Add VR gradient and grid background to non-WebVR scene.

chrome/browser/android/vr_shell/ui_scene_manager.cc

Index: chrome/browser/android/vr_shell/ui_scene_manager.cc
diff --git a/chrome/browser/android/vr_shell/ui_scene_manager.cc b/chrome/browser/android/vr_shell/ui_scene_manager.cc
index b2aadfb32b2b6fc35e9afbeed8cef08b2fa70b53..ee71a3ab14022fb8314f0d51f07c02c7331e7277 100644
--- a/chrome/browser/android/vr_shell/ui_scene_manager.cc
+++ b/chrome/browser/android/vr_shell/ui_scene_manager.cc
@@ -20,21 +20,31 @@ static constexpr int kWarningTimeoutSeconds = 30;
 static constexpr float kWarningDistance = 0.7;
 static constexpr float kWarningAngleRadians = 16.3 * M_PI / 180.0;
 
+static constexpr float kBackplaneSize = 1000.0;

[amp, 2017/04/27 17:28:53]

As long as you are changing things here want to merge in my change to add more
constants instead of magic numbers throughout the file?

https://codereview.chromium.org/2832843004/

[cjgrant, 2017/04/27 18:50:20]

I would have said yes, but your CL is now in the CQ. :)

[amp, 2017/04/27 18:54:27]

Indeed, thanks Michael!

It was small enough I didn't care either way if it went in on it's own or with
another change.

+static constexpr float kBackgroundDistanceMultiplier = 1.414;
+
+static constexpr float kSceneSize = 25.0;
+static constexpr float kSceneHeight = 4.0;
+static constexpr int kFloorGridlineCount = 40;
+static constexpr vr::Colorf kBackgroundHorizonColor = {0.57, 0.57, 0.57, 1.0};
+static constexpr vr::Colorf kBackgroundCenterColor = {0.48, 0.48, 0.48, 1.0};
+
+// Tiny distance to offset textures that should appear in the same plane.
+static constexpr float kTextureOffset = 0.01;
+
 }  // namespace
 
 UiSceneManager::UiSceneManager(UiScene* scene)
     : scene_(scene), weak_ptr_factory_(this) {
   std::unique_ptr<UiElement> element;
 
-  // For now, use an ID range that does not conflict with the HTML UI.
-  int id = 1000;
+  int id = 0;
 
-  // Permanent WebVR security warning.
   // TODO(mthiesse): Programatically compute the proper texture size for these
   // textured UI elements.
   element = base::MakeUnique<PermanentSecurityWarning>(512);
-  element->id = id++;
   element->name = "Permanent security warning";

[mthiesse, 2017/04/27 15:47:11]

Hmm. Is there an easy way to make these element names show up in debug builds
only? We should avoid unnecessary strings in release builds.

[cjgrant, 2017/04/27 18:50:19]

Agreed on no strings.  I don't know of any fanciness other than the usual #if
DEBUG / #if NDEBUG type approach (assuming that works).  Looking back, we added
these names to aid in E2E testing that talked to HTML UI and native.  Maybe we
ought to just turf out the name field now, as it doesn't help with much else.

[cjgrant, 2017/04/27 21:28:33]

Done.

+  element->id = id++;
   element->fill = vr_shell::Fill::NONE;
   element->size = {0.226f, 0.078f, 1};
   element->scale = {kWarningDistance, kWarningDistance, 1};
@@ -47,10 +57,9 @@ UiSceneManager::UiSceneManager(UiScene* scene)
   permanent_security_warning_ = element.get();
   scene_->AddUiElement(std::move(element));
 
-  // Transient WebVR security warning.
   element = base::MakeUnique<TransientSecurityWarning>(1024);
-  element->id = id++;
   element->name = "Transient security warning";
+  element->id = id++;
   element->fill = vr_shell::Fill::NONE;
   element->size = {0.512f, 0.160f, 1};
   element->scale = {kWarningDistance, kWarningDistance, 1};
@@ -61,16 +70,78 @@ UiSceneManager::UiSceneManager(UiScene* scene)
   transient_security_warning_ = element.get();
   scene_->AddUiElement(std::move(element));
 
-  // Main web content quad.
   element = base::MakeUnique<UiElement>();
-  element->id = id++;
   element->name = "Content";
+  element->id = id++;
   element->fill = vr_shell::Fill::CONTENT;
   element->size = {2.4f, 1.6f, 1};
   element->translation = {0, -0.1f, -2.5f};
   element->visible = false;
   main_content_ = element.get();
+  browser_ui_elements_.push_back(element.get());
+  scene_->AddUiElement(std::move(element));
+
+  // Place an invisible but hittable plane behind the content quad, to keep the

[cjgrant, 2017/04/27 15:11:14]

Thoughts on this wall of initialization.  I thought about classes or helpers to
represent these background quads, I don't think it's worth it.  Each is a
different one-off element, so if anything I'd break out this init to a separate
method, called by the constructor.

[mthiesse, 2017/04/27 15:47:11]

I think member functions for each element creation would be good for
readability, even if little to no code is shared.

[cjgrant, 2017/04/27 18:50:19]

Done.  Let me know what you think...

+  // reticle roughly planar with the content if near content.
+  element = base::MakeUnique<UiElement>();
+  element->name = "Backplane";
+  element->id = id++;
+  element->fill = vr_shell::Fill::NONE;
+  element->size = {kBackplaneSize, kBackplaneSize, 1.0};
+  element->translation = {0.0, 0.0, -kTextureOffset};
+  element->parent_id = main_content_->id;
+  browser_ui_elements_.push_back(element.get());
   scene_->AddUiElement(std::move(element));
+
+  element = base::MakeUnique<UiElement>();
+  element->name = "Floor";
+  element->id = id++;
+  element->size = {kSceneSize, kSceneSize, 1.0};
+  element->translation = {0.0, -kSceneHeight / 2, 0.0};
+  element->rotation = {1.0, 0.0, 0.0, -M_PI / 2.0};
+  element->fill = vr_shell::Fill::OPAQUE_GRADIENT;
+  element->edge_color = kBackgroundHorizonColor;
+  element->center_color = kBackgroundCenterColor;
+  element->draw_phase = 0;
+  browser_ui_elements_.push_back(element.get());
+  scene_->AddUiElement(std::move(element));
+
+  element = base::MakeUnique<UiElement>();
+  element->name = "Ceiling";
+  element->id = id++;
+  element->fill = vr_shell::Fill::OPAQUE_GRADIENT;
+  element->size = {kSceneSize, kSceneSize, 1.0};
+  element->translation = {0.0, kSceneHeight / 2, 0.0};
+  element->rotation = {1.0, 0.0, 0.0, M_PI / 2};
+  element->fill = vr_shell::Fill::OPAQUE_GRADIENT;
+  element->edge_color = kBackgroundHorizonColor;
+  element->center_color = kBackgroundCenterColor;
+  element->draw_phase = 0;
+  browser_ui_elements_.push_back(element.get());
+  scene_->AddUiElement(std::move(element));
+
+  element = base::MakeUnique<UiElement>();
+  element->name = "Floor grid";
+  element->id = id++;
+  element->fill = vr_shell::Fill::GRID_GRADIENT;
+  element->size = {kSceneSize, kSceneSize, 1.0};
+  element->translation = {0.0, -kSceneHeight / 2 + kTextureOffset, 0.0};
+  element->rotation = {1.0, 0.0, 0.0, -M_PI / 2};
+  element->fill = vr_shell::Fill::GRID_GRADIENT;
+  element->center_color = kBackgroundHorizonColor;
+  vr::Colorf edge_color = kBackgroundHorizonColor;
+  edge_color.a = 0.0;
+  element->edge_color = edge_color;
+  element->gridline_count = kFloorGridlineCount;
+  element->draw_phase = 0;
+  browser_ui_elements_.push_back(element.get());
+  scene_->AddUiElement(std::move(element));
+
+  scene_->SetBackgroundColor(kBackgroundHorizonColor);
+
+  // Limit reticle distance to a sphere based on content distance.
+  scene_->SetBackgroundDistance(main_content_->translation.z() *
+                                -kBackgroundDistanceMultiplier);
 }
 
 UiSceneManager::~UiSceneManager() {}
@@ -81,7 +152,12 @@ base::WeakPtr<UiSceneManager> UiSceneManager::GetWeakPtr() {
 
 void UiSceneManager::SetWebVRMode(bool web_vr) {
   web_vr_mode_ = web_vr;
-  main_content_->visible = !web_vr_mode_;
+
+  // Make all VR scene UI elements visible if not in WebVR.
+  for (UiElement* element : browser_ui_elements_) {
+    element->visible = !web_vr_mode_;
+  }
+
   ConfigureSecurityWarnings();
 }