From b57e69efda77b62069ef4950ded91a194e9fe7db Mon Sep 17 00:00:00 2001
From: Brad Harding <brad@doomretro.com>
Date: Fri, 6 Dec 2024 10:32:09 +1100
Subject: [PATCH] Optimize openings

---
 src/r_defs.h  |  2 +-
 src/r_plane.c |  2 +-
 src/r_plane.h |  2 +-
 src/r_segs.c  | 36 ++----------------------------------
 4 files changed, 5 insertions(+), 37 deletions(-)

diff --git a/src/r_defs.h b/src/r_defs.h
index 1c41228a8..97594ce58 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -46,7 +46,7 @@
 #define SIL_BOTH    3
 
 #define MAXDRAWSEGS 1280
-#define MAXOPENINGS 16384
+#define MAXOPENINGS MAXSCREENAREA
 
 //
 // INTERNAL MAP TYPES
diff --git a/src/r_plane.c b/src/r_plane.c
index 781e1b5fb..e940f2da0 100644
--- a/src/r_plane.c
+++ b/src/r_plane.c
@@ -53,7 +53,7 @@ static visplane_t   **freehead = &freetail;     // killough
 visplane_t          *floorplane;
 visplane_t          *ceilingplane;
 
-int                 *openings;                  // dropoff overflow
+int                 openings[MAXOPENINGS];
 int                 *lastopening;               // dropoff overflow
 
 // Clip values are the solid pixel bounding the range.
diff --git a/src/r_plane.h b/src/r_plane.h
index eed3712f7..e594896c8 100644
--- a/src/r_plane.h
+++ b/src/r_plane.h
@@ -44,7 +44,7 @@ extern int      floorclip[MAXWIDTH];
 extern int      ceilingclip[MAXWIDTH];
 extern fixed_t  *yslope;
 extern fixed_t  yslopes[LOOKDIRS][MAXHEIGHT];
-extern int      *openings;  // dropoff overflow
+extern int      openings[MAXOPENINGS];
 
 void R_ClearPlanes(void);
 void R_DrawPlanes(void);
diff --git a/src/r_segs.c b/src/r_segs.c
index fddece399..d4cc0ecc8 100644
--- a/src/r_segs.c
+++ b/src/r_segs.c
@@ -633,40 +633,8 @@ void R_StoreWallRange(const int start, const int stop)
     ds_p->curline = curline;
     rw_stopx = stop + 1;
 
-    // killough 01/06/98, 02/01/98: remove limit on openings
-    {
-        const size_t    pos = lastopening - openings;
-        const size_t    need = ((size_t)rw_stopx - start) * sizeof(*lastopening) + pos;
-        static size_t   maxopenings;
-
-        if (need > maxopenings)
-        {
-            const int   *oldopenings = openings;
-            const int   *oldlast = lastopening;
-
-            do
-                maxopenings = (maxopenings ? maxopenings * 2 : MAXOPENINGS);
-            while (need > maxopenings);
-
-            openings = I_Realloc(openings, maxopenings * sizeof(*openings));
-            lastopening = openings + pos;
-
-            // jff 08/09/98 borrowed fix for openings from ZDOOM 1.14
-            // [RH] We also need to adjust the openings pointers that
-            //    were already stored in drawsegs.
-            for (drawseg_t *ds = drawsegs; ds < ds_p; ds++)
-            {
-                if (ds->maskedtexturecol + ds->x1 >= oldopenings && ds->maskedtexturecol + ds->x1 <= oldlast)
-                    ds->maskedtexturecol = ds->maskedtexturecol - oldopenings + openings;
-
-                if (ds->sprtopclip + ds->x1 >= oldopenings && ds->sprtopclip + ds->x1 <= oldlast)
-                    ds->sprtopclip = ds->sprtopclip - oldopenings + openings;
-
-                if (ds->sprbottomclip + ds->x1 >= oldopenings && ds->sprbottomclip + ds->x1 <= oldlast)
-                    ds->sprbottomclip = ds->sprbottomclip - oldopenings + openings;
-            }
-        }
-    }
+    if ((rw_stopx - start) * sizeof(*lastopening) + (lastopening - openings) > MAXOPENINGS)
+        return;
 
     worldtop = frontsector->interpceilingheight - viewz;
     worldbottom = frontsector->interpfloorheight - viewz;