Implementation of elbow model for the controller position and rotation.

chrome/browser/android/vr_shell/vr_controller.cc

Index: chrome/browser/android/vr_shell/vr_controller.cc
diff --git a/chrome/browser/android/vr_shell/vr_controller.cc b/chrome/browser/android/vr_shell/vr_controller.cc
index b64671687be12e2dc4d8823ac6d5ef4400fd27f2..efbece142e203b729eb728fb7554ce9df5df4845 100644
--- a/chrome/browser/android/vr_shell/vr_controller.cc
+++ b/chrome/browser/android/vr_shell/vr_controller.cc
@@ -9,6 +9,7 @@
 #include <utility>
 
 #include "base/logging.h"
+#include "base/memory/ptr_util.h"
 #include "base/time/time.h"
 #include "chrome/browser/android/vr_shell/vr_math.h"
 #include "third_party/gvr-android-sdk/src/libraries/headers/vr/gvr/capi/include/gvr.h"
@@ -41,8 +42,6 @@ constexpr float kNanoSecondsPerSecond = 1.0e9f;
 
 constexpr int kMaxNumOfExtrapolations = 2;
 
-static constexpr gvr::Vec3f kControllerPosition = {0.2f, -0.5f, -0.15f};
-
 class Vector {
  public:
   static inline void ClampTouchpadPosition(gvr::Vec2f* position) {
@@ -87,7 +86,10 @@ class Vector {
 VrController::VrController(gvr_context* vr_context) {
   DVLOG(1) << __FUNCTION__ << "=" << this;
   Initialize(vr_context);
+  elbow_model_ = base::MakeUnique<ElbowModel>(handedness_);
   Reset();
+  last_timestamp_nanos_ =
+      gvr::GvrApi::GetTimePointNow().monotonic_system_time_nanos;
 }
 
 VrController::~VrController() {
@@ -137,19 +139,20 @@ gvr::Quatf VrController::Orientation() const {
 }
 
 gvr::Mat4f VrController::GetTransform() const {
-  // TODO(acondor): Position and orientation needs to be obtained
-  // from an elbow model.
-  // Placing the controller in a fixed position for now.
-  gvr::Mat4f mat;
-  SetIdentityM(mat);
-  // Changing rotation point.
-  TranslateM(mat, mat, 0, 0, 0.05);
-  mat = MatrixMul(QuatToMatrix(Orientation()), mat);
-  TranslateM(mat, mat, kControllerPosition.x, kControllerPosition.y,
-             kControllerPosition.z - 0.05);
+  auto mat = QuatToMatrix(elbow_model_->GetControllerRotation());
+  auto position = elbow_model_->GetControllerPosition();
+  TranslateM(mat, mat, position.x, position.y, position.z);
   return mat;
 }
 
+float VrController::GetOpacity() const {
+  return elbow_model_->GetAlphaValue();
+}
+
+gvr::Vec3f VrController::GetPointerStart() const {
+  return elbow_model_->GetControllerPosition();
+}
+
 VrControllerModel::State VrController::GetModelState() const {
   if (ButtonState(gvr::ControllerButton::GVR_CONTROLLER_BUTTON_CLICK))
     return VrControllerModel::TOUCHPAD;
@@ -184,7 +187,7 @@ bool VrController::IsConnected() {
   return controller_state_->GetConnectionState() == gvr::kControllerConnected;
 }
 
-void VrController::UpdateState() {
+void VrController::UpdateState(const gvr::Vec3f& head_direction) {
   const int32_t old_status = controller_state_->GetApiStatus();
   const int32_t old_connection_state = controller_state_->GetConnectionState();
   // Read current controller state.
@@ -196,6 +199,14 @@ void VrController::UpdateState() {
             << gvr_controller_connection_state_to_string(
                    controller_state_->GetConnectionState());
   }
+
+  float delta_time_seconds =

[asimjour1, 2017/04/19 18:58:12]

this conversion is repeated a few times, could you please use a function for
this.

[acondor_, 2017/04/21 21:04:32]

Done.

+      (gvr::GvrApi::GetTimePointNow().monotonic_system_time_nanos -
+       last_timestamp_nanos_) /
+      kNanoSecondsPerSecond;
+  elbow_model_->Update({IsConnected(), Orientation(),
+                        controller_state_->GetGyro(), head_direction,
+                        delta_time_seconds});
 }
 
 void VrController::UpdateTouchInfo() {