Android WebVR implementation, Cardboard 0.5.5 SDK

content/browser/vr/android/cardboard/cardboard_vr_device.cc

+// Copyright 2015 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 "content/browser/vr/android/cardboard/cardboard_vr_device.h"
+
+#include <math.h>
+#include <algorithm>
+
+#include "base/android/jni_android.h"
+#include "base/android/jni_array.h"
+#include "base/android/jni_string.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
+#include "content/browser/vr/vr_transform_util.h"
+#include "jni/CardboardVRDevice_jni.h"
+
+using base::android::AttachCurrentThread;
+
+namespace content {
+
+bool CardboardVRDevice::RegisterCardboardVRDevice(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+CardboardVRDevice::CardboardVRDevice(VRDeviceProvider* provider)
+    : VRDevice(provider), frame_index_(0) {
+  JNIEnv* env = AttachCurrentThread();
+  j_cardboard_device_.Reset(Java_CardboardVRDevice_create(
+      env, base::android::GetApplicationContext()));
+  j_head_matrix_.Reset(env, env->NewFloatArray(16));
+}
+
+CardboardVRDevice::~CardboardVRDevice() {
+  Java_CardboardVRDevice_stopTracking(AttachCurrentThread(),
+                                      j_cardboard_device_.obj());
+}
+
+VRDeviceInfoPtr CardboardVRDevice::GetVRDevice() {
+  VRDeviceInfoPtr device = VRDeviceInfo::New();

[jdduke (slow), 2015/07/23 19:10:57]

Oh, could you add a TRACE_EVENT entry for this function and GetSensorState (or
is there tracing at a slightly higher level in the VR stack?). Not sure what the
best category would be, maybe "input" or "browser"?

+
+  JNIEnv* env = AttachCurrentThread();
+
+  ScopedJavaLocalRef<jstring> j_device_name =
+      Java_CardboardVRDevice_getDeviceName(env, j_cardboard_device_.obj());
+  device->deviceName =
+      base::android::ConvertJavaStringToUTF8(env, j_device_name.obj());
+
+  ScopedJavaLocalRef<jfloatArray> j_fov(env, env->NewFloatArray(4));
+  Java_CardboardVRDevice_getFieldOfView(env, j_cardboard_device_.obj(),
+                                        j_fov.obj());
+
+  std::vector<float> fov;
+  base::android::JavaFloatArrayToFloatVector(env, j_fov.obj(), &fov);
+
+  device->hmdInfo = VRHMDInfo::New();
+  VRHMDInfoPtr& hmdInfo = device->hmdInfo;
+
+  hmdInfo->leftEye = VREyeParameters::New();
+  hmdInfo->rightEye = VREyeParameters::New();
+  VREyeParametersPtr& left_eye = hmdInfo->leftEye;
+  VREyeParametersPtr& right_eye = hmdInfo->rightEye;
+
+  left_eye->recommendedFieldOfView = VRFieldOfView::New();
+  left_eye->recommendedFieldOfView->upDegrees = fov[0];
+  left_eye->recommendedFieldOfView->downDegrees = fov[1];
+  left_eye->recommendedFieldOfView->leftDegrees = fov[2];
+  left_eye->recommendedFieldOfView->rightDegrees = fov[3];
+
+  // Cardboard devices always assume a mirrored FOV, so this is just the left
+  // eye FOV with the left and right degrees swapped.
+  right_eye->recommendedFieldOfView = VRFieldOfView::New();
+  right_eye->recommendedFieldOfView->upDegrees = fov[0];
+  right_eye->recommendedFieldOfView->downDegrees = fov[1];
+  right_eye->recommendedFieldOfView->leftDegrees = fov[3];
+  right_eye->recommendedFieldOfView->rightDegrees = fov[2];
+
+  // Cardboard does not support configurable FOV.
+  left_eye->maximumFieldOfView = left_eye->recommendedFieldOfView.Clone();
+  right_eye->maximumFieldOfView = right_eye->recommendedFieldOfView.Clone();
+  left_eye->minimumFieldOfView = left_eye->recommendedFieldOfView.Clone();
+  right_eye->minimumFieldOfView = right_eye->recommendedFieldOfView.Clone();
+
+  float ipd = Java_CardboardVRDevice_getIpd(env, j_cardboard_device_.obj());
+
+  left_eye->eyeTranslation = VRVector3::New();
+  left_eye->eyeTranslation->x = ipd * -0.5f;
+  left_eye->eyeTranslation->y = 0.0f;
+  left_eye->eyeTranslation->z = 0.0f;
+
+  right_eye->eyeTranslation = VRVector3::New();
+  right_eye->eyeTranslation->x = ipd * 0.5f;
+  right_eye->eyeTranslation->y = 0.0f;
+  right_eye->eyeTranslation->z = 0.0f;
+
+  ScopedJavaLocalRef<jintArray> j_screen_size(env, env->NewIntArray(2));
+  Java_CardboardVRDevice_getScreenSize(env, j_cardboard_device_.obj(),
+                                       j_screen_size.obj());
+
+  std::vector<int> screen_size;
+  base::android::JavaIntArrayToIntVector(env, j_screen_size.obj(),
+                                         &screen_size);
+
+  left_eye->renderRect = VRRect::New();
+  left_eye->renderRect->x = 0;
+  left_eye->renderRect->y = 0;
+  left_eye->renderRect->width = screen_size[0] / 2.0;
+  left_eye->renderRect->height = screen_size[1];
+
+  right_eye->renderRect = VRRect::New();
+  right_eye->renderRect->x = screen_size[0] / 2.0;
+  right_eye->renderRect->y = 0;
+  right_eye->renderRect->width = screen_size[0] / 2.0;
+  right_eye->renderRect->height = screen_size[1];
+
+  return device.Pass();
+}
+
+VRSensorStatePtr CardboardVRDevice::GetSensorState() {
+  VRSensorStatePtr state = VRSensorState::New();
+
+  state->timestamp = base::Time::Now().ToJsTime();
+  state->frameIndex = frame_index_++;
+
+  JNIEnv* env = AttachCurrentThread();
+  Java_CardboardVRDevice_getSensorState(env, j_cardboard_device_.obj(),
+                                        j_head_matrix_.obj());
+
+  std::vector<float> head_matrix;
+  base::android::JavaFloatArrayToFloatVector(env, j_head_matrix_.obj(),
+                                             &head_matrix);
+
+  state->orientation = MatrixToOrientationQuaternion(
+      &head_matrix[0], &head_matrix[4], &head_matrix[8]);
+
+  state->position = VRVector3::New();
+  state->position->x = -head_matrix[12];
+  state->position->y = head_matrix[13];
+  state->position->z = head_matrix[14];
+
+  return state.Pass();
+}
+
+void CardboardVRDevice::ResetSensor() {
+  Java_CardboardVRDevice_resetSensor(AttachCurrentThread(),
+                                     j_cardboard_device_.obj());
+}
+
+}  // namespace content