1 /* 2000-08-13T14:36:17Z
3 * graphics manipulation crap
8 #define MIN_SCREEN_XPOS_RAW 0
9 #define MIN_SCREEN_YPOS_RAW 0
10 #define MAX_SCREEN_XPOS_RAW MAX(0, lev.width - SCR_FIELDX)
11 #define MAX_SCREEN_YPOS_RAW MAX(0, lev.height - SCR_FIELDY)
13 #define MIN_SCREEN_XPOS (MIN_SCREEN_XPOS_RAW + CAVE_BUFFER_XOFFSET)
14 #define MIN_SCREEN_YPOS (MIN_SCREEN_YPOS_RAW + CAVE_BUFFER_YOFFSET)
15 #define MAX_SCREEN_XPOS (MAX_SCREEN_XPOS_RAW + CAVE_BUFFER_XOFFSET)
16 #define MAX_SCREEN_YPOS (MAX_SCREEN_YPOS_RAW + CAVE_BUFFER_YOFFSET)
18 #define MIN_SCREEN_X (MIN_SCREEN_XPOS * TILEX)
19 #define MIN_SCREEN_Y (MIN_SCREEN_YPOS * TILEY)
20 #define MAX_SCREEN_X (MAX_SCREEN_XPOS * TILEX)
21 #define MAX_SCREEN_Y (MAX_SCREEN_YPOS * TILEY)
23 #define VALID_SCREEN_X(x) ((x) < MIN_SCREEN_X ? MIN_SCREEN_X : \
24 (x) > MAX_SCREEN_X ? MAX_SCREEN_X : (x))
25 #define VALID_SCREEN_Y(y) ((y) < MIN_SCREEN_Y ? MIN_SCREEN_Y : \
26 (y) > MAX_SCREEN_Y ? MAX_SCREEN_Y : (y))
28 #define PLAYER_SCREEN_X(p) ((( frame) * ply[p].oldx + \
29 (8 - frame) * ply[p].x) * TILEX / 8 \
30 - ((SCR_FIELDX - 1) * TILEX) / 2)
31 #define PLAYER_SCREEN_Y(p) ((( frame) * ply[p].oldy + \
32 (8 - frame) * ply[p].y) * TILEY / 8 \
33 - ((SCR_FIELDY - 1) * TILEY) / 2)
35 #define USE_EXTENDED_GRAPHICS_ENGINE 1
38 int frame; /* current screen frame */
39 int screen_x, screen_y; /* current scroll position */
41 /* tiles currently on screen */
42 static int screentiles[MAX_PLAYFIELD_WIDTH + 2][MAX_PLAYFIELD_HEIGHT + 2];
43 static int crumbled_state[MAX_PLAYFIELD_WIDTH + 2][MAX_PLAYFIELD_HEIGHT + 2];
45 int getFieldbufferOffsetX_EM(void)
47 return screen_x % TILEX;
50 int getFieldbufferOffsetY_EM(void)
52 return screen_y % TILEY;
55 void BlitScreenToBitmap_EM(Bitmap *target_bitmap)
57 /* blit all (up to four) parts of the scroll buffer to the target bitmap */
59 int x = screen_x % (MAX_BUF_XSIZE * TILEX);
60 int y = screen_y % (MAX_BUF_YSIZE * TILEY);
63 int full_xsize = lev.width * TILEX;
64 int full_ysize = lev.height * TILEY;
65 int sx = SX + (full_xsize < xsize ? (xsize - full_xsize) / 2 : 0);
66 int sy = SY + (full_ysize < ysize ? (ysize - full_ysize) / 2 : 0);
67 int sxsize = (full_xsize < xsize ? full_xsize : xsize);
68 int sysize = (full_ysize < ysize ? full_ysize : ysize);
70 if (x < 2 * TILEX && y < 2 * TILEY)
72 BlitBitmap(screenBitmap, target_bitmap, x, y,
73 sxsize, sysize, sx, sy);
75 else if (x < 2 * TILEX && y >= 2 * TILEY)
77 BlitBitmap(screenBitmap, target_bitmap, x, y,
78 sxsize, MAX_BUF_YSIZE * TILEY - y,
80 BlitBitmap(screenBitmap, target_bitmap, x, 0,
81 sxsize, y - 2 * TILEY,
82 sx, sy + MAX_BUF_YSIZE * TILEY - y);
84 else if (x >= 2 * TILEX && y < 2 * TILEY)
86 BlitBitmap(screenBitmap, target_bitmap, x, y,
87 MAX_BUF_XSIZE * TILEX - x, sysize,
89 BlitBitmap(screenBitmap, target_bitmap, 0, y,
90 x - 2 * TILEX, sysize,
91 sx + MAX_BUF_XSIZE * TILEX - x, sy);
95 BlitBitmap(screenBitmap, target_bitmap, x, y,
96 MAX_BUF_XSIZE * TILEX - x, MAX_BUF_YSIZE * TILEY - y,
98 BlitBitmap(screenBitmap, target_bitmap, 0, y,
99 x - 2 * TILEX, MAX_BUF_YSIZE * TILEY - y,
100 sx + MAX_BUF_XSIZE * TILEX - x, sy);
101 BlitBitmap(screenBitmap, target_bitmap, x, 0,
102 MAX_BUF_XSIZE * TILEX - x, y - 2 * TILEY,
103 sx, sy + MAX_BUF_YSIZE * TILEY - y);
104 BlitBitmap(screenBitmap, target_bitmap, 0, 0,
105 x - 2 * TILEX, y - 2 * TILEY,
106 sx + MAX_BUF_XSIZE * TILEX - x, sy + MAX_BUF_YSIZE * TILEY - y);
110 void BackToFront_EM(void)
112 BlitBitmap(backbuffer, window, SX, SY, SXSIZE, SYSIZE, SX, SY);
115 static struct GraphicInfo_EM *getObjectGraphic(int x, int y)
117 int tile = lev.draw[x][y];
118 struct GraphicInfo_EM *g = &graphic_info_em_object[tile][frame];
120 if (!game.use_native_emc_graphics_engine)
121 getGraphicSourceObjectExt_EM(g, tile, 7 - frame, x - lev.left, y - lev.top);
126 static struct GraphicInfo_EM *getPlayerGraphic(int player_nr, int anim)
128 struct GraphicInfo_EM *g = &graphic_info_em_player[player_nr][anim][frame];
130 if (!game.use_native_emc_graphics_engine)
131 getGraphicSourcePlayerExt_EM(g, player_nr, anim, 7 - frame);
136 static void DrawLevelField_EM(int x, int y, int sx, int sy,
139 struct GraphicInfo_EM *g = getObjectGraphic(x, y);
140 int src_x = g->src_x + g->src_offset_x * TILESIZE_VAR / TILESIZE;
141 int src_y = g->src_y + g->src_offset_y * TILESIZE_VAR / TILESIZE;
142 int dst_x = sx * TILEX + g->dst_offset_x * TILESIZE_VAR / TILESIZE;
143 int dst_y = sy * TILEY + g->dst_offset_y * TILESIZE_VAR / TILESIZE;
144 int width = g->width * TILESIZE_VAR / TILESIZE;
145 int height = g->height * TILESIZE_VAR / TILESIZE;
146 int left = screen_x / TILEX;
147 int top = screen_y / TILEY;
149 /* do not draw fields that are outside the visible screen area */
150 if (x < left || x >= left + MAX_BUF_XSIZE ||
151 y < top || y >= top + MAX_BUF_YSIZE)
156 if (width > 0 && height > 0)
157 BlitBitmapMasked(g->bitmap, screenBitmap,
158 src_x, src_y, width, height, dst_x, dst_y);
162 if ((width != TILEX || height != TILEY) && !g->preserve_background)
163 ClearRectangle(screenBitmap, sx * TILEX, sy * TILEY, TILEX, TILEY);
165 if (width > 0 && height > 0)
166 BlitBitmap(g->bitmap, screenBitmap,
167 src_x, src_y, width, height, dst_x, dst_y);
171 static void DrawLevelFieldCrumbled_EM(int x, int y, int sx, int sy,
172 int crm, boolean draw_masked)
174 struct GraphicInfo_EM *g;
175 int crumbled_border_size;
176 int left = screen_x / TILEX;
177 int top = screen_y / TILEY;
180 /* do not draw fields that are outside the visible screen area */
181 if (x < left || x >= left + MAX_BUF_XSIZE ||
182 y < top || y >= top + MAX_BUF_YSIZE)
185 if (crm == 0) /* no crumbled edges for this tile */
188 g = getObjectGraphic(x, y);
190 crumbled_border_size =
191 g->crumbled_border_size * TILESIZE_VAR / g->crumbled_tile_size;
193 for (i = 0; i < 4; i++)
197 int width, height, cx, cy;
199 if (i == 1 || i == 2)
201 width = crumbled_border_size;
203 cx = (i == 2 ? TILEX - crumbled_border_size : 0);
209 height = crumbled_border_size;
211 cy = (i == 3 ? TILEY - crumbled_border_size : 0);
214 if (width > 0 && height > 0)
216 int src_x = g->crumbled_src_x + cx;
217 int src_y = g->crumbled_src_y + cy;
218 int dst_x = sx * TILEX + cx;
219 int dst_y = sy * TILEY + cy;
222 BlitBitmapMasked(g->crumbled_bitmap, screenBitmap,
223 src_x, src_y, width, height, dst_x, dst_y);
225 BlitBitmap(g->crumbled_bitmap, screenBitmap,
226 src_x, src_y, width, height, dst_x, dst_y);
232 static void DrawLevelPlayer_EM(int x1, int y1, int player_nr, int anim,
235 struct GraphicInfo_EM *g = getPlayerGraphic(player_nr, anim);
236 int src_x = g->src_x, src_y = g->src_y;
239 /* do not draw fields that are outside the visible screen area */
240 if (x1 < screen_x - TILEX || x1 >= screen_x + MAX_BUF_XSIZE * TILEX ||
241 y1 < screen_y - TILEY || y1 >= screen_y + MAX_BUF_YSIZE * TILEY)
244 x1 %= MAX_BUF_XSIZE * TILEX;
245 y1 %= MAX_BUF_YSIZE * TILEY;
249 /* draw the player to current location */
252 BlitBitmapMasked(g->bitmap, screenBitmap,
253 src_x, src_y, TILEX, TILEY, dst_x, dst_y);
255 /* draw the player to opposite wrap-around column */
256 dst_x = x1 - MAX_BUF_XSIZE * TILEX;
258 BlitBitmapMasked(g->bitmap, screenBitmap,
259 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
261 /* draw the player to opposite wrap-around row */
263 dst_y = y1 - MAX_BUF_YSIZE * TILEY;
264 BlitBitmapMasked(g->bitmap, screenBitmap,
265 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
269 /* draw the player to current location */
272 BlitBitmap(g->bitmap, screenBitmap,
273 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
275 /* draw the player to opposite wrap-around column */
276 dst_x = x1 - MAX_BUF_XSIZE * TILEX;
278 BlitBitmap(g->bitmap, screenBitmap,
279 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
281 /* draw the player to opposite wrap-around row */
283 dst_y = y1 - MAX_BUF_YSIZE * TILEY;
284 BlitBitmap(g->bitmap, screenBitmap,
285 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
289 /* draw differences between game tiles and screen tiles
291 * implicitly handles scrolling and restoring background under the sprites
294 static void animscreen(void)
297 int left = screen_x / TILEX;
298 int top = screen_y / TILEY;
299 static int xy[4][2] =
307 if (!game.use_native_emc_graphics_engine)
308 for (y = lev.top; y < lev.bottom; y++)
309 for (x = lev.left; x < lev.right; x++)
310 SetGfxAnimation_EM(&graphic_info_em_object[lev.draw[x][y]][frame],
311 lev.draw[x][y], 7 - frame,
312 x - lev.left, y - lev.top);
314 for (y = top; y < top + MAX_BUF_YSIZE; y++)
316 for (x = left; x < left + MAX_BUF_XSIZE; x++)
318 int sx = x % MAX_BUF_XSIZE;
319 int sy = y % MAX_BUF_YSIZE;
320 int tile = lev.draw[x][y];
321 struct GraphicInfo_EM *g = &graphic_info_em_object[tile][frame];
322 int obj = g->unique_identifier;
324 boolean redraw_screen_tile = FALSE;
326 /* re-calculate crumbled state of this tile */
327 if (g->has_crumbled_graphics)
329 for (i = 0; i < 4; i++)
331 int xx = x + xy[i][0];
332 int yy = y + xy[i][1];
335 if (xx < 0 || xx >= CAVE_BUFFER_WIDTH ||
336 yy < 0 || yy >= CAVE_BUFFER_HEIGHT)
339 tile_next = lev.draw[xx][yy];
341 if (!graphic_info_em_object[tile_next][frame].has_crumbled_graphics)
346 redraw_screen_tile = (screentiles[sx][sy] != obj ||
347 crumbled_state[sx][sy] != crm);
349 /* only redraw screen tiles if they (or their crumbled state) changed */
350 if (redraw_screen_tile)
352 DrawLevelField_EM(x, y, sx, sy, FALSE);
353 DrawLevelFieldCrumbled_EM(x, y, sx, sy, crm, FALSE);
355 screentiles[sx][sy] = obj;
356 crumbled_state[sx][sy] = crm;
363 /* blit players to the screen
365 * handles transparency and movement
368 static void blitplayer(struct PLAYER *ply)
375 /* x1/y1 are left/top and x2/y2 are right/down part of the player movement */
376 x1 = (frame * ply->oldx + (8 - frame) * ply->x) * TILEX / 8;
377 y1 = (frame * ply->oldy + (8 - frame) * ply->y) * TILEY / 8;
381 if ((int)(x2 - screen_x) < ((MAX_BUF_XSIZE - 1) * TILEX - 1) &&
382 (int)(y2 - screen_y) < ((MAX_BUF_YSIZE - 1) * TILEY - 1))
384 /* some casts to "int" are needed because of negative calculation values */
385 int dx = (int)ply->x - (int)ply->oldx;
386 int dy = (int)ply->y - (int)ply->oldy;
387 int old_x = (int)ply->oldx + (7 - (int)frame) * dx / 8;
388 int old_y = (int)ply->oldy + (7 - (int)frame) * dy / 8;
389 int new_x = old_x + SIGN(dx);
390 int new_y = old_y + SIGN(dy);
391 int old_sx = old_x % MAX_BUF_XSIZE;
392 int old_sy = old_y % MAX_BUF_YSIZE;
393 int new_sx = new_x % MAX_BUF_XSIZE;
394 int new_sy = new_y % MAX_BUF_YSIZE;
395 int new_crm = crumbled_state[new_sx][new_sy];
397 /* only diggable elements can be crumbled in the classic EM engine */
398 boolean player_is_digging = (new_crm != 0);
400 if (player_is_digging)
402 /* draw the field the player is moving to (under the player) */
403 DrawLevelField_EM(new_x, new_y, new_sx, new_sy, FALSE);
404 DrawLevelFieldCrumbled_EM(new_x, new_y, new_sx, new_sy, new_crm, FALSE);
406 /* draw the player (masked) over the element he is just digging away */
407 DrawLevelPlayer_EM(x1, y1, ply->num, ply->anim, TRUE);
409 /* draw the field the player is moving from (masked over the player) */
410 DrawLevelField_EM(old_x, old_y, old_sx, old_sy, TRUE);
414 /* draw the player under the element which is on the same field */
415 DrawLevelPlayer_EM(x1, y1, ply->num, ply->anim, FALSE);
417 /* draw the field the player is moving from (masked over the player) */
418 DrawLevelField_EM(old_x, old_y, old_sx, old_sy, TRUE);
420 /* draw the field the player is moving to (masked over the player) */
421 DrawLevelField_EM(new_x, new_y, new_sx, new_sy, TRUE);
424 /* redraw screen tiles in the next frame (player may have left the tiles) */
425 screentiles[old_sx][old_sy] = -1;
426 screentiles[new_sx][new_sy] = -1;
430 void game_initscreen(void)
437 player_nr = (game.centered_player_nr != -1 ? game.centered_player_nr : 0);
439 screen_x = VALID_SCREEN_X(PLAYER_SCREEN_X(player_nr));
440 screen_y = VALID_SCREEN_Y(PLAYER_SCREEN_Y(player_nr));
442 for (y = 0; y < MAX_BUF_YSIZE; y++)
444 for (x = 0; x < MAX_BUF_XSIZE; x++)
446 screentiles[x][y] = -1;
447 crumbled_state[x][y] = 0;
452 static int getMaxCenterDistancePlayerNr(int center_x, int center_y)
454 int max_dx = 0, max_dy = 0;
455 int player_nr = game_em.last_moving_player;
458 for (i = 0; i < MAX_PLAYERS; i++)
462 int sx = PLAYER_SCREEN_X(i);
463 int sy = PLAYER_SCREEN_Y(i);
465 if (game_em.last_player_direction[i] != MV_NONE &&
466 (ABS(sx - center_x) > max_dx ||
467 ABS(sy - center_y) > max_dy))
469 max_dx = MAX(max_dx, ABS(sx - center_x));
470 max_dy = MAX(max_dy, ABS(sy - center_y));
480 static void setMinimalPlayerBoundaries(int *sx1, int *sy1, int *sx2, int *sy2)
482 boolean num_checked_players = 0;
485 for (i = 0; i < MAX_PLAYERS; i++)
489 int sx = PLAYER_SCREEN_X(i);
490 int sy = PLAYER_SCREEN_Y(i);
492 if (num_checked_players == 0)
499 *sx1 = MIN(*sx1, sx);
500 *sy1 = MIN(*sy1, sy);
501 *sx2 = MAX(*sx2, sx);
502 *sy2 = MAX(*sy2, sy);
505 num_checked_players++;
510 boolean checkIfAllPlayersFitToScreen(void)
512 int sx1 = 0, sy1 = 0, sx2 = 0, sy2 = 0;
514 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
516 return (sx2 - sx1 <= SCR_FIELDX * TILEX &&
517 sy2 - sy1 <= SCR_FIELDY * TILEY);
520 static void setScreenCenteredToAllPlayers(int *sx, int *sy)
522 int sx1 = screen_x, sy1 = screen_y, sx2 = screen_x, sy2 = screen_y;
524 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
526 *sx = (sx1 + sx2) / 2;
527 *sy = (sy1 + sy2) / 2;
530 static void setMaxCenterDistanceForAllPlayers(int *max_dx, int *max_dy,
531 int center_x, int center_y)
533 int sx1 = center_x, sy1 = center_y, sx2 = center_x, sy2 = center_y;
535 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
537 *max_dx = MAX(ABS(sx1 - center_x), ABS(sx2 - center_x));
538 *max_dy = MAX(ABS(sy1 - center_y), ABS(sy2 - center_y));
541 static boolean checkIfAllPlayersAreVisible(int center_x, int center_y)
545 setMaxCenterDistanceForAllPlayers(&max_dx, &max_dy, center_x, center_y);
547 return (max_dx <= SCR_FIELDX * TILEX / 2 &&
548 max_dy <= SCR_FIELDY * TILEY / 2);
551 void RedrawPlayfield_EM(boolean force_redraw)
553 boolean draw_new_player_location = FALSE;
554 boolean quick_relocation = setup.quick_switch;
555 int max_center_distance_player_nr =
556 getMaxCenterDistancePlayerNr(screen_x, screen_y);
557 int stepsize = TILEX / 8;
558 int offset_raw = game.scroll_delay_value;
559 int offset_x = MIN(offset_raw, (SCR_FIELDX - 2) / 2) * TILEX;
560 int offset_y = MIN(offset_raw, (SCR_FIELDY - 2) / 2) * TILEY;
561 int screen_x_old = screen_x;
562 int screen_y_old = screen_y;
566 if (game.set_centered_player)
568 boolean all_players_fit_to_screen = checkIfAllPlayersFitToScreen();
570 /* switching to "all players" only possible if all players fit to screen */
571 if (game.centered_player_nr_next == -1 && !all_players_fit_to_screen)
573 game.centered_player_nr_next = game.centered_player_nr;
574 game.set_centered_player = FALSE;
577 /* do not switch focus to non-existing (or non-active) player */
578 if (game.centered_player_nr_next >= 0 &&
579 !ply[game.centered_player_nr_next].alive)
581 game.centered_player_nr_next = game.centered_player_nr;
582 game.set_centered_player = FALSE;
586 /* also allow focus switching when screen is scrolled to half tile */
587 if (game.set_centered_player)
589 game.centered_player_nr = game.centered_player_nr_next;
591 draw_new_player_location = TRUE;
594 game.set_centered_player = FALSE;
597 if (game.centered_player_nr == -1)
599 if (draw_new_player_location || offset_raw == 0)
601 setScreenCenteredToAllPlayers(&sx, &sy);
605 sx = PLAYER_SCREEN_X(max_center_distance_player_nr);
606 sy = PLAYER_SCREEN_Y(max_center_distance_player_nr);
611 sx = PLAYER_SCREEN_X(game.centered_player_nr);
612 sy = PLAYER_SCREEN_Y(game.centered_player_nr);
615 if (draw_new_player_location && quick_relocation)
617 screen_x = VALID_SCREEN_X(sx);
618 screen_y = VALID_SCREEN_Y(sy);
619 screen_x_old = screen_x;
620 screen_y_old = screen_y;
623 if (draw_new_player_location && !quick_relocation)
625 unsigned int game_frame_delay_value = getGameFrameDelay_EM(20);
626 int wait_delay_value = game_frame_delay_value;
627 int screen_xx = VALID_SCREEN_X(sx);
628 int screen_yy = VALID_SCREEN_Y(sy);
630 while (screen_x != screen_xx || screen_y != screen_yy)
632 int dx = (screen_xx < screen_x ? +1 : screen_xx > screen_x ? -1 : 0);
633 int dy = (screen_yy < screen_y ? +1 : screen_yy > screen_y ? -1 : 0);
634 int dxx = 0, dyy = 0;
636 if (dx == 0 && dy == 0) /* no scrolling needed at all */
639 if (ABS(screen_xx - screen_x) >= TILEX)
641 screen_x -= dx * TILEX;
642 dxx = dx * TILEX / 2;
646 screen_x = screen_xx;
650 if (ABS(screen_yy - screen_y) >= TILEY)
652 screen_y -= dy * TILEY;
653 dyy = dy * TILEY / 2;
657 screen_y = screen_yy;
661 /* scroll in two steps of half tile size to make things smoother */
667 for (i = 0; i < MAX_PLAYERS; i++)
670 BlitScreenToBitmap_EM(backbuffer);
673 Delay(wait_delay_value);
675 /* scroll second step to align at full tile size */
681 for (i = 0; i < MAX_PLAYERS; i++)
684 BlitScreenToBitmap_EM(backbuffer);
687 Delay(wait_delay_value);
690 screen_x_old = screen_x;
691 screen_y_old = screen_y;
696 for (y = 0; y < MAX_BUF_YSIZE; y++)
698 for (x = 0; x < MAX_BUF_XSIZE; x++)
700 screentiles[x][y] = -1;
701 crumbled_state[x][y] = 0;
706 /* calculate new screen scrolling position, with regard to scroll delay */
707 screen_x = VALID_SCREEN_X(sx + offset_x < screen_x ? sx + offset_x :
708 sx - offset_x > screen_x ? sx - offset_x :
710 screen_y = VALID_SCREEN_Y(sy + offset_y < screen_y ? sy + offset_y :
711 sy - offset_y > screen_y ? sy - offset_y :
714 /* prevent scrolling further than double player step size when scrolling */
715 if (ABS(screen_x - screen_x_old) > 2 * stepsize)
717 int dx = SIGN(screen_x - screen_x_old);
719 screen_x = screen_x_old + dx * 2 * stepsize;
721 if (ABS(screen_y - screen_y_old) > 2 * stepsize)
723 int dy = SIGN(screen_y - screen_y_old);
725 screen_y = screen_y_old + dy * 2 * stepsize;
728 /* prevent scrolling away from the other players when focus on all players */
729 if (game.centered_player_nr == -1)
731 /* check if all players are still visible with new scrolling position */
732 if (checkIfAllPlayersAreVisible(screen_x_old, screen_y_old) &&
733 !checkIfAllPlayersAreVisible(screen_x, screen_y))
735 /* reset horizontal scroll position to last value, if needed */
736 if (!checkIfAllPlayersAreVisible(screen_x, screen_y_old))
737 screen_x = screen_x_old;
739 /* reset vertical scroll position to last value, if needed */
740 if (!checkIfAllPlayersAreVisible(screen_x_old, screen_y))
741 screen_y = screen_y_old;
745 /* prevent scrolling (for screen correcting) if no player is moving */
746 if (!game_em.any_player_moving)
748 screen_x = screen_x_old;
749 screen_y = screen_y_old;
753 /* prevent scrolling against the players move direction */
754 int player_nr = (game.centered_player_nr == -1 ?
755 max_center_distance_player_nr : game.centered_player_nr);
756 int player_move_dir = game_em.last_player_direction[player_nr];
757 int dx = SIGN(screen_x - screen_x_old);
758 int dy = SIGN(screen_y - screen_y_old);
760 if ((dx < 0 && player_move_dir != MV_LEFT) ||
761 (dx > 0 && player_move_dir != MV_RIGHT))
762 screen_x = screen_x_old;
764 if ((dy < 0 && player_move_dir != MV_UP) ||
765 (dy > 0 && player_move_dir != MV_DOWN))
766 screen_y = screen_y_old;
769 // skip redrawing playfield in warp mode or when testing tapes with "autotest"
770 if (DrawingDeactivatedField())
775 for (i = 0; i < MAX_PLAYERS; i++)