Rendering Daydream controller in a fixed position.

chrome/browser/android/vr_shell/vr_controller_model.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/vr_controller_model.h"
+
+namespace vr_shell {
+
+namespace {
+
+enum {
+  ELEMENTS_BUFFER_ID = 0,
+  INDICES_BUFFER_ID = 1,
+};
+
+constexpr char kPosition[] = "POSITION";
+constexpr char kTextCoord[] = "TEXCOORD_0";
+
+}  // namespace
+
+constexpr char const VrControllerModel::kComponentName[];
+constexpr char const VrControllerModel::kDefaultVersion[];
+constexpr char const VrControllerModel::kModelsDirectory[];
+constexpr char const VrControllerModel::kModelFilename[];
+constexpr char const VrControllerModel::kTexturesDirectory[];
+constexpr char const* VrControllerModel::kTextureFilenames[];
+
+VrControllerModel::VrControllerModel(std::unique_ptr<gltf::Asset> gltf_asset)
+    : gltf_asset_(std::move(gltf_asset)),
+      texture_bitmaps_(State::STATE_COUNT) {}
+
+VrControllerModel::~VrControllerModel() = default;
+
+const GLvoid* VrControllerModel::ElementsBuffer() const {
+  const gltf::BufferView* buffer_view =

[bajones, 2017/03/29 17:38:58]

The elements buffer and indices buffer are something that get looked up from the
table multiple times every frame. Since this class is for a very narrow use case
let's cache the BufferView once the model is loaded instead of looking it up
every time.

[acondor_, 2017/03/29 20:13:26]

Actually, they are used just once (during SetUp call in the renderer).

+      gltf_asset_->GetBufferView(ELEMENTS_BUFFER_ID);
+  DCHECK(buffer_view && buffer_view->target == GL_ARRAY_BUFFER);
+  return Buffer() + buffer_view->byte_offset;
+}
+
+GLsizeiptr VrControllerModel::ElementsBufferSize() const {
+  const gltf::BufferView* buffer_view =
+      gltf_asset_->GetBufferView(ELEMENTS_BUFFER_ID);
+  DCHECK(buffer_view && buffer_view->target == GL_ARRAY_BUFFER);
+  return buffer_view->byte_length;
+}
+
+const GLvoid* VrControllerModel::IndicesBuffer() const {
+  const gltf::BufferView* buffer_view =
+      gltf_asset_->GetBufferView(INDICES_BUFFER_ID);
+  DCHECK(buffer_view && buffer_view->target == GL_ELEMENT_ARRAY_BUFFER);
+  return Buffer() + buffer_view->byte_offset;
+}
+
+GLsizeiptr VrControllerModel::IndicesBufferSize() const {
+  const gltf::BufferView* buffer_view =
+      gltf_asset_->GetBufferView(INDICES_BUFFER_ID);
+  DCHECK(buffer_view && buffer_view->target == GL_ELEMENT_ARRAY_BUFFER);
+  return buffer_view->byte_length;
+}
+
+GLenum VrControllerModel::DrawMode() const {
+  const gltf::Mesh* mesh = gltf_asset_->GetMesh(0);
+  DCHECK(mesh && mesh->primitives.size());
+  return mesh->primitives[0]->mode;
+}
+
+const gltf::Accessor* VrControllerModel::IndicesAccessor() const {
+  const gltf::Mesh* mesh = gltf_asset_->GetMesh(0);
+  DCHECK(mesh && mesh->primitives.size());
+  return mesh->primitives[0]->indices;
+}
+
+const gltf::Accessor* VrControllerModel::PositionAccessor() const {
+  return Accessor(kPosition);
+}
+
+const gltf::Accessor* VrControllerModel::TextureCoordinateAccessor() const {
+  return Accessor(kTextCoord);
+}
+
+void VrControllerModel::SetTexture(int state,
+                                   std::unique_ptr<SkBitmap> bitmap) {
+  DCHECK(state >= 0 && state < STATE_COUNT);
+  texture_bitmaps_[state] = std::move(bitmap);
+}
+
+const SkBitmap* VrControllerModel::GetTexture(int state) const {
+  DCHECK(state >= 0 && state < STATE_COUNT);
+  return texture_bitmaps_[state].get();
+}
+
+void VrControllerModel::Free() {
+  gltf_asset_->FreeBuffers();
+  texture_bitmaps_.clear();
+}
+
+const char* VrControllerModel::Buffer() const {
+  const gltf::Buffer* buffer = gltf_asset_->GetBuffer(0);
+  DCHECK(buffer);
+  return buffer->data();
+}
+
+const gltf::Accessor* VrControllerModel::Accessor(
+    const std::string& key) const {
+  const gltf::Mesh* mesh = gltf_asset_->GetMesh(0);
+  DCHECK(mesh && mesh->primitives.size());
+  auto it = mesh->primitives[0]->attributes.find(key);

[bajones, 2017/03/29 17:38:58]

Same goes for the accessor, but even more so. Doing multiple string compares
each frame to find a static resource is something that should be avoided. Let's
cache the accessors in question so that PositionAccessor() and
TextureCoordinateAccessor() don't have to do any searches.

[acondor_, 2017/03/29 20:13:26]

No need with the new approach on the Renderer.

+  DCHECK(it != mesh->primitives[0]->attributes.begin());
+  return it->second;
+}
+
+}  // namespace vr_shell