vk: brush: do not link pairs that were explicitly excluded in patches

This doesn't work as expected in some cases, as surfaces might still get
linked transitively by neighbours. Solving this seems non-trivial for
now, but maybe we can just live with it

ref/vk/vk_brush.c

@@ -809,14 +809,22 @@ static int getSurfaceTexture(const msurface_t *surf, int surface_index) {
 static qboolean shouldSmoothLinkSurfaces(const model_t* mod, int surf1, int surf2) {
 	//return Q_min(surf1, surf2) == 741 && Q_max(surf1, surf2) == 743;
 
-	// TODO patch filtering
-
 	// Do not join surfaces with different textures. Assume they belong to different objects.
 	const int t1 = getSurfaceTexture(mod->surfaces + surf1, surf1);
 	const int t2 = getSurfaceTexture(mod->surfaces + surf2, surf2);
 	if (t1 != t2)
 		return false;
 
+	// Filter explicit exclusion
+	for (int i = 0; i < g_map_entities.smoothing.excluded_count; i+=2) {
+		const int cand1 = g_map_entities.smoothing.excluded[i];
+		const int cand2 = g_map_entities.smoothing.excluded[i+1];
+
+		if ((cand1 == surf1 && cand2 == surf2)
+			|| (cand1 == surf2 && cand2 == surf1))
+			return false;
+	}
+
 	vec3_t n1, n2;
 	getSurfaceNormal(mod->surfaces + surf1, n1);
 	getSurfaceNormal(mod->surfaces + surf2, n2);

ref/vk/vk_mapents.c

@@ -518,7 +518,22 @@ static void patchEntity( const entity_props_t *props, uint32_t have_fields ) {
 				WARN("vk_mapents: trying to patch unsupported entity %d class %d", ei, ref->class);
 		}
 	}
+}
 
+static void appendExludedPairs(const entity_props_t *props) {
+	if (props->_xvk_smoothing_excluded_pairs.num % 2 != 0) {
+		ERR("vk_mapents: smoothing group exclusion list should be list of pairs -- divisible by 2; cutting the tail");
+	}
+
+	int count = props->_xvk_smoothing_excluded_pairs.num & ~1;
+	if (g_map_entities.smoothing.excluded_count + count > COUNTOF(g_map_entities.smoothing.excluded)) {
+		ERR("vk_mapents: smoothing exclusion group capacity exceeded, go complain in github issues");
+		count = COUNTOF(g_map_entities.smoothing.excluded) - g_map_entities.smoothing.excluded_count;
+	}
+
+	memcpy(g_map_entities.smoothing.excluded + g_map_entities.smoothing.excluded_count, props->_xvk_smoothing_excluded_pairs.values, count * sizeof(int));
+
+	g_map_entities.smoothing.excluded_count += count;
 }
 
 static void parseEntities( char *string, qboolean is_patch ) {
@@ -570,8 +585,14 @@ static void parseEntities( char *string, qboolean is_patch ) {
 							addPatchSurface( &values, have_fields );
 						} else if (have_fields & Field__xvk_ent_id) {
 							patchEntity( &values, have_fields );
-						} else if (have_fields & Field__xvk_smoothing_threshold) {
-							g_map_entities.smoothing.threshold = cosf(DEG2RAD(values._xvk_smoothing_threshold));
+						} else {
+							if (have_fields & Field__xvk_smoothing_threshold) {
+								g_map_entities.smoothing.threshold = cosf(DEG2RAD(values._xvk_smoothing_threshold));
+							}
+
+							if (have_fields & Field__xvk_smoothing_excluded_pairs) {
+								appendExludedPairs(&values);
+							}
 						}
 					}
 					break;
@@ -679,6 +700,7 @@ void XVK_ParseMapEntities( void ) {
 	g_map_entities.entity_count = 0;
 	g_map_entities.func_walls_count = 0;
 	g_map_entities.smoothing.threshold = cosf(DEG2RAD(45.f));
+	g_map_entities.smoothing.excluded_count = 0;
 
 	parseEntities( map->entities, false );
 	orientSpotlights();

ref/vk/vk_mapents.h

@@ -27,6 +27,7 @@
 	X(20, vec2_t, _xvk_tex_scale, Vec2) \
 	X(21, string, model, String) \
 	X(22, float, _xvk_smoothing_threshold, Float) \
+	X(23, int_array_t, _xvk_smoothing_excluded_pairs, IntArray) \
 
 /* NOTE: not used
 	X(22, int, rendermode, Int) \
@@ -132,6 +133,10 @@ typedef struct {
 
 	struct {
 		float threshold;
+
+#define MAX_EXCLUDED_SMOOTHING_SURFACES_PAIRS 32
+		int excluded[MAX_EXCLUDED_SMOOTHING_SURFACES_PAIRS * 2];
+		int excluded_count;
 	} smoothing;
 } xvk_map_entities_t;