Bug 1630007 - Apply XRSpace effective origin position and orientation using matrix multiplication. r=kip,daoshengmu

Differential Revision: https://phabricator.services.mozilla.com/D70923

--HG--
extra : moz-landing-system : lando

dom/vr/XRFrame.cpp

@@ -60,14 +60,6 @@ already_AddRefed<XRViewerPose> XRFrame::GetViewerPose(
   float depthNear = (float)renderState->DepthNear();
   float depthFar = (float)renderState->DepthFar();
 
-  const gfx::PointDouble3D& originPosition =
-      aReferenceSpace.GetEffectiveOriginPosition();
-  const gfx::QuaternionDouble& originOrientation =
-      aReferenceSpace.GetEffectiveOriginOrientation();
-
-  gfx::QuaternionDouble invOriginOrientation = originOrientation;
-  invOriginOrientation.Invert();
-
   gfx::VRDisplayClient* display = mSession->GetDisplayClient();
   if (display) {
     // Have a VRDisplayClient
@@ -86,14 +78,17 @@ already_AddRefed<XRViewerPose> XRFrame::GetViewerPose(
     // TODO: Remove those extra inverts when WebVR support is disabled.
     viewerOrientation.Invert();
 
-    viewerPosition = invOriginOrientation.RotatePoint(viewerPosition);
-    viewerPosition -= originPosition;
-    viewerOrientation *= invOriginOrientation;
-
     gfx::Matrix4x4Double headTransform;
     headTransform.SetRotationFromQuaternion(viewerOrientation);
     headTransform.PostTranslate(viewerPosition);
 
+    gfx::Matrix4x4Double originTransform;
+    originTransform.SetRotationFromQuaternion(
+        aReferenceSpace.GetEffectiveOriginOrientation());
+    originTransform.PreTranslate(-aReferenceSpace.GetEffectiveOriginPosition());
+
+    headTransform *= originTransform;
+
     auto addEye = [&](XREye xrEye, VRDisplayState::Eye eye) {
       auto offset = displayInfo.GetEyeTranslation(eye);
       auto eyeFromHead = gfx::Matrix4x4Double::Translation(
@@ -165,21 +160,13 @@ XRPose* XRFrame::GetPose(const XRSpace& aSpace, const XRSpace& aBaseSpace,
   // TODO (Bug 1616393) - Check if poses must be limited:
   // https://immersive-web.github.io/webxr/#poses-must-be-limited
 
-  const gfx::PointDouble3D& originPosition =
-      aBaseSpace.GetEffectiveOriginPosition();
-  gfx::PointDouble3D position = aSpace.GetEffectiveOriginPosition();
-  gfx::QuaternionDouble orientation = aSpace.GetEffectiveOriginOrientation();
+  gfx::Matrix4x4Double base;
+  base.SetRotationFromQuaternion(aBaseSpace.GetEffectiveOriginOrientation());
+  base.PreTranslate(-aBaseSpace.GetEffectiveOriginPosition());
 
-  gfx::QuaternionDouble invOriginOrientation(
-      aBaseSpace.GetEffectiveOriginOrientation());
-  invOriginOrientation.Invert();
+  gfx::Matrix4x4Double matrix = aSpace.GetEffectiveOriginTransform() * base;
 
-  position = invOriginOrientation.RotatePoint(position);
-  position -= originPosition;
-  orientation *= invOriginOrientation;
-
-  RefPtr<XRRigidTransform> transform =
-      new XRRigidTransform(mParent, position, orientation);
+  RefPtr<XRRigidTransform> transform = new XRRigidTransform(mParent, matrix);
   RefPtr<XRPose> pose = new XRPose(mParent, transform, false);
 
   return pose;

dom/vr/XRRigidTransform.cpp

@@ -42,6 +42,21 @@ XRRigidTransform::XRRigidTransform(nsISupports* aParent,
                               aOrientation.z, aOrientation.w);
 }
 
+XRRigidTransform::XRRigidTransform(nsISupports* aParent,
+                                   const gfx::Matrix4x4Double& aTransform)
+    : mParent(aParent), mMatrixArray(nullptr) {
+  mozilla::HoldJSObjects(this);
+  gfx::PointDouble3D position;
+  gfx::PointDouble3D scale;
+  gfx::QuaternionDouble orientation;
+
+  aTransform.Decompose(position, orientation, scale);
+
+  mPosition = new DOMPoint(aParent, position.x, position.y, position.z, 1.0f);
+  mOrientation = new DOMPoint(aParent, orientation.x, orientation.y,
+                              orientation.z, orientation.w);
+}
+
 XRRigidTransform::~XRRigidTransform() { mozilla::DropJSObjects(this); }
 
 /* static */ already_AddRefed<XRRigidTransform> XRRigidTransform::Constructor(

dom/vr/XRRigidTransform.h

@@ -25,6 +25,8 @@ class XRRigidTransform final : public nsWrapperCache {
   explicit XRRigidTransform(nsISupports* aParent,
                             const gfx::PointDouble3D& aPosition,
                             const gfx::QuaternionDouble& aOrientation);
+  explicit XRRigidTransform(nsISupports* aParent,
+                            const gfx::Matrix4x4Double& aTransform);
   static already_AddRefed<XRRigidTransform> Constructor(
       const GlobalObject& aGlobal, const DOMPointInit& aOrigin,
       const DOMPointInit& aDirection, ErrorResult& aRv);

dom/vr/XRSpace.cpp

@@ -40,7 +40,8 @@ JSObject* XRSpace::WrapObject(JSContext* aCx,
 XRSession* XRSpace::GetSession() const { return mSession; }
 
 gfx::QuaternionDouble XRSpace::GetEffectiveOriginOrientation() const {
-  gfx::QuaternionDouble orientation = mNativeOrigin->GetOrientation() * mOriginOffsetOrientation;
+  gfx::QuaternionDouble orientation =
+      mNativeOrigin->GetOrientation() * mOriginOffsetOrientation;
   return orientation;
 }
 
@@ -52,6 +53,13 @@ gfx::PointDouble3D XRSpace::GetEffectiveOriginPosition() const {
   return position;
 }
 
+gfx::Matrix4x4Double XRSpace::GetEffectiveOriginTransform() const {
+  gfx::Matrix4x4Double transform;
+  transform.SetRotationFromQuaternion(GetEffectiveOriginOrientation());
+  transform.PostTranslate(GetEffectiveOriginPosition());
+  return transform;
+}
+
 bool XRSpace::IsPositionEmulated() const {
   gfx::VRDisplayClient* display = mSession->GetDisplayClient();
   if (!display) {

dom/vr/XRSpace.h

@@ -37,6 +37,7 @@ class XRSpace : public DOMEventTargetHelper {
   // Non webIDL Members
   gfx::QuaternionDouble GetEffectiveOriginOrientation() const;
   gfx::PointDouble3D GetEffectiveOriginPosition() const;
+  gfx::Matrix4x4Double GetEffectiveOriginTransform() const;
   bool IsPositionEmulated() const;
 
  protected: