Interpolate scrolling textures

bradharding · Oct 24, 2024 · fc11fd8 · fc11fd8
1 parent 50f1aba
commit fc11fd8
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Showing 5 changed files with 82 additions and 8 deletions.
diff --git a/src/p_saveg.c b/src/p_saveg.c
@@ -1266,6 +1266,9 @@ void P_UnarchiveWorld(void)
             if (ABS((side->rowoffset = saveg_read32())) < FRACUNIT)
                 side->rowoffset <<= FRACBITS;
 
+            side->basetextureoffset = side->textureoffset;
+            side->baserowoffset = side->rowoffset;
+
             side->toptexture = saveg_read16();
             side->bottomtexture = saveg_read16();
             side->midtexture = saveg_read16();

diff --git a/src/p_setup.c b/src/p_setup.c
@@ -1388,6 +1388,8 @@ static void P_LoadSectors(int lump)
 
         ss->oldceilinggametime = -1;
         ss->oldfloorgametime = -1;
+        ss->oldceilingoffsetgametime = -1;
+        ss->oldflooroffsetgametime = -1;
 
         // [BH] Apply any level-specific fixes.
         if (canmodify && r_fixmaperrors && gamemode != shareware)
@@ -2201,8 +2203,8 @@ static void P_LoadSideDefs2(int lump)
         sector_t        *sec;
         unsigned short  sector_num = SHORT(msd->sector);
 
-        sd->textureoffset = SHORT(msd->textureoffset) << FRACBITS;
-        sd->rowoffset = SHORT(msd->rowoffset) << FRACBITS;
+        sd->textureoffset = sd->basetextureoffset = sd->oldtextureoffset = SHORT(msd->textureoffset) << FRACBITS;
+        sd->rowoffset = sd->baserowoffset = SHORT(msd->rowoffset) << FRACBITS;
 
         // cph 09/30/06: catch out-of-range sector numbers; use sector 0 instead
         if (sector_num >= numsectors)

diff --git a/src/p_spec.c b/src/p_spec.c
@@ -2801,26 +2801,53 @@ void T_Scroll(scroll_t *scroller)
         {
             side_t  *side = sides + scroller->affectee;
 
-            side->textureoffset += dx;
-            side->rowoffset += dy;
+            if (side->oldgametime != gametime)
+            {
+                side->oldtextureoffset = side->basetextureoffset;
+                side->oldrowoffset = side->baserowoffset;
+                side->oldgametime = gametime;
+            }
+
+            side->basetextureoffset += dx;
+            side->baserowoffset += dy;
+            side->textureoffset = side->basetextureoffset;
+            side->rowoffset = side->baserowoffset;
             break;
         }
 
         case sc_floor:                  // killough 03/07/98: Scroll floor texture
         {
             sector_t    *sec = sectors + scroller->affectee;
 
-            sec->floorxoffset += dx;
-            sec->flooryoffset += dy;
+            if (sec->oldflooroffsetgametime != gametime)
+            {
+                sec->oldfloorxoffset = sec->basefloorxoffset;
+                sec->oldflooryoffset = sec->baseflooryoffset;
+                sec->oldflooroffsetgametime = gametime;
+            }
+
+            sec->basefloorxoffset += dx;
+            sec->baseflooryoffset += dy;
+            sec->floorxoffset = sec->basefloorxoffset;
+            sec->flooryoffset = sec->baseflooryoffset;
             break;
         }
 
         case sc_ceiling:                // killough 03/07/98: Scroll ceiling texture
         {
             sector_t    *sec = sectors + scroller->affectee;
 
-            sec->ceilingxoffset += dx;
-            sec->ceilingyoffset += dy;
+            if (sec->oldceilingoffsetgametime != gametime)
+            {
+                sec->oldceilingxoffset = sec->baseceilingxoffset;
+                sec->oldceilingyoffset = sec->baseceilingyoffset;
+                sec->oldceilingoffsetgametime = gametime;
+            }
+
+            sec->baseceilingxoffset += dx;
+            sec->baseceilingyoffset += dy;
+            sec->ceilingxoffset = sec->baseceilingxoffset;
+            sec->ceilingyoffset = sec->baseceilingyoffset;
             break;
         }
 

diff --git a/src/r_bsp.c b/src/r_bsp.c
@@ -215,6 +215,22 @@ static void R_InterpolateSector(sector_t *sector)
             else
                 heightsec->interpceilingheight = heightsec->ceilingheight;
         }
+
+        if (sector->oldflooroffsetgametime == gametime - 1)
+        {
+            sector->floorxoffset = sector->oldfloorxoffset +
+                FixedMul(sector->basefloorxoffset - sector->oldfloorxoffset, fractionaltic);
+            sector->flooryoffset = sector->oldflooryoffset +
+                FixedMul(sector->baseflooryoffset - sector->oldflooryoffset, fractionaltic);
+        }
+
+        if (sector->oldceilingoffsetgametime == gametime - 1)
+        {
+            sector->ceilingxoffset = sector->oldceilingxoffset +
+                FixedMul(sector->baseceilingxoffset - sector->oldceilingxoffset, fractionaltic);
+            sector->ceilingyoffset = sector->oldceilingyoffset +
+                FixedMul(sector->baseceilingyoffset - sector->oldceilingyoffset, fractionaltic);
+        }
     }
     else
     {
@@ -229,6 +245,17 @@ static void R_InterpolateSector(sector_t *sector)
     }
 }
 
+static void R_InterpolateTextureOffsets(side_t *side)
+{
+    if (vid_capfps != TICRATE && side->oldgametime == gametime - 1)
+    {
+        side->textureoffset = side->oldtextureoffset
+            + FixedMul(side->basetextureoffset - side->oldtextureoffset, fractionaltic);
+        side->rowoffset = side->oldrowoffset
+            + FixedMul(side->baserowoffset - side->oldrowoffset, fractionaltic);
+    }
+}
+
 //
 // killough 03/07/98: Hack floor/ceiling heights for deep water etc.
 //
@@ -388,6 +415,8 @@ static void R_AddLine(seg_t *line)
     if (x1 >= x2)
         return;
 
+    R_InterpolateTextureOffsets(line->sidedef);
+
     // Single sided line?
     if ((backsector = line->backsector))
     {

diff --git a/src/r_defs.h b/src/r_defs.h
@@ -152,6 +152,8 @@ typedef struct sector_s
     //      if old values were not updated recently.
     int                 oldfloorgametime;
     int                 oldceilinggametime;
+    int                 oldceilingoffsetgametime;
+    int                 oldflooroffsetgametime;
 
     // [AM] Interpolated floor and ceiling height.
     //      Calculated once per tic and used inside
@@ -168,6 +170,11 @@ typedef struct sector_s
     fixed_t             floorxoffset, flooryoffset;
     fixed_t             ceilingxoffset, ceilingyoffset;
 
+    fixed_t             basefloorxoffset, baseflooryoffset;
+    fixed_t             oldfloorxoffset, oldflooryoffset;
+    fixed_t             baseceilingxoffset, baseceilingyoffset;
+    fixed_t             oldceilingxoffset, oldceilingyoffset;
+
     // killough 04/11/98: support for lightlevels coming from another sector
     struct sector_s     *floorlightsec;
     struct sector_s     *ceilinglightsec;
@@ -233,6 +240,12 @@ typedef struct
     bool                missingtoptexture;
     bool                missingmidtexture;
     bool                missingbottomtexture;
+
+    fixed_t             oldtextureoffset;
+    fixed_t             oldrowoffset;
+    fixed_t             basetextureoffset;
+    fixed_t             baserowoffset;
+    int                 oldgametime;
 } side_t;
 
 //