Support for parsing external file references in a glTF resource.

chrome/browser/android/vr_shell/gltf_parser.h

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_VR_SHELL_GLTF_PARSER_H_
 #define CHROME_BROWSER_ANDROID_VR_SHELL_GLTF_PARSER_H_
 
 #include <memory>
 #include <string>
 #include <unordered_map>
 
+#include "base/files/file_path.h"
 #include "base/values.h"
 #include "chrome/browser/android/vr_shell/gltf_asset.h"
 
 namespace vr_shell {
 
 // Parser for glTF 1.0 specification
 // https://github.com/KhronosGroup/glTF/tree/master/specification/1.0
 // Supported objects are limited to: buffers, bufferViews, accessors,
 // meshes (limited), nodes (limited), scenes (limited).
 // Non-supported objects include: materials, techniques, skins, shaders,
 // programs, animations, cameras, images, textures, extensions.
 // This parser is not intended to be used on user or third-party data,
 // but only on thoroughly tested Chromium resource files.
 // TODO(acondor): Implement glTF 2.0 parser. gltf::Asset is mostly version
 // agnostic.
 class GltfParser {
  public:
   GltfParser();
   ~GltfParser();
-  std::unique_ptr<gltf::Asset> Parse(const base::DictionaryValue& dict);
+  // Note: If your glTF references external files, this function will perform
+  // IO, and a base path must be specified.
+  std::unique_ptr<gltf::Asset> Parse(
+      const base::DictionaryValue& dict,
+      const base::FilePath& path = base::FilePath());
+  // Note: This function will perform IO.
+  std::unique_ptr<gltf::Asset> Parse(const base::FilePath& gltf_path);
 
  private:
-  bool ParseInternal(const base::DictionaryValue& dict);
+  struct Helper {
+    std::unique_ptr<gltf::Asset> asset;
+    base::FilePath path;
+    std::unordered_map<std::string, std::size_t> buffer_ids;
+    std::unordered_map<std::string, std::size_t> buffer_view_ids;
+    std::unordered_map<std::string, std::size_t> accessor_ids;
+    std::unordered_map<std::string, std::size_t> node_ids;
+    std::unordered_map<std::string, std::size_t> mesh_ids;
+    std::unordered_map<std::string, std::size_t> scene_ids;
+    explicit Helper(const base::FilePath& path);
+    ~Helper();
+  };
+
   bool SetBuffers(const base::DictionaryValue& dict);
   bool SetBufferViews(const base::DictionaryValue& dict);
   bool SetAccessors(const base::DictionaryValue& dict);
   bool SetMeshes(const base::DictionaryValue& dict);
   bool SetNodes(const base::DictionaryValue& dict);
   bool SetScenes(const base::DictionaryValue& dict);
   std::unique_ptr<gltf::Mesh::Primitive> ProcessPrimitive(
       const base::DictionaryValue& dict);
+  std::unique_ptr<gltf::Buffer> ProcessUri(const std::string& uri_str);
 
-  std::unique_ptr<gltf::Asset> asset_;
-  std::unordered_map<std::string, std::size_t> buffer_ids_;
-  std::unordered_map<std::string, std::size_t> buffer_view_ids_;
-  std::unordered_map<std::string, std::size_t> accessor_ids_;
-  std::unordered_map<std::string, std::size_t> node_ids_;
-  std::unordered_map<std::string, std::size_t> mesh_ids_;
-  std::unordered_map<std::string, std::size_t> scene_ids_;
+  Helper* helper_;
 
   DISALLOW_COPY_AND_ASSIGN(GltfParser);
 };
 
 }  // namespace vr_shell
 
 #endif  // CHROME_BROWSER_ANDROID_VR_SHELL_GLTF_PARSER_H_