VrShell: implement insecure content warning display

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 <thread>
 
 #include "chrome/browser/android/vr_shell/ui_scene.h"
 #include "chrome/browser/android/vr_shell/vr_compositor.h"
@@ skipping 54 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, 256};
+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
+
 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);
   float zdiff = (vec1.z - vec2.z);
   float scale = xdiff * xdiff + ydiff * ydiff + zdiff * zdiff;
   return std::sqrt(scale);
@@ skipping 217 matching lines @@
     // TODO: Not sure what object_from_reference_matrix is. The new api removed
     // it. For now, removing it seems working fine.
     ApplyNeckModel(head_pose);
   }
 
   // Bind back to the default framebuffer.
   frame.BindBuffer(0);
 
   if (webvr_mode_) {
     DrawWebVr();
+    if (!webvr_secure_origin_) {
+      DrawWebVrOverlay(target_time.monotonic_system_time_nanos);
+    }
   } else {
     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;
@@ skipping 43 matching lines @@
       PerspectiveMatrixFromView(params.GetSourceFov(), kZNear, kZFar),
       view_matrix);
 
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
   // TODO(mthiesse): Draw order for transparency.
   DrawUI(render_matrix);
   DrawCursor(render_matrix);
 }
 
+bool VrShell::IsUiTextureReady() {
+  return ui_tex_width_ > 0 && ui_tex_height_ > 0;
+}
+
+Rectf VrShell::MakeUiGlCopyRect(Recti pixel_rect) {
+  DCHECK(IsUiTextureReady());

[mthiesse, 2016/10/03 17:47:30]

This is for a security warning, so CHECK is probably warranted over DCHECK.

[klausw, 2016/10/03 20:55:12]

Done. Without the CHECK it would fail with a "division by zero" exception in the
following lines.

+  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_});
+}
+
 void VrShell::DrawUI(const gvr::Mat4f& render_matrix) {
   for (const auto& rect : scene_.GetUiElements()) {
     if (!rect->visible) {
       continue;
     }
 
     Rectf copy_rect;
     jint texture_handle;
     if (rect->id == kBrowserUiElementId) {
       copy_rect = {0, 0, 1, 1};
@@ skipping 76 matching lines @@
   glDepthMask(GL_FALSE);
   glDisable(GL_DEPTH_TEST);
   glDisable(GL_SCISSOR_TEST);
   glDisable(GL_BLEND);
   glDisable(GL_POLYGON_OFFSET_FILL);
 
   // Don't need to clear, since we're drawing over the entire render target.
 
   glViewport(0, 0, render_size_.width, render_size_.height);
   vr_shell_renderer_->GetWebVrRenderer()->Draw(content_texture_id_);
+}
 
-  if (!webvr_secure_origin_) {
-    // TODO(klausw): Draw the insecure origin warning here.
+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);
+
+  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);
+  const float small_icon_width =
+      kWebVrWarningPermanentRect.width / 1000.f * kWebVrWarningDistance;

[mthiesse, 2016/10/03 17:47:30]

What is this 1000.0f factor?

[klausw, 2016/10/03 20:55:12]

Added a comment:

  // 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_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::OnPause(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   if (gvr_api_ == nullptr)
     return;
   gvr_api_->PauseTracking();
 }
 
 void VrShell::OnResume(JNIEnv* env, const JavaParamRef<jobject>& obj) {
   if (gvr_api_ == nullptr)
@@ skipping 26 matching lines @@
   // TODO(bshe): ui_text_width_ and ui_tex_height_ should be only used on render
   // thread.
   ui_tex_width_ = width;
   ui_tex_height_ = height;
 }
 
 void VrShell::SetWebVrMode(JNIEnv* env,
                            const base::android::JavaParamRef<jobject>& obj,
                            bool enabled) {
   webvr_mode_ = enabled;
+  if (enabled) {
+    const int64_t warning_seconds = 30;

[mthiesse, 2016/10/03 17:47:30]

Move constant to top of file.

[klausw, 2016/10/03 20:55:12]

Done.

+    int64_t now = gvr::GvrApi::GetTimePointNow().monotonic_system_time_nanos;
+    webvr_warning_end_nanos_ = now + warning_seconds * 1000 * 1000 * 1000;

[mthiesse, 2016/10/03 17:47:30]

Extract constant for seconds to nanos.

[klausw, 2016/10/03 20:55:12]

Done.

+  } else {
+    webvr_warning_end_nanos_ = 0;
+  }
 }
 
 void VrShell::SetWebVRSecureOrigin(bool secure_origin) {
   webvr_secure_origin_ = secure_origin;
 }
 
 void VrShell::SubmitWebVRFrame() {
 }
 
 void VrShell::UpdateWebVRTextureBounds(
@@ skipping 62 matching lines @@
       content::WebContents::FromJavaWebContents(content_web_contents));
   content::ContentViewCore* ui_core = content::ContentViewCore::FromWebContents(
       content::WebContents::FromJavaWebContents(ui_web_contents));
   return reinterpret_cast<intptr_t>(new VrShell(
       env, obj, c_core,
       reinterpret_cast<ui::WindowAndroid*>(content_window_android), ui_core,
       reinterpret_cast<ui::WindowAndroid*>(ui_window_android)));
 }
 
 }  // namespace vr_shell