VrShell: implement insecure content warning display

chrome/browser/android/vr_shell/vr_shell.cc

Index: chrome/browser/android/vr_shell/vr_shell.cc
diff --git a/chrome/browser/android/vr_shell/vr_shell.cc b/chrome/browser/android/vr_shell/vr_shell.cc
index 0eb5a06b11f81fa994bbdfaab47dfcca4781a223..0d340367a114f3ea8beac5dd48185489fb9447cb 100644
--- a/chrome/browser/android/vr_shell/vr_shell.cc
+++ b/chrome/browser/android/vr_shell/vr_shell.cc
@@ -250,6 +250,9 @@ void VrShell::DrawFrame(JNIEnv* env, const JavaParamRef<jobject>& obj) {
 
   if (webvr_mode_) {
     DrawWebVr();
+    if (!webvr_secure_origin_) {
+      DrawWebVrOverlay(target_time.monotonic_system_time_nanos);
+    }
   } else {
     DrawVrShell(target_time.monotonic_system_time_nanos);
   }
@@ -405,10 +408,86 @@ void VrShell::DrawWebVr() {
 
   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 the UI texture hasn't been initialized yet, we can't draw yet.
+  if (ui_tex_width_ == 0.0f || ui_tex_height_ == 0.0f) {
+    return;
   }
+
+  // Draw insecure content warning icons.
+  const float warning_depth = 0.7f;  // Distance in meters.
+
+  // Show IDS_WEBSITE_SETTINGS_INSECURE_WEBVR_CONTENT_PERMANENT text.
+  gvr::Mat4f icon_pos;
+  SetIdentityM(icon_pos);
+  const float small_icon_width = 2 * 0.15f * warning_depth;
+  const float small_icon_height = small_icon_width / 2.0f;  // 2:1 aspect.
+  const float small_icon_angle = 20.0f * 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, -warning_depth);
+  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));
+  Rectf copy_rect = {256.f / ui_tex_width_, 0.f / ui_tex_height_,

[cjgrant, 2016/09/28 14:57:52]

Could you move these coordinates (here and below) to constants up at the top of
the file?  This will naturally break any time the HTML UI is changed.

Optionally, I'd adding a private helper method on this class.  Something like:

Rectf copy_rect = MakeUiCopyRect(pixel_x, pixel_y, width, height),

to handle int-to-float casting and division.

+                     128.f / ui_tex_width_, 64.f / ui_tex_height_};
+  vr_shell_renderer_->GetTexturedQuadRenderer()->Draw(
+      ui_texture_id_, combined, copy_rect);
+
+  // 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 = 2 * 0.25f * warning_depth;
+  const float large_icon_height = large_icon_width / 2.0f;  // 2:1 aspect.
+  ScaleM(icon_pos, icon_pos, large_icon_width, large_icon_height, 1.0f);
+  TranslateM(icon_pos, icon_pos, 0.0f, 0.0f, -warning_depth);
+  combined = MatrixMul(projection_matrix,
+                       MatrixMul(view_matrix, icon_pos));
+  copy_rect = {0.f / ui_tex_width_, 0.f / ui_tex_height_,
+               256.f / ui_tex_width_, 128.f / ui_tex_height_};
+  vr_shell_renderer_->GetTexturedQuadRenderer()->Draw(
+      ui_texture_id_, combined, copy_rect);
+
 }
 
 void VrShell::OnPause(JNIEnv* env, const JavaParamRef<jobject>& obj) {
@@ -447,6 +526,13 @@ void VrShell::SetWebVrMode(JNIEnv* env,
                            const base::android::JavaParamRef<jobject>& obj,
                            bool enabled) {
   webvr_mode_ = enabled;
+  if (enabled) {
+    const int64_t warning_seconds = 30;
+    int64_t now = gvr::GvrApi::GetTimePointNow().monotonic_system_time_nanos;
+    webvr_warning_end_nanos_ = now + warning_seconds * 1000 * 1000 * 1000;
+  } else {
+    webvr_warning_end_nanos_ = 0;
+  }
 }
 
 void VrShell::SetWebVRSecureOrigin(bool secure_origin) {