Improved weapon interpolation

[MrAlaux]

This approach, similar to that of mobj interpolation, eliminates some issues from the old approach, namely interpolation having to be reset upon sprite changes and view-size changes; we now interpolate sx2 and sy2, which are independent of resolution and sprite size, instead of the vissprite itself, which is dependent on those factors.

I think it's not necessary to save/load oldsx2, oldsy2 in/from savegames.

While we're on this, what's the purpose of pspr_interp = false in the following AM_Drawer() code?

woof/src/am_map.c

Lines 2314 to 2318 in dcf9341

	if (automapoverlay == AM_OVERLAY_OFF)
	{
	AM_clearFB(mapcolor_back); //jff 1/5/98 background default color
	pspr_interp = false;
	}

I think we can remove it.

[rfomin]

While we're on this, what's the purpose of pspr_interp = false in the following AM_Drawer() code?

There were issues: #693 I agree that we don't need it anymore. I don't think we need pspr_interp at all:

diff --git a/src/am_map.c b/src/am_map.c
index 1b859153..aebd15d8 100644
--- a/src/am_map.c
+++ b/src/am_map.c
@@ -2312,10 +2312,7 @@ void AM_Drawer (void)
   }
 
   if (automapoverlay == AM_OVERLAY_OFF)
-  {
     AM_clearFB(mapcolor_back);       //jff 1/5/98 background default color
-    pspr_interp = false;
-  }
   // [Alaux] Dark automap overlay
   else if (automapoverlay == AM_OVERLAY_DARK && !MN_MenuIsShaded())
     V_ShadeScreen();
diff --git a/src/p_mobj.c b/src/p_mobj.c
index b8eed65f..9bb8d6fd 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -1127,8 +1127,6 @@ void P_SpawnPlayer (mapthing_t* mthing)
 
   p->momx = p->momy = 0;   // killough 10/98: initialize bobbing to 0.
 
-  pspr_interp = false;
-
   // setup gun psprite
 
   P_SetupPsprites (p);
diff --git a/src/p_pspr.c b/src/p_pspr.c
index 526e57fc..826b534d 100644
--- a/src/p_pspr.c
+++ b/src/p_pspr.c
@@ -167,9 +167,12 @@ static void P_BringUpWeapon(player_t *player)
 
   player->pendingweapon = wp_nochange;
 
+  pspdef_t *psp = &player->psprites[ps_weapon];
+
   // killough 12/98: prevent pistol from starting visibly at bottom of screen:
-  player->psprites[ps_weapon].sy = demo_version >= DV_MBF ? 
-    WEAPONBOTTOM+FRACUNIT*2 : WEAPONBOTTOM;
+  psp->sy = demo_version >= DV_MBF ? WEAPONBOTTOM + FRACUNIT * 2 : WEAPONBOTTOM;
+
+  psp->sy2 = psp->oldsy2 = psp->sy;
 
   P_SetPsprite(player, ps_weapon, newstate);
 }
diff --git a/src/r_things.c b/src/r_things.c
index 4002abd3..975fac56 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -787,8 +787,6 @@ void R_NearbySprites (void)
 // R_DrawPSprite
 //
 
-boolean pspr_interp = true; // weapon bobbing interpolation
-
 void R_DrawPSprite (pspdef_t *psp)
 {
   fixed_t       tx;
@@ -823,15 +821,13 @@ void R_DrawPSprite (pspdef_t *psp)
 
   fixed_t sx2, sy2;
 
-  if (uncapped && oldleveltime < leveltime && pspr_interp)
+  if (uncapped && oldleveltime < leveltime)
   {
     sx2 = LerpFixed(psp->oldsx2, psp->sx2);
     sy2 = LerpFixed(psp->oldsy2, psp->sy2);
   }
   else
   {
-    pspr_interp = true;
-
     sx2 = psp->sx2;
     sy2 = psp->sy2;
   }
diff --git a/src/r_things.h b/src/r_things.h
index f85d45a0..40321c55 100644
--- a/src/r_things.h
+++ b/src/r_things.h
@@ -39,7 +39,6 @@ extern int64_t sprtopscreen; // [FG] 64-bit integer math
 extern fixed_t pspritescale;
 extern fixed_t pspriteiscale;
 
-extern boolean pspr_interp; // weapon bobbing interpolation
 extern boolean flipcorpses;
 
 extern lighttable_t **spritelights;

Nice simplification, thanks!

[rfomin]

LGTM

[fabiangreffrath]

LGTM as well, thank you!

(Apparently, PrBoom+'s interpolation code is too different to be directly applicable to the Crispy/Woof approach.)

[fabiangreffrath]

I think it's not necessary to save/load oldsx2, oldsy2 in/from savegames.

But we could set them equal to sx2, sy2 upon restoring a savegame just to be sure.

[MrAlaux]

Apparently, PrBoom+'s interpolation code is too different to be directly applicable to the Crispy/Woof approach.

FWIW, I tried DSDA 0.28.2 out of curiosity, and its bobbing seems to have the same issues as with the approach that we're replacing here.

I think it's not necessary to save/load oldsx2, oldsy2 in/from savegames.

But we could set them equal to sx2, sy2 upon restoring a savegame just to be sure.

I agree; done in 7064a8e. Anything else? Otherwise, I'll merge.

EDIT: Oops, I rushed it and didn't do it properly. Give me a second.

EDIT 2: Should be fixed in b028290.

[fabiangreffrath]

EDIT: Oops, I rushed it and didn't do it properly. Give me a second.

EDIT 2: Should be fixed in b028290.

Yes, now it's right. Please go ahead!