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_POS_X(nr) (((7 - frame) * ply[nr].oldx + \
29 (1 + frame) * ply[nr].x) * TILEX / 8)
30 #define PLAYER_POS_Y(nr) (((7 - frame) * ply[nr].oldy + \
31 (1 + frame) * ply[nr].y) * TILEY / 8)
33 #define PLAYER_SCREEN_X(nr) (PLAYER_POS_X(nr) - \
34 (SCR_FIELDX - 1) * TILEX / 2)
35 #define PLAYER_SCREEN_Y(nr) (PLAYER_POS_Y(nr) - \
36 (SCR_FIELDY - 1) * TILEY / 2)
38 #define USE_EXTENDED_GRAPHICS_ENGINE 1
41 int frame; /* current screen frame */
42 int screen_x, screen_y; /* current scroll position */
44 /* tiles currently on screen */
45 static int screen_tiles[MAX_PLAYFIELD_WIDTH + 2][MAX_PLAYFIELD_HEIGHT + 2];
46 static int crumbled_state[MAX_PLAYFIELD_WIDTH + 2][MAX_PLAYFIELD_HEIGHT + 2];
48 /* graphic info for game objects/frames and players/actions/frames */
49 struct GraphicInfo_EM graphic_info_em_object[TILE_MAX][8];
50 struct GraphicInfo_EM graphic_info_em_player[MAX_PLAYERS][PLY_MAX][8];
52 int getFieldbufferOffsetX_EM(void)
54 return screen_x % TILEX;
57 int getFieldbufferOffsetY_EM(void)
59 return screen_y % TILEY;
62 void BlitScreenToBitmap_EM(Bitmap *target_bitmap)
64 /* blit all (up to four) parts of the scroll buffer to the target bitmap */
66 int x = screen_x % (MAX_BUF_XSIZE * TILEX);
67 int y = screen_y % (MAX_BUF_YSIZE * TILEY);
70 int full_xsize = lev.width * TILEX;
71 int full_ysize = lev.height * TILEY;
72 int sx = SX + (full_xsize < xsize ? (xsize - full_xsize) / 2 : 0);
73 int sy = SY + (full_ysize < ysize ? (ysize - full_ysize) / 2 : 0);
74 int sxsize = (full_xsize < xsize ? full_xsize : xsize);
75 int sysize = (full_ysize < ysize ? full_ysize : ysize);
77 if (x < 2 * TILEX && y < 2 * TILEY)
79 BlitBitmap(screenBitmap, target_bitmap, x, y,
80 sxsize, sysize, sx, sy);
82 else if (x < 2 * TILEX && y >= 2 * TILEY)
84 BlitBitmap(screenBitmap, target_bitmap, x, y,
85 sxsize, MAX_BUF_YSIZE * TILEY - y,
87 BlitBitmap(screenBitmap, target_bitmap, x, 0,
88 sxsize, y - 2 * TILEY,
89 sx, sy + MAX_BUF_YSIZE * TILEY - y);
91 else if (x >= 2 * TILEX && y < 2 * TILEY)
93 BlitBitmap(screenBitmap, target_bitmap, x, y,
94 MAX_BUF_XSIZE * TILEX - x, sysize,
96 BlitBitmap(screenBitmap, target_bitmap, 0, y,
97 x - 2 * TILEX, sysize,
98 sx + MAX_BUF_XSIZE * TILEX - x, sy);
102 BlitBitmap(screenBitmap, target_bitmap, x, y,
103 MAX_BUF_XSIZE * TILEX - x, MAX_BUF_YSIZE * TILEY - y,
105 BlitBitmap(screenBitmap, target_bitmap, 0, y,
106 x - 2 * TILEX, MAX_BUF_YSIZE * TILEY - y,
107 sx + MAX_BUF_XSIZE * TILEX - x, sy);
108 BlitBitmap(screenBitmap, target_bitmap, x, 0,
109 MAX_BUF_XSIZE * TILEX - x, y - 2 * TILEY,
110 sx, sy + MAX_BUF_YSIZE * TILEY - y);
111 BlitBitmap(screenBitmap, target_bitmap, 0, 0,
112 x - 2 * TILEX, y - 2 * TILEY,
113 sx + MAX_BUF_XSIZE * TILEX - x, sy + MAX_BUF_YSIZE * TILEY - y);
117 static void BackToFront_EM(void)
119 BlitBitmap(backbuffer, window, SX, SY, SXSIZE, SYSIZE, SX, SY);
122 static struct GraphicInfo_EM *getObjectGraphic(int x, int y)
124 int tile = lev.draw[x][y];
125 struct GraphicInfo_EM *g = &graphic_info_em_object[tile][frame];
127 if (!game.use_native_emc_graphics_engine)
128 getGraphicSourceObjectExt_EM(g, tile, frame, x - lev.left, y - lev.top);
133 static struct GraphicInfo_EM *getPlayerGraphic(int player_nr, int anim)
135 struct GraphicInfo_EM *g = &graphic_info_em_player[player_nr][anim][frame];
137 if (!game.use_native_emc_graphics_engine)
138 getGraphicSourcePlayerExt_EM(g, player_nr, anim, frame);
143 static void DrawLevelField_EM(int x, int y, int sx, int sy,
146 struct GraphicInfo_EM *g = getObjectGraphic(x, y);
147 int src_x = g->src_x + g->src_offset_x * TILESIZE_VAR / TILESIZE;
148 int src_y = g->src_y + g->src_offset_y * TILESIZE_VAR / TILESIZE;
149 int dst_x = sx * TILEX + g->dst_offset_x * TILESIZE_VAR / TILESIZE;
150 int dst_y = sy * TILEY + g->dst_offset_y * TILESIZE_VAR / TILESIZE;
151 int width = g->width * TILESIZE_VAR / TILESIZE;
152 int height = g->height * TILESIZE_VAR / TILESIZE;
153 int left = screen_x / TILEX;
154 int top = screen_y / TILEY;
156 /* do not draw fields that are outside the visible screen area */
157 if (x < left || x >= left + MAX_BUF_XSIZE ||
158 y < top || y >= top + MAX_BUF_YSIZE)
163 if (width > 0 && height > 0)
164 BlitBitmapMasked(g->bitmap, screenBitmap,
165 src_x, src_y, width, height, dst_x, dst_y);
169 if ((width != TILEX || height != TILEY) && !g->preserve_background)
170 ClearRectangle(screenBitmap, sx * TILEX, sy * TILEY, TILEX, TILEY);
172 if (width > 0 && height > 0)
173 BlitBitmap(g->bitmap, screenBitmap,
174 src_x, src_y, width, height, dst_x, dst_y);
178 static void DrawLevelFieldCrumbled_EM(int x, int y, int sx, int sy,
179 int crm, boolean draw_masked)
181 struct GraphicInfo_EM *g;
182 int crumbled_border_size;
183 int left = screen_x / TILEX;
184 int top = screen_y / TILEY;
187 /* do not draw fields that are outside the visible screen area */
188 if (x < left || x >= left + MAX_BUF_XSIZE ||
189 y < top || y >= top + MAX_BUF_YSIZE)
192 if (crm == 0) /* no crumbled edges for this tile */
195 g = getObjectGraphic(x, y);
197 crumbled_border_size =
198 g->crumbled_border_size * TILESIZE_VAR / g->crumbled_tile_size;
200 for (i = 0; i < 4; i++)
204 int width, height, cx, cy;
206 if (i == 1 || i == 2)
208 width = crumbled_border_size;
210 cx = (i == 2 ? TILEX - crumbled_border_size : 0);
216 height = crumbled_border_size;
218 cy = (i == 3 ? TILEY - crumbled_border_size : 0);
221 if (width > 0 && height > 0)
223 int src_x = g->crumbled_src_x + cx;
224 int src_y = g->crumbled_src_y + cy;
225 int dst_x = sx * TILEX + cx;
226 int dst_y = sy * TILEY + cy;
229 BlitBitmapMasked(g->crumbled_bitmap, screenBitmap,
230 src_x, src_y, width, height, dst_x, dst_y);
232 BlitBitmap(g->crumbled_bitmap, screenBitmap,
233 src_x, src_y, width, height, dst_x, dst_y);
239 static void DrawLevelPlayer_EM(int x1, int y1, int player_nr, int anim,
242 struct GraphicInfo_EM *g = getPlayerGraphic(player_nr, anim);
243 int src_x = g->src_x, src_y = g->src_y;
246 /* do not draw fields that are outside the visible screen area */
247 if (x1 < screen_x - TILEX || x1 >= screen_x + MAX_BUF_XSIZE * TILEX ||
248 y1 < screen_y - TILEY || y1 >= screen_y + MAX_BUF_YSIZE * TILEY)
251 x1 %= MAX_BUF_XSIZE * TILEX;
252 y1 %= MAX_BUF_YSIZE * TILEY;
256 /* draw the player to current location */
259 BlitBitmapMasked(g->bitmap, screenBitmap,
260 src_x, src_y, TILEX, TILEY, dst_x, dst_y);
262 /* draw the player to opposite wrap-around column */
263 dst_x = x1 - MAX_BUF_XSIZE * TILEX;
265 BlitBitmapMasked(g->bitmap, screenBitmap,
266 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
268 /* draw the player to opposite wrap-around row */
270 dst_y = y1 - MAX_BUF_YSIZE * TILEY;
271 BlitBitmapMasked(g->bitmap, screenBitmap,
272 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
276 /* draw the player to current location */
279 BlitBitmap(g->bitmap, screenBitmap,
280 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
282 /* draw the player to opposite wrap-around column */
283 dst_x = x1 - MAX_BUF_XSIZE * TILEX;
285 BlitBitmap(g->bitmap, screenBitmap,
286 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
288 /* draw the player to opposite wrap-around row */
290 dst_y = y1 - MAX_BUF_YSIZE * TILEY;
291 BlitBitmap(g->bitmap, screenBitmap,
292 g->src_x, g->src_y, TILEX, TILEY, dst_x, dst_y);
296 /* draw differences between game tiles and screen tiles
298 * implicitly handles scrolling and restoring background under the sprites
301 static void animscreen(void)
304 int left = screen_x / TILEX;
305 int top = screen_y / TILEY;
306 static int xy[4][2] =
314 if (!game.use_native_emc_graphics_engine)
315 for (y = lev.top; y < lev.bottom; y++)
316 for (x = lev.left; x < lev.right; x++)
317 SetGfxAnimation_EM(&graphic_info_em_object[lev.draw[x][y]][frame],
318 lev.draw[x][y], frame,
319 x - lev.left, y - lev.top);
321 for (y = top; y < top + MAX_BUF_YSIZE; y++)
323 for (x = left; x < left + MAX_BUF_XSIZE; x++)
325 int sx = x % MAX_BUF_XSIZE;
326 int sy = y % MAX_BUF_YSIZE;
327 int tile = lev.draw[x][y];
328 struct GraphicInfo_EM *g = &graphic_info_em_object[tile][frame];
329 int obj = g->unique_identifier;
331 boolean redraw_screen_tile = FALSE;
333 /* re-calculate crumbled state of this tile */
334 if (g->has_crumbled_graphics)
336 for (i = 0; i < 4; i++)
338 int xx = x + xy[i][0];
339 int yy = y + xy[i][1];
342 if (xx < 0 || xx >= CAVE_BUFFER_WIDTH ||
343 yy < 0 || yy >= CAVE_BUFFER_HEIGHT)
346 tile_next = lev.draw[xx][yy];
348 if (!graphic_info_em_object[tile_next][frame].has_crumbled_graphics)
353 redraw_screen_tile = (screen_tiles[sx][sy] != obj ||
354 crumbled_state[sx][sy] != crm);
356 /* only redraw screen tiles if they (or their crumbled state) changed */
357 if (redraw_screen_tile)
359 DrawLevelField_EM(x, y, sx, sy, FALSE);
360 DrawLevelFieldCrumbled_EM(x, y, sx, sy, crm, FALSE);
362 screen_tiles[sx][sy] = obj;
363 crumbled_state[sx][sy] = crm;
370 /* blit players to the screen
372 * handles transparency and movement
375 static void blitplayer(int nr)
382 /* x1/y1 are left/top and x2/y2 are right/down part of the player movement */
383 x1 = PLAYER_POS_X(nr);
384 y1 = PLAYER_POS_Y(nr);
388 if ((int)(x2 - screen_x) < ((MAX_BUF_XSIZE - 1) * TILEX - 1) &&
389 (int)(y2 - screen_y) < ((MAX_BUF_YSIZE - 1) * TILEY - 1))
391 /* some casts to "int" are needed because of negative calculation values */
392 int dx = (int)ply[nr].x - (int)ply[nr].oldx;
393 int dy = (int)ply[nr].y - (int)ply[nr].oldy;
394 int old_x = (int)ply[nr].oldx + (int)frame * dx / 8;
395 int old_y = (int)ply[nr].oldy + (int)frame * dy / 8;
396 int new_x = old_x + SIGN(dx);
397 int new_y = old_y + SIGN(dy);
398 int old_sx = old_x % MAX_BUF_XSIZE;
399 int old_sy = old_y % MAX_BUF_YSIZE;
400 int new_sx = new_x % MAX_BUF_XSIZE;
401 int new_sy = new_y % MAX_BUF_YSIZE;
402 int new_crm = crumbled_state[new_sx][new_sy];
404 /* only diggable elements can be crumbled in the classic EM engine */
405 boolean player_is_digging = (new_crm != 0);
407 if (player_is_digging)
409 /* draw the field the player is moving to (under the player) */
410 DrawLevelField_EM(new_x, new_y, new_sx, new_sy, FALSE);
411 DrawLevelFieldCrumbled_EM(new_x, new_y, new_sx, new_sy, new_crm, FALSE);
413 /* draw the player (masked) over the element he is just digging away */
414 DrawLevelPlayer_EM(x1, y1, ply[nr].num, ply[nr].anim, TRUE);
416 /* draw the field the player is moving from (masked over the player) */
417 DrawLevelField_EM(old_x, old_y, old_sx, old_sy, TRUE);
421 /* draw the player under the element which is on the same field */
422 DrawLevelPlayer_EM(x1, y1, ply[nr].num, ply[nr].anim, FALSE);
424 /* draw the field the player is moving from (masked over the player) */
425 DrawLevelField_EM(old_x, old_y, old_sx, old_sy, TRUE);
427 /* draw the field the player is moving to (masked over the player) */
428 DrawLevelField_EM(new_x, new_y, new_sx, new_sy, TRUE);
431 /* redraw screen tiles in the next frame (player may have left the tiles) */
432 screen_tiles[old_sx][old_sy] = -1;
433 screen_tiles[new_sx][new_sy] = -1;
437 void game_initscreen(void)
444 player_nr = (game.centered_player_nr != -1 ? game.centered_player_nr : 0);
446 screen_x = VALID_SCREEN_X(PLAYER_SCREEN_X(player_nr));
447 screen_y = VALID_SCREEN_Y(PLAYER_SCREEN_Y(player_nr));
449 for (y = 0; y < MAX_BUF_YSIZE; y++)
451 for (x = 0; x < MAX_BUF_XSIZE; x++)
453 screen_tiles[x][y] = -1;
454 crumbled_state[x][y] = 0;
459 static int getMaxCenterDistancePlayerNr(int center_x, int center_y)
461 int max_dx = 0, max_dy = 0;
462 int player_nr = game_em.last_moving_player;
465 for (i = 0; i < MAX_PLAYERS; i++)
469 int sx = PLAYER_SCREEN_X(i);
470 int sy = PLAYER_SCREEN_Y(i);
472 if (game_em.last_player_direction[i] != MV_NONE &&
473 (ABS(sx - center_x) > max_dx ||
474 ABS(sy - center_y) > max_dy))
476 max_dx = MAX(max_dx, ABS(sx - center_x));
477 max_dy = MAX(max_dy, ABS(sy - center_y));
487 static void setMinimalPlayerBoundaries(int *sx1, int *sy1, int *sx2, int *sy2)
489 boolean num_checked_players = 0;
492 for (i = 0; i < MAX_PLAYERS; i++)
496 int sx = PLAYER_SCREEN_X(i);
497 int sy = PLAYER_SCREEN_Y(i);
499 if (num_checked_players == 0)
506 *sx1 = MIN(*sx1, sx);
507 *sy1 = MIN(*sy1, sy);
508 *sx2 = MAX(*sx2, sx);
509 *sy2 = MAX(*sy2, sy);
512 num_checked_players++;
517 boolean checkIfAllPlayersFitToScreen(void)
519 int sx1 = 0, sy1 = 0, sx2 = 0, sy2 = 0;
521 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
523 return (sx2 - sx1 <= SCR_FIELDX * TILEX &&
524 sy2 - sy1 <= SCR_FIELDY * TILEY);
527 static void setScreenCenteredToAllPlayers(int *sx, int *sy)
529 int sx1 = screen_x, sy1 = screen_y, sx2 = screen_x, sy2 = screen_y;
531 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
533 *sx = (sx1 + sx2) / 2;
534 *sy = (sy1 + sy2) / 2;
537 static void setMaxCenterDistanceForAllPlayers(int *max_dx, int *max_dy,
538 int center_x, int center_y)
540 int sx1 = center_x, sy1 = center_y, sx2 = center_x, sy2 = center_y;
542 setMinimalPlayerBoundaries(&sx1, &sy1, &sx2, &sy2);
544 *max_dx = MAX(ABS(sx1 - center_x), ABS(sx2 - center_x));
545 *max_dy = MAX(ABS(sy1 - center_y), ABS(sy2 - center_y));
548 static boolean checkIfAllPlayersAreVisible(int center_x, int center_y)
552 setMaxCenterDistanceForAllPlayers(&max_dx, &max_dy, center_x, center_y);
554 return (max_dx <= SCR_FIELDX * TILEX / 2 &&
555 max_dy <= SCR_FIELDY * TILEY / 2);
558 void RedrawPlayfield_EM(boolean force_redraw)
560 boolean draw_new_player_location = FALSE;
561 boolean draw_new_player_location_fast = FALSE;
562 boolean quick_relocation = setup.quick_switch;
563 int max_center_distance_player_nr =
564 getMaxCenterDistancePlayerNr(screen_x, screen_y);
565 int stepsize = TILEX / 8;
566 int offset_raw = game.scroll_delay_value;
567 int offset_x = MIN(offset_raw, (SCR_FIELDX - 2) / 2) * TILEX;
568 int offset_y = MIN(offset_raw, (SCR_FIELDY - 2) / 2) * TILEY;
569 int screen_x_old = screen_x;
570 int screen_y_old = screen_y;
574 if (game.set_centered_player)
576 boolean all_players_fit_to_screen = checkIfAllPlayersFitToScreen();
578 /* switching to "all players" only possible if all players fit to screen */
579 if (game.centered_player_nr_next == -1 && !all_players_fit_to_screen)
581 game.centered_player_nr_next = game.centered_player_nr;
582 game.set_centered_player = FALSE;
585 /* do not switch focus to non-existing (or non-active) player */
586 if (game.centered_player_nr_next >= 0 &&
587 !ply[game.centered_player_nr_next].alive)
589 game.centered_player_nr_next = game.centered_player_nr;
590 game.set_centered_player = FALSE;
594 /* also allow focus switching when screen is scrolled to half tile */
595 if (game.set_centered_player)
597 game.centered_player_nr = game.centered_player_nr_next;
599 draw_new_player_location = TRUE;
600 draw_new_player_location_fast = game.set_centered_player_fast;
603 game.set_centered_player = FALSE;
604 game.set_centered_player_fast = FALSE;
607 if (game.centered_player_nr == -1)
609 if (draw_new_player_location || offset_raw == 0)
611 setScreenCenteredToAllPlayers(&sx, &sy);
615 sx = PLAYER_SCREEN_X(max_center_distance_player_nr);
616 sy = PLAYER_SCREEN_Y(max_center_distance_player_nr);
621 sx = PLAYER_SCREEN_X(game.centered_player_nr);
622 sy = PLAYER_SCREEN_Y(game.centered_player_nr);
625 if (draw_new_player_location && quick_relocation)
627 screen_x = VALID_SCREEN_X(sx);
628 screen_y = VALID_SCREEN_Y(sy);
629 screen_x_old = screen_x;
630 screen_y_old = screen_y;
633 if (draw_new_player_location && !quick_relocation)
635 unsigned int frame_delay_value_old = GetVideoFrameDelay();
636 int wait_delay_value = frame_delay_value_old;
637 int screen_xx = VALID_SCREEN_X(sx);
638 int screen_yy = VALID_SCREEN_Y(sy);
640 if (draw_new_player_location_fast)
641 wait_delay_value /= 4;
643 SetVideoFrameDelay(wait_delay_value);
645 while (screen_x != screen_xx || screen_y != screen_yy)
647 int dx = (screen_xx < screen_x ? +1 : screen_xx > screen_x ? -1 : 0);
648 int dy = (screen_yy < screen_y ? +1 : screen_yy > screen_y ? -1 : 0);
649 int dxx = 0, dyy = 0;
651 if (dx == 0 && dy == 0) /* no scrolling needed at all */
654 if (ABS(screen_xx - screen_x) >= TILEX)
656 screen_x -= dx * TILEX;
657 dxx = dx * TILEX / 2;
661 screen_x = screen_xx;
665 if (ABS(screen_yy - screen_y) >= TILEY)
667 screen_y -= dy * TILEY;
668 dyy = dy * TILEY / 2;
672 screen_y = screen_yy;
676 /* scroll in two steps of half tile size to make things smoother */
682 for (i = 0; i < MAX_PLAYERS; i++)
685 BlitScreenToBitmap_EM(backbuffer);
688 /* scroll second step to align at full tile size */
694 for (i = 0; i < MAX_PLAYERS; i++)
697 BlitScreenToBitmap_EM(backbuffer);
701 SetVideoFrameDelay(frame_delay_value_old);
703 screen_x_old = screen_x;
704 screen_y_old = screen_y;
709 for (y = 0; y < MAX_BUF_YSIZE; y++)
711 for (x = 0; x < MAX_BUF_XSIZE; x++)
713 screen_tiles[x][y] = -1;
714 crumbled_state[x][y] = 0;
719 /* calculate new screen scrolling position, with regard to scroll delay */
720 screen_x = VALID_SCREEN_X(sx + offset_x < screen_x ? sx + offset_x :
721 sx - offset_x > screen_x ? sx - offset_x :
723 screen_y = VALID_SCREEN_Y(sy + offset_y < screen_y ? sy + offset_y :
724 sy - offset_y > screen_y ? sy - offset_y :
727 /* prevent scrolling further than double player step size when scrolling */
728 if (ABS(screen_x - screen_x_old) > 2 * stepsize)
730 int dx = SIGN(screen_x - screen_x_old);
732 screen_x = screen_x_old + dx * 2 * stepsize;
734 if (ABS(screen_y - screen_y_old) > 2 * stepsize)
736 int dy = SIGN(screen_y - screen_y_old);
738 screen_y = screen_y_old + dy * 2 * stepsize;
741 /* prevent scrolling away from the other players when focus on all players */
742 if (game.centered_player_nr == -1)
744 /* check if all players are still visible with new scrolling position */
745 if (checkIfAllPlayersAreVisible(screen_x_old, screen_y_old) &&
746 !checkIfAllPlayersAreVisible(screen_x, screen_y))
748 /* reset horizontal scroll position to last value, if needed */
749 if (!checkIfAllPlayersAreVisible(screen_x, screen_y_old))
750 screen_x = screen_x_old;
752 /* reset vertical scroll position to last value, if needed */
753 if (!checkIfAllPlayersAreVisible(screen_x_old, screen_y))
754 screen_y = screen_y_old;
758 /* prevent scrolling (for screen correcting) if no player is moving */
759 if (!game_em.any_player_moving)
761 screen_x = screen_x_old;
762 screen_y = screen_y_old;
766 /* prevent scrolling against the players move direction */
767 int player_nr = (game.centered_player_nr == -1 ?
768 max_center_distance_player_nr : game.centered_player_nr);
769 int player_move_dir = game_em.last_player_direction[player_nr];
770 int dx = SIGN(screen_x - screen_x_old);
771 int dy = SIGN(screen_y - screen_y_old);
773 if ((dx < 0 && player_move_dir != MV_LEFT) ||
774 (dx > 0 && player_move_dir != MV_RIGHT))
775 screen_x = screen_x_old;
777 if ((dy < 0 && player_move_dir != MV_UP) ||
778 (dy > 0 && player_move_dir != MV_DOWN))
779 screen_y = screen_y_old;
782 // skip redrawing playfield in warp mode or when testing tapes with "autotest"
783 if (DrawingDeactivatedField())
788 for (i = 0; i < MAX_PLAYERS; i++)