From b46810484214ff1a5ab109e0131cb2582cb57f83 Mon Sep 17 00:00:00 2001
From: "K. S. Ernest (iFire) Lee" <ernest.lee@chibifire.com>
Date: Fri, 7 Jan 2022 19:01:09 -0800
Subject: [PATCH] Skip Draco-compressed glTF 3d format files.

---
 modules/gltf/gltf_document.cpp | 51 ++++++++++++++++++++++------------
 modules/gltf/gltf_document.h   |  1 +
 2 files changed, 35 insertions(+), 17 deletions(-)

diff --git a/modules/gltf/gltf_document.cpp b/modules/gltf/gltf_document.cpp
index 0d41ff025ec..5a931ed8390 100644
--- a/modules/gltf/gltf_document.cpp
+++ b/modules/gltf/gltf_document.cpp
@@ -6901,78 +6901,83 @@ Error GLTFDocument::append_from_buffer(PackedByteArray p_bytes, String p_base_pa
 
 Error GLTFDocument::_parse_gltf_state(Ref<GLTFState> state, const String &p_search_path, float p_bake_fps) {
 	Error err;
-	/* STEP 0 PARSE SCENE */
+
+	/* PARSE EXTENSIONS */
+	err = _parse_gltf_extensions(state);
+	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
+
+	/* PARSE SCENE */
 	err = _parse_scenes(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 1 PARSE NODES */
+	/* PARSE NODES */
 	err = _parse_nodes(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 2 PARSE BUFFERS */
+	/* PARSE BUFFERS */
 	err = _parse_buffers(state, p_search_path);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 3 PARSE BUFFER VIEWS */
+	/* PARSE BUFFER VIEWS */
 	err = _parse_buffer_views(state);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 4 PARSE ACCESSORS */
+	/* PARSE ACCESSORS */
 	err = _parse_accessors(state);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 5 PARSE IMAGES */
+	/* PARSE IMAGES */
 	err = _parse_images(state, p_search_path);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 6 PARSE TEXTURES */
+	/* PARSE TEXTURES */
 	err = _parse_textures(state);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 7 PARSE TEXTURES */
+	/* PARSE TEXTURES */
 	err = _parse_materials(state);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 9 PARSE SKINS */
+	/* PARSE SKINS */
 	err = _parse_skins(state);
 
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 10 DETERMINE SKELETONS */
+	/* DETERMINE SKELETONS */
 	err = _determine_skeletons(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 11 CREATE SKELETONS */
+	/* CREATE SKELETONS */
 	err = _create_skeletons(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 12 CREATE SKINS */
+	/* CREATE SKINS */
 	err = _create_skins(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 13 PARSE MESHES (we have enough info now) */
+	/* PARSE MESHES (we have enough info now) */
 	err = _parse_meshes(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 14 PARSE LIGHTS */
+	/* PARSE LIGHTS */
 	err = _parse_lights(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 15 PARSE CAMERAS */
+	/* PARSE CAMERAS */
 	err = _parse_cameras(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 16 PARSE ANIMATIONS */
+	/* PARSE ANIMATIONS */
 	err = _parse_animations(state);
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 
-	/* STEP 17 ASSIGN SCENE NAMES */
+	/* ASSIGN SCENE NAMES */
 	_assign_scene_names(state);
 
 	Node3D *root = memnew(Node3D);
@@ -6999,3 +7004,15 @@ Error GLTFDocument::append_from_file(String p_path, Ref<GLTFState> r_state, uint
 	ERR_FAIL_COND_V(err != OK, ERR_PARSE_ERROR);
 	return err;
 }
+
+Error GLTFDocument::_parse_gltf_extensions(Ref<GLTFState> state) {
+	ERR_FAIL_NULL_V(state, ERR_PARSE_ERROR);
+	if (state->json.has("extensionsRequired") && state->json["extensionsRequired"].get_type() == Variant::ARRAY) {
+		Array extensions_required = state->json["extensionsRequired"];
+		if (extensions_required.find("KHR_draco_mesh_compression") != -1) {
+			ERR_PRINT("glTF2 extension KHR_draco_mesh_compression is not supported.");
+			return ERR_UNAVAILABLE;
+		}
+	}
+	return OK;
+}
diff --git a/modules/gltf/gltf_document.h b/modules/gltf/gltf_document.h
index 8f8f5b410a8..c0649e01298 100644
--- a/modules/gltf/gltf_document.h
+++ b/modules/gltf/gltf_document.h
@@ -392,6 +392,7 @@ public:
 
 public:
 	Error _parse_gltf_state(Ref<GLTFState> state, const String &p_search_path, float p_bake_fps);
+	Error _parse_gltf_extensions(Ref<GLTFState> state);
 	void _process_mesh_instances(Ref<GLTFState> state, Node *scene_root);
 	void _generate_scene_node(Ref<GLTFState> state, Node *scene_parent,
 			Node3D *scene_root,