diff --git a/source/src/protos.h b/source/src/protos.h
index 18611c24..1c02c271 100644
--- a/source/src/protos.h
+++ b/source/src/protos.h
@@ -299,7 +299,7 @@ extern void setuptmu(int n, const char *rgbfunc = NULL, const char *alphafunc =
 extern void mipstats(int a, int b, int c);
 extern void render_flat(int tex, int x, int y, int size, int h, sqr *l1, sqr *l2, sqr *l3, sqr *l4, bool isceil);
 extern void render_flatdelta(int wtex, int x, int y, int size, float h1, float h2, float h3, float h4, sqr *l1, sqr *l2, sqr *l3, sqr *l4, bool isceil);
-extern void render_square(int wtex, float floor1, float floor2, float ceil1, float ceil2, int x1, int y1, int x2, int y2, int size, sqr *l1, sqr *l2, bool topleft);
+extern void render_square(int wtex, float floor1, float floor2, float ceil1, float ceil2, int x1, int y1, int x2, int y2, int size, sqr *l1, sqr *l2, bool topleft, int dir);
 extern void render_tris(int x, int y, int size, bool topleft, sqr *h1, sqr *h2, sqr *s, sqr *t, sqr *u, sqr *v);
 extern void resetcubes();
 extern void setupstrips();
diff --git a/source/src/rendercubes.cpp b/source/src/rendercubes.cpp
index 7845e473..b0efe9c0 100644
--- a/source/src/rendercubes.cpp
+++ b/source/src/rendercubes.cpp
@@ -113,11 +113,19 @@ void addstrip(int type, int tex, int start, int n)
     v.r = ls->r; v.g = ls->g; v.b = ls->b; v.a = 255; \
 }
 
+enum
+{
+    STRIP_FLOOR = 1,
+    STRIP_DELTA,
+    STRIP_WALL
+};
+
 int nquads;
 const float TEXTURESCALE = 32.0f;
-bool floorstrip = false, deltastrip = false;
-int oh, oy, ox, striptex;                         // the o* vars are used by the stripification
-int ol3r, ol3g, ol3b, ol4r, ol4g, ol4b;      
+int striptype = 0, striptex, oh, oy, ox, odir;                         // the o* vars are used by the stripification
+int ol1r, ol1g, ol1b, ol2r, ol2g, ol2b;      
+float ofloor, oceil;
+bool ohf;
 int firstindex;
 bool showm = false;
 
@@ -129,14 +137,14 @@ COMMAND(showmip, ARG_NONE);
 VAR(mergestrips, 0, 1, 1);
 
 #define stripend(verts) \
-    if(floorstrip || deltastrip) { \
+    if(striptype) { \
         int type = GL_TRIANGLE_STRIP, len = verts.length()-firstindex; \
         if(mergestrips) switch(len) { \
             case 3: type = GL_TRIANGLES; break; \
             case 4: type = GL_QUADS; swap(verts.last(), verts[verts.length()-2]); break; \
          } \
          addstrip(type, striptex, firstindex, len); \
-         floorstrip = deltastrip = false; \
+         striptype = 0; \
     }
 
 void finishstrips() { stripend(verts); }
@@ -156,7 +164,7 @@ void render_flat(int wtex, int x, int y, int size, int h, sqr *l1, sqr *l4, sqr
     float xo = xf*x;
     float yo = yf*y;
 
-    bool first = !floorstrip || x!=ox+size || striptex!=wtex || h!=oh || y!=oy;
+    bool first = striptype!=STRIP_FLOOR || x!=ox+size || striptex!=wtex || h!=oh || y!=oy;
 
     if(first)       // start strip here
     {
@@ -165,7 +173,7 @@ void render_flat(int wtex, int x, int y, int size, int h, sqr *l1, sqr *l4, sqr
         striptex = wtex;
         oh = h;
         oy = y;
-        floorstrip = true;
+        striptype = STRIP_FLOOR;
         if(isceil)
         {
             vert(x, y,      h, l1, xo, yo);
@@ -176,33 +184,33 @@ void render_flat(int wtex, int x, int y, int size, int h, sqr *l1, sqr *l4, sqr
             vert(x, y+size, h, l2, xo, yo+ys);
             vert(x, y,      h, l1, xo, yo);
         }
-        ol3r = l1->r;
-        ol3g = l1->g;
-        ol3b = l1->b;
-        ol4r = l2->r;
-        ol4g = l2->g;
-        ol4b = l2->b;
+        ol1r = l1->r;
+        ol1g = l1->g;
+        ol1b = l1->b;
+        ol2r = l2->r;
+        ol2g = l2->g;
+        ol2b = l2->b;
     }
     else        // continue strip
     {
         int lighterr = lighterror*2;
-        if((abs(ol3r-l3->r)<lighterr && abs(ol4r-l4->r)<lighterr        // skip vertices if light values are close enough
-        &&  abs(ol3g-l3->g)<lighterr && abs(ol4g-l4->g)<lighterr
-        &&  abs(ol3b-l3->b)<lighterr && abs(ol4b-l4->b)<lighterr) || !wtex)   
+        if((abs(ol1r-l3->r)<lighterr && abs(ol2r-l4->r)<lighterr        // skip vertices if light values are close enough
+        &&  abs(ol1g-l3->g)<lighterr && abs(ol2g-l4->g)<lighterr
+        &&  abs(ol1b-l3->b)<lighterr && abs(ol2b-l4->b)<lighterr) || !wtex)   
         {
             verts.setsizenodelete(verts.length()-2);
             nquads--;
         }
         else
         {
-            uchar *p3 = (uchar *)(&verts[verts.length()-1].r);
-            ol3r = p3[0];  
-            ol3g = p3[1];  
-            ol3b = p3[2];
-            uchar *p4 = (uchar *)(&verts[verts.length()-2].r);  
-            ol4r = p4[0];
-            ol4g = p4[1];
-            ol4b = p4[2];
+            uchar *p1 = (uchar *)(&verts[verts.length()-1].r);
+            ol1r = p1[0];  
+            ol1g = p1[1];  
+            ol1b = p1[2];
+            uchar *p2 = (uchar *)(&verts[verts.length()-2].r);  
+            ol2r = p2[0];
+            ol2g = p2[1];
+            ol2b = p2[2];
         }
     }
 
@@ -233,7 +241,7 @@ void render_flatdelta(int wtex, int x, int y, int size, float h1, float h4, floa
     float xo = xf*x;
     float yo = yf*y;
 
-    bool first = !deltastrip || x!=ox+size || striptex!=wtex || y!=oy; 
+    bool first = striptype!=STRIP_DELTA || x!=ox+size || striptex!=wtex || y!=oy; 
 
     if(first) 
     {
@@ -241,7 +249,7 @@ void render_flatdelta(int wtex, int x, int y, int size, float h1, float h4, floa
         firstindex = verts.length();
         striptex = wtex;
         oy = y;
-        deltastrip = true;
+        striptype = STRIP_DELTA;
         if(isceil)
         {
             vert(x, y,      h1, l1, xo, yo);
@@ -252,12 +260,6 @@ void render_flatdelta(int wtex, int x, int y, int size, float h1, float h4, floa
             vert(x, y+size, h2, l2, xo, yo+ys);
             vert(x, y,      h1, l1, xo, yo);
         }
-        ol3r = l1->r;
-        ol3g = l1->g;
-        ol3b = l1->b;
-        ol4r = l2->r;
-        ol4g = l2->g;
-        ol4b = l2->b;
     }
 
     if(isceil)
@@ -313,34 +315,77 @@ void render_tris(int x, int y, int size, bool topleft,
     }
 }
 
-void render_square(int wtex, float floor1, float floor2, float ceil1, float ceil2, int x1, int y1, int x2, int y2, int size, sqr *l1, sqr *l2, bool flip)   // wall quads
+void render_square(int wtex, float floor1, float floor2, float ceil1, float ceil2, int x1, int y1, int x2, int y2, int size, sqr *l1, sqr *l2, bool flip, int dir)   // wall quads
 {
-    stripend(verts);
     if(showm) { l1 = &sbright; l2 = &sdark; }
 
     Texture *t = lookupworldtexture(wtex);
     float xf = TEXTURESCALE/t->xs;
-    float yf = TEXTURESCALE/t->ys;
+    float yf = -TEXTURESCALE/t->ys;
     float xs = size*xf;
     float xo = xf*(x1==x2 ? min(y1,y2) : min(x1,x2));
 
+    bool first = striptype!=STRIP_WALL || striptex!=wtex || ox!=x1 || oy!=y1 || ofloor!=floor1 || oceil!=ceil1 || odir!=dir,
+         hf = floor1!=floor2 || ceil1!=ceil2; 
+
+    if(first)
+    {
+        stripend(verts);
+        firstindex = verts.length();
+        striptex = wtex;
+        striptype = STRIP_WALL;
+
+        if(!flip)
+        {
+            vert(x1, y1, ceil1,  l1, xo, yf*ceil1);
+            vert(x1, y1, floor1, l1, xo, yf*floor1);
+        }
+        else
+        {
+            vert(x1, y1, floor1, l1, xo, yf*floor1);
+            vert(x1, y1, ceil1,  l1, xo, yf*ceil1);
+        }
+        ol1r = l1->r;
+        ol1g = l1->g;
+        ol1b = l1->b;
+    }
+    else        // continue strip
+    {
+        int lighterr = lighterror*2;
+        if((!hf && !ohf
+        && abs(ol1r-l2->r)<lighterr        // skip vertices if light values are close enough
+        &&  abs(ol1g-l2->g)<lighterr
+        &&  abs(ol1b-l2->b)<lighterr) || !wtex)
+        {
+            verts.setsizenodelete(verts.length()-2);
+            nquads--;
+        }
+        else
+        {
+            uchar *p1 = (uchar *)(&verts[verts.length()-1].r);
+            ol1r = p1[0];
+            ol1g = p1[1];
+            ol1b = p1[2];
+        }
+    }
+
     if(!flip)
     {
-        vert(x2, y2, ceil2, l2, xo+xs, -yf*ceil2);
-        vert(x1, y1, ceil1, l1, xo,    -yf*ceil1);
-        if(mergestrips) vert(x1, y1, floor1, l1, xo, -floor1*yf);
-        vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
-        if(!mergestrips) vert(x1, y1, floor1, l1, xo, -floor1*yf);
+        vert(x2, y2, ceil2,  l2, xo+xs, yf*ceil2);
+        vert(x2, y2, floor2, l2, xo+xs, yf*floor2);
     }
     else
     {
-        vert(x1, y1, ceil1, l1, xo,    -yf*ceil1);
-        vert(x2, y2, ceil2, l2, xo+xs, -yf*ceil2);
-        if(mergestrips) vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
-        vert(x1, y1, floor1, l1, xo,    -floor1*yf);
-        if(!mergestrips) vert(x2, y2, floor2, l2, xo+xs, -floor2*yf);
+        vert(x2, y2, floor2, l2, xo+xs, yf*floor2);
+        vert(x2, y2, ceil2,  l2, xo+xs, yf*ceil2);
     }
-    addstrip(mergestrips ? GL_QUADS : GL_TRIANGLE_STRIP, wtex, verts.length()-4, 4);
+
+    ox = x2;
+    oy = y2;
+    ofloor = floor2;
+    oceil = ceil2;
+    odir = dir;
+    ohf = hf;
     nquads++;
 }
 
@@ -348,7 +393,7 @@ void resetcubes()
 {
     verts.setsizenodelete(0);
 
-    floorstrip = deltastrip = false;
+    striptype = 0;
     nquads = 0;
 
     sbright.r = sbright.g = sbright.b = 255;
@@ -364,7 +409,7 @@ static void resetshadowverts()
 {
     shadowverts.setsizenodelete(0);
 
-    floorstrip = deltastrip = false;
+    striptype = 0;
 }
 
 static void rendershadowstrips()
@@ -422,7 +467,7 @@ void rendershadow_tris(int x, int y, bool topleft, sqr *h1, sqr *h2)
 
 static void rendershadow_flat(int x, int y, int h) // floor quads
 {
-    bool first = !floorstrip || x!=ox+1 || h!=oh || y!=oy;
+    bool first = striptype!=STRIP_FLOOR || x!=ox+1 || h!=oh || y!=oy;
 
     if(first)       // start strip here
     {
@@ -431,7 +476,7 @@ static void rendershadow_flat(int x, int y, int h) // floor quads
         striptex = DEFAULT_FLOOR;
         oh = h;
         oy = y;
-        floorstrip = true;
+        striptype = STRIP_FLOOR;
         shadowvert(x, y+1, h);
         shadowvert(x, y,   h);
     }
@@ -448,7 +493,7 @@ static void rendershadow_flat(int x, int y, int h) // floor quads
 
 static void rendershadow_flatdelta(int x, int y, float h1, float h4, float h3, float h2)  // floor quads on a slope
 {
-    bool first = !deltastrip || x!=ox+1 || y!=oy;
+    bool first = striptype!=STRIP_DELTA || x!=ox+1 || y!=oy;
 
     if(first)
     {
@@ -456,7 +501,7 @@ static void rendershadow_flatdelta(int x, int y, float h1, float h4, float h3, f
         firstindex = shadowverts.length();
         striptex = DEFAULT_FLOOR;
         oy = y;
-        deltastrip = true;
+        striptype = STRIP_DELTA;
         shadowvert(x, y+1, h2);
         shadowvert(x, y,   h1);
     }
diff --git a/source/src/worldrender.cpp b/source/src/worldrender.cpp
index 768c939e..156fcb56 100644
--- a/source/src/worldrender.cpp
+++ b/source/src/worldrender.cpp
@@ -4,7 +4,7 @@
 #include "pch.h"
 #include "cube.h"
 
-void render_wall(sqr *o, sqr *s, int x1, int y1, int x2, int y2, int mip, sqr *d1, sqr *d2, bool topleft)
+void render_wall(sqr *o, sqr *s, int x1, int y1, int x2, int y2, int mip, sqr *d1, sqr *d2, bool topleft, int dir)
 {
     if(minimap) return;
     if(SOLID(o) || o->type==SEMISOLID)
@@ -16,7 +16,7 @@ void render_wall(sqr *o, sqr *s, int x1, int y1, int x2, int y2, int mip, sqr *d
         float f2 = s->ceil;
         if(s->type==CHF) { f1 += d1->vdelta/4.0f; f2 += d2->vdelta/4.0f; }
         //if(f1-c1<=0 && f2-c2<=0) return;
-        render_square(o->wtex, c1, c2, f1, f2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft);
+        render_square(o->wtex, c1, c2, f1, f2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft, dir);
         return;
     }
     {
@@ -35,7 +35,7 @@ void render_wall(sqr *o, sqr *s, int x1, int y1, int x2, int y2, int mip, sqr *d
             f2 -= d2->vdelta/4.0f;
         }
         if(f1>=c1 && f2>=c2) goto skip;
-        render_square(o->wtex, f1, f2, c1, c2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft);
+        render_square(o->wtex, f1, f2, c1, c2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft, dir);
     }
     skip:
     {
@@ -54,7 +54,7 @@ void render_wall(sqr *o, sqr *s, int x1, int y1, int x2, int y2, int mip, sqr *d
             c2 += d2->vdelta/4.0f;
         }
         if(c1<=f1 && c2<=f2) return;
-        render_square(o->utex, f1, f2, c1, c2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft);
+        render_square(o->utex, f1, f2, c1, c2, x1<<mip, y1<<mip, x2<<mip, y2<<mip, 1<<mip, d1, d2, topleft, dir);
     }
 }
 
@@ -142,7 +142,7 @@ void render_seg_new(float vx, float vy, float vh, int mip, int x, int y, int xs,
 
     #define LOOPH {for(int yy = y; yy<ys; yy++) for(int xx = x; xx<xs; xx++) { \
                   sqr *s = SWS(w,xx,yy,mfactor); if(s->occluded) continue; \
-                  if(s->defer && !s->occluded && mip && xx>=lx && xx<rx && yy>=ly && yy<ry)
+                  if(s->defer && mip && xx>=lx && xx<rx && yy>=ly && yy<ry)
     #define LOOPD sqr *t = SWS(s,1,0,mfactor); \
                   sqr *u = SWS(s,1,1,mfactor); \
                   sqr *v = SWS(s,0,1,mfactor);
@@ -195,13 +195,13 @@ void render_seg_new(float vx, float vy, float vh, int mip, int x, int y, int xs,
             sqr *h2 = NULL;
             if(SOLID(z))
             {
-                if(SOLID(w))      { render_wall(w, h2 = s, xx+1, yy, xx, yy+1, mip, t, v, false); topleft = false; }
-                else if(SOLID(v)) { render_wall(v, h2 = s, xx, yy, xx+1, yy+1, mip, s, u, false); }
+                if(SOLID(w))      { render_wall(w, h2 = s, xx+1, yy, xx, yy+1, mip, t, v, false, 4); topleft = false; }
+                else if(SOLID(v)) { render_wall(v, h2 = s, xx, yy, xx+1, yy+1, mip, s, u, false, 5); }
             }
             else if(SOLID(t))
             {
-                if(SOLID(w))      { render_wall(w, h1 = s, xx+1, yy+1, xx, yy, mip, u, s, false); }
-                else if(SOLID(v)) { render_wall(v, h1 = s, xx, yy+1, xx+1, yy, mip, v, t, false); topleft = false; }
+                if(SOLID(w))      { render_wall(w, h1 = s, xx+1, yy+1, xx, yy, mip, u, s, false, 6); }
+                else if(SOLID(v)) { render_wall(v, h1 = s, xx, yy+1, xx+1, yy, mip, v, t, false, 7); topleft = false; }
             }
             else
             {
@@ -209,13 +209,13 @@ void render_seg_new(float vx, float vy, float vh, int mip, int x, int y, int xs,
                 bool wv = w->ceil-w->floor < v->ceil-v->floor;
                 if(z->ceil-z->floor < t->ceil-t->floor)
                 {
-                    if(wv) { render_wall(h1 = s, h2 = v, xx+1, yy, xx, yy+1, mip, t, v, false); topleft = false; }
-                    else   { render_wall(h1 = s, h2 = w, xx, yy, xx+1, yy+1, mip, s, u, false); }
+                    if(wv) { render_wall(h1 = s, h2 = v, xx+1, yy, xx, yy+1, mip, t, v, false, 4); topleft = false; }
+                    else   { render_wall(h1 = s, h2 = w, xx, yy, xx+1, yy+1, mip, s, u, false, 5); }
                 }
                 else
                 {
-                    if(wv) { render_wall(h2 = s, h1 = v, xx+1, yy+1, xx, yy, mip, u, s, false); }
-                    else   { render_wall(h2 = s, h1 = w, xx, yy+1, xx+1, yy, mip, v, t, false); topleft = false; }
+                    if(wv) { render_wall(h2 = s, h1 = v, xx+1, yy+1, xx, yy, mip, u, s, false, 6); }
+                    else   { render_wall(h2 = s, h1 = w, xx, yy+1, xx+1, yy, mip, v, t, false, 7); topleft = false; }
                 }
             }
             render_tris(xx<<mip, yy<<mip, 1<<mip, topleft, h1, h2, s, t, u, v);
@@ -227,19 +227,18 @@ void render_seg_new(float vx, float vy, float vh, int mip, int x, int y, int xs,
 
             if(xx>=vxx && xx!=0 && yy!=sz-1 && !SOLID(z) && (!SOLID(s) || z->type!=CORNER)
                 && (z->type!=SEMISOLID || issemi(mip, xx-1, yy, 1, 0, 1, 1)))
-                render_wall(s, z, xx,   yy,   xx,   yy+1, mip, s, v, true);
+                render_wall(s, z, xx,   yy,   xx,   yy+1, mip, s, v, true, 0);
             if(xx<=vxx && inner && !SOLID(t) && (!SOLID(s) || t->type!=CORNER)
                 && (t->type!=SEMISOLID || issemi(mip, xx+1, yy, 0, 0, 0, 1)))
-                render_wall(s, t, xx+1, yy,   xx+1, yy+1, mip, t, u, false);
+                render_wall(s, t, xx+1, yy,   xx+1, yy+1, mip, t, u, false, 1);
             if(yy>=vyy && yy!=0 && xx!=sz-1 && !SOLID(w) && (!SOLID(s) || w->type!=CORNER)
                 && (w->type!=SEMISOLID || issemi(mip, xx, yy-1, 0, 1, 1, 1)))
-                render_wall(s, w, xx,   yy,   xx+1, yy,   mip, s, t, false);
+                render_wall(s, w, xx,   yy,   xx+1, yy,   mip, s, t, false, 2);
             if(yy<=vyy && inner && !SOLID(v) && (!SOLID(s) || v->type!=CORNER)
                 && (v->type!=SEMISOLID || issemi(mip, xx, yy+1, 0, 0, 1, 0)))
-                render_wall(s, v, xx,   yy+1, xx+1, yy+1, mip, v, u, true);
+                render_wall(s, v, xx,   yy+1, xx+1, yy+1, mip, v, u, true, 3);
         }
     }}
-
 }
 
 void distlod(int &low, int &high, int angle, float widef)