+void R_PrepareBrushModel(entity_render_t *ent)
+{
+ int i, numsurfaces, *surfacevisframes, *surfacepvsframes;
+ msurface_t *surf;
+ model_t *model;
+#if WORLDNODECULLBACKFACES
+ vec3_t modelorg;
+#endif
+
+ // because bmodels can be reused, we have to decide which things to render
+ // from scratch every time
+ model = ent->model;
+ if (model == NULL)
+ return;
+#if WORLDNODECULLBACKFACES
+ Matrix4x4_Transform(&ent->inversematrix, r_vieworigin, modelorg);
+#endif
+ numsurfaces = model->brushq1.nummodelsurfaces;
+ surf = model->brushq1.surfaces + model->brushq1.firstmodelsurface;
+ surfacevisframes = model->brushq1.surfacevisframes + model->brushq1.firstmodelsurface;
+ surfacepvsframes = model->brushq1.surfacepvsframes + model->brushq1.firstmodelsurface;
+ for (i = 0;i < numsurfaces;i++, surf++)
+ {
+#if WORLDNODECULLBACKFACES
+ // mark any backface surfaces as not visible
+ if (PlaneDist(modelorg, surf->plane) < surf->plane->dist)
+ {
+ if ((surf->flags & SURF_PLANEBACK))
+ surfacevisframes[i] = r_framecount;
+ }
+ else if (!(surf->flags & SURF_PLANEBACK))
+ surfacevisframes[i] = r_framecount;
+#else
+ surfacevisframes[i] = r_framecount;
+#endif
+ surf->dlightframe = -1;
+ }
+ R_PrepareSurfaces(ent);
+}
+
+void R_SurfaceWorldNode (entity_render_t *ent)
+{
+ int i, *surfacevisframes, *surfacepvsframes, surfnum;
+ msurface_t *surf;
+ mleaf_t *leaf;
+ model_t *model;
+ vec3_t modelorg;
+
+ // equivilant to quake's RecursiveWorldNode but faster and more effective
+ model = ent->model;
+ if (model == NULL)
+ return;
+ surfacevisframes = model->brushq1.surfacevisframes + model->brushq1.firstmodelsurface;
+ surfacepvsframes = model->brushq1.surfacepvsframes + model->brushq1.firstmodelsurface;
+ Matrix4x4_Transform(&ent->inversematrix, r_vieworigin, modelorg);
+
+ for (leaf = model->brushq1.pvsleafchain;leaf;leaf = leaf->pvschain)
+ {
+ if (!R_CullBox (leaf->mins, leaf->maxs))
+ {
+ c_leafs++;
+ leaf->visframe = r_framecount;
+ }
+ }
+
+ for (i = 0;i < model->brushq1.pvssurflistlength;i++)
+ {
+ surfnum = model->brushq1.pvssurflist[i];
+ surf = model->brushq1.surfaces + surfnum;
+#if WORLDNODECULLBACKFACES
+ if (PlaneDist(modelorg, surf->plane) < surf->plane->dist)
+ {
+ if ((surf->flags & SURF_PLANEBACK) && !R_CullBox (surf->poly_mins, surf->poly_maxs))
+ surfacevisframes[surfnum] = r_framecount;
+ }
+ else
+ {
+ if (!(surf->flags & SURF_PLANEBACK) && !R_CullBox (surf->poly_mins, surf->poly_maxs))
+ surfacevisframes[surfnum] = r_framecount;
+ }
+#else
+ if (!R_CullBox (surf->poly_mins, surf->poly_maxs))
+ surfacevisframes[surfnum] = r_framecount;
+#endif
+ }
+}
+
+static void R_PortalWorldNode(entity_render_t *ent, mleaf_t *viewleaf)
+{
+ int c, leafstackpos, *mark, *surfacevisframes;
+#if WORLDNODECULLBACKFACES
+ int n;
+ msurface_t *surf;
+#endif
+ mleaf_t *leaf, *leafstack[8192];
+ mportal_t *p;
+ vec3_t modelorg;
+ msurface_t *surfaces;
+ if (ent->model == NULL)
+ return;
+ // LordHavoc: portal-passage worldnode with PVS;
+ // follows portals leading outward from viewleaf, does not venture
+ // offscreen or into leafs that are not visible, faster than Quake's
+ // RecursiveWorldNode
+ surfaces = ent->model->brushq1.surfaces;
+ surfacevisframes = ent->model->brushq1.surfacevisframes;
+ Matrix4x4_Transform(&ent->inversematrix, r_vieworigin, modelorg);
+ viewleaf->worldnodeframe = r_framecount;
+ leafstack[0] = viewleaf;
+ leafstackpos = 1;
+ while (leafstackpos)
+ {
+ c_leafs++;
+ leaf = leafstack[--leafstackpos];
+ leaf->visframe = r_framecount;
+ // draw any surfaces bounding this leaf
+ if (leaf->nummarksurfaces)