+#if 1
+
+ /* check if scrolling the playfield requires redrawing the viewport bitmap */
+ if ((mScrollX != mScrollX_last ||
+ mScrollY != mScrollY_last) &&
+ (ABS(mScrollX - mScrollX_last) >= TILEX ||
+ ABS(mScrollY - mScrollY_last) >= TILEY))
+ {
+ int dx = (ABS(mScrollX - mScrollX_last) < TILEX ? 0 :
+ mScrollX < mScrollX_last ? 1 : mScrollX > mScrollX_last ? -1 : 0);
+ int dy = (ABS(mScrollY - mScrollY_last) < TILEY ? 0 :
+ mScrollY < mScrollY_last ? 1 : mScrollY > mScrollY_last ? -1 : 0);
+
+ mScrollX_last -= dx * TILEX;
+ mScrollY_last -= dy * TILEY;
+
+ ScrollPlayfield(dx, dy);
+
+#if 0
+ printf("::: %ld, %ld\n", mScrollX, mScrollY);
+#endif
+ }
+
+#else
+