- Restored the old drawseg/sprite distance check from 2.0.63. The code that

replaced it did the check at the center of the area intersected by the
  sprite and the drawseg, whereas 2.0.63 only did the check at the location
  of the sprite on the map.


SVN r1411 (trunk)

docs/rh-log.txt

@@ -1,4 +1,8 @@
 February 6, 2009
+- Restored the old drawseg/sprite distance check from 2.0.63. The code that
+  replaced it did the check at the center of the area intersected by the
+  sprite and the drawseg, whereas 2.0.63 only did the check at the location
+  of the sprite on the map.
 - Commented out the CALL_ACTION(A_Look, actor) for targetless friendly
   monsters in A_DoChase(). They can still find new targets without this,
   and with it, they got stuck on the first frame of their see state.

src/r_bsp.h

@@ -35,6 +35,7 @@ struct drawseg_t
 	short		sx1, sx2;		// left, right of parent seg on screen
 	fixed_t		sz1, sz2;		// z for left, right of parent seg on screen
 	fixed_t		siz1, siz2;		// 1/z for left, right of parent seg on screen
+	fixed_t		cx, cy, cdx, cdy;
 	BYTE 		silhouette;		// 0=none, 1=bottom, 2=top, 3=both
 	BYTE		bFogBoundary;
 	int			shade;

src/r_defs.h

@@ -915,6 +915,7 @@ struct vissprite_t
 	fixed_t			startfrac;		// horizontal position of x1
 	fixed_t			xscale, yscale;
 	fixed_t			xiscale;		// negative if flipped
+	fixed_t			depth;
 	fixed_t			idepth;			// 1/z
 	fixed_t			texturemid;
 	DWORD			FillColor;

src/r_segs.cpp

@@ -1533,6 +1533,10 @@ void R_StoreWallRange (int start, int stop)
 	ds_p->sx2 = WallSX2;
 	ds_p->sz1 = WallSZ1;
 	ds_p->sz2 = WallSZ2;
+	ds_p->cx = WallTX1;
+	ds_p->cy = WallTY1;
+	ds_p->cdx = WallTX2 - WallTX1;
+	ds_p->cdy = WallTY2 - WallTY1;
 	ds_p->siz1 = (DWORD)DivScale32 (1, WallSZ1) >> 1;
 	ds_p->siz2 = (DWORD)DivScale32 (1, WallSZ2) >> 1;
 	ds_p->x1 = rw_x = start;

src/r_things.cpp

@@ -1403,6 +1403,7 @@ void R_ProjectSprite (AActor *thing, int fakeside)
 	vis->FillColor = thing->fillcolor;
 	vis->xscale = xscale;
 	vis->yscale = Scale (InvZtoScale, yscale, tz)>>4;
+	vis->depth = tz;
 	vis->idepth = (DWORD)DivScale32 (1, tz) >> 1;	// tz is 20.12, so idepth ought to be 12.20, but
 	vis->cx = tx2;									// signed math makes it 13.19
 	vis->gx = fx;
@@ -2115,20 +2116,19 @@ void R_DrawSprite (vissprite_t *spr)
 		r1 = MAX<int> (ds->x1, spr->x1);
 		r2 = MIN<int> (ds->x2, spr->x2);
 
-		fixed_t nearidepth, faridepth;
-		if (ds->siz1 > ds->siz2)
+		fixed_t neardepth, fardepth;
+		if (ds->sz1 < ds->sz2)
 		{
-			nearidepth = ds->siz1, faridepth = ds->siz2;
+			neardepth = ds->sz1, fardepth = ds->sz2;
 		}
 		else
 		{
-			nearidepth = ds->siz2, faridepth = ds->siz1;
+			neardepth = ds->sz2, fardepth = ds->sz1;
 		}
-		// (siz2 - siz1)*(rx - sx1)/(sx2 - sx1)
-		// Lower values are further away
-		if (nearidepth < spr->idepth || (faridepth < spr->idepth &&
+		if (neardepth > spr->depth || (fardepth > spr->depth &&
 			// Check if sprite is in front of draw seg:
-			Scale (ds->siz2 - ds->siz1, (r1+r2)/2 - ds->sx1, ds->sx2 - ds->sx1) + ds->siz1 < spr->idepth))
+			DMulScale24 (spr->depth - ds->cy, ds->cdx, ds->cdy, ds->cx - spr->cx) < 0))
+
 		{
 			// seg is behind sprite, so draw the mid texture if it has one
 			if (ds->maskedtexturecol != -1 || ds->bFogBoundary)
@@ -2430,6 +2430,7 @@ void R_ProjectParticle (particle_t *particle, const sector_t *sector, int shade,
 	vis->xscale = xscale;
 //	vis->yscale = FixedMul (xscale, InvZtoScale);
 	vis->yscale = xscale;
+	vis->depth = tz;
 	vis->idepth = (DWORD)DivScale32 (1, tz) >> 1;
 	vis->cx = tx;
 	vis->gx = particle->x;