- int sx1 = mScrollX_last - 2 * TILEX;
- int sy1 = mScrollY_last - 2 * TILEY;
- int sx2 = mScrollX_last + SXSIZE + 1 * TILEX;
- int sy2 = mScrollY_last + SYSIZE + 1 * TILEY;
+ int scx = (mScrollX_last < 0 ? 0 : mScrollX_last);
+ int scy = (mScrollY_last < 0 ? 0 : mScrollY_last);
+ int sx1 = scx - 2 * TILEX;
+ int sy1 = scy - 2 * TILEY;
+ int sx2 = scx + SXSIZE + 1 * TILEX;
+ int sy2 = scy + SYSIZE + 1 * TILEY;