fixed potential crash bug in BD engine

[rocksndiamonds.git] / src / game_bd / bd_graphics.c

diff --git a/src/game_bd/bd_graphics.c b/src/game_bd/bd_graphics.c
index 084fb3f0f91cd7712514329e4e91781143498214..d355212ed6e28bc0a382088cc6163d7591ba9b90 100644 (file)
--- a/src/game_bd/bd_graphics.c
+++ b/src/game_bd/bd_graphics.c
@@ -291,12 +291,36 @@ static inline boolean is_player(const int element)
   return (gd_elements[element & O_MASK].properties & P_PLAYER) != 0;
 }
 
+// returns true if the element is diggable
+static inline boolean is_diggable(const int element)
+{
+  return (gd_elements[element & O_MASK].properties & P_DIGGABLE) != 0;
+}
+
 // returns true if the element is collectible
 static inline boolean is_collectible(const int element)
 {
   return (gd_elements[element & O_MASK].properties & P_COLLECTIBLE) != 0;
 }
 
+// returns true if the element is pushable
+static inline boolean is_pushable(const int element)
+{
+  return (gd_elements[element & O_MASK].properties & P_PUSHABLE) != 0;
+}
+
+// returns true if the element can move
+static inline boolean can_move(const int element)
+{
+  return (gd_elements[element & O_MASK].properties & P_CAN_MOVE) != 0;
+}
+
+// returns true if the element can fall
+static inline boolean can_fall(const int element)
+{
+  return (gd_elements[element & O_MASK].properties & P_CAN_FALL) != 0;
+}
+
 // returns true if the element is exploding
 static inline boolean is_explosion(const int element)
 {
@@ -374,7 +398,7 @@ static void gd_drawcave_tile(Bitmap *dest, GdGame *game, int x, int y, boolean d
   int dy = (dir == GD_MV_UP   ? +1 : dir == GD_MV_DOWN  ? -1 : 0);
   int old_x = cave->getx(cave, x + dx, y + dy);
   int old_y = cave->gety(cave, x + dx, y + dy);
-  int tile_from = game->element_buffer[old_y][old_x];
+  int tile_from = game->element_buffer[old_y][old_x] & ~SKIPPED;   // should never be skipped
   struct GraphicInfo_BD *g_from = &graphic_info_bd_object[tile_from][frame];
   boolean old_is_player = is_player(tile_from);
   boolean old_is_moving = (game->dir_buffer[old_y][old_x] != GD_MV_STILL);