added option to swap game elements in EM caves using V5/V6 EMC graphics

[rocksndiamonds.git] / src / game_em / reademc.c

diff --git a/src/game_em/reademc.c b/src/game_em/reademc.c
index a8449a04dd4113b1ffb03b1bcc3498e2e3f4d62c..3f366227a6785c7d0cee3010ac22f8c723c66209 100644 (file)
--- a/src/game_em/reademc.c
+++ b/src/game_em/reademc.c
@@ -42,7 +42,7 @@
 
 #define GET_BE16(x)            ((&x)[0] << 8 | (&x)[1])
 
-static const short map_emc[256] =
+static const short map_emc_raw[256] =
 {
   Cstone,              Cstone,         Cdiamond,       Cdiamond,       //   0
   Calien,              Calien,         Cpause,         Cpause,         //   4
@@ -113,6 +113,21 @@ static const short map_emc[256] =
   Cwall_1,             Cblank,         Calpha_copyr,   Cfake_acid_1    // 252
 };
 
+static const short swap_emc[CAVE_TILE_MAX] =
+{
+  [Cdirt]              = Cgrass,
+  [Cgrass]             = Cdirt,
+
+  [Csteel_1]           = Csteel_2,
+  [Csteel_2]           = Csteel_1,
+
+  [Cwall_1]            = Cwall_2,
+  [Cwall_2]            = Cwall_1,
+
+  [Croundwall_1]       = Croundwall_2,
+  [Croundwall_2]       = Croundwall_1
+};
+
 static struct
 {
   int bit_nr;
@@ -256,6 +271,19 @@ static int eater_offset[8] =
 void convert_em_level(unsigned char *src, int file_version)
 {
   int i, x, y, temp;
+  short map_emc[256];
+
+  /* initialize element mapping */
+
+  for (i = 0; i < 256; i++)
+    map_emc[i] = map_emc_raw[i];
+
+  /* swap tiles for pre-EMC caves (older than V5/V6), if needed */
+
+  if (swapTiles_EM(file_version < FILE_VERSION_EM_V5))
+    for (i = 0; i < 256; i++)
+      if (swap_emc[map_emc[i]] != 0)
+       map_emc[i] = swap_emc[map_emc[i]];
 
   /* common to all emc caves */