int sysize = (full_ysize < ysize ? full_ysize : ysize);
int xxsize = MAX_BUF_XSIZE * TILEX - x;
int yysize = MAX_BUF_YSIZE * TILEY - y;
int sysize = (full_ysize < ysize ? full_ysize : ysize);
int xxsize = MAX_BUF_XSIZE * TILEX - x;
int yysize = MAX_BUF_YSIZE * TILEY - y;