1 files changed, 73 insertions, 0 deletions
diff --git a/dom/vr/XRBoundedReferenceSpace.cpp b/dom/vr/XRBoundedReferenceSpace.cpp
new file mode 100644
index 0000000000..8d6eb25fdf
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+++ b/dom/vr/XRBoundedReferenceSpace.cpp
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+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this file,
+ * You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/XRBoundedReferenceSpace.h"
+#include "mozilla/dom/XRRigidTransform.h"
+#include "mozilla/dom/DOMPoint.h"
+#include "VRDisplayClient.h"
+
+namespace mozilla::dom {
+
+XRBoundedReferenceSpace::XRBoundedReferenceSpace(nsIGlobalObject* aParent,
+                                                 XRSession* aSession,
+                                                 XRNativeOrigin* aNativeOrigin)
+    : XRReferenceSpace(aParent, aSession, aNativeOrigin,
+                       XRReferenceSpaceType::Bounded_floor) {}
+
+JSObject* XRBoundedReferenceSpace::WrapObject(
+    JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
+  return XRBoundedReferenceSpace_Binding::Wrap(aCx, this, aGivenProto);
+}
+
+void XRBoundedReferenceSpace::GetBoundsGeometry(
+    nsTArray<RefPtr<DOMPointReadOnly>>& result) {
+  const auto size =
+      mSession->GetDisplayClient()->GetDisplayInfo().GetStageSize();
+  if (size.width == 0 || size.height == 0) {
+    return;
+  }
+
+  // https://immersive-web.github.io/webxr/#dom-xrboundedreferencespace-boundsgeometry
+  // bounds geometry must be premultiplied by the inverse of the origin offset.
+  gfx::PointDouble3D offset = mNativeOrigin->GetPosition();
+
+  const auto addPoint = [&](const double x, const double z) {
+    RefPtr<DOMPointReadOnly> obj = new DOMPointReadOnly(
+        GetParentObject(), x - offset.x, 0.0f, z - offset.z, 1.0f);
+    result.EmplaceBack(obj);
+  };
+
+  addPoint(-size.width * 0.5f, size.height * 0.5f);
+  addPoint(size.width * 0.5f, size.height * 0.5f);
+  addPoint(size.width * 0.5f, -size.height * 0.5f);
+  addPoint(-size.width * 0.5f, -size.height * 0.5f);
+
+  // TODO (Bug 1611526): Support WebXR bounded reference spaces
+}
+
+already_AddRefed<XRReferenceSpace>
+XRBoundedReferenceSpace::GetOffsetReferenceSpace(
+    const XRRigidTransform& aOriginOffset) {
+  RefPtr<XRBoundedReferenceSpace> offsetReferenceSpace =
+      new XRBoundedReferenceSpace(GetParentObject(), mSession, mNativeOrigin);
+
+  // https://immersive-web.github.io/webxr/#multiply-transforms
+  // An XRRigidTransform is essentially a rotation followed by a translation
+  gfx::QuaternionDouble otherOrientation = aOriginOffset.RawOrientation();
+  // The resulting rotation is the two combined
+  offsetReferenceSpace->mOriginOffsetOrientation =
+      mOriginOffsetOrientation * otherOrientation;
+  // We first apply the rotation of aOriginOffset to
+  // mOriginOffsetPosition offset, then translate by the offset of
+  // aOriginOffset
+  offsetReferenceSpace->mOriginOffsetPosition =
+      otherOrientation.RotatePoint(mOriginOffsetPosition) +
+      aOriginOffset.RawPosition();
+
+  return offsetReferenceSpace.forget();
+}
+
+}  // namespace mozilla::dom