Patch from Nuke.YKT to fix a TROR in Polymost issue

Report by oasiz: It only occurs when you try to sandwich surfaces and kind of punch through. It seems similar to the kind of behavior that the pre-TROR fixes did (where you had to stand on the TROR sector for things to work). This seems to work if the weird wall is punching IN on your sector but not OUT to another.

git-svn-id: https://svn.eduke32.com/eduke32@7492 1a8010ca-5511-0410-912e-c29ae57300e0

source/build/src/polymost.cpp

@@ -3376,8 +3376,8 @@ skip: ;
             }
             else
             {
-                if ((yax_vsp[yaxbunch][i].tag == 1) || (n0.y >= yax_vsp[yaxbunch][i].cy[0]-DOMOST_OFFSET)) k++;
+                if ((yax_vsp[yaxbunch][i].tag == 0) || (n0.y >= yax_vsp[yaxbunch][i].cy[0]-DOMOST_OFFSET)) k++;
-                if ((yax_vsp[yaxbunch][ni].tag == 1) || (n1.y >= yax_vsp[yaxbunch][i].cy[1]-DOMOST_OFFSET)) k += 3;
+                if ((yax_vsp[yaxbunch][ni].tag == 0) || (n1.y >= yax_vsp[yaxbunch][i].cy[1]-DOMOST_OFFSET)) k += 3;
                 switch (k)
                 {
                 case 4:
@@ -3428,6 +3428,163 @@ skip: ;
     while (i);
 #endif
 }
+
+static int32_t should_clip_cfwall(float x0, float y0, float x1, float y1)
+{
+    int const dir = (x0 < x1);
+
+    if (dir && yax_globallev >= YAX_MAXDRAWS)
+        return 1;
+
+    if (!dir && yax_globallev <= YAX_MAXDRAWS)
+        return 1;
+
+    if (dir) //clip dmost (floor)
+    {
+        y0 -= DOMOST_OFFSET;
+        y1 -= DOMOST_OFFSET;
+    }
+    else //clip umost (ceiling)
+    {
+        if (x0 == x1) return 1;
+        swapfloat(&x0, &x1);
+        swapfloat(&y0, &y1);
+        y0 += DOMOST_OFFSET;
+        y1 += DOMOST_OFFSET; //necessary?
+    }
+
+    x0 -= DOMOST_OFFSET;
+    x1 += DOMOST_OFFSET;
+
+    // Test if span is outside screen bounds
+    if (x1 < xbl || x0 > xbr)
+        return 1;
+
+    vec2f_t dm0 = { x0, y0 };
+    vec2f_t dm1 = { x1, y1 };
+
+    float const slop = (dm1.y - dm0.y) / (dm1.x - dm0.x);
+
+    if (dm0.x < xbl)
+    {
+        dm0.y += slop*(xbl-dm0.x);
+        dm0.x = xbl;
+    }
+
+    if (dm1.x > xbr)
+    {
+        dm1.y += slop*(xbr-dm1.x);
+        dm1.x = xbr;
+    }
+
+    vec2f_t n0, n1;
+    float spx[6], spcy[6], spfy[6];
+    int32_t spt[6];
+
+    for (bssize_t newi, i=vsp[0].n; i; i=newi)
+    {
+        newi = vsp[i].n; n0.x = vsp[i].x; n1.x = vsp[newi].x;
+
+        if ((dm0.x >= n1.x) || (n0.x >= dm1.x) || (vsp[i].ctag <= 0)) continue;
+
+        float const dx = n1.x-n0.x;
+        float const cy[2] = { vsp[i].cy[0], vsp[i].fy[0] },
+                    cv[2] = { vsp[i].cy[1]-cy[0], vsp[i].fy[1]-cy[1] };
+
+        int scnt = 0;
+
+        spx[scnt] = n0.x; spt[scnt] = -1; scnt++;
+
+        //Test if left edge requires split (dm0.x,dm0.y) (nx0,cy(0)),<dx,cv(0)>
+        if ((dm0.x > n0.x) && (dm0.x < n1.x))
+        {
+            float const t = (dm0.x-n0.x)*cv[dir] - (dm0.y-cy[dir])*dx;
+            if (((!dir) && (t < 0.f)) || ((dir) && (t > 0.f)))
+                { spx[scnt] = dm0.x; spt[scnt] = -1; scnt++; }
+        }
+
+        //Test for intersection on umost (0) and dmost (1)
+
+        float const d[2] = { ((dm0.y - dm1.y) * dx) - ((dm0.x - dm1.x) * cv[0]),
+                             ((dm0.y - dm1.y) * dx) - ((dm0.x - dm1.x) * cv[1]) };
+
+        float const n[2] = { ((dm0.y - cy[0]) * dx) - ((dm0.x - n0.x) * cv[0]),
+                             ((dm0.y - cy[1]) * dx) - ((dm0.x - n0.x) * cv[1]) };
+
+        float const fnx[2] = { dm0.x + ((n[0] / d[0]) * (dm1.x - dm0.x)),
+                               dm0.x + ((n[1] / d[1]) * (dm1.x - dm0.x)) };
+
+        if ((Bfabsf(d[0]) > Bfabsf(n[0])) && (d[0] * n[0] >= 0.f) && (fnx[0] > n0.x) && (fnx[0] < n1.x))
+            spx[scnt] = fnx[0], spt[scnt++] = 0;
+
+        if ((Bfabsf(d[1]) > Bfabsf(n[1])) && (d[1] * n[1] >= 0.f) && (fnx[1] > n0.x) && (fnx[1] < n1.x))
+            spx[scnt] = fnx[1], spt[scnt++] = 1;
+
+        //Nice hack to avoid full sort later :)
+        if ((scnt >= 2) && (spx[scnt-1] < spx[scnt-2]))
+        {
+            swapfloat(&spx[scnt-1], &spx[scnt-2]);
+            swaplong(&spx[scnt-1], &spx[scnt-2]);
+        }
+
+        //Test if right edge requires split
+        if ((dm1.x > n0.x) && (dm1.x < n1.x))
+        {
+            float const t = (dm1.x-n0.x)*cv[dir] - (dm1.y-cy[dir])*dx;
+            if (((!dir) && (t < 0.f)) || ((dir) && (t > 0.f)))
+                { spx[scnt] = dm1.x; spt[scnt] = -1; scnt++; }
+        }
+
+        spx[scnt] = n1.x; spt[scnt] = -1; scnt++;
+
+        float const rdx = 1.f/dx;
+        for (bssize_t z=0; z<scnt; z++)
+        {
+            float const t = (spx[z]-n0.x)*rdx;
+            spcy[z] = t*cv[0]+cy[0];
+            spfy[z] = t*cv[1]+cy[1];
+        }
+
+        for (bssize_t z=0; z<scnt-1; z++)
+        {
+            float const dx0 = spx[z];
+            float const dx1 = spx[z+1];
+            n0.y = (dx0-dm0.x)*slop + dm0.y;
+            n1.y = (dx1-dm0.x)*slop + dm0.y;
+
+            //      dx0           dx1
+            //       ~             ~
+            //----------------------------
+            //     t0+=0         t1+=0
+            //   vsp[i].cy[0]  vsp[i].cy[1]
+            //============================
+            //     t0+=1         t1+=3
+            //============================
+            //   vsp[i].fy[0]    vsp[i].fy[1]
+            //     t0+=2         t1+=6
+            //
+            //     ny0 ?         ny1 ?
+
+            int k = 4;
+            if (dir)
+            {
+                if ((spt[z] == 0) || (n0.y <= spcy[z]+DOMOST_OFFSET)) k--;
+                if ((spt[z+1] == 0) || (n1.y <= spcy[z+1]+DOMOST_OFFSET)) k -= 3;
+                if (k != 0)
+                    return 1;
+            }
+            else
+            {
+                if ((spt[z] == 1) || (n0.y >= spfy[z]-DOMOST_OFFSET)) k++;
+                if ((spt[z+1] == 1) || (n1.y >= spfy[z+1]-DOMOST_OFFSET)) k += 3;
+                if (k != 8)
+                    return 1;
+            }
+        }
+    }
+    return 0;
+}
+
 #endif
 
 #define POINT2(i) (wall[wall[i].point2])
@@ -4746,7 +4903,11 @@ static void polymost_drawalls(int32_t const bunch)
                 //if ((usehightile && hicfindsubst(globalpicnum, globalpal, hictinting[globalpal].f & HICTINT_ALWAYSUSEART)))
                     calc_and_apply_fog(fogshade(wal->shade, wal->pal), sec->visibility, get_floor_fogpal(sec));
 
-                pow2xsplit = 1; polymost_domost(x1,ocy1,x0,ocy0,cy1,ocy1,cy0,ocy0);
+                pow2xsplit = 1;
+#ifdef YAX_ENABLE
+                if (should_clip_cfwall(x1,cy1,x0,cy0))
+#endif
+                polymost_domost(x1,ocy1,x0,ocy0,cy1,ocy1,cy0,ocy0);
                 if (wal->cstat&8) { xtex.u = ogux; ytex.u = oguy; otex.u = oguo; }
             }
             if (((ofy0 < fy0) || (ofy1 < fy1)) && (!((sec->floorstat&sector[nextsectnum].floorstat)&1)))
@@ -4787,7 +4948,11 @@ static void polymost_drawalls(int32_t const bunch)
                 //if ((usehightile && hicfindsubst(globalpicnum, globalpal, hictinting[globalpal].f & HICTINT_ALWAYSUSEART)))
                     calc_and_apply_fog(fogshade(nwal->shade, nwal->pal), sec->visibility, get_floor_fogpal(sec));
 
-                pow2xsplit = 1; polymost_domost(x0,ofy0,x1,ofy1,ofy0,fy0,ofy1,fy1);
+                pow2xsplit = 1;
+#ifdef YAX_ENABLE
+                if (should_clip_cfwall(x0,fy0,x1,fy1))
+#endif
+                polymost_domost(x0,ofy0,x1,ofy1,ofy0,fy0,ofy1,fy1);
                 if (wal->cstat&(2+8)) { otex.u = oguo; xtex.u = ogux; ytex.u = oguy; }
             }
         }
@@ -5233,14 +5398,14 @@ void polymost_drawrooms()
             newi = yax_vsp[yax_globalbunch*2][i].n;
             if (!newi)
                 break;
-            polymost_domost(yax_vsp[yax_globalbunch*2][newi].x, yax_vsp[yax_globalbunch*2][i].cy[1], yax_vsp[yax_globalbunch*2][i].x, yax_vsp[yax_globalbunch*2][i].cy[0]);
+            polymost_domost(yax_vsp[yax_globalbunch*2][newi].x, yax_vsp[yax_globalbunch*2][i].cy[1]-DOMOST_OFFSET, yax_vsp[yax_globalbunch*2][i].x, yax_vsp[yax_globalbunch*2][i].cy[0]-DOMOST_OFFSET);
         }
         for (i = yax_vsp[yax_globalbunch*2+1][0].n; i; i=newi)
         {
             newi = yax_vsp[yax_globalbunch*2+1][i].n;
             if (!newi)
                 break;
-            polymost_domost(yax_vsp[yax_globalbunch*2+1][i].x, yax_vsp[yax_globalbunch*2+1][i].cy[0], yax_vsp[yax_globalbunch*2+1][newi].x, yax_vsp[yax_globalbunch*2+1][i].cy[1]);
+            polymost_domost(yax_vsp[yax_globalbunch*2+1][i].x, yax_vsp[yax_globalbunch*2+1][i].cy[0]+DOMOST_OFFSET, yax_vsp[yax_globalbunch*2+1][newi].x, yax_vsp[yax_globalbunch*2+1][i].cy[1]+DOMOST_OFFSET);
         }
         g_nodraw = nodrawbak;
     }