Implementing glTF 1.0 parser

chrome/browser/android/vr_shell/gltf_parser_unittest.cc

+// 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.
+
+#include "chrome/browser/android/vr_shell/gltf_parser.h"
+
+#include <memory>
+
+#include "base/memory/ptr_util.h"
+#include "base/values.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace vr_shell {
+
+TEST(GltfParser, Parse) {
+  base::DictionaryValue asset;

[mthiesse, 2017/03/21 20:24:38]

I think rather than constructing a dictionary that matches what you would json
parse out of a gltf file, we should be using an actual gltf file and parsing it
here in the test. It would also be easier to update or replace the test data
that way.

cjgrant@, thoughts?

[cjgrant, 2017/03/21 20:38:02]

I agree.  The JSON would be easier to read, and even though you have to touch
two files, I think building the dictionary manually is cumbersome.  We do that
in UI unit tests, and it's nasty.

However, if we want to stress-test the parser, we could use the base::Value
dictionary methods to break/modify that original dictionary, and ensure the
parser reports failures.

[acondor_, 2017/03/22 16:25:29]

Done.

+  asset.SetString("asset.version", "1.0");
+
+  auto buffers = base::MakeUnique<base::DictionaryValue>();
+  auto buffer_dict = base::MakeUnique<base::DictionaryValue>();
+  buffer_dict->SetString(
+      "uri", "data:application/octet-stream;base64,SEVMTE8gV09STEQh");
+  buffer_dict->SetInteger("byteLength", 12);
+  buffers->Set("dummyBuffer", std::move(buffer_dict));
+  asset.Set("buffers", std::move(buffers));
+
+  auto buffer_views = base::MakeUnique<base::DictionaryValue>();
+  auto buffer_view_dict = base::MakeUnique<base::DictionaryValue>();
+  buffer_view_dict->SetString("buffer", "dummyBuffer");
+  buffer_view_dict->SetInteger("byteLength", 20);
+  buffer_view_dict->SetInteger("byteOffset", 10);
+  buffer_view_dict->SetInteger("target", 1);
+  buffer_views->Set("dummyBufferView", std::move(buffer_view_dict));
+  asset.Set("bufferViews", std::move(buffer_views));
+
+  auto accessors = base::MakeUnique<base::DictionaryValue>();
+  auto accessor_dict = base::MakeUnique<base::DictionaryValue>();
+  accessor_dict->SetString("bufferView", "dummyBufferView");
+  accessor_dict->SetInteger("byteOffset", 10);
+  accessor_dict->SetInteger("byteStride", 16);
+  accessor_dict->SetInteger("componentType", 5);
+  accessor_dict->SetInteger("count", 24);
+  accessor_dict->SetString("type", "VEC3");
+  accessors->Set("dummyAccessor", std::move(accessor_dict));
+  asset.Set("accessors", std::move(accessors));
+
+  auto meshes = base::MakeUnique<base::DictionaryValue>();
+  auto mesh_dict = base::MakeUnique<base::DictionaryValue>();
+  auto primitive_list = base::MakeUnique<base::ListValue>();
+  auto primitive_dict = base::MakeUnique<base::DictionaryValue>();
+  auto attributes_dict = base::MakeUnique<base::DictionaryValue>();
+  attributes_dict->SetString("POSITION", "dummyAccessor");
+  primitive_dict->Set("attributes", std::move(attributes_dict));
+  primitive_dict->SetString("indices", "dummyAccessor");
+  primitive_dict->SetInteger("mode", 4);
+  primitive_list->Append(std::move(primitive_dict));
+  mesh_dict->Set("primitives", std::move(primitive_list));
+  meshes->Set("dummyMesh", std::move(mesh_dict));
+  asset.Set("meshes", std::move(meshes));
+
+  auto nodes = base::MakeUnique<base::DictionaryValue>();
+  auto node_dict = base::MakeUnique<base::DictionaryValue>();
+  auto children_list = base::MakeUnique<base::ListValue>();
+  children_list->AppendString("dummyNode2");
+  node_dict->Set("children", std::move(children_list));
+  nodes->Set("dummyNode1", std::move(node_dict));
+  node_dict = base::MakeUnique<base::DictionaryValue>();
+  auto mesh_list = base::MakeUnique<base::ListValue>();
+  mesh_list->AppendString("dummyMesh");
+  node_dict->Set("meshes", std::move(mesh_list));
+  nodes->Set("dummyNode2", std::move(node_dict));
+  asset.Set("nodes", std::move(nodes));
+
+  auto scenes = base::MakeUnique<base::DictionaryValue>();
+  auto scene_dict = base::MakeUnique<base::DictionaryValue>();
+  auto node_list = base::MakeUnique<base::ListValue>();
+  node_list->AppendString("dummyNode1");
+  scene_dict->Set("nodes", std::move(node_list));
+  scenes->Set("dummyScene", std::move(scene_dict));
+  asset.Set("scenes", std::move(scenes));
+
+  asset.SetString("scene", "dummyScene");
+
+  GltfParser parser;
+  auto gltf_model = parser.Parse(asset);
+  EXPECT_TRUE(gltf_model);
+
+  const gltf::Buffer* buffer = gltf_model->GetBuffer(0);
+  EXPECT_NE(nullptr, buffer);
+  EXPECT_EQ(nullptr, gltf_model->GetBuffer(1));
+  EXPECT_EQ("HELLO WORLD!", *buffer);
+  EXPECT_EQ(12u, buffer->length());
+
+  const gltf::BufferView* buffer_view = gltf_model->GetBufferView(0);
+  EXPECT_NE(nullptr, buffer_view);
+  EXPECT_EQ(nullptr, gltf_model->GetBufferView(1));
+  EXPECT_EQ(buffer, buffer_view->buffer);
+  EXPECT_EQ(20, buffer_view->byte_length);
+  EXPECT_EQ(10, buffer_view->byte_offset);
+  EXPECT_EQ(1, buffer_view->target);
+
+  const gltf::Accessor* accessor = gltf_model->GetAccessor(0);
+  EXPECT_NE(nullptr, accessor);
+  EXPECT_EQ(nullptr, gltf_model->GetAccessor(1));
+  EXPECT_EQ(buffer_view, accessor->buffer_view);
+  EXPECT_EQ(10, accessor->byte_offset);
+  EXPECT_EQ(16, accessor->byte_stride);
+  EXPECT_EQ(5, accessor->component_type);
+  EXPECT_EQ(24, accessor->count);
+  EXPECT_EQ(gltf::VEC3, accessor->type);
+
+  const gltf::Mesh* mesh = gltf_model->GetMesh(0);
+  EXPECT_NE(nullptr, mesh);
+  EXPECT_EQ(nullptr, gltf_model->GetAccessor(1));
+  EXPECT_EQ(1u, mesh->primitives.size());
+  gltf::Mesh::Primitive* primitive = mesh->primitives[0].get();
+  EXPECT_EQ(1u, primitive->attributes.size());
+  auto attr_it = primitive->attributes.begin();
+  EXPECT_EQ("POSITION", attr_it->first);
+  EXPECT_EQ(accessor, attr_it->second);
+  EXPECT_EQ(accessor, primitive->indices);
+  EXPECT_EQ(4, primitive->mode);
+
+  const gltf::Node* node_1 = gltf_model->GetNode(0);
+  const gltf::Node* node_2 = gltf_model->GetNode(1);
+  EXPECT_NE(nullptr, node_1);
+  EXPECT_NE(nullptr, node_2);
+  EXPECT_EQ(nullptr, gltf_model->GetNode(2));
+  EXPECT_EQ(1u, node_1->children.size());
+  EXPECT_EQ(0u, node_1->meshes.size());
+  EXPECT_EQ(node_2, node_1->children[0]);
+  EXPECT_EQ(0u, node_2->children.size());
+  EXPECT_EQ(1u, node_2->meshes.size());
+  EXPECT_EQ(mesh, node_2->meshes[0]);
+
+  const gltf::Scene* scene = gltf_model->GetScene(0);
+  EXPECT_NE(nullptr, scene);
+  EXPECT_EQ(nullptr, gltf_model->GetNode(2));
+  EXPECT_EQ(1u, scene->nodes.size());
+  EXPECT_EQ(node_1, scene->nodes[0]);
+
+  EXPECT_EQ(scene, gltf_model->GetMainScene());
+}
+
+}  // namespace vr_shell