VR: Add a loading indicator to the scene.

chrome/browser/android/vr_shell/ui_elements/textured_element.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/ui_elements/textured_element.h"
 
 #include "base/trace_event/trace_event.h"
 #include "cc/paint/skia_paint_canvas.h"
 #include "chrome/browser/android/vr_shell/textures/ui_texture.h"
 #include "chrome/browser/android/vr_shell/vr_shell_renderer.h"
 #include "third_party/skia/include/core/SkSurface.h"
 
 namespace vr_shell {
 
 TexturedElement::TexturedElement(int maximum_width)
     : texture_handle_(-1), maximum_width_(maximum_width) {}
 
 TexturedElement::~TexturedElement() = default;
 
 void TexturedElement::Initialize() {
   TRACE_EVENT0("gpu", "TexturedElement::Initialize");
   glGenTextures(1, &texture_handle_);
   DCHECK(GetTexture() != nullptr);
   texture_size_ = GetTexture()->GetPreferredTextureSize(maximum_width_);
+  initialized_ = true;
   UpdateTexture();
   set_fill(Fill::SELF);
   gfx::SizeF drawn_size = GetTexture()->GetDrawnSize();
   float y = drawn_size.height() / drawn_size.width() * size().x();
   set_size({size().x(), y, 1});
 }
 
 void TexturedElement::UpdateTexture() {
+  if (!initialized_)
+    return;
   sk_sp<SkSurface> surface = SkSurface::MakeRasterN32Premul(
       texture_size_.width(), texture_size_.height());
   GetTexture()->DrawAndLayout(surface->getCanvas(), texture_size_);
   Flush(surface.get());
 }
 
 void TexturedElement::Render(VrShellRenderer* renderer,
                              vr::Mat4f view_proj_matrix) const {
+  if (!initialized_)
+    return;
   gfx::SizeF drawn_size = GetTexture()->GetDrawnSize();
   gfx::RectF copy_rect(0, 0, drawn_size.width() / texture_size_.width(),
                        drawn_size.height() / texture_size_.height());
   renderer->GetTexturedQuadRenderer()->AddQuad(
       texture_handle_, view_proj_matrix, copy_rect, opacity());
 }
 
 void TexturedElement::Flush(SkSurface* surface) {
   cc::SkiaPaintCanvas paint_canvas(surface->getCanvas());
   paint_canvas.flush();
   SkPixmap pixmap;
   CHECK(surface->peekPixels(&pixmap));
 
   glBindTexture(GL_TEXTURE_2D, texture_handle_);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, pixmap.width(), pixmap.height(), 0,
                GL_RGBA, GL_UNSIGNED_BYTE, pixmap.addr());
 }
 
 }  // namespace vr_shell