gltfpack: Rework -kn and -km to explicitly assume naming

The behavior of -kn is still the same as it used to be - it keeps named
nodes and maintains the transform effects of these nodes on the rest of
the scene, including prohibiting mesh merging for attached meshes. The
setting was renamed to keep_nodes to reflect that better.

The behavior of -km is now matching that for materials - it keeps named
materials, prevents merging them with other materials and keeps them in
the file.

gltf/gltfpack.cpp

@@ -182,7 +182,7 @@ static void process(cgltf_data* data, const char* input_path, const char* output
 			continue;
 
 		// note: when -kn is specified, we keep mesh-node attachment so that named nodes can be transformed
-		if (settings.keep_named)
+		if (settings.keep_nodes)
 			continue;
 
 		// we keep skinned meshes or meshes with morph targets as is
@@ -230,17 +230,7 @@ static void process(cgltf_data* data, const char* input_path, const char* output
 
 	std::vector<MaterialInfo> materials(data->materials_count);
 
-	if (settings.keep_materials)
-	{
-		for (size_t i = 0; i < materials.size(); ++i)
-		{
-			materials[i].keep = true;
-		}
-	}
-	else
-	{
-		markNeededMaterials(data, materials, meshes);
-	}
+	markNeededMaterials(data, materials, meshes, settings);
 
 #ifndef NDEBUG
 	std::vector<Mesh> debug_meshes;
@@ -886,16 +876,16 @@ int main(int argc, char** argv)
 		}
 		else if (strcmp(arg, "-kn") == 0)
 		{
-			settings.keep_named = true;
-		}
-		else if (strcmp(arg, "-ke") == 0)
-		{
-			settings.keep_extras = true;
+			settings.keep_nodes = true;
 		}
 		else if (strcmp(arg, "-km") == 0)
 		{
 			settings.keep_materials = true;
 		}
+		else if (strcmp(arg, "-ke") == 0)
+		{
+			settings.keep_extras = true;
+		}
 		else if (strcmp(arg, "-mm") == 0)
 		{
 			settings.mesh_merge = true;
@@ -1054,8 +1044,8 @@ int main(int argc, char** argv)
 			fprintf(stderr, "\t-ac: keep constant animation tracks even if they don't modify the node transform\n");
 			fprintf(stderr, "\nScene:\n");
 			fprintf(stderr, "\t-kn: keep named nodes and meshes attached to named nodes so that named nodes can be transformed externally\n");
+			fprintf(stderr, "\t-km: keep named materials and disable named material merging\n");
 			fprintf(stderr, "\t-ke: keep extras data\n");
-			fprintf(stderr, "\t-km: keep unused materials\n");
 			fprintf(stderr, "\t-mm: merge instances of the same mesh together when possible\n");
 			fprintf(stderr, "\t-mi: use EXT_mesh_gpu_instancing when serializing multiple mesh instances\n");
 			fprintf(stderr, "\nMiscellaneous:\n");

gltf/gltfpack.h

@@ -93,9 +93,9 @@ struct Settings
 	int anim_freq;
 	bool anim_const;
 
-	bool keep_named;
-	bool keep_extras;
+	bool keep_nodes;
 	bool keep_materials;
+	bool keep_extras;
 
 	bool mesh_merge;
 	bool mesh_instancing;
@@ -249,7 +249,7 @@ void filterEmptyMeshes(std::vector<Mesh>& meshes);
 
 bool usesTextureSet(const cgltf_material& material, int set);
 void mergeMeshMaterials(cgltf_data* data, std::vector<Mesh>& meshes, const Settings& settings);
-void markNeededMaterials(cgltf_data* data, std::vector<MaterialInfo>& materials, const std::vector<Mesh>& meshes);
+void markNeededMaterials(cgltf_data* data, std::vector<MaterialInfo>& materials, const std::vector<Mesh>& meshes, const Settings& settings);
 
 void analyzeImages(cgltf_data* data, std::vector<ImageInfo>& images);
 const char* inferMimeType(const char* path);

gltf/material.cpp

@@ -168,8 +168,14 @@ void mergeMeshMaterials(cgltf_data* data, std::vector<Mesh>& meshes, const Setti
 		if (!mesh.material)
 			continue;
 
+		if (settings.keep_materials && mesh.material->name && *mesh.material->name)
+			continue;
+
 		for (int j = 0; j < mesh.material - data->materials; ++j)
 		{
+			if (settings.keep_materials && data->materials[j].name && *data->materials[j].name)
+				continue;
+
 			if (areMaterialsEqual(data, *mesh.material, data->materials[j], settings))
 			{
 				mesh.material = &data->materials[j];
@@ -179,7 +185,7 @@ void mergeMeshMaterials(cgltf_data* data, std::vector<Mesh>& meshes, const Setti
 	}
 }
 
-void markNeededMaterials(cgltf_data* data, std::vector<MaterialInfo>& materials, const std::vector<Mesh>& meshes)
+void markNeededMaterials(cgltf_data* data, std::vector<MaterialInfo>& materials, const std::vector<Mesh>& meshes, const Settings& settings)
 {
 	// mark all used materials as kept
 	for (size_t i = 0; i < meshes.size(); ++i)
@@ -193,6 +199,20 @@ void markNeededMaterials(cgltf_data* data, std::vector<MaterialInfo>& materials,
 			mi.keep = true;
 		}
 	}
+
+	// mark all named materials as kept if requested
+	if (settings.keep_materials)
+	{
+		for (size_t i = 0; i < data->materials_count; ++i)
+		{
+			cgltf_material& material = data->materials[i];
+
+			if (material.name && *material.name)
+			{
+				materials[i].keep = true;
+			}
+		}
+	}
 }
 
 bool usesTextureSet(const cgltf_material& material, int set)

gltf/mesh.cpp

@@ -157,7 +157,7 @@ static bool canMergeMeshNodes(cgltf_node* lhs, cgltf_node* rhs, const Settings&
 	if (lhs_transform || rhs_transform)
 		return false;
 
-	if (settings.keep_named)
+	if (settings.keep_nodes)
 	{
 		if (lhs->name && *lhs->name)
 			return false;

gltf/node.cpp

@@ -92,7 +92,7 @@ void markNeededNodes(cgltf_data* data, std::vector<NodeInfo>& nodes, const std::
 	}
 
 	// mark all named nodes as needed (if -kn is specified)
-	if (settings.keep_named)
+	if (settings.keep_nodes)
 	{
 		for (size_t i = 0; i < data->nodes_count; ++i)
 		{