dom/vr/XRBoundedReferenceSpace.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 file,
   5  * You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "mozilla/dom/XRBoundedReferenceSpace.h"
   8 #include "mozilla/dom/XRRigidTransform.h"
   9 #include "mozilla/dom/DOMPoint.h"
  10 #include "VRDisplayClient.h"
  11
  12 namespace mozilla::dom {
  13
  14 XRBoundedReferenceSpace::XRBoundedReferenceSpace(nsIGlobalObject* aParent,
  15                                                  XRSession* aSession,
  16                                                  XRNativeOrigin* aNativeOrigin)
  17     : XRReferenceSpace(aParent, aSession, aNativeOrigin,
  18                        XRReferenceSpaceType::Bounded_floor) {}
  19
  20 JSObject* XRBoundedReferenceSpace::WrapObject(
  21     JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
  22   return XRBoundedReferenceSpace_Binding::Wrap(aCx, this, aGivenProto);
  23 }
  24
  25 void XRBoundedReferenceSpace::GetBoundsGeometry(
  26     nsTArray<RefPtr<DOMPointReadOnly>>& result) {
  27   const auto size =
  28       mSession->GetDisplayClient()->GetDisplayInfo().GetStageSize();
  29   if (size.width == 0 || size.height == 0) {
  30     return;
  31   }
  32
  33   // https://immersive-web.github.io/webxr/#dom-xrboundedreferencespace-boundsgeometry
  34   // bounds geometry must be premultiplied by the inverse of the origin offset.
  35   gfx::PointDouble3D offset = mNativeOrigin->GetPosition();
  36
  37   const auto addPoint = [&](const double x, const double z) {
  38     RefPtr<DOMPointReadOnly> obj = new DOMPointReadOnly(
  39         GetParentObject(), x - offset.x, 0.0f, z - offset.z, 1.0f);
  40     result.EmplaceBack(obj);
  41   };
  42
  43   addPoint(-size.width * 0.5f, size.height * 0.5f);
  44   addPoint(size.width * 0.5f, size.height * 0.5f);
  45   addPoint(size.width * 0.5f, -size.height * 0.5f);
  46   addPoint(-size.width * 0.5f, -size.height * 0.5f);
  47
  48   // TODO (Bug 1611526): Support WebXR bounded reference spaces
  49 }
  50
  51 already_AddRefed<XRReferenceSpace>
  52 XRBoundedReferenceSpace::GetOffsetReferenceSpace(
  53     const XRRigidTransform& aOriginOffset) {
  54   RefPtr<XRBoundedReferenceSpace> offsetReferenceSpace =
  55       new XRBoundedReferenceSpace(GetParentObject(), mSession, mNativeOrigin);
  56
  57   // https://immersive-web.github.io/webxr/#multiply-transforms
  58   // An XRRigidTransform is essentially a rotation followed by a translation
  59   gfx::QuaternionDouble otherOrientation = aOriginOffset.RawOrientation();
  60   // The resulting rotation is the two combined
  61   offsetReferenceSpace->mOriginOffsetOrientation =
  62       mOriginOffsetOrientation * otherOrientation;
  63   // We first apply the rotation of aOriginOffset to
  64   // mOriginOffsetPosition offset, then translate by the offset of
  65   // aOriginOffset
  66   offsetReferenceSpace->mOriginOffsetPosition =
  67       otherOrientation.RotatePoint(mOriginOffsetPosition) +
  68       aOriginOffset.RawPosition();
  69
  70   return offsetReferenceSpace.forget();
  71 }
  72
  73 }  // namespace mozilla::dom