Amend r4394: don't use full brightness (glColor() factor 1) with hightiles.

This is done by factoring out some polymer.c:polymer_getbuildmaterial() code
into polymer_eligible_for_artmapping() and using that. The one in polymer.c
can still determine to not use ART mapping on some ("rare"?) occasions, so
it's not 100% in sync.

git-svn-id: https://svn.eduke32.com/eduke32@4407 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/build/include/polymer.h

@@ -351,6 +351,12 @@ static inline void polymer_invalidateartmap(int32_t tilenum)
     }
 }
 
+// Compare with eligible_for_tileshades()
+static inline int32_t polymer_eligible_for_artmap(int32_t tilenum, const pthtyp *pth)
+{
+    return ((!pth || !pth->hicr) && tilenum < (MAXTILES - 4));
+}
+
 # ifdef POLYMER_C
 
 // CORE

polymer/eduke32/build/include/polymost.h

@@ -56,6 +56,7 @@ extern int32_t r_usetileshades;
 extern int16_t globalpicnum;
 extern int32_t globalpal;
 
+// Compare with polymer_eligible_for_artmap()
 static inline int32_t eligible_for_tileshades(int32_t picnum, int32_t pal)
 {
     return (!usehightile || !hicfindsubst(picnum, pal, 0)) &&

polymer/eduke32/build/src/polymer.c

@@ -4621,7 +4621,7 @@ static void         polymer_getbuildmaterial(_prmaterial* material, int16_t tile
     }
 
     // Lazily fill in all the textures we need, move this to precaching later
-    if (pr_artmapping && (!pth || !pth->hicr) && tilenum < (MAXTILES - 4)) {
+    if (pr_artmapping && polymer_eligible_for_artmap(tilenum, pth)) {
         if (!prartmaps[tilenum]) {
             char *tilebuffer = (char *)waloff[tilenum];
             char *tempbuffer = (char *)Bmalloc(tilesizx[tilenum] * tilesizy[tilenum]);

polymer/eduke32/build/src/polymost.c

@@ -1526,7 +1526,8 @@ void drawpoly(double *dpx, double *dpy, int32_t n, int32_t method)
             float pc[4];
 
 #ifdef POLYMER
-            if (getrendermode() == REND_POLYMER && pr_artmapping)
+            if (getrendermode() == REND_POLYMER && pr_artmapping &&
+                    polymer_eligible_for_artmap(globalpicnum, pth))
                 pc[0] = pc[1] = pc[2] = 1.0f;
             else
 #endif