fixed support for wrap-around levels in EM engine for old tapes
[rocksndiamonds.git] / src / game_em / convert.c
index 2672054fb4388034e83e52bec6e0bd6108e552d1..bae0130c3920adcd4ed56a4e3e0ea4a0474855d5 100644 (file)
-/* 2000-08-20T09:41:18Z
+/* 2007-04-04 08:33:37
  *
- * identify all emerald mine caves and turn them into v6 format.
- * fixes illegal tiles, acid, wheel, limits times, cleans flags.
- *
- * these tables weed out bad tiles for older caves (eg. wheel on -> wheel off)
- * and clean up v6 caves (acid, number limits) which should(!) be
- * inconsequential, but no doubt it will break some caves.
+ * convert intermediate cave format to internal cave structure for
+ * use in logic(). initializes entire internal structure.
  */
 
-#include "global.h"
-#include "tile.h"
-#include "level.h"
-
-
-static unsigned char remap_v6[256] =
-{
-  /* filter crap for v6 */
-
-  0,0,2,2,4,4,118,118,8,9,10,11,12,13,14,15,
-  16,16,18,18,20,21,22,23,24,25,26,27,28,28,118,28,
-  0,16,2,18,36,37,37,37,40,41,42,43,44,45,128,128,
-  128,148,148,148,45,45,45,148,0,57,58,59,60,61,62,63,
-  64,65,66,67,68,69,69,69,69,73,74,75,118,75,75,75,
-  75,75,75,75,75,153,153,153,153,153,153,153,153,153,153,153,
-  153,153,153,99,100,68,68,68,68,68,68,68,68,118,118,118,
-  118,118,114,115,131,118,118,119,120,121,122,118,118,118,118,118,
-  128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
-  144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
-  160,161,162,163,164,165,165,118,168,169,170,171,172,173,174,175,
-  176,177,178,179,180,181,182,183,184,185,186,187,188,189,68,191,
-  192,193,194,195,196,197,198,199,200,201,202,203,204,205,206,207,
-  208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
-  224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
-  240,241,242,243,244,245,153,153,153,153,153,153,153,153,153,153
-};
-
-static unsigned char remap_v5[256] =
-{
-  /* filter crap for v5 */
-
-  0,0,2,2,4,4,118,118,8,9,10,11,12,13,14,15,
-  16,16,18,18,20,21,22,23,24,25,26,27,28,28,118,28,
-  0,16,2,18,36,37,37,37,147,41,42,43,44,45,128,128,
-  128,148,148,148,45,45,45,148,0,57,58,59,60,61,62,63,
-  64,65,66,67,68,153,153,153,153,153,153,153,153,153,153,153,
-  153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,
-  153,153,153,153,153,68,68,68,68,68,68,68,68,118,118,118,
-  118,118,114,115,131,118,118,119,120,121,122,118,118,118,118,118,
-  128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
-  144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,
-  160,153,153,153,153,153,153,118,168,169,170,171,172,173,174,175,
-  176,177,178,179,180,181,182,183,184,185,186,187,188,189,68,153,
-  153,153,153,153,153,153,153,153,200,201,202,203,204,205,206,207,
-  208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
-  224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
-  240,241,153,153,153,153,153,153,153,153,153,153,153,153,153,153
-};
+#include "main_em.h"
 
-static unsigned char remap_v4[256] =
-{
-  /* filter crap for v4 */
-
-  0,0,2,2,4,4,118,118,8,9,10,11,12,13,14,15,
-  16,16,18,18,20,21,22,23,24,25,26,27,28,28,118,28,
-  0,16,2,18,36,37,37,37,147,41,42,43,44,45,128,128,
-  128,148,148,148,45,45,45,148,0,153,153,59,60,61,62,63,
-  64,65,66,153,153,153,153,153,153,153,153,153,153,153,153,153,
-  153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,
-  153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,153,
-  153,118,114,115,131,118,118,119,120,121,122,118,118,118,118,118,
-  128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
-  144,145,146,147,148,149,150,151,152,68,154,155,156,157,158,160,
-  160,160,160,160,160,160,160,160,160,160,160,160,160,160,160,175,
-  153,153,153,153,153,153,153,153,153,153,153,153,153,153,68,153,
-  153,153,153,153,153,153,153,153,200,201,202,203,204,205,206,207,
-  208,209,210,211,212,213,214,215,216,217,218,219,220,221,222,223,
-  224,225,226,227,228,229,230,231,232,233,234,235,236,237,238,239,
-  240,241,153,153,153,153,153,153,153,153,153,153,153,153,153,153
-};
 
-static unsigned char remap_v4eater[28] =
+static const short map[CAVE_TILE_MAX] =
 {
-  /* filter crap for v4 */
-
-  128,18,2,0,4,8,16,20,28,37,
-  41,45,130,129,131,132,133,134,135,136,
-  146,147,175,65,66,64,2,18
+  [Cblank]             = Xblank,
+  [Cgrass]             = Xgrass,
+  [Cdirt]              = Xdirt,
+  [Cplant]             = Xplant,
+  [Cwall_1]            = Xwall_1,
+  [Cwall_2]            = Xwall_2,
+  [Cwall_3]            = Xwall_3,
+  [Cwall_4]            = Xwall_4,
+  [Croundwall_1]       = Xroundwall_1,
+  [Croundwall_2]       = Xroundwall_2,
+  [Croundwall_3]       = Xroundwall_3,
+  [Croundwall_4]       = Xroundwall_4,
+  [Csteel_1]           = Xsteel_1,
+  [Csteel_2]           = Xsteel_2,
+  [Csteel_3]           = Xsteel_3,
+  [Csteel_4]           = Xsteel_4,
+  [Candroid]           = Xandroid,
+  [Ceater_n]           = Xeater_n,
+  [Ceater_e]           = Xeater_e,
+  [Ceater_s]           = Xeater_s,
+  [Ceater_w]           = Xeater_w,
+  [Calien]             = Xalien,
+  [Cbug_1_n]           = Xbug_1_n,
+  [Cbug_1_e]           = Xbug_1_e,
+  [Cbug_1_s]           = Xbug_1_s,
+  [Cbug_1_w]           = Xbug_1_w,
+  [Cbug_2_n]           = Xbug_2_n,
+  [Cbug_2_e]           = Xbug_2_e,
+  [Cbug_2_s]           = Xbug_2_s,
+  [Cbug_2_w]           = Xbug_2_w,
+  [Ctank_1_n]          = Xtank_1_n,
+  [Ctank_1_e]          = Xtank_1_e,
+  [Ctank_1_s]          = Xtank_1_s,
+  [Ctank_1_w]          = Xtank_1_w,
+  [Ctank_2_n]          = Xtank_2_n,
+  [Ctank_2_e]          = Xtank_2_e,
+  [Ctank_2_s]          = Xtank_2_s,
+  [Ctank_2_w]          = Xtank_2_w,
+  [Cemerald]           = Xemerald,
+  [Cdiamond]           = Xdiamond,
+  [Cstone]             = Xstone,
+  [Cbomb]              = Xbomb,
+  [Cnut]               = Xnut,
+  [Cspring]            = Xspring,
+  [Cpush_emerald_e]    = Xpush_emerald_e,
+  [Cpush_emerald_w]    = Xpush_emerald_w,
+  [Cpush_diamond_e]    = Xpush_diamond_e,
+  [Cpush_diamond_w]    = Xpush_diamond_w,
+  [Cpush_stone_e]      = Xpush_stone_e,
+  [Cpush_stone_w]      = Xpush_stone_w,
+  [Cpush_bomb_e]       = Xpush_bomb_e,
+  [Cpush_bomb_w]       = Xpush_bomb_w,
+  [Cpush_nut_e]                = Xpush_nut_e,
+  [Cpush_nut_w]                = Xpush_nut_w,
+  [Cpush_spring_e]     = Xpush_spring_e,
+  [Cpush_spring_w]     = Xpush_spring_w,
+  [Cdynamite]          = Xdynamite,
+  [Cdynamite_1]                = Xdynamite_1,
+  [Cdynamite_2]                = Xdynamite_2,
+  [Cdynamite_3]                = Xdynamite_3,
+  [Cdynamite_4]                = Xdynamite_4,
+  [Ckey_1]             = Xkey_1,
+  [Ckey_2]             = Xkey_2,
+  [Ckey_3]             = Xkey_3,
+  [Ckey_4]             = Xkey_4,
+  [Ckey_5]             = Xkey_5,
+  [Ckey_6]             = Xkey_6,
+  [Ckey_7]             = Xkey_7,
+  [Ckey_8]             = Xkey_8,
+  [Cdoor_1]            = Xdoor_1,
+  [Cdoor_2]            = Xdoor_2,
+  [Cdoor_3]            = Xdoor_3,
+  [Cdoor_4]            = Xdoor_4,
+  [Cdoor_5]            = Xdoor_5,
+  [Cdoor_6]            = Xdoor_6,
+  [Cdoor_7]            = Xdoor_7,
+  [Cdoor_8]            = Xdoor_8,
+  [Cfake_door_1]       = Xfake_door_1,
+  [Cfake_door_2]       = Xfake_door_2,
+  [Cfake_door_3]       = Xfake_door_3,
+  [Cfake_door_4]       = Xfake_door_4,
+  [Cfake_door_5]       = Xfake_door_5,
+  [Cfake_door_6]       = Xfake_door_6,
+  [Cfake_door_7]       = Xfake_door_7,
+  [Cfake_door_8]       = Xfake_door_8,
+  [Cballoon]           = Xballoon,
+  [Cball_1]            = Xball_1,
+  [Cball_2]            = Xball_2,
+  [Camoeba_1]          = Xamoeba_1,
+  [Camoeba_2]          = Xamoeba_2,
+  [Camoeba_3]          = Xamoeba_3,
+  [Camoeba_4]          = Xamoeba_4,
+  [Camoeba_5]          = Xamoeba_5,
+  [Camoeba_6]          = Xamoeba_6,
+  [Camoeba_7]          = Xamoeba_7,
+  [Camoeba_8]          = Xamoeba_8,
+  [Cdrip]              = Xdrip,
+  [Cwonderwall]                = Xwonderwall,
+  [Cwheel]             = Xwheel,
+  [Cswitch]            = Xswitch,
+  [Cbumper]            = Xbumper,
+  [Cacid_nw]           = Xacid_nw,
+  [Cacid_ne]           = Xacid_ne,
+  [Cacid_sw]           = Xacid_sw,
+  [Cacid_s]            = Xacid_s,
+  [Cacid_se]           = Xacid_se,
+  [Cacid_1]            = Xacid_1,
+  [Cacid_2]            = Xacid_2,
+  [Cacid_3]            = Xacid_3,
+  [Cacid_4]            = Xacid_4,
+  [Cacid_5]            = Xacid_5,
+  [Cacid_6]            = Xacid_6,
+  [Cacid_7]            = Xacid_7,
+  [Cacid_8]            = Xacid_8,
+  [Cfake_acid_1]       = Xfake_acid_1,
+  [Cfake_acid_2]       = Xfake_acid_2,
+  [Cfake_acid_3]       = Xfake_acid_3,
+  [Cfake_acid_4]       = Xfake_acid_4,
+  [Cfake_acid_5]       = Xfake_acid_5,
+  [Cfake_acid_6]       = Xfake_acid_6,
+  [Cfake_acid_7]       = Xfake_acid_7,
+  [Cfake_acid_8]       = Xfake_acid_8,
+  [Cfake_blank]                = Xfake_blank,
+  [Cfake_grass]                = Xfake_grass,
+  [Cfake_amoeba]       = Xfake_amoeba,
+  [Clenses]            = Xlenses,
+  [Cmagnify]           = Xmagnify,
+  [Csand]              = Xsand,
+  [Csand_stone]                = Xsand_stone,
+  [Cslide_ns]          = Xslide_ns,
+  [Cslide_ew]          = Xslide_ew,
+  [Cwind_n]            = Xwind_n,
+  [Cwind_e]            = Xwind_e,
+  [Cwind_s]            = Xwind_s,
+  [Cwind_w]            = Xwind_w,
+  [Cwind_any]          = Xwind_any,
+  [Cwind_stop]         = Xwind_stop,
+  [Cexit]              = Xexit,
+  [Cexit_1]            = Xexit_1,
+  [Cexit_2]            = Xexit_2,
+  [Cexit_3]            = Xexit_3,
+  [Cpause]             = Xpause,
+  [Cdecor_1]           = Xdecor_1,
+  [Cdecor_2]           = Xdecor_2,
+  [Cdecor_3]           = Xdecor_3,
+  [Cdecor_4]           = Xdecor_4,
+  [Cdecor_5]           = Xdecor_5,
+  [Cdecor_6]           = Xdecor_6,
+  [Cdecor_7]           = Xdecor_7,
+  [Cdecor_8]           = Xdecor_8,
+  [Cdecor_9]           = Xdecor_9,
+  [Cdecor_10]          = Xdecor_10,
+  [Cdecor_11]          = Xdecor_11,
+  [Cdecor_12]          = Xdecor_12,
+  [Calpha_0]           = Xalpha_0,
+  [Calpha_1]           = Xalpha_1,
+  [Calpha_2]           = Xalpha_2,
+  [Calpha_3]           = Xalpha_3,
+  [Calpha_4]           = Xalpha_4,
+  [Calpha_5]           = Xalpha_5,
+  [Calpha_6]           = Xalpha_6,
+  [Calpha_7]           = Xalpha_7,
+  [Calpha_8]           = Xalpha_8,
+  [Calpha_9]           = Xalpha_9,
+  [Calpha_excla]       = Xalpha_excla,
+  [Calpha_apost]       = Xalpha_apost,
+  [Calpha_comma]       = Xalpha_comma,
+  [Calpha_minus]       = Xalpha_minus,
+  [Calpha_perio]       = Xalpha_perio,
+  [Calpha_colon]       = Xalpha_colon,
+  [Calpha_quest]       = Xalpha_quest,
+  [Calpha_a]           = Xalpha_a,
+  [Calpha_b]           = Xalpha_b,
+  [Calpha_c]           = Xalpha_c,
+  [Calpha_d]           = Xalpha_d,
+  [Calpha_e]           = Xalpha_e,
+  [Calpha_f]           = Xalpha_f,
+  [Calpha_g]           = Xalpha_g,
+  [Calpha_h]           = Xalpha_h,
+  [Calpha_i]           = Xalpha_i,
+  [Calpha_j]           = Xalpha_j,
+  [Calpha_k]           = Xalpha_k,
+  [Calpha_l]           = Xalpha_l,
+  [Calpha_m]           = Xalpha_m,
+  [Calpha_n]           = Xalpha_n,
+  [Calpha_o]           = Xalpha_o,
+  [Calpha_p]           = Xalpha_p,
+  [Calpha_q]           = Xalpha_q,
+  [Calpha_r]           = Xalpha_r,
+  [Calpha_s]           = Xalpha_s,
+  [Calpha_t]           = Xalpha_t,
+  [Calpha_u]           = Xalpha_u,
+  [Calpha_v]           = Xalpha_v,
+  [Calpha_w]           = Xalpha_w,
+  [Calpha_x]           = Xalpha_x,
+  [Calpha_y]           = Xalpha_y,
+  [Calpha_z]           = Xalpha_z,
+  [Calpha_arrow_e]     = Xalpha_arrow_e,
+  [Calpha_arrow_w]     = Xalpha_arrow_w,
+  [Calpha_copyr]       = Xalpha_copyr
 };
 
-boolean cleanup_em_level(unsigned char *src, int *length)
+int map_em_element_C_to_X(int element_em_cave)
 {
-  unsigned int i;
-
-  if (*length >= 2172 &&
-      src[2106] == 255 &&
-      src[2107] == 54 &&
-      src[2108] == 48 &&
-      src[2109] == 48)
+  if (element_em_cave < 0 || element_em_cave >= CAVE_TILE_MAX)
   {
-    for (i = 0; i < 2048; i++)
-      src[i] = remap_v6[src[i]];
-    for (i = 2048; i < 2084; i++)
-      src[i] = remap_v6[src[i]];
-    for (i = 2112; i < 2148; i++)
-      src[i] = remap_v6[src[i]];
-
-    goto v6;
-  }
+    Error(ERR_WARN, "invalid EM cave element %d", element_em_cave);
 
-  if (*length >= 2110 &&
-      src[2106] == 255 &&
-      src[2107] == 53 &&
-      src[2108] == 48 &&
-      src[2109] == 48)
-  {
-    for (i = 0; i < 2048; i++)
-      src[i] = remap_v5[src[i]];
-    for (i = 2048; i < 2084; i++)
-      src[i] = remap_v5[src[i]];
-    for (i = 2112; i < 2148; i++)
-      src[i] = src[i - 64];
-
-    goto v5;
+    return Xblank;
   }
 
-  if (*length >= 2106 &&
-      src[1983] == 116)
-  {
-    for (i = 0; i < 2048; i++)
-      src[i] = remap_v4[src[i]];
-    for (i = 2048; i < 2084; i++)
-      src[i] = remap_v4eater[src[i] >= 28 ? 0 : src[i]];
-    for (i = 2112; i < 2148; i++) src[i] = src[i - 64];
-
-    goto v4;
-  }
-
-  if (*length >= 2106 &&
-      src[0] == 241 &&
-      src[1983] == 27)
-  {
-    unsigned char j = 94;
-
-    for (i = 0; i < 2106; i++)
-      src[i] = (src[i] ^ (j += 7)) - 0x11;
-    src[1] = 131;
-    for (i = 0; i < 2048; i++)
-      src[i] = remap_v4[src[i]];
-    for (i = 2048; i < 2084; i++)
-      src[i] = remap_v4eater[src[i] >= 28 ? 0 : src[i]];
-    for (i = 2112; i < 2148; i++)
-      src[i] = src[i - 64];
-
-    goto v3;
-  }
+  return map[element_em_cave];
+}
 
-  return FALSE;                /* unrecognized cave */
-
- v3:
- v4:
- v5:
-
-  /* id */
-  src[2106] = 255;
-  src[2107] = 54;
-  src[2108] = 48;
-  src[2109] = 48;
-
-  /* time */
-  i = src[2094] * 10;
-  src[2110] = i >> 8;
-  src[2111] = i;
-
-  for (i = 2148; i < 2172; i++)
-    src[i] = 0;
-
-  /* ball data */
-  src[2159] = 128;
-
- v6:
-
-  /* fix wheel */
-  for (i = 0; i < 2048; i++)
-    if (src[i] == 40)
-      break;
-  for (i++; i < 2048; i++)
-    if (src[i] == 40)
-      src[i] = 147;
-
-  /* fix acid */
-  for (i = 64; i < 2048; i++)
-    if (src[i] == 63)
-      src[i - 64] = 101;
-
-  /* fix acid in eater 1 */
-  for (i = 2051; i < 2057; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 2 */
-  for (i = 2060; i < 2066; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 3 */
-  for (i = 2069; i < 2075; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 4 */
-  for (i = 2078; i < 2084; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 5 */
-  for (i = 2115; i < 2121; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 6 */
-  for (i = 2124; i < 2130; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 7 */
-  for (i = 2133; i < 2139; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* fix acid in eater 8 */
-  for (i = 2142; i < 2148; i++)
-    if (src[i] == 63)
-      src[i - 3] = 101;
-
-  /* old style time */
-  src[2094] = 0;
-
-  /* player 1 pos */
-  src[2096] &= 7;
-  src[src[2096] << 8 | src[2097]] = 128;
-
-  /* player 2 pos */
-  src[2098] &= 7;
-  src[src[2098] << 8 | src[2099]] = 128;
-
-  /* amoeba speed */
-  if ((src[2100] << 8 | src[2101]) > 9999)
-  {
-    src[2100] = 39;
-    src[2101] = 15;
-  }
+int map_em_element_X_to_C(int element_em_game)
+{
+  static unsigned short map_reverse[GAME_TILE_MAX];
+  static boolean map_reverse_initialized = FALSE;
 
-  /* time wonderwall */
-  if ((src[2102] << 8 | src[2103]) > 9999)
+  if (!map_reverse_initialized)
   {
-    src[2102] = 39;
-    src[2103] = 15;
-  }
+    int i;
 
-  /* time */
-  if ((src[2110] << 8 | src[2111]) > 9999)
-  {
-    src[2110] = 39;
-    src[2111] = 15;
-  }
+    // return "Cblank" for all undefined elements in mapping array
+    for (i = 0; i < GAME_TILE_MAX; i++)
+      map_reverse[i] = Cblank;
 
-  /* wind direction */
-  i = src[2149];
-  i &= 15;
-  i &= -i;
-  src[2149] = i;
+    for (i = 0; i < CAVE_TILE_MAX; i++)
+      map_reverse[map[i]] = i;
 
-  /* time lenses */
-  if ((src[2154] << 8 | src[2155]) > 9999)
-  {
-    src[2154] = 39;
-    src[2155] = 15;
+    map_reverse_initialized = TRUE;
   }
 
-  /* time magnify */
-  if ((src[2156] << 8 | src[2157]) > 9999)
+  if (element_em_game < 0 || element_em_game >= GAME_TILE_MAX)
   {
-    src[2156] = 39;
-    src[2157] = 15;
-  }
+    Error(ERR_WARN, "invalid EM game element %d", element_em_game);
 
-  /* ball object */
-  src[2158] = 0;
-  src[2159] = remap_v6[src[2159]];
-
-  /* ball pause */
-  if ((src[2160] << 8 | src[2161]) > 9999)
-  {
-    src[2160] = 39;
-    src[2161] = 15;
+    return Cblank;
   }
 
-  /* ball data */
-  src[2162] &= 129;
-  if (src[2162] & 1)
-    src[2163] = 0;
+  int element_em_cave = map_reverse[element_em_game];
 
-  /* android move pause */
-  if ((src[2164] << 8 | src[2165]) > 9999)
-  {
-    src[2164] = 39;
-    src[2165] = 15;
-  }
+  if (element_em_cave == Cblank && element_em_game != Xblank)
+    Error(ERR_WARN, "unknown EM game element %d", element_em_game);
 
-  /* android clone pause */
-  if ((src[2166] << 8 | src[2167]) > 9999)
-  {
-    src[2166] = 39;
-    src[2167] = 15;
-  }
+  return element_em_cave;
+}
 
-  /* android data */
-  src[2168] &= 31;
+void prepare_em_level(void)
+{
+  int i, j, x, y;
+  int players_left;
+  boolean team_mode;
 
-  /* size of v6 cave */
-  *length = 2172;
+  /* reset all runtime variables to their initial values */
 
-  return TRUE;
-}
+  game_init_cave_buffers();
 
-/* 2000-07-30T00:26:00Z
- *
- * Read emerald mine caves version 6
- *
- * v4 and v5 emerald mine caves are converted to v6 (which completely supports
- * older versions)
- * 
- * converting to the internal format loses /significant/ information which can
- * break lots of caves.
- * 
- * major incompatibilities:
- * - borderless caves behave completely differently, the player no longer
- *   "warps" to the other side.
- * - a compile time option for spring can make it behave differently when it
- *   rolls.
- * - a compile time option for rolling objects (stone, nut, spring, bomb) only
- *   in eater.
- * - acid is always deadly even with no base beneath it.
- *
- * so far all below have not broken any caves:
- *
- * - active wheel inside an eater will not function, eater explosions will not
- *   change settings.
- * - initial collect objects (emerald, diamond, dynamite) don't exist.
- * - initial rolling objects will be moved manually and made into sitting
- *   objects.
- * - drips always appear from dots.
- * - more than one thing can fall into acid at the same time.
- * - acid explodes when the player walks into it, rather than splashing.
- * - simultaneous explosions may be in a slightly different order.
- * - quicksand states have been reduced.
- * - acid base is effectively an indestructable wall now which can affect eater
- *   explosions.
- * - android can clone forever with a clone pause of 0 (emeralds, diamonds,
- *   nuts, stones, bombs, springs).
- *
- * 2001-03-12T02:46:55Z
- * - rolling stuff is now allowed in the cave, i didn't like making this
- *   decision.
- * - if BAD_ROLL is not defined, initial rolling objects are moved by hand.
- * - initial collect objects break some cave in elvis mine 5.
- * - different timing for wonderwall break some cave in exception mine 2.
- * - i think i'm pretty locked into always using the bad roll. *sigh*
- * - rolling spring is now turned into regular spring. it appears the emc
- *   editor only uses the force code for initially moving spring. i will
- *   follow this in my editor.
- */
+  lev.width  = cav.width;
+  lev.height = cav.height;
 
-static unsigned short remap_emerald[256] =
-{
-  Xstone, Xstone, Xdiamond, Xdiamond, Xalien, Xalien, Xblank, Xblank,
-  Xtank_n, Xtank_e, Xtank_s, Xtank_w, Xtank_gon, Xtank_goe, Xtank_gos, Xtank_gow,
-  Xbomb, Xbomb, Xemerald, Xemerald, Xbug_n, Xbug_e, Xbug_s, Xbug_w,
-  Xbug_gon, Xbug_goe, Xbug_gos, Xbug_gow, Xdrip_eat, Xdrip_eat, Xdrip_eat, Xdrip_eat,
-  Xstone, Xbomb, Xdiamond, Xemerald, Xwonderwall, Xnut, Xnut, Xnut,
-  Xwheel, Xeater_n, Xeater_s, Xeater_w, Xeater_e, Xsand_stone, Xblank, Xblank,
-  Xblank, Xsand, Xsand, Xsand, Xsand_stone, Xsand_stone, Xsand_stone, Xsand,
-  Xstone, Xgrow_ew, Xgrow_ns, Xdynamite_1, Xdynamite_2, Xdynamite_3, Xdynamite_4, Xacid_s,
-  Xexit_1, Xexit_2, Xexit_3, Xballoon, Xplant, Xspring, Xspring, Xspring,
-  Xspring, Xball_1, Xball_2, Xandroid, Xblank, Xandroid, Xandroid, Xandroid,
-  Xandroid, Xandroid, Xandroid, Xandroid, Xandroid, Xblank, Xblank, Xblank,
-  Xblank, Xblank, Xblank, Xblank, Xblank, Xblank, Xblank, Xblank,
-
-#ifdef BAD_ROLL
-
-  Xblank, Xblank, Xblank, Xspring_force_w, Xspring_force_e, Xacid_1, Xacid_2, Xacid_3,
-  Xacid_4, Xacid_5, Xacid_6, Xacid_7, Xacid_8, Xblank, Xblank, Xblank,
-  Xblank, Xblank, Xnut_force_w, Xnut_force_e, Xsteel_1, Xblank, Xblank, Xbomb_force_w,
-  Xbomb_force_e, Xstone_force_w, Xstone_force_e, Xblank, Xblank, Xblank, Xblank, Xblank,
-
-#else
-
-  Xblank, Xblank, Xblank, Xspring, Xspring, Xacid_1, Xacid_2, Xacid_3,
-  Xacid_4, Xacid_5, Xacid_6, Xacid_7, Xacid_8, Xblank, Xblank, Xblank,
-  Xblank, Xblank, Xnut, Xnut, Xsteel_1, Xblank, Xblank, Xbomb,
-  Xbomb, Xstone, Xstone, Xblank, Xblank, Xblank, Xblank, Xblank,
-
-#endif
-
-  Xblank, Xround_wall_1, Xgrass, Xsteel_1, Xwall_1, Xkey_1, Xkey_2, Xkey_3,
-  Xkey_4, Xdoor_1, Xdoor_2, Xdoor_3, Xdoor_4, Xdripper, Xfake_door_1, Xfake_door_2,
-  Xfake_door_3, Xfake_door_4, Xwonderwall, Xwheel, Xsand, Xacid_nw, Xacid_ne, Xacid_sw,
-  Xacid_se, Xfake_blank, Xamoeba_1, Xamoeba_2, Xamoeba_3, Xamoeba_4, Xexit, Xalpha_arrow_w,
-  Xfake_grass, Xlenses, Xmagnify, Xfake_blank, Xfake_grass, Xswitch, Xswitch, Xblank,
-  Xdecor_8, Xdecor_9, Xdecor_10, Xdecor_5, Xalpha_comma, Xalpha_quote, Xalpha_minus, Xdynamite,
-  Xsteel_3, Xdecor_6, Xdecor_7, Xsteel_2, Xround_wall_2, Xdecor_2, Xdecor_4, Xdecor_3,
-  Xwind_nesw, Xwind_e, Xwind_s, Xwind_w, Xwind_n, Xdirt, Xplant, Xkey_5,
-  Xkey_6, Xkey_7, Xkey_8, Xdoor_5, Xdoor_6, Xdoor_7, Xdoor_8, Xbumper,
-  Xalpha_a, Xalpha_b, Xalpha_c, Xalpha_d, Xalpha_e, Xalpha_f, Xalpha_g, Xalpha_h,
-  Xalpha_i, Xalpha_j, Xalpha_k, Xalpha_l, Xalpha_m, Xalpha_n, Xalpha_o, Xalpha_p,
-  Xalpha_q, Xalpha_r, Xalpha_s, Xalpha_t, Xalpha_u, Xalpha_v, Xalpha_w, Xalpha_x,
-  Xalpha_y, Xalpha_z, Xalpha_0, Xalpha_1, Xalpha_2, Xalpha_3, Xalpha_4, Xalpha_5,
-  Xalpha_6, Xalpha_7, Xalpha_8, Xalpha_9, Xalpha_perio, Xalpha_excla, Xalpha_colon, Xalpha_quest,
-  Xalpha_arrow_e, Xdecor_1, Xfake_door_5, Xfake_door_6, Xfake_door_7, Xfake_door_8, Xblank, Xblank,
-  Xblank, Xblank, Xblank, Xblank, Xblank, Xblank, Xblank, Xblank,
-};
+  lev.left = CAVE_BUFFER_XOFFSET;
+  lev.top  = CAVE_BUFFER_YOFFSET;
+  lev.right = lev.left + lev.width;
+  lev.bottom = lev.top + lev.height;
 
-void convert_em_level(unsigned char *src)
-{
-  unsigned int x, y, temp;
-
-  temp = ((src[0x83E] << 8 | src[0x83F]) * 25 + 3) / 4;
-  if (temp == 0 || temp > 9999)
-    temp = 9999;
-  lev.time_initial = temp;
-  lev.required_initial = src[0x82F];
-
-  temp = src[0x830] << 8 | src[0x831];
-  ply1.x_initial = (temp & 63) + 1;
-  ply1.y_initial = (temp >> 6 & 31) + 1;
-  temp = src[0x832] << 8 | src[0x833];
-  ply2.x_initial = (temp & 63) + 1;
-  ply2.y_initial = (temp >> 6 & 31) + 1;
-
-  temp = (src[0x834] << 8 | src[0x835]) * 28;
-  if (temp > 9999)
-    temp = 9999;
-  lev.amoeba_time = temp;
-
-  lev.android_move_time = src[0x874] << 8 | src[0x875];
-  lev.android_clone_time = src[0x876] << 8 | src[0x877];
-
-  lev.ball_random = src[0x872] & 1 ? 1 : 0;
-  lev.ball_state_initial = src[0x872] & 128 ? 1 : 0;
-  lev.ball_time = src[0x870] << 8 | src[0x871];
-
-  lev.emerald_score = src[0x824];
-  lev.diamond_score = src[0x825];
-  lev.alien_score = src[0x826];
-  lev.tank_score = src[0x827];
-  lev.bug_score = src[0x828];
-  lev.eater_score = src[0x829];
-  lev.nut_score = src[0x82A];
-  lev.dynamite_score = src[0x82B];
-  lev.key_score = src[0x82C];
-  lev.exit_score = src[0x82D] * 8 / 5;
-  lev.lenses_score = src[0x867];
-  lev.magnify_score = src[0x868];
-  lev.slurp_score = src[0x869];
-
-  lev.lenses_time = src[0x86A] << 8 | src[0x86B];
-  lev.lenses_cnt_initial = 0;
-
-  lev.magnify_time = src[0x86C] << 8 | src[0x86D];
-  lev.magnify_cnt_initial = 0;
-
-  lev.wheel_time = src[0x838] << 8 | src[0x839];
-  lev.wheel_cnt_initial = 0;
-  lev.wheel_x_initial = 1;
-  lev.wheel_y_initial = 1;
-
-  lev.wind_time = 9999;
-  lev.wind_cnt_initial = src[0x865] & 15 ? lev.wind_time : 0;
-  temp = src[0x865];
-  lev.wind_direction_initial = (temp & 8 ? 0 :
-                               temp & 1 ? 1 :
-                               temp & 2 ? 2 :
-                               temp & 4 ? 3 : 0);
-
-  lev.wonderwall_state_initial = 0;
-  lev.wonderwall_time_initial = src[0x836] << 8 | src[0x837];
-
-  for (x = 0; x < 9; x++)
-    lev.eater_array[0][x] = remap_emerald[src[0x800 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[1][x] = remap_emerald[src[0x809 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[2][x] = remap_emerald[src[0x812 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[3][x] = remap_emerald[src[0x81B + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[4][x] = remap_emerald[src[0x840 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[5][x] = remap_emerald[src[0x849 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[6][x] = remap_emerald[src[0x852 + x]];
-  for (x = 0; x < 9; x++)
-    lev.eater_array[7][x] = remap_emerald[src[0x85B + x]];
-
-  temp = remap_emerald[src[0x86F]];
-  for (y = 0; y < 8; y++)
+  if (cav.infinite)
   {
-    if (src[0x872] & 1)
-    {
-      for (x = 0; x < 8; x++)
-       lev.ball_array[y][x] = temp;
-    }
-    else
+    /* add linked cave buffer columns for wrap-around movement */
+    for (x = 0; x < lev.left; x++)
     {
-      lev.ball_array[y][1] = (src[0x873] & 1) ? temp : Xblank;  /* north */
-      lev.ball_array[y][6] = (src[0x873] & 2) ? temp : Xblank;  /* south */
-      lev.ball_array[y][3] = (src[0x873] & 4) ? temp : Xblank;  /* west */
-      lev.ball_array[y][4] = (src[0x873] & 8) ? temp : Xblank;  /* east */
-      lev.ball_array[y][7] = (src[0x873] & 16) ? temp : Xblank; /* southeast */
-      lev.ball_array[y][5] = (src[0x873] & 32) ? temp : Xblank; /* southwest */
-      lev.ball_array[y][2] = (src[0x873] & 64) ? temp : Xblank; /* northeast */
-      lev.ball_array[y][0] = (src[0x873] & 128) ? temp : Xblank;/* northwest */
+      lev.cavecol[x] = lev.cavecol[lev.width + x];
+      lev.nextcol[x] = lev.nextcol[lev.width + x];
+      lev.drawcol[x] = lev.drawcol[lev.width + x];
+      lev.boomcol[x] = lev.boomcol[lev.width + x];
+
+      lev.cavecol[lev.right + x] = lev.cavecol[lev.left + x];
+      lev.nextcol[lev.right + x] = lev.nextcol[lev.left + x];
+      lev.drawcol[lev.right + x] = lev.drawcol[lev.left + x];
+      lev.boomcol[lev.right + x] = lev.boomcol[lev.left + x];
     }
   }
 
-  for (temp = 0; temp < TILE_MAX; temp++)
-    lev.android_array[temp] = Xblank;
+  for (x = 0; x < lev.width; x++)
+    for (y = 0; y < lev.height; y++)
+      lev.cave[lev.left + x][lev.top + y] = map[cav.cave[x][y]];
 
-  temp = src[0x878] << 8 | src[0x879];
-
-  if (temp & 1)
-  {
-    lev.android_array[Xemerald] =
-      lev.android_array[Xemerald_pause] =
-      lev.android_array[Xemerald_fall] =
-      lev.android_array[Yemerald_sB] =
-      lev.android_array[Yemerald_eB] =
-      lev.android_array[Yemerald_wB] = Xemerald;
-  }
+  for (x = lev.left; x < lev.right; x++)
+    for (y = lev.top; y < lev.bottom; y++)
+      lev.next[x][y] = lev.draw[x][y] = lev.cave[x][y];
 
-  if (temp & 2)
-  {
-    lev.android_array[Xdiamond] =
-      lev.android_array[Xdiamond_pause] =
-      lev.android_array[Xdiamond_fall] =
-      lev.android_array[Ydiamond_sB] =
-      lev.android_array[Ydiamond_eB] =
-      lev.android_array[Ydiamond_wB] = Xdiamond;
-  }
+  lev.time = cav.time_seconds;
+  lev.gems_needed = cav.gems_needed;
+  lev.score = 0;
 
-  if (temp & 4)
-  {
-    lev.android_array[Xstone] =
-      lev.android_array[Xstone_pause] =
-      lev.android_array[Xstone_fall] =
-      lev.android_array[Ystone_sB] =
-      lev.android_array[Ystone_eB] =
-      lev.android_array[Ystone_wB] = Xstone;
-  }
+  lev.testmode = cav.testmode;
 
-  if (temp & 8)
+  if (lev.testmode)
   {
-    lev.android_array[Xbomb] =
-      lev.android_array[Xbomb_pause] =
-      lev.android_array[Xbomb_fall] =
-      lev.android_array[Ybomb_sB] =
-      lev.android_array[Ybomb_eB] =
-      lev.android_array[Ybomb_wB] = Xbomb;
+    lev.time = 0;
+    lev.gems_needed = 0;
   }
 
-  if (temp & 16)
-  {
-    lev.android_array[Xnut] =
-      lev.android_array[Xnut_pause] =
-      lev.android_array[Xnut_fall] =
-      lev.android_array[Ynut_sB] =
-      lev.android_array[Ynut_eB] =
-      lev.android_array[Ynut_wB] = Xnut;
-  }
+  lev.eater_score      = cav.eater_score;
+  lev.alien_score      = cav.alien_score;
+  lev.bug_score                = cav.bug_score;
+  lev.tank_score       = cav.tank_score;
+  lev.emerald_score    = cav.emerald_score;
+  lev.diamond_score    = cav.diamond_score;
+  lev.nut_score                = cav.nut_score;
+  lev.slurp_score      = cav.slurp_score;
+  lev.dynamite_score   = cav.dynamite_score;
+  lev.key_score                = cav.key_score;
+  lev.lenses_score     = cav.lenses_score;
+  lev.magnify_score    = cav.magnify_score;
+  lev.exit_score       = cav.exit_score;
+
+  lev.amoeba_time = cav.amoeba_time;
+
+  lev.android_move_time = cav.android_move_time;
+  lev.android_move_cnt  = cav.android_move_time;
+
+  lev.android_clone_time = cav.android_clone_time;
+  lev.android_clone_cnt  = cav.android_clone_time;
+
+  lev.ball_time   = cav.ball_time;
+  lev.ball_cnt    = cav.ball_time;
+  lev.ball_active = cav.ball_active;
+  lev.ball_random = cav.ball_random;
+  lev.ball_pos    = 0;
 
-  if (temp & 32)
-  {
-    lev.android_array[Xtank_n] =
-      lev.android_array[Xtank_gon] =
-      lev.android_array[Ytank_nB] =
-      lev.android_array[Ytank_n_e] =
-      lev.android_array[Ytank_n_w] = Xtank_n;
-
-    lev.android_array[Xtank_e] =
-      lev.android_array[Xtank_goe] =
-      lev.android_array[Ytank_eB] =
-      lev.android_array[Ytank_e_s] =
-      lev.android_array[Ytank_e_n] = Xtank_e;
-
-    lev.android_array[Xtank_s] =
-      lev.android_array[Xtank_gos] =
-      lev.android_array[Ytank_sB] =
-      lev.android_array[Ytank_s_w] =
-      lev.android_array[Ytank_s_e] = Xtank_s;
-
-    lev.android_array[Xtank_w] =
-      lev.android_array[Xtank_gow] =
-      lev.android_array[Ytank_wB] =
-      lev.android_array[Ytank_w_n] =
-      lev.android_array[Ytank_w_s] = Xtank_w;
-  }
+  lev.eater_pos = 0;
+  lev.shine_cnt = 0;
 
-  if (temp & 64)
-  {
-    lev.android_array[Xeater_n] = lev.android_array[Yeater_nB] = Xeater_n;
-    lev.android_array[Xeater_e] = lev.android_array[Yeater_eB] = Xeater_e;
-    lev.android_array[Xeater_s] = lev.android_array[Yeater_sB] = Xeater_s;
-    lev.android_array[Xeater_w] = lev.android_array[Yeater_wB] = Xeater_w;
-  }
+  lev.lenses_time = cav.lenses_time;
+  lev.lenses_cnt  = cav.lenses_active ? cav.lenses_time : 0;
 
-  if (temp & 128)
-  {
-    lev.android_array[Xbug_n] =
-      lev.android_array[Xbug_gon] =
-      lev.android_array[Ybug_nB] =
-      lev.android_array[Ybug_n_e] =
-      lev.android_array[Ybug_n_w] = Xbug_gon;
-
-    lev.android_array[Xbug_e] =
-      lev.android_array[Xbug_goe] =
-      lev.android_array[Ybug_eB] =
-      lev.android_array[Ybug_e_s] =
-      lev.android_array[Ybug_e_n] = Xbug_goe;
-
-    lev.android_array[Xbug_s] =
-      lev.android_array[Xbug_gos] =
-      lev.android_array[Ybug_sB] =
-      lev.android_array[Ybug_s_w] =
-      lev.android_array[Ybug_s_e] = Xbug_gos;
-
-    lev.android_array[Xbug_w] =
-      lev.android_array[Xbug_gow] =
-      lev.android_array[Ybug_wB] =
-      lev.android_array[Ybug_w_n] =
-      lev.android_array[Ybug_w_s] = Xbug_gow;
-  }
+  lev.magnify_time = cav.magnify_time;
+  lev.magnify_cnt  = cav.magnify_active ? cav.magnify_time : 0;
 
-  if (temp & 256)
-  {
-    lev.android_array[Xalien] = lev.android_array[Xalien_pause] =
-      lev.android_array[Yalien_nB] = lev.android_array[Yalien_eB] =
-      lev.android_array[Yalien_sB] = lev.android_array[Yalien_wB] = Xalien;
-  }
+  lev.wheel_time = cav.wheel_time;
+  lev.wheel_cnt  = cav.wheel_active ? cav.wheel_time : 0;
+  lev.wheel_x    = cav.wheel_x;
+  lev.wheel_y    = cav.wheel_y;
 
-  if (temp & 512)
-  {
-    lev.android_array[Xspring] =
-      lev.android_array[Xspring_pause] =
-      lev.android_array[Xspring_e] =
-      lev.android_array[Yspring_eB] =
-      lev.android_array[Yspring_kill_eB] =
-      lev.android_array[Xspring_w] =
-      lev.android_array[Yspring_wB] =
-      lev.android_array[Yspring_kill_wB] =
-      lev.android_array[Xspring_fall] =
-      lev.android_array[Yspring_sB] = Xspring;
-  }
+  lev.wind_time      = cav.wind_time;
+  lev.wind_cnt       = cav.wind_time;
+  lev.wind_direction = cav.wind_direction;
 
-  if (temp & 1024)
-  {
-    lev.android_array[Yballoon_nB] =
-      lev.android_array[Yballoon_eB] =
-      lev.android_array[Yballoon_sB] =
-      lev.android_array[Yballoon_wB] =
-      lev.android_array[Xballoon] = Xballoon;
-  }
+  lev.wonderwall_time   = cav.wonderwall_time;
+  lev.wonderwall_active = cav.wonderwall_active;
 
-  if (temp & 2048)
-  {
-    lev.android_array[Xdripper] =
-      lev.android_array[XdripperB] =
-      lev.android_array[Xamoeba_1] =
-      lev.android_array[Xamoeba_2] =
-      lev.android_array[Xamoeba_3] =
-      lev.android_array[Xamoeba_4] =
-      lev.android_array[Xamoeba_5] =
-      lev.android_array[Xamoeba_6] =
-      lev.android_array[Xamoeba_7] =
-      lev.android_array[Xamoeba_8] = Xdrip_eat;
-  }
+  lev.killed_out_of_time = FALSE;
 
-  if (temp & 4096)
-  {
-    lev.android_array[Xdynamite] = Xdynamite;
-  }
+  lev.num_ball_arrays = cav.num_ball_arrays;
 
-  for (temp = 1; temp < 2047; temp++)
-  {
-    switch (src[temp])
-    {
-      case 0x24:                               /* wonderwall */
-       lev.wonderwall_state_initial = 1;
-       lev.wonderwall_time_initial = 9999;
-       break;
-
-      case 0x28:                               /* wheel */
-       lev.wheel_x_initial = temp & 63;
-       lev.wheel_y_initial = temp >> 6;
-       lev.wheel_cnt_initial = lev.wheel_time;
-       break;
-
-#ifndef BAD_ROLL
-      case 0x63:                               /* spring roll left */
-       src[temp - 1] = 0x45;
-       src[temp] = 0x80;
-       break;
-
-      case 0x64:                               /* spring roll right */
-       src[temp + 1] = 0x45;
-       src[temp] = 0x80;
-       break;
-
-      case 0x72:                               /* nut roll left */
-       src[temp - 1] = 0x25;
-       src[temp] = 0x80;
-       break;
-
-      case 0x73:                               /* nut roll right */
-       src[temp + 1] = 0x25;
-       src[temp] = 0x80;
-       break;
-
-      case 0x77:                               /* bomb roll left */
-       src[temp - 1] = 0x10;
-       src[temp] = 0x80;
-       break;
-
-      case 0x78:                               /* bomb roll right */
-       src[temp + 1] = 0x10;
-       src[temp] = 0x80;
-       break;
-
-      case 0x79:                               /* stone roll left */
-       src[temp - 1] = 0x00;
-       src[temp] = 0x80;
-       break;
-
-      case 0x7A:                               /* stone roll right */
-       src[temp + 1] = 0x00;
-       src[temp] = 0x80;
-       break;
-#endif
-
-      case 0xA3:                               /* fake blank */
-       lev.lenses_cnt_initial = 9999;
-       break;
-
-      case 0xA4:                               /* fake grass */
-       lev.magnify_cnt_initial = 9999;
-       break;
-    }
-  }
+  for (i = 0; i < 8; i++)
+    for (j = 0; j < 9; j++)
+      lev.eater_array[i][j] = map[cav.eater_array[i][j]];
 
-  lev.home_initial = 1;                /* initial number of players in this level */
+  for (i = 0; i < 8; i++)
+    for (j = 0; j < 8; j++)
+      lev.ball_array[i][j] = map[cav.ball_array[i][j]];
 
-  ply1.alive_initial = (lev.home_initial >= 1);
-  ply2.alive_initial = (lev.home_initial >= 2);
+  for (i = 0; i < GAME_TILE_MAX; i++)
+    lev.android_array[i] = map[cav.android_array[i]];
 
-  /* first fill the complete playfield with the default border element */
-  for (y = 0; y < HEIGHT; y++)
-    for (x = 0; x < WIDTH; x++)
-      native_em_level.cave[x][y] = ZBORDER;
+  lev.home_initial = 0;
 
-  /* then copy the real level contents from level file into the playfield */
-  temp = 0;
-  for (y = 0; y < lev.height; y++)
-    for (x = 0; x < lev.width; x++)
-      native_em_level.cave[x + 1][y + 1] = remap_emerald[src[temp++]];
-
-  /* at last, set the two players at their positions in the playfield */
-  if (ply1.alive_initial)
-    native_em_level.cave[ply1.x_initial][ply1.y_initial] = Zplayer;
-  if (ply2.alive_initial)
-    native_em_level.cave[ply2.x_initial][ply2.y_initial] = Zplayer;
-}
+  /* check for players in this level */
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    ply[i].exists = FALSE;
+    ply[i].alive = FALSE;
 
-void prepare_em_level(void)
-{
-  unsigned int x, y;
+    if (cav.player_x[i] != -1 &&
+       cav.player_y[i] != -1)
+    {
+      ply[i].exists = TRUE;
 
-  /* reset all runtime variables to their initial values */
+      lev.home_initial++;
+    }
+  }
 
-  for (y = 0; y < HEIGHT; y++)
-    for (x = 0; x < WIDTH; x++)
-      Cave[y][x] = native_em_level.cave[x][y];
+  team_mode = getTeamMode_EM();
 
-  for (y = 0; y < HEIGHT; y++)
-    for (x = 0; x < WIDTH; x++)
-      Next[y][x] = Cave[y][x];
+  if (!team_mode)
+    lev.home_initial = 1;
 
-  for (y = 0; y < HEIGHT; y++)
-    for (x = 0; x < WIDTH; x++)
-      Draw[y][x] = Cave[y][x];
+  lev.home = lev.home_initial;
+  players_left = lev.home_initial;
 
-  lev.time = lev.time_initial;
-  lev.required = lev.required_initial;
-  lev.score = 0;
+  /* assign active players */
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    if (ply[i].exists && isActivePlayer_EM(i))
+    {
+      if (players_left)
+      {
+       ply[i].alive = TRUE;
+       players_left--;
+      }
+    }
+  }
 
-  lev.android_move_cnt  = lev.android_move_time;
-  lev.android_clone_cnt = lev.android_clone_time;
+  /* remove inactive players */
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    if (ply[i].exists && !ply[i].alive)
+    {
+      int x = cav.player_x[i];
+      int y = cav.player_y[i];
 
-  lev.ball_pos = 0;
-  lev.ball_state = lev.ball_state_initial;
-  lev.ball_cnt = lev.ball_time;
+      lev.cave[lev.left + x][lev.top + y] = Xblank;
+      lev.next[lev.left + x][lev.top + y] = Xblank;
+      lev.draw[lev.left + x][lev.top + y] = Xblank;
+    }
+  }
 
-  lev.eater_pos = 0;
-  lev.shine_cnt = 0;
+  for (i = 0; i < MAX_PLAYERS; i++)
+  {
+    ply[i].num = i;
+    ply[i].anim = PLY_still;
+
+    ply[i].x = cav.player_x[i] + lev.left;
+    ply[i].y = cav.player_y[i] + lev.top;
+    ply[i].prev_x = ply[i].x;
+    ply[i].prev_y = ply[i].y;
+
+    ply[i].dynamite    = 0;
+    ply[i].dynamite_cnt        = 0;
+    ply[i].keys                = 0;
+
+    ply[i].last_move_dir = MV_NONE;
+
+    ply[i].joy_n       = FALSE;
+    ply[i].joy_e       = FALSE;
+    ply[i].joy_s       = FALSE;
+    ply[i].joy_w       = FALSE;
+    ply[i].joy_snap    = FALSE;
+    ply[i].joy_drop    = FALSE;
+    ply[i].joy_stick   = FALSE;
+  }
 
-  lev.lenses_cnt = lev.lenses_cnt_initial;
-  lev.magnify_cnt = lev.magnify_cnt_initial;
+  // the following engine variables are initialized to version-specific values
+  // in function InitGameEngine() (src/game.c):
+  //
+  // - game_em.use_single_button (default: TRUE)
+  // - game_em.use_snap_key_bug (default: FALSE)
+  // - game_em.use_old_explosions (default: FALSE)
+  // - game_em.use_wrap_around (default: TRUE)
 
-  lev.wheel_cnt = lev.wheel_cnt_initial;
-  lev.wheel_x   = lev.wheel_x_initial;
-  lev.wheel_y   = lev.wheel_y_initial;
+  game_em.level_solved = FALSE;
+  game_em.game_over = FALSE;
 
-  lev.wind_cnt       = lev.wind_cnt_initial;
-  lev.wind_direction = lev.wind_direction_initial;
+  game_em.any_player_moving = FALSE;
+  game_em.any_player_snapping = FALSE;
 
-  lev.wonderwall_state = lev.wonderwall_state_initial;
-  lev.wonderwall_time  = lev.wonderwall_time_initial;
+  game_em.last_moving_player = 0;      /* default: first player */
 
-  lev.home = lev.home_initial;
+  for (i = 0; i < MAX_PLAYERS; i++)
+    game_em.last_player_direction[i] = MV_NONE;
 
-  ply1.num = 0;
-  ply1.alive = ply1.alive_initial;
-  ply1.dynamite = 0;
-  ply1.dynamite_cnt = 0;
-  ply1.keys = 0;
-  ply1.anim = 0;
-  ply1.oldx = ply1.x = ply1.x_initial;
-  ply1.oldy = ply1.y = ply1.y_initial;
-  ply1.joy_n = ply1.joy_e = ply1.joy_s = ply1.joy_w = ply1.joy_fire = 0;
-  ply1.joy_stick = ply1.joy_spin = 0;
-
-  ply2.num = 1;
-  ply2.alive = ply2.alive_initial;
-  ply2.dynamite = 0;
-  ply2.dynamite_cnt = 0;
-  ply2.keys = 0;
-  ply2.anim = 0;
-  ply2.oldx = ply2.x = ply2.x_initial;
-  ply2.oldy = ply2.y = ply2.y_initial;
-  ply2.joy_n = ply2.joy_e = ply2.joy_s = ply2.joy_w = ply2.joy_fire = 0;
-  ply2.joy_stick = ply2.joy_spin = 0;
+  lev.exit_x = lev.exit_y = -1;        /* kludge for playing player exit sound */
 }