+/* static variables for playfield scan mode (scanning forward or backward) */
+static int playfield_scan_start_x = 0;
+static int playfield_scan_start_y = 0;
+static int playfield_scan_delta_x = 1;
+static int playfield_scan_delta_y = 1;
+
+#define SCAN_PLAYFIELD(x, y) for ((y) = playfield_scan_start_y; \
+ (y) >= 0 && (y) <= lev_fieldy - 1; \
+ (y) += playfield_scan_delta_y) \
+ for ((x) = playfield_scan_start_x; \
+ (x) >= 0 && (x) <= lev_fieldx - 1; \
+ (x) += playfield_scan_delta_x) \
+
+static void InitPlayfieldScanModeVars()
+{
+ if (game.use_reverse_scan_direction)
+ {
+ playfield_scan_start_x = lev_fieldx - 1;
+ playfield_scan_start_y = lev_fieldy - 1;
+
+ playfield_scan_delta_x = -1;
+ playfield_scan_delta_y = -1;
+ }
+ else
+ {
+ playfield_scan_start_x = 0;
+ playfield_scan_start_y = 0;
+
+ playfield_scan_delta_x = 1;
+ playfield_scan_delta_y = 1;
+ }
+}
+
+static void InitPlayfieldScanMode(int mode)
+{
+ game.use_reverse_scan_direction =
+ (mode == CA_ARG_SCAN_MODE_REVERSE ? TRUE : FALSE);
+
+ InitPlayfieldScanModeVars();
+}
+
+static int get_move_delay_from_stepsize(int move_stepsize)
+{
+ move_stepsize =
+ MIN(MAX(MOVE_STEPSIZE_MIN, move_stepsize), MOVE_STEPSIZE_MAX);
+
+ /* make sure that stepsize value is always a power of 2 */
+ move_stepsize = (1 << log_2(move_stepsize));
+
+ return TILEX / move_stepsize;
+}
+
+static void SetPlayerMoveSpeed(struct PlayerInfo *player, int move_stepsize,
+ boolean init_game)
+{
+ int move_delay = get_move_delay_from_stepsize(move_stepsize);
+ boolean cannot_move = (move_stepsize == STEPSIZE_NOT_MOVING ? TRUE : FALSE);
+
+ /* do no immediately change move delay -- the player might just be moving */
+ player->move_delay_value_next = move_delay;
+
+ /* information if player can move must be set separately */
+ player->cannot_move = cannot_move;
+
+ if (init_game)
+ {
+ player->move_delay = game.initial_move_delay;
+ player->move_delay_value = game.initial_move_delay_value;
+
+ player->move_delay_value_next = -1;
+
+ player->move_delay_reset_counter = 0;
+ }
+}