gfx/vr/VRDisplayPresentation.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "VRDisplayPresentation.h"
   8
   9 #include "mozilla/dom/DocGroup.h"
  10 #include "mozilla/Unused.h"
  11 #include "VRDisplayClient.h"
  12 #include "VRLayerChild.h"
  13
  14 using namespace mozilla;
  15 using namespace mozilla::gfx;
  16
  17 VRDisplayPresentation::VRDisplayPresentation(
  18     VRDisplayClient* aDisplayClient,
  19     const nsTArray<mozilla::dom::VRLayer>& aLayers, uint32_t aGroup)
  20     : mDisplayClient(aDisplayClient), mDOMLayers(aLayers), mGroup(aGroup) {
  21   CreateLayers();
  22 }
  23
  24 void VRDisplayPresentation::UpdateLayers(
  25     const nsTArray<mozilla::dom::VRLayer>& aLayers) {
  26   mDOMLayers = aLayers;
  27   CreateLayers();
  28 }
  29
  30 uint32_t VRDisplayPresentation::GetGroup() const { return mGroup; }
  31
  32 void VRDisplayPresentation::CreateLayers() {
  33   VRManagerChild* manager = VRManagerChild::Get();
  34   if (!manager) {
  35     // This should not happen, but let's log it and avoid a crash in case
  36     // of regression.
  37     NS_WARNING("VRManagerChild::Get returned null!");
  38     return;
  39   }
  40
  41   unsigned int iLayer = 0;
  42   for (dom::VRLayer& layer : mDOMLayers) {
  43     dom::HTMLCanvasElement* canvasElement = layer.mSource;
  44     if (!canvasElement) {
  45       /// XXX In the future we will support WebVR in WebWorkers here
  46       continue;
  47     }
  48
  49     Rect leftBounds(0.0, 0.0, 0.5, 1.0);
  50     if (layer.mLeftBounds.Length() == 4) {
  51       leftBounds.SetRect(layer.mLeftBounds[0], layer.mLeftBounds[1],
  52                          layer.mLeftBounds[2], layer.mLeftBounds[3]);
  53     } else if (layer.mLeftBounds.Length() != 0) {
  54       /**
  55        * We ignore layers with an incorrect number of values.
  56        * In the future, VRDisplay.requestPresent may throw in
  57        * this case.  See https://github.com/w3c/webvr/issues/71
  58        */
  59       continue;
  60     }
  61
  62     Rect rightBounds(0.5, 0.0, 0.5, 1.0);
  63     if (layer.mRightBounds.Length() == 4) {
  64       rightBounds.SetRect(layer.mRightBounds[0], layer.mRightBounds[1],
  65                           layer.mRightBounds[2], layer.mRightBounds[3]);
  66     } else if (layer.mRightBounds.Length() != 0) {
  67       /**
  68        * We ignore layers with an incorrect number of values.
  69        * In the future, VRDisplay.requestPresent may throw in
  70        * this case.  See https://github.com/w3c/webvr/issues/71
  71        */
  72       continue;
  73     }
  74
  75     nsCOMPtr<nsIEventTarget> target =
  76         canvasElement->OwnerDoc()->EventTargetFor(TaskCategory::Other);
  77
  78     if (mLayers.Length() <= iLayer) {
  79       // Not enough layers, let's add one
  80       RefPtr<VRLayerChild> vrLayer =
  81           static_cast<VRLayerChild*>(manager->CreateVRLayer(
  82               mDisplayClient->GetDisplayInfo().GetDisplayID(), target, mGroup));
  83       if (!vrLayer) {
  84         NS_WARNING("CreateVRLayer returned null!");
  85         continue;
  86       }
  87       vrLayer->Initialize(canvasElement, leftBounds, rightBounds);
  88       mLayers.AppendElement(vrLayer);
  89     } else {
  90       // We already have a layer, let's update it
  91       mLayers[iLayer]->Initialize(canvasElement, leftBounds, rightBounds);
  92     }
  93     iLayer++;
  94   }
  95
  96   // Truncate any excess layers that weren't included in the updated list
  97   mLayers.SetLength(iLayer);
  98 }
  99
 100 void VRDisplayPresentation::DestroyLayers() {
 101   for (VRLayerChild* layer : mLayers) {
 102     if (layer->IsIPCOpen()) {
 103       Unused << layer->SendDestroy();
 104     }
 105   }
 106   mLayers.Clear();
 107 }
 108
 109 void VRDisplayPresentation::GetDOMLayers(nsTArray<dom::VRLayer>& result) {
 110   result = mDOMLayers;
 111 }
 112
 113 VRDisplayPresentation::~VRDisplayPresentation() {
 114   DestroyLayers();
 115   mDisplayClient->PresentationDestroyed();
 116 }
 117
 118 void VRDisplayPresentation::SubmitFrame() {
 119   for (VRLayerChild* layer : mLayers) {
 120     layer->SubmitFrame(mDisplayClient->GetDisplayInfo());
 121     break;  // Currently only one layer supported, submit only the first
 122   }
 123 }