added preprocessor macro for enhanced readability of some code parts

diff --git a/src/game.c b/src/game.c
index de245df51c6b571301d58eca00d70e43fce5135d..1a204ba844a32892dfbe820aef484ab388aef870 100644 (file)
--- a/src/game.c
+++ b/src/game.c
@@ -827,6 +827,14 @@ static struct GamePanelControlInfo game_panel_controls[] =
 #define DOUBLE_PLAYER_SPEED(p) (HALVE_MOVE_DELAY( (p)->move_delay_value))
 #define HALVE_PLAYER_SPEED(p)  (DOUBLE_MOVE_DELAY((p)->move_delay_value))
 
+/* values for scroll positions */
+#define SCROLL_POSITION_X(x)   ((x) < SBX_Left  + MIDPOSX ? SBX_Left : \
+                                (x) > SBX_Right + MIDPOSX ? SBX_Right :\
+                                (x) - MIDPOSX)
+#define SCROLL_POSITION_Y(y)   ((y) < SBY_Upper + MIDPOSY ? SBY_Upper :\
+                                (y) > SBY_Lower + MIDPOSY ? SBY_Lower :\
+                                (y) - MIDPOSY)
+
 /* values for other actions */
 #define MOVE_STEPSIZE_NORMAL   (TILEX / MOVE_DELAY_NORMAL_SPEED)
 #define MOVE_STEPSIZE_MIN      (1)
@@ -3896,23 +3904,13 @@ void InitGame()
       }
     }
 
-    scroll_x = (start_x < SBX_Left  + MIDPOSX ? SBX_Left :
-               start_x > SBX_Right + MIDPOSX ? SBX_Right :
-               start_x - MIDPOSX);
-
-    scroll_y = (start_y < SBY_Upper + MIDPOSY ? SBY_Upper :
-               start_y > SBY_Lower + MIDPOSY ? SBY_Lower :
-               start_y - MIDPOSY);
+    scroll_x = SCROLL_POSITION_X(start_x);
+    scroll_y = SCROLL_POSITION_Y(start_y);
   }
   else
   {
-    scroll_x = (local_player->jx < SBX_Left  + MIDPOSX ? SBX_Left :
-               local_player->jx > SBX_Right + MIDPOSX ? SBX_Right :
-               local_player->jx - MIDPOSX);
-
-    scroll_y = (local_player->jy < SBY_Upper + MIDPOSY ? SBY_Upper :
-               local_player->jy > SBY_Lower + MIDPOSY ? SBY_Lower :
-               local_player->jy - MIDPOSY);
+    scroll_x = SCROLL_POSITION_X(local_player->jx);
+    scroll_y = SCROLL_POSITION_Y(local_player->jy);
   }
 
   /* !!! FIX THIS (START) !!! */
@@ -4924,36 +4922,21 @@ void DrawRelocateScreen(int old_x, int old_y, int x, int y, int move_dir,
   {
     /* relocation _with_ centering of screen */
 
-    new_scroll_x = (x < SBX_Left  + MIDPOSX ? SBX_Left :
-                   x > SBX_Right + MIDPOSX ? SBX_Right :
-                   x - MIDPOSX);
-
-    new_scroll_y = (y < SBY_Upper + MIDPOSY ? SBY_Upper :
-                   y > SBY_Lower + MIDPOSY ? SBY_Lower :
-                   y - MIDPOSY);
+    new_scroll_x = SCROLL_POSITION_X(x);
+    new_scroll_y = SCROLL_POSITION_Y(y);
   }
   else
   {
     /* relocation _without_ centering of screen */
 
-    int center_scroll_x = (old_x < SBX_Left  + MIDPOSX ? SBX_Left :
-                          old_x > SBX_Right + MIDPOSX ? SBX_Right :
-                          old_x - MIDPOSX);
-
-    int center_scroll_y = (old_y < SBY_Upper + MIDPOSY ? SBY_Upper :
-                          old_y > SBY_Lower + MIDPOSY ? SBY_Lower :
-                          old_y - MIDPOSY);
-
+    int center_scroll_x = SCROLL_POSITION_X(old_x);
+    int center_scroll_y = SCROLL_POSITION_Y(old_y);
     int offset_x = x + (scroll_x - center_scroll_x);
     int offset_y = y + (scroll_y - center_scroll_y);
 
-    new_scroll_x = (offset_x < SBX_Left  + MIDPOSX ? SBX_Left :
-                   offset_x > SBX_Right + MIDPOSX ? SBX_Right :
-                   offset_x - MIDPOSX);
-
-    new_scroll_y = (offset_y < SBY_Upper + MIDPOSY ? SBY_Upper :
-                   offset_y > SBY_Lower + MIDPOSY ? SBY_Lower :
-                   offset_y - MIDPOSY);
+    /* for new screen position, apply previous offset to center position */
+    new_scroll_x = SCROLL_POSITION_X(offset_x);
+    new_scroll_y = SCROLL_POSITION_Y(offset_y);
   }
 
   if (quick_relocation)