From 430d7cfbd2c35e6aeb2ad46336f12f149afe631f Mon Sep 17 00:00:00 2001
From: toasterbabe <rollerorbital@gmail.com>
Date: Thu, 18 Aug 2016 15:45:44 +0100
Subject: [PATCH] Noticed some sorting issues, so introduced the sortscale
 struct variable. (SORRY, NO FLAG YET)

---
 src/r_things.c | 28 ++++++++++++++++------------
 src/r_things.h |  2 +-
 2 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/src/r_things.c b/src/r_things.c
index c8667ca40..96224fd62 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -1027,7 +1027,7 @@ static void R_SplitSprite(vissprite_t *sprite, mobj_t *thing)
 		if (testheight <= sprite->gz)
 			return;
 
-		cutfrac = (INT16)((centeryfrac - FixedMul(testheight - viewz, sprite->scale))>>FRACBITS);
+		cutfrac = (INT16)((centeryfrac - FixedMul(testheight - viewz, sprite->sortscale))>>FRACBITS);
 		if (cutfrac < 0)
 			continue;
 		if (cutfrac > viewheight)
@@ -1100,7 +1100,7 @@ static void R_ProjectSprite(mobj_t *thing)
 	fixed_t tr_x, tr_y;
 	fixed_t gxt, gyt;
 	fixed_t tx, tz;
-	fixed_t xscale, yscale; //added : 02-02-98 : aaargll..if I were a math-guy!!!
+	fixed_t xscale, yscale, sortscale; //added : 02-02-98 : aaargll..if I were a math-guy!!!
 
 	INT32 x1, x2;
 
@@ -1152,7 +1152,7 @@ static void R_ProjectSprite(mobj_t *thing)
 
 	// aspect ratio stuff
 	xscale = FixedDiv(projection, tz);
-	yscale = FixedDiv(projectiony, tz);
+	sortscale = FixedDiv(projectiony, tz);
 
 	// decide which patch to use for sprite relative to player
 #ifdef RANGECHECK
@@ -1294,7 +1294,10 @@ static void R_ProjectSprite(mobj_t *thing)
 		scalestep = (yscale2 - yscale)/range;
 	}
 	else
+	{
+		yscale = sortscale;
 		scalestep = 0;
+	}
 
 	xscale = FixedMul(xscale, ang_scale);
 
@@ -1379,6 +1382,7 @@ static void R_ProjectSprite(mobj_t *thing)
 	vis->heightsec = heightsec; //SoM: 3/17/2000
 	vis->mobjflags = thing->flags;
 	vis->scale = yscale; //<<detailshift;
+	vis->sortscale = sortscale;
 	vis->dispoffset = thing->info->dispoffset; // Monster Iestyn: 23/11/15
 	vis->gx = thing->x;
 	vis->gy = thing->y;
@@ -1778,14 +1782,14 @@ void R_SortVisSprites(void)
 		bestscale = bestdispoffset = INT32_MAX;
 		for (ds = unsorted.next; ds != &unsorted; ds = ds->next)
 		{
-			if (ds->scale < bestscale)
+			if (ds->sortscale < bestscale)
 			{
-				bestscale = ds->scale;
+				bestscale = ds->sortscale;
 				bestdispoffset = ds->dispoffset;
 				best = ds;
 			}
 			// order visprites of same scale by dispoffset, smallest first
-			else if (ds->scale == bestscale && ds->dispoffset < bestdispoffset)
+			else if (ds->sortscale == bestscale && ds->dispoffset < bestdispoffset)
 			{
 				bestdispoffset = ds->dispoffset;
 				best = ds;
@@ -2039,8 +2043,8 @@ static void R_CreateDrawNodes(void)
 				if (r2->sprite->szt > rover->sz || r2->sprite->sz < rover->szt)
 					continue;
 
-				if (r2->sprite->scale > rover->scale
-				 || (r2->sprite->scale == rover->scale && r2->sprite->dispoffset > rover->dispoffset))
+				if (r2->sprite->sortscale > rover->scale
+				 || (r2->sprite->sortscale == rover->scale && r2->sprite->dispoffset > rover->dispoffset))
 				{
 					entry = R_CreateDrawNode(NULL);
 					(entry->prev = r2->prev)->next = entry;
@@ -2193,8 +2197,8 @@ void R_ClipSprites(void)
 				scale = ds->scale2;
 			}
 
-			if (scale < spr->scale ||
-			    (lowscale < spr->scale &&
+			if (scale < spr->sortscale ||
+			    (lowscale < spr->sortscale &&
 			     !R_PointOnSegSide (spr->gx, spr->gy, ds->curline)))
 			{
 				// masked mid texture?
@@ -2245,7 +2249,7 @@ void R_ClipSprites(void)
 			fixed_t mh, h;
 			INT32 phs = viewplayer->mo->subsector->sector->heightsec;
 			if ((mh = sectors[spr->heightsec].floorheight) > spr->gz &&
-				(h = centeryfrac - FixedMul(mh -= viewz, spr->scale)) >= 0 &&
+				(h = centeryfrac - FixedMul(mh -= viewz, spr->sortscale)) >= 0 &&
 				(h >>= FRACBITS) < viewheight)
 			{
 				if (mh <= 0 || (phs != -1 && viewz > sectors[phs].floorheight))
@@ -2263,7 +2267,7 @@ void R_ClipSprites(void)
 			}
 
 			if ((mh = sectors[spr->heightsec].ceilingheight) < spr->gzt &&
-			    (h = centeryfrac - FixedMul(mh-viewz, spr->scale)) >= 0 &&
+			    (h = centeryfrac - FixedMul(mh-viewz, spr->sortscale)) >= 0 &&
 			    (h >>= FRACBITS) < viewheight)
 			{
 				if (phs != -1 && viewz >= sectors[phs].ceilingheight)
diff --git a/src/r_things.h b/src/r_things.h
index 0941082aa..360ead433 100644
--- a/src/r_things.h
+++ b/src/r_things.h
@@ -135,7 +135,7 @@ typedef struct vissprite_s
 	fixed_t pz, pzt; // physical bottom/top for sorting with 3D floors
 
 	fixed_t startfrac; // horizontal position of x1
-	fixed_t scale;
+	fixed_t scale, sortscale; // sortscale only differs from scale for flat sprites
 	fixed_t scalestep; // only for flat sprites, 0 otherwise
 	fixed_t xiscale; // negative if flipped