+ LX += step_size * XS;
+ LY += step_size * YS;
+ }
+ else
+ {
+ // advance laser position until reaching the next tile (slopes)
+ while (LX / TILEX == ELX && (LX + 2) / TILEX == ELX &&
+ LY / TILEY == ELY && (LY + 2) / TILEY == ELY)
+ {
+ LX += XS;
+ LY += YS;
+ }
+ }