added functions to get range corrected x/y cave position for BD engine

diff --git a/src/game_bd/bd_cave.h b/src/game_bd/bd_cave.h
index 189e2777d69687375c72e2a86bd283d57050f359..d97f280fbcf6c255b7fc836009e429671a8db829 100644 (file)
--- a/src/game_bd/bd_cave.h
+++ b/src/game_bd/bd_cave.h
@@ -550,7 +550,13 @@ typedef struct _gd_cave
   boolean pneumatic_hammer_sound;
 
   /* internal variables, used during the game. private data :) */
-  GdElement* (*getp) (const struct _gd_cave*, int x, int y);    /* returns a pointer to the element at x, y. this points to a perfect border or a line shifting get function. */
+
+  /* returns range corrected x/y position (points to perfect or line shifting get function) */
+  int (*getx) (const struct _gd_cave*, int x, int y);
+  int (*gety) (const struct _gd_cave*, int x, int y);
+
+  /* returns pointer to element at x, y (points to perfect border or a line shifting get function) */
+  GdElement* (*getp) (const struct _gd_cave*, int x, int y);
 
   boolean hatched;            /* hatching has happened. (timers may run, ...) */
   boolean gate_open;            /* self-explaining */

diff --git a/src/game_bd/bd_caveengine.c b/src/game_bd/bd_caveengine.c
index d33222e0ffb330846331d899edd0b07cc9a12b43..5f97940a9b6af721de585fb51ede95fcdc455d1e 100644 (file)
--- a/src/game_bd/bd_caveengine.c
+++ b/src/game_bd/bd_caveengine.c
@@ -303,6 +303,38 @@ static void play_sound_of_element_pushing(GdCave *cave, GdElement element, int x
   }
 }
 
+static inline int getx(const GdCave *cave, const int x, const int y)
+{
+  return cave->getx(cave, x, y);
+}
+
+static inline int gety(const GdCave *cave, const int x, const int y)
+{
+  return cave->gety(cave, x, y);
+}
+
+/* perfect (non-lineshifting) GET x/y functions; returns range corrected x/y position */
+static inline int getx_perfect(const GdCave *cave, const int x, const int y)
+{
+  return (x + cave->w) % cave->w;
+}
+
+static inline int gety_perfect(const GdCave *cave, const int x, const int y)
+{
+  return (y + cave->h) % cave->h;
+}
+
+/* line shifting GET x/y function; returns range corrected x/y position */
+static inline int getx_shift(const GdCave *cave, int x, int y)
+{
+  return (x + cave->w) % cave->w;
+}
+
+static inline int gety_shift(const GdCave *cave, int x, int y)
+{
+  return ((x < 0 ? y - 1 : x >= cave->w ? y + 1 : y) + cave->h) % cave->h;
+}
+
 static inline GdElement *getp(const GdCave *cave, const int x, const int y)
 {
   return cave->getp(cave, x, y);
@@ -1517,9 +1549,17 @@ void gd_cave_iterate(GdCave *cave, GdDirection player_move, boolean player_fire,
 
   /* set cave get function; to implement perfect or lineshifting borders */
   if (cave->lineshift)
+  {
     cave->getp = getp_shift;
+    cave->getx = getx_shift;
+    cave->gety = gety_shift;
+  }
   else
+  {
     cave->getp = getp_perfect;
+    cave->getx = getx_perfect;
+    cave->gety = gety_perfect;
+  }
 
   /* increment this. if the scan routine comes across player, clears it (sets to zero). */
   if (cave->player_seen_ago < 100)