2.2 sight checks backport

src/p_sight.c

@@ -2,7 +2,7 @@
 //-----------------------------------------------------------------------------
 // Copyright (C) 1993-1996 by id Software, Inc.
 // Copyright (C) 1998-2000 by DooM Legacy Team.
-// Copyright (C) 1999-2018 by Sonic Team Junior.
+// Copyright (C) 1999-2020 by Sonic Team Junior.
 //
 // This program is free software distributed under the
 // terms of the GNU General Public License, version 2.
@@ -14,6 +14,7 @@
 #include "doomdef.h"
 #include "doomstat.h"
 #include "p_local.h"
+#include "p_slopes.h"
 #include "r_main.h"
 #include "r_state.h"
 
@@ -103,12 +104,20 @@ static fixed_t P_InterceptVector2(divline_t *v2, divline_t *v1)
 static boolean P_CrossSubsecPolyObj(polyobj_t *po, register los_t *los)
 {
 	size_t i;
+	sector_t *polysec;
+
+	if (!(po->flags & POF_RENDERALL))
+		return true; // the polyobject isn't visible, so we can ignore it
+
+	polysec = po->lines[0]->backsector;
 
 	for (i = 0; i < po->numLines; ++i)
 	{
 		line_t *line = po->lines[i];
 		divline_t divl;
 		const vertex_t *v1,*v2;
+		fixed_t frac;
+		fixed_t topslope, bottomslope;
 
 		// already checked other side?
 		if (line->validcount == validcount)
@@ -140,7 +149,22 @@ static boolean P_CrossSubsecPolyObj(polyobj_t *po, register los_t *los)
 			continue;
 
 		// stop because it is not two sided
-		return false;
+		//if (!(po->flags & POF_TESTHEIGHT))
+			//return false;
+
+		frac = P_InterceptVector2(&los->strace, &divl);
+
+		// get slopes of top and bottom of this polyobject line
+		topslope = FixedDiv(polysec->ceilingheight - los->sightzstart , frac);
+		bottomslope = FixedDiv(polysec->floorheight - los->sightzstart , frac);
+
+		if (topslope >= los->topslope && bottomslope <= los->bottomslope)
+			return false; // view completely blocked
+
+		// TODO: figure out if it's worth considering partially blocked cases or not?
+		// maybe to adjust los's top/bottom slopes if needed
+		//if (los->topslope <= los->bottomslope)
+			//return false;
 	}
 
 	return true;
@@ -193,6 +217,15 @@ static boolean P_CrossSubsector(size_t num, register los_t *los)
 		const sector_t *front, *back;
 		const vertex_t *v1,*v2;
 		fixed_t frac;
+		fixed_t frontf, backf, frontc, backc;
+#ifdef ESLOPE
+		fixed_t fracx, fracy;
+#endif
+
+		/* SRB2Kart doesn't have this?
+		if (seg->glseg)
+			continue;
+		*/
 
 		// already checked other side?
 		if (line->validcount == validcount)
@@ -227,36 +260,51 @@ static boolean P_CrossSubsector(size_t num, register los_t *los)
 		if (!(line->flags & ML_TWOSIDED))
 			return false;
 
+		// calculate fractional intercept (how far along we are divided by how far we are from t2)
+		frac = P_InterceptVector2(&los->strace, &divl);
+
+		front = seg->frontsector;
+		back  = seg->backsector;
+#ifdef ESLOPE
+		// calculate position at intercept
+		fracx = los->strace.x + FixedMul(los->strace.dx, frac);
+		fracy = los->strace.y + FixedMul(los->strace.dy, frac);
+		// calculate sector heights
+		frontf = (front->f_slope) ? P_GetZAt(front->f_slope, fracx, fracy) : front->floorheight;
+		frontc = (front->c_slope) ? P_GetZAt(front->c_slope, fracx, fracy) : front->ceilingheight;
+		backf  = (back->f_slope)  ? P_GetZAt(back->f_slope, fracx, fracy)  : back->floorheight;
+		backc  = (back->c_slope)  ? P_GetZAt(back->c_slope, fracx, fracy)  : back->ceilingheight;
+#else
+		frontf = front->floorheight;
+		frontc = front->ceilingheight;
+		backf  = back->floorheight;
+		backc  = back->ceilingheight;
+#endif
 		// crosses a two sided line
 		// no wall to block sight with?
-		if ((front = seg->frontsector)->floorheight ==
+		if (frontf == backf && frontc == backc
-			(back = seg->backsector)->floorheight   &&
+		&& !front->ffloors & !back->ffloors) // (and no FOFs)
-			front->ceilingheight == back->ceilingheight)
 			continue;
 
 		// possible occluder
 		// because of ceiling height differences
-		popentop = front->ceilingheight < back->ceilingheight ?
+		popentop = min(frontc, backc);
-			front->ceilingheight : back->ceilingheight ;
 
 		// because of floor height differences
-		popenbottom = front->floorheight > back->floorheight ?
+		popenbottom = max(frontf, backf);
-			front->floorheight : back->floorheight ;
 
 		// quick test for totally closed doors
 		if (popenbottom >= popentop)
 			return false;
 
-		frac = P_InterceptVector2(&los->strace, &divl);
+		if (frontf != backf)
-
-		if (front->floorheight != back->floorheight)
 		{
 			fixed_t slope = FixedDiv(popenbottom - los->sightzstart , frac);
 			if (slope > los->bottomslope)
 				los->bottomslope = slope;
 		}
 
-		if (front->ceilingheight != back->ceilingheight)
+		if (frontc != backc)
 		{
 			fixed_t slope = FixedDiv(popentop - los->sightzstart , frac);
 			if (slope < los->topslope)
@@ -265,6 +313,58 @@ static boolean P_CrossSubsector(size_t num, register los_t *los)
 
 		if (los->topslope <= los->bottomslope)
 			return false;
+
+		// Monster Iestyn: check FOFs!
+		if (front->ffloors || back->ffloors)
+		{
+			ffloor_t *rover;
+			fixed_t topslope, bottomslope;
+			fixed_t topz, bottomz;
+			// check front sector's FOFs first
+			for (rover = front->ffloors; rover; rover = rover->next)
+			{
+				if (!(rover->flags & FF_EXISTS)
+					|| !(rover->flags & FF_RENDERSIDES) || rover->flags & FF_TRANSLUCENT)
+				{
+					continue;
+				}
+
+#ifdef ESLOPE
+				topz    = (*rover->t_slope) ? P_GetZAt(*rover->t_slope, fracx, fracy) : *rover->topheight;
+				bottomz = (*rover->b_slope) ? P_GetZAt(*rover->b_slope, fracx, fracy) : *rover->bottomheight;
+#else
+				topz    = *rover->topheight;
+				bottomz = *rover->bottomheight;
+#endif
+				topslope    = FixedDiv(topz - los->sightzstart , frac);
+				bottomslope = FixedDiv(bottomz - los->sightzstart , frac);
+				if (topslope >= los->topslope && bottomslope <= los->bottomslope)
+					return false; // view completely blocked
+			}
+			// check back sector's FOFs as well
+			for (rover = back->ffloors; rover; rover = rover->next)
+			{
+				if (!(rover->flags & FF_EXISTS)
+					|| !(rover->flags & FF_RENDERSIDES) || rover->flags & FF_TRANSLUCENT)
+				{
+					continue;
+				}
+
+#ifdef ESLOPE
+				topz    = (*rover->t_slope) ? P_GetZAt(*rover->t_slope, fracx, fracy) : *rover->topheight;
+				bottomz = (*rover->b_slope) ? P_GetZAt(*rover->b_slope, fracx, fracy) : *rover->bottomheight;
+#else
+				topz    = *rover->topheight;
+				bottomz = *rover->bottomheight;
+#endif
+				topslope    = FixedDiv(topz - los->sightzstart , frac);
+				bottomslope = FixedDiv(bottomz - los->sightzstart , frac);
+				if (topslope >= los->topslope && bottomslope <= los->bottomslope)
+					return false; // view completely blocked
+			}
+			// TODO: figure out if it's worth considering partially blocked cases or not?
+			// maybe to adjust los's top/bottom slopes if needed
+		}
 	}
 
 	// passed the subsector ok
@@ -375,6 +475,8 @@ boolean P_CheckSight(mobj_t *t1, mobj_t *t2)
 	if (s1 == s2) // Both sectors are the same.
 	{
 		ffloor_t *rover;
+		fixed_t topz1, bottomz1; // top, bottom heights at t1's position
+		fixed_t topz2, bottomz2; // likewise but for t2
 
 		for (rover = s1->ffloors; rover; rover = rover->next)
 		{
@@ -387,9 +489,30 @@ boolean P_CheckSight(mobj_t *t1, mobj_t *t2)
 				continue;
 			}
 
+#ifdef ESLOPE
+			if (*rover->t_slope)
+			{
+				topz1 = P_GetZAt(*rover->t_slope, t1->x, t1->y);
+				topz2 = P_GetZAt(*rover->t_slope, t2->x, t2->y);
+			}
+			else
+				topz1 = topz2 = *rover->topheight;
+
+			if (*rover->b_slope)
+			{
+				bottomz1 = P_GetZAt(*rover->b_slope, t1->x, t1->y);
+				bottomz2 = P_GetZAt(*rover->b_slope, t2->x, t2->y);
+			}
+			else
+				bottomz1 = bottomz2 = *rover->bottomheight;
+#else
+			topz1 = topz2 = *rover->topheight;
+			bottomz1 = bottomz2 = *rover->bottomheight;
+#endif
+
 			// Check for blocking floors here.
-			if ((los.sightzstart < *rover->bottomheight && t2->z >= *rover->topheight)
+			if ((los.sightzstart < bottomz1 && t2->z >= topz2)
-				|| (los.sightzstart >= *rover->topheight && t2->z + t2->height < *rover->bottomheight))
+				|| (los.sightzstart >= topz1 && t2->z + t2->height < bottomz2))
 			{
 				// no way to see through that
 				return false;
@@ -400,19 +523,19 @@ boolean P_CheckSight(mobj_t *t1, mobj_t *t2)
 
 			if (!(rover->flags & FF_INVERTPLANES))
 			{
-				if (los.sightzstart >= *rover->topheight && t2->z + t2->height < *rover->topheight)
+				if (los.sightzstart >= topz1 && t2->z + t2->height < topz2)
 					return false; // blocked by upper outside plane
 
-				if (los.sightzstart < *rover->bottomheight && t2->z >= *rover->bottomheight)
+				if (los.sightzstart < bottomz1 && t2->z >= bottomz2)
 					return false; // blocked by lower outside plane
 			}
 
 			if (rover->flags & FF_INVERTPLANES || rover->flags & FF_BOTHPLANES)
 			{
-				if (los.sightzstart < *rover->topheight && t2->z >= *rover->topheight)
+				if (los.sightzstart < topz1 && t2->z >= topz2)
 					return false; // blocked by upper inside plane
 
-				if (los.sightzstart >= *rover->bottomheight && t2->z + t2->height < *rover->bottomheight)
+				if (los.sightzstart >= bottomz1 && t2->z + t2->height < bottomz2)
 					return false; // blocked by lower inside plane
 			}
 		}