Use the HTML UI to render WebVR warnings

chrome/browser/android/vr_shell/vr_shell.cc

 // Copyright 2016 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_shell.h"
 
 #include "base/metrics/histogram_macros.h"
 #include "chrome/browser/android/vr_shell/ui_elements.h"
 #include "chrome/browser/android/vr_shell/ui_interface.h"
 #include "chrome/browser/android/vr_shell/ui_scene.h"
@@ skipping 55 matching lines @@
 static constexpr float kReticleOffset = 0.99f;
 
 // Limit the rendering distance of the reticle to the distance to a corner of
 // the content quad, times this value. This lets the rendering distance
 // adjust according to content quad placement.
 static constexpr float kReticleDistanceMultiplier = 1.5f;
 
 // UI element 0 is the browser content rectangle.
 static constexpr int kBrowserUiElementId = 0;
 
-// Positions and sizes of statically placed UI elements in the UI texture.
-// TODO(klausw): replace the hardcoded positions with JS position/offset
-// retrieval once the infrastructure for that is hooked up.
-//
-// UI is designed with 1 pixel = 1mm at 1m distance. It's rescaled to
-// maintain the same angular resolution if placed closer or further.
-// The warning overlays should be fairly close since they cut holes
-// into geometry (they ignore the Z buffer), leading to odd effects
-// if they are far away.
-static constexpr vr_shell::Recti kWebVrWarningTransientRect = {
-  0, 128, 512, 250};
-static constexpr vr_shell::Recti kWebVrWarningPermanentRect = {0, 0, 512, 128};
-static constexpr float kWebVrWarningDistance = 0.7f;  // meters
-static constexpr float kWebVrWarningPermanentAngle = 16.3f;  // degrees up
-// How long the transient warning needs to be displayed.
-static constexpr int64_t kWebVrWarningSeconds = 30;
-
 static constexpr int kFramePrimaryBuffer = 0;
 static constexpr int kFrameHeadlockedBuffer = 1;
 
 vr_shell::VrShell* g_instance;
 
 static const char kVrShellUIURL[] = "chrome://vr-shell-ui";
 
 float Distance(const gvr::Vec3f& vec1, const gvr::Vec3f& vec2) {
   float xdiff = (vec1.x - vec2.x);
   float ydiff = (vec1.y - vec2.y);
@@ skipping 334 matching lines @@
     // The head pose has redundant data. Assume we're only using the
     // object_from_reference_matrix, we're not updating position_external.
     // TODO: Not sure what object_from_reference_matrix is. The new api removed
     // it. For now, removing it seems working fine.
     gvr_api_->ApplyNeckModel(head_pose, 1.0f);
   }
 
   // Bind the primary framebuffer.
   frame.BindBuffer(kFramePrimaryBuffer);
 
+  HandleQueuedTasks();
+
+  // Update the render position of all UI elements (including desktop).
+  float screen_tilt = desktop_screen_tilt_ * M_PI / 180.0f;
+  scene_->UpdateTransforms(screen_tilt, UiScene::TimeInMicroseconds());
+
   if (webvr_mode_) {
     DrawWebVr();
-    // Wait for the DOM contents to be loaded before rendering to avoid drawing
-    // white rectangles with no content.
-    if (!webvr_secure_origin_ && IsUiTextureReady()) {
-      size_t last_viewport = buffer_viewport_list_->GetSize();
-      buffer_viewport_list_->SetBufferViewport(last_viewport++,
-          *headlocked_left_viewport_);
-      buffer_viewport_list_->SetBufferViewport(last_viewport++,
-          *headlocked_right_viewport_);
 
-      // Bind the headlocked framebuffer.
-      frame.BindBuffer(kFrameHeadlockedBuffer);
-      DrawWebVrOverlay(target_time.monotonic_system_time_nanos);
-    }
+    size_t last_viewport = buffer_viewport_list_->GetSize();
+    buffer_viewport_list_->SetBufferViewport(last_viewport++,
+        *headlocked_left_viewport_);
+    buffer_viewport_list_->SetBufferViewport(last_viewport++,
+        *headlocked_right_viewport_);
+
+    // Bind the headlocked framebuffer.
+    frame.BindBuffer(kFrameHeadlockedBuffer);

[bajones, 2016/10/24 21:12:27]

I don't know how much of a perf hit this introduces, but it seems like always
compositing in the headlocked layer is wasted cycles? Is there a reasonable way
to determine if the HTML UI has anything to be drawn?

Also, I don't think that we'll always want all parts of the HTML UI to be
headlocked when in WebVR (the omnibar is a good example) so I'd rather see this
viewport setting moved down into DrawVRShell and only used for elements
explicitly marked as headlocked.

[cjgrant, 2016/10/24 21:34:57]

On determining if there's anything to draw:  Yes, that's easy.  I skipped it to
keep the "worst case" visible, rather than degrading when a UI element appears,
but I'll switch this up.

On non-headlocked elements, sure, lets do this now.  I assume you're thinking
this:
- Enumerate UI elements, draw any that aren't headlocked.
- If any headlocked elements:
  - Bind the headlocked buffer
  - Enumerate again, draw any that are headlocked.

[cjgrant, 2016/10/25 20:09:07]

So this refactor was a little bigger than I expected, but I think we're better
off now.

 
     // When using async reprojection, we need to know which pose was used in
     // the WebVR app for drawing this frame. Due to unknown amounts of
     // buffering in the compositor and SurfaceTexture, we read the pose number
     // from a corner pixel. There's no point in doing this for legacy
     // distortion rendering since that doesn't need a pose, and reading back
     // pixels is an expensive operation. TODO(klausw): stop doing this once we
     // have working no-compositor rendering for WebVR.
     if (gvr_api_->GetAsyncReprojectionEnabled()) {
       uint32_t webvr_pose_frame = GetPixelEncodedPoseIndex();
       head_pose = webvr_head_pose_[webvr_pose_frame % kPoseRingBufferSize];
     }
   } else {
-    DrawVrShell(head_pose);
+    UpdateController(GetForwardVector(head_pose));
   }
 
+  DrawVrShell(head_pose);
+
   frame.Unbind();
   frame.Submit(*buffer_viewport_list_, head_pose);
 }
 
 void VrShell::DrawVrShell(const gvr::Mat4f& head_pose) {
-  float screen_tilt = desktop_screen_tilt_ * M_PI / 180.0f;
-
-  HandleQueuedTasks();
-
-  // Update the render position of all UI elements (including desktop).
-  scene_->UpdateTransforms(screen_tilt, UiScene::TimeInMicroseconds());
-
-  UpdateController(GetForwardVector(head_pose));
-
-  // Use culling to remove back faces.
-  glEnable(GL_CULL_FACE);
-
-  // Enable depth testing.
-  glEnable(GL_DEPTH_TEST);
-  glEnable(GL_SCISSOR_TEST);
-
-  glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+  if (!webvr_mode_) {
+    glEnable(GL_CULL_FACE);

[cjgrant, 2016/10/24 20:05:09]

Brandon, in this CL, I try to leave the sequence of GL-related calls untouched
in the webVR and 2D cases.  However, in a follow-on change, I'd like to refactor
this such that the GL calls are as similar as possible.

I don't know enough GL yet, but I'd be starting with:
- Removing some of the "disable everything" calls in the WebVR case
- Figuring out how to clear the buffer before doing any rendering, instead of
clearing one eye at a time as we do in the VrShell rendering.

If this stuff is trivially simple to you, can we chat offline about it?

[bajones, 2016/10/24 21:12:27]

Sure, let's grab a moment to chat. Stick something on my calendar.

+    glEnable(GL_DEPTH_TEST);
+    glEnable(GL_SCISSOR_TEST);
+    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+  } else {
+    glClear(GL_COLOR_BUFFER_BIT);
+  }
 
   buffer_viewport_list_->GetBufferViewport(GVR_LEFT_EYE,
                                            buffer_viewport_.get());
   DrawEye(GVR_LEFT_EYE, head_pose, *buffer_viewport_);
   buffer_viewport_list_->GetBufferViewport(GVR_RIGHT_EYE,
                                            buffer_viewport_.get());
   DrawEye(GVR_RIGHT_EYE, head_pose, *buffer_viewport_);
 }
 
 void VrShell::DrawEye(gvr::Eye eye,
@@ skipping 11 matching lines @@
             pixel_rect.right - pixel_rect.left,
             pixel_rect.top - pixel_rect.bottom);
 
   const gvr::Mat4f fov_render_matrix = MatrixMul(
       PerspectiveMatrixFromView(params.GetSourceFov(), kZNear, kZFar),
       eye_matrix);
   const gvr::Mat4f world_render_matrix = MatrixMul(
       PerspectiveMatrixFromView(params.GetSourceFov(), kZNear, kZFar),
       view_matrix);
 
-  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+  if (!webvr_mode_) {
+    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+  }
 
   // TODO(mthiesse): Draw order for transparency.
   DrawUI(world_render_matrix, fov_render_matrix);
-  DrawCursor(world_render_matrix);
-}
-
-bool VrShell::IsUiTextureReady() {
-  return ui_tex_width_ > 0 && ui_tex_height_ > 0 && dom_contents_loaded_;
-}
-
-Rectf VrShell::MakeUiGlCopyRect(Recti pixel_rect) {
-  CHECK(IsUiTextureReady());
-  return Rectf({
-      static_cast<float>(pixel_rect.x) / ui_tex_width_,
-      static_cast<float>(pixel_rect.y) / ui_tex_height_,
-      static_cast<float>(pixel_rect.width) / ui_tex_width_,
-      static_cast<float>(pixel_rect.height) / ui_tex_height_});
+  if (!webvr_mode_) {
+    DrawCursor(world_render_matrix);
+  }
 }
 
 void VrShell::DrawUI(const gvr::Mat4f& world_matrix,
                      const gvr::Mat4f& fov_matrix) {
   for (const auto& rect : scene_->GetUiElements()) {
     if (!rect->visible) {
       continue;
     }
+    if (webvr_mode_ && rect->id == kBrowserUiElementId) {
+      continue;
+    }
 
     Rectf copy_rect;
     jint texture_handle;
     if (rect->id == kBrowserUiElementId) {
       copy_rect = {0, 0, 1, 1};
       texture_handle = content_texture_id_;
     } else {
       copy_rect.x = static_cast<float>(rect->copy_rect.x) / ui_tex_width_;
       copy_rect.y = static_cast<float>(rect->copy_rect.y) / ui_tex_height_;
       copy_rect.width = static_cast<float>(rect->copy_rect.width) /
@@ skipping 94 matching lines @@
   glDisable(GL_BLEND);
   glDisable(GL_POLYGON_OFFSET_FILL);
 
   // Don't need to clear, since we're drawing over the entire render target.
   glClear(GL_COLOR_BUFFER_BIT);
 
   glViewport(0, 0, render_size_.width, render_size_.height);
   vr_shell_renderer_->GetWebVrRenderer()->Draw(content_texture_id_);
 }
 
-void VrShell::DrawWebVrOverlay(int64_t present_time_nanos) {
-  // Draw WebVR security warning overlays for each eye. This uses the
-  // eye-from-head matrices but not the pose, goal is to place the icons in an
-  // eye-relative position so that they follow along with head rotations.
-
-  gvr::Mat4f left_eye_view_matrix =
-      gvr_api_->GetEyeFromHeadMatrix(GVR_LEFT_EYE);
-  gvr::Mat4f right_eye_view_matrix =
-      gvr_api_->GetEyeFromHeadMatrix(GVR_RIGHT_EYE);
-
-  glClear(GL_COLOR_BUFFER_BIT);
-
-  buffer_viewport_list_->GetBufferViewport(GVR_LEFT_EYE,
-                                           buffer_viewport_.get());
-  DrawWebVrEye(left_eye_view_matrix, *buffer_viewport_, present_time_nanos);
-  buffer_viewport_list_->GetBufferViewport(GVR_RIGHT_EYE,
-                                           buffer_viewport_.get());
-  DrawWebVrEye(right_eye_view_matrix, *buffer_viewport_, present_time_nanos);
-}
-
-void VrShell::DrawWebVrEye(const gvr::Mat4f& view_matrix,
-                           const gvr::BufferViewport& params,
-                           int64_t present_time_nanos) {
-  gvr::Recti pixel_rect =
-      CalculatePixelSpaceRect(render_size_, params.GetSourceUv());
-  glViewport(pixel_rect.left, pixel_rect.bottom,
-             pixel_rect.right - pixel_rect.left,
-             pixel_rect.top - pixel_rect.bottom);
-  glScissor(pixel_rect.left, pixel_rect.bottom,
-            pixel_rect.right - pixel_rect.left,
-            pixel_rect.top - pixel_rect.bottom);
-
-  gvr::Mat4f projection_matrix =
-      PerspectiveMatrixFromView(params.GetSourceFov(), kZNear, kZFar);
-
-  if (!IsUiTextureReady()) {
-    // If the UI texture hasn't been initialized yet, we can't draw the overlay.
-    return;
-  }
-
-  // Show IDS_WEBSITE_SETTINGS_INSECURE_WEBVR_CONTENT_PERMANENT text.
-  gvr::Mat4f icon_pos;
-  SetIdentityM(icon_pos);
-  // The UI is designed in pixels with the assumption that 1px = 1mm at 1m
-  // distance. Scale mm-to-m and adjust to keep the same angular size if the
-  // distance changes.
-  const float small_icon_width =
-      kWebVrWarningPermanentRect.width / 1000.f * kWebVrWarningDistance;
-  const float small_icon_height =
-      kWebVrWarningPermanentRect.height / 1000.f * kWebVrWarningDistance;
-  const float small_icon_angle =
-      kWebVrWarningPermanentAngle * M_PI / 180.f;  // Degrees to radians.
-  ScaleM(icon_pos, icon_pos, small_icon_width, small_icon_height, 1.0f);
-  TranslateM(icon_pos, icon_pos, 0.0f, 0.0f, -kWebVrWarningDistance);
-  icon_pos = MatrixMul(
-      QuatToMatrix(QuatFromAxisAngle({1.f, 0.f, 0.f}, small_icon_angle)),
-      icon_pos);
-  gvr::Mat4f combined = MatrixMul(projection_matrix,
-                                  MatrixMul(view_matrix, icon_pos));
-  vr_shell_renderer_->GetTexturedQuadRenderer()->Draw(
-      ui_texture_id_, combined, MakeUiGlCopyRect(kWebVrWarningPermanentRect));
-
-  // Check if we also need to show the transient warning.
-  if (present_time_nanos > webvr_warning_end_nanos_) {
-    return;
-  }
-
-  // Show IDS_WEBSITE_SETTINGS_INSECURE_WEBVR_CONTENT_TRANSIENT text.
-  SetIdentityM(icon_pos);
-  const float large_icon_width =
-      kWebVrWarningTransientRect.width / 1000.f * kWebVrWarningDistance;
-  const float large_icon_height =
-      kWebVrWarningTransientRect.height / 1000.f * kWebVrWarningDistance;
-  ScaleM(icon_pos, icon_pos, large_icon_width, large_icon_height, 1.0f);
-  TranslateM(icon_pos, icon_pos, 0.0f, 0.0f, -kWebVrWarningDistance);
-  combined = MatrixMul(projection_matrix,
-                       MatrixMul(view_matrix, icon_pos));
-  vr_shell_renderer_->GetTexturedQuadRenderer()->Draw(
-      ui_texture_id_, combined, MakeUiGlCopyRect(kWebVrWarningTransientRect));
-
-}
-
 void VrShell::OnTriggerEvent(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   // Set a flag to handle this on the render thread at the next frame.
   touch_pending_ = true;
 }
 
 void VrShell::OnPause(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   if (gvr_api_ == nullptr)
     return;
   controller_->OnPause();
   gvr_api_->PauseTracking();
@@ skipping 29 matching lines @@
       SK_ColorTRANSPARENT);
   html_interface_->OnDomContentsLoaded();
   dom_contents_loaded_ = true;
 }
 
 void VrShell::SetWebVrMode(JNIEnv* env,
                            const base::android::JavaParamRef<jobject>& obj,
                            bool enabled) {
   webvr_mode_ = enabled;
   if (enabled) {
-    int64_t now = gvr::GvrApi::GetTimePointNow().monotonic_system_time_nanos;
-    constexpr int64_t seconds_to_nanos = 1000 * 1000 * 1000;
-    webvr_warning_end_nanos_ = now + kWebVrWarningSeconds * seconds_to_nanos;
     html_interface_->SetMode(UiInterface::Mode::WEB_VR);
   } else {
-    webvr_warning_end_nanos_ = 0;
     html_interface_->SetMode(UiInterface::Mode::STANDARD);
   }
 }
 
 void VrShell::SetWebVRSecureOrigin(bool secure_origin) {
-  webvr_secure_origin_ = secure_origin;
+  html_interface_->SetSecureOrigin(secure_origin);
 }
 
 void VrShell::SubmitWebVRFrame() {
 }
 
 void VrShell::UpdateWebVRTextureBounds(
     int eye, float left, float top, float width, float height) {
   gvr::Rectf bounds = { left, top, width, height };
   vr_shell_renderer_->GetWebVrRenderer()->UpdateTextureBounds(eye, bounds);
 }
@@ skipping 92 matching lines @@
            const JavaParamRef<jobject>& ui_web_contents,
            jlong ui_window_android) {
   return reinterpret_cast<intptr_t>(new VrShell(
       env, obj, content::WebContents::FromJavaWebContents(content_web_contents),
       reinterpret_cast<ui::WindowAndroid*>(content_window_android),
       content::WebContents::FromJavaWebContents(ui_web_contents),
       reinterpret_cast<ui::WindowAndroid*>(ui_window_android)));
 }
 
 }  // namespace vr_shell