TILEX * (dx != 0 ? i : 0),
+	       FY + TILEY * (dy != 0 ? i : 0));
+  }
+#else
+
   int softscroll_offset = (setup.soft_scrolling ? TILEX : 0);
-  int x, y;
 
 #if 1
   BlitBitmap(drawto_field, bitmap_db_field2,
@@ -10591,16 +10615,17 @@ void ScrollLevel(int dx, int dy)
 	     SYSIZE - TILEY * (dy != 0) + 2 * softscroll_offset,
 	     FX + TILEX * (dx == 1) - softscroll_offset,
 	     FY + TILEY * (dy == 1) - softscroll_offset);
+#endif
 #endif
 
-  if (dx)
+  if (dx != 0)
   {
     x = (dx == 1 ? BX1 : BX2);
     for (y = BY1; y <= BY2; y++)
       DrawScreenField(x, y);
   }
 
-  if (dy)
+  if (dy != 0)
   {
     y = (dy == 1 ? BY1 : BY2);
     for (x = BX1; x <= BX2; x++)