Migrate WebVR Cardboard implementation to GVR

device/vr/android/gvr/gvr_device.cc

Index: device/vr/android/gvr/gvr_device.cc
diff --git a/device/vr/android/gvr/gvr_device.cc b/device/vr/android/gvr/gvr_device.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2de6b12f0c8de234f8cee89354b35d8e0b0028d3
--- /dev/null
+++ b/device/vr/android/gvr/gvr_device.cc
@@ -0,0 +1,136 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "device/vr/android/gvr/gvr_device.h"
+
+#include <math.h>
+#include <algorithm>
+
+#include "base/time/time.h"
+#include "base/trace_event/trace_event.h"
+#include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr.h"
+#include "third_party/gvr-android-sdk/src/ndk-beta/include/vr/gvr/capi/include/gvr_types.h"
+#include "ui/gfx/transform.h"
+#include "ui/gfx/transform_util.h"
+
+namespace device {
+
+namespace {
+
+static const uint64_t kPredictionTimeWithoutVsyncNanos = 50000000;
+
+}  // namespace
+
+GvrDevice::GvrDevice(VRDeviceProvider* provider, gvr::GvrApi* gvr_api)
+    : VRDevice(provider), gvr_api_(gvr_api) {}
+
+GvrDevice::~GvrDevice() {}
+
+VRDisplayPtr GvrDevice::GetVRDevice() {
+  TRACE_EVENT0("input", "GvrDevice::GetVRDevice");
+
+  VRDisplayPtr device = VRDisplay::New();
+
+  device->capabilities = VRDisplayCapabilities::New();
+  device->capabilities->hasOrientation = true;
+  device->capabilities->hasPosition = false;
+  device->capabilities->hasExternalDisplay = false;
+  device->capabilities->canPresent = true;
+
+  device->leftEye = VREyeParameters::New();
+  device->rightEye = VREyeParameters::New();
+  VREyeParametersPtr& left_eye = device->leftEye;
+  VREyeParametersPtr& right_eye = device->rightEye;
+
+  device->displayName = gvr_api_->GetViewerModel();
+
+  gvr::BufferViewportList gvr_buffer_viewports =
+      gvr_api_->CreateEmptyBufferViewportList();
+  gvr_buffer_viewports.SetToRecommendedBufferViewports();
+
+  gvr::BufferViewport eye_viewport = gvr_api_->CreateBufferViewport();
+  gvr_buffer_viewports.GetBufferViewport(GVR_LEFT_EYE, &eye_viewport);
+  gvr::Rectf eye_fov = eye_viewport.GetSourceFov();
+  left_eye->fieldOfView = VRFieldOfView::New();
+  left_eye->fieldOfView->upDegrees = eye_fov.top;
+  left_eye->fieldOfView->downDegrees = eye_fov.bottom;
+  left_eye->fieldOfView->leftDegrees = eye_fov.left;
+  left_eye->fieldOfView->rightDegrees = eye_fov.right;
+
+  eye_viewport = gvr_api_->CreateBufferViewport();
+  gvr_buffer_viewports.GetBufferViewport(GVR_RIGHT_EYE, &eye_viewport);
+  eye_fov = eye_viewport.GetSourceFov();
+  right_eye->fieldOfView = VRFieldOfView::New();
+  right_eye->fieldOfView->upDegrees = eye_fov.top;
+  right_eye->fieldOfView->downDegrees = eye_fov.bottom;
+  right_eye->fieldOfView->leftDegrees = eye_fov.left;
+  right_eye->fieldOfView->rightDegrees = eye_fov.right;
+
+  gvr::Mat4f left_eye_mat = gvr_api_->GetEyeFromHeadMatrix(GVR_LEFT_EYE);
+  gvr::Mat4f right_eye_mat = gvr_api_->GetEyeFromHeadMatrix(GVR_RIGHT_EYE);
+
+  left_eye->offset = mojo::Array<float>::New(3);
+  left_eye->offset[0] = -left_eye_mat.m[0][3];
+  left_eye->offset[1] = -left_eye_mat.m[1][3];
+  left_eye->offset[2] = -left_eye_mat.m[2][3];
+
+  right_eye->offset = mojo::Array<float>::New(3);
+  right_eye->offset[0] = -right_eye_mat.m[0][3];
+  right_eye->offset[1] = -right_eye_mat.m[1][3];
+  right_eye->offset[2] = -right_eye_mat.m[2][3];
+
+  gvr::Sizei render_target_size = gvr_api_->GetRecommendedRenderTargetSize();
+
+  left_eye->renderWidth = render_target_size.width / 2;
+  left_eye->renderHeight = render_target_size.height;
+
+  right_eye->renderWidth = render_target_size.width / 2;
+  right_eye->renderHeight = render_target_size.height;
+
+  return device;
+}
+
+VRPosePtr GvrDevice::GetPose() {
+  TRACE_EVENT0("input", "GvrDevice::GetSensorState");
+
+  VRPosePtr pose = VRPose::New();
+
+  pose->timestamp = base::Time::Now().ToJsTime();
+
+  gvr::ClockTimePoint target_time = gvr::GvrApi::GetTimePointNow();
+  target_time.monotonic_system_time_nanos += kPredictionTimeWithoutVsyncNanos;
+
+  gvr::Mat4f head_mat = gvr_api_->GetHeadPoseInStartSpace(target_time);
+
+  gfx::Transform inv_transform(
+      head_mat.m[0][0], head_mat.m[0][1], head_mat.m[0][2], head_mat.m[0][3],
+      head_mat.m[1][0], head_mat.m[1][1], head_mat.m[1][2], head_mat.m[1][3],
+      head_mat.m[2][0], head_mat.m[2][1], head_mat.m[2][2], head_mat.m[2][3],
+      head_mat.m[3][0], head_mat.m[3][1], head_mat.m[3][2], head_mat.m[3][3]);
+
+  gfx::Transform transform;
+  if (inv_transform.GetInverse(&transform)) {
+    gfx::DecomposedTransform decomposed_transform;
+    gfx::DecomposeTransform(&decomposed_transform, transform);
+
+    pose->orientation = mojo::Array<float>::New(4);
+    pose->orientation[0] = decomposed_transform.quaternion[0];
+    pose->orientation[1] = decomposed_transform.quaternion[1];
+    pose->orientation[2] = decomposed_transform.quaternion[2];
+    pose->orientation[3] = decomposed_transform.quaternion[3];
+
+    pose->position = mojo::Array<float>::New(3);
+    pose->position[0] = decomposed_transform.translate[0];
+    pose->position[1] = decomposed_transform.translate[1];
+    pose->position[2] = decomposed_transform.translate[2];
+  }
+
+  return pose;
+}
+
+void GvrDevice::ResetPose() {
+  gvr_api_->ResetTracking();
+}
+
+}  // namespace device