From c17db807349d400fb9bc6cac5bd28b15bb4b9329 Mon Sep 17 00:00:00 2001
From: terminx <terminx@1a8010ca-5511-0410-912e-c29ae57300e0>
Date: Sun, 8 Sep 2019 01:00:57 +0000
Subject: [PATCH] Fix npot sky rendering in Polymost

Patch from Nuke.YKT.

git-svn-id: https://svn.eduke32.com/eduke32@8076 1a8010ca-5511-0410-912e-c29ae57300e0

# Conflicts:
#	source/build/src/polymost.cpp
---
 source/build/src/polymost.cpp | 56 +++++++++++++++++++++--------------
 1 file changed, 34 insertions(+), 22 deletions(-)

diff --git a/source/build/src/polymost.cpp b/source/build/src/polymost.cpp
index ee48d97b1..2718531af 100644
--- a/source/build/src/polymost.cpp
+++ b/source/build/src/polymost.cpp
@@ -3982,8 +3982,6 @@ static void polymost_flatskyrender(vec2f_t const* const dpxy, int32_t const n, i
     flatskyrender = 0;
     vec2f_t xys[8];
 
-    polymost_setClamp(2);
-
     // Transform polygon to sky coordinates
     for (int i = 0; i < n; i++)
     {
@@ -4028,6 +4026,11 @@ static void polymost_flatskyrender(vec2f_t const* const dpxy, int32_t const n, i
         if (xys[i].x > x1) x1 = xys[i].x;
     }
 
+    int const npot = (1<<(picsiz[globalpicnum]&15)) != tilesiz[globalpicnum].x;
+    int const xpanning = (r_parallaxskypanning?global_cf_xpanning:0);
+
+    polymost_setClamp((npot || xpanning != 0) ? 0 : 2);
+
     int picnumbak = globalpicnum;
     ti = globalpicnum;
     o.y = fviewingrange/(ghalfx*256.f); o.z = 1.f/o.y;
@@ -4038,7 +4041,14 @@ static void polymost_flatskyrender(vec2f_t const* const dpxy, int32_t const n, i
     do
     {
         globalpicnum = dapskyoff[y&((1<<dapskybits)-1)]+ti;
-        otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + (float)((r_parallaxskypanning)?global_cf_xpanning:0)) - xtex.u*ghalfx;
+        if (npot)
+        {
+            fx = ((float)((y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
+            int tang = (y<<(11-dapskybits))&2047;
+            otex.u = otex.d*(t*((float)(tang)) * (1.f/2048.f) + xpanning) - xtex.u*fx;
+        }
+        else
+            otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + xpanning) - xtex.u*ghalfx;
         y++;
         o.x = fx; fx = ((float)((y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
 
@@ -4321,6 +4331,7 @@ static void polymost_drawalls(int32_t const bunch)
                     skyclamphack = 0;
                     flatskyrender = 1;
                     globalshade += globvis2*xdimscale*fviewingrange*(1.f / (64.f * 65536.f * 256.f * 1024.f));
+                    polymost_setVisibility(0.f);
                     polymost_domost(x0,fy0,x1,fy1);
                     flatskyrender = 0;
                 }
@@ -4388,7 +4399,8 @@ static void polymost_drawalls(int32_t const bunch)
                     ytex.v = vv[1];
                     otex.v = r_parallaxskypanning ? vv[0] + dd*(float)sec->floorypanning*(float)i*(1.f/256.f) : vv[0];
 
-					int const npot = (1 << (picsiz[globalpicnum] & 15)) != tilesiz[globalpicnum].x;
+                    int const npot = (1<<(picsiz[globalpicnum]&15)) != tilesiz[globalpicnum].x;
+                    int const xpanning = (r_parallaxskypanning?sec->floorxpanning:0);
 
                     i = globalpicnum;
                     float const r = (fy1-fy0)/(x1-x0); //slope of line
@@ -4399,15 +4411,14 @@ static void polymost_drawalls(int32_t const bunch)
                     do
                     {
                         globalpicnum = dapskyoff[y&((1<<dapskybits)-1)]+i;
-						if (!npot)
-	   
-	                        otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + (float)((r_parallaxskypanning)?sec->floorxpanning:0)) - xtex.u*ghalfx;
-						else
-						{
-		                    int32_t picbits = picsiz[globalpicnum]&15;
-	    	                int32_t np2 = tilesiz[globalpicnum].x != (1<<picbits);
-	        	            otex.u = otex.d*(t*((float)(fglobalang-(np2 ? 0 : (y<<(11-dapskybits))))) * (1.f/2048.f) + (float)((r_parallaxskypanning)?sec->floorxpanning:0)) - xtex.u*ghalfx;
-						}
+                        if (npot)
+                        {
+                            fx = ((float)((y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
+                            int tang = (y<<(11-dapskybits))&2047;
+                            otex.u = otex.d*(t*((float)(tang)) * (1.f/2048.f) + xpanning) - xtex.u*fx;
+                        }
+                        else
+                            otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + xpanning) - xtex.u*ghalfx;
                         y++;
                         o.x = fx; fx = ((float)((y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
                         if (fx > x1) { fx = x1; i = -1; }
@@ -4746,7 +4757,8 @@ static void polymost_drawalls(int32_t const bunch)
                 ytex.v = vv[1];
                 otex.v = r_parallaxskypanning ? vv[0] + dd*(float)sec->ceilingypanning*(float)i*(1.f/256.f) : vv[0];
 
-				int const npot = (1 << (picsiz[globalpicnum] & 15)) != tilesiz[globalpicnum].x;
+                    int const npot = (1<<(picsiz[globalpicnum]&15)) != tilesiz[globalpicnum].x;
+                    int const xpanning = (r_parallaxskypanning?sec->ceilingxpanning:0);
 
                 i = globalpicnum;
                 float const r = (cy1-cy0)/(x1-x0); //slope of line
@@ -4757,14 +4769,14 @@ static void polymost_drawalls(int32_t const bunch)
                 do
                 {
                     globalpicnum = dapskyoff[y&((1<<dapskybits)-1)]+i;
-					if (!npot)
-	                    otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + (float)((r_parallaxskypanning)?sec->ceilingxpanning:0)) - xtex.u*ghalfx;
-					else
-					{
-						int32_t picbits = picsiz[globalpicnum]&15;
-                    	int32_t np2 = tilesiz[globalpicnum].x != (1<<picbits);
-                    	otex.u = otex.d*(t*((float)(fglobalang-(np2 ? 0 : (y<<(11-dapskybits))))) * (1.f/2048.f) + (float)((r_parallaxskypanning)?sec->ceilingxpanning:0)) - xtex.u*ghalfx;
-					}
+                        if (npot)
+                        {
+                            fx = ((float)((y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
+                            int tang = (y<<(11-dapskybits))&2047;
+                            otex.u = otex.d*(t*((float)(tang)) * (1.f/2048.f) + xpanning) - xtex.u*fx;
+                        }
+                        else
+                            otex.u = otex.d*(t*((float)(fglobalang-(y<<(11-dapskybits)))) * (1.f/2048.f) + xpanning) - xtex.u*ghalfx;
                     y++;
                     o.x = fx; fx = (((float) (y<<(11-dapskybits))-fglobalang))*o.z+ghalfx;
                     if (fx > x1) { fx = x1; i = -1; }