vk: filter smoothing normals by texture

thanks to G.I.F

ref/vk/vk_brush.c

@@ -799,18 +799,32 @@ static void getSurfaceNormal( const msurface_t *surf, vec3_t out_normal) {
 	//VectorScale(normal, surf->plane.
 }
 
+static int getSurfaceTexture(const msurface_t *surf, int surface_index) {
+	const xvk_patch_surface_t *const psurf = R_VkPatchGetSurface(surface_index);
+	if (psurf && psurf->tex_id >= 0)
+		return psurf->tex_id;
+	return surf->texinfo->texture->gl_texturenum;
+}
+
 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;
+
 	vec3_t n1, n2;
 	getSurfaceNormal(mod->surfaces + surf1, n1);
 	getSurfaceNormal(mod->surfaces + surf2, n2);
 
-	// TODO patch filtering
 	const float dot = DotProduct(n1, n2);
-	DEBUG("Smoothing: dot(%d, %d) = %f (t=%f)", surf1, surf2, dot, g_map_entities.smoothing_threshold);
+	DEBUG("Smoothing: dot(%d, %d) = %f (t=%f)", surf1, surf2, dot, g_map_entities.smoothing.threshold);
 
-	return dot >= g_map_entities.smoothing_threshold;
+	return dot >= g_map_entities.smoothing.threshold;
 }
 
 static int lvFindValue(const linked_value_t *li, int count, int needle) {

ref/vk/vk_mapents.c

@@ -571,7 +571,7 @@ static void parseEntities( char *string, qboolean is_patch ) {
 						} 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));
+							g_map_entities.smoothing.threshold = cosf(DEG2RAD(values._xvk_smoothing_threshold));
 						}
 					}
 					break;
@@ -678,7 +678,7 @@ void XVK_ParseMapEntities( void ) {
 	g_map_entities.single_environment_index = NoEnvironmentLights;
 	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.threshold = cosf(DEG2RAD(45.f));
 
 	parseEntities( map->entities, false );
 	orientSpotlights();

ref/vk/vk_mapents.h

@@ -130,7 +130,9 @@ typedef struct {
 //#define MAX_MAP_ENTITIES 2048
 	xvk_mapent_ref_t refs[MAX_MAP_ENTITIES];
 
-	float smoothing_threshold;
+	struct {
+		float threshold;
+	} smoothing;
 } xvk_map_entities_t;
 
 extern xvk_map_entities_t g_map_entities;