// 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.

module device.mojom;

// A field of view, given by 4 degrees describing the view from a center point.
struct VRFieldOfView {
  float upDegrees;
  float downDegrees;
  float leftDegrees;
  float rightDegrees;
};

// A display's position, orientation, velocity, and acceleration state at the
// given timestamp.
struct VRPose {
  double timestamp;
  array<float, 4>? orientation;
  array<float, 3>? position;
  array<float, 3>? angularVelocity;
  array<float, 3>? linearVelocity;
  array<float, 3>? angularAcceleration;
  array<float, 3>? linearAcceleration;
  // The poseIndex is a sequential ID that's incremented on each distinct
  // getPose result, it may wrap around for long sessions.
  uint32 poseIndex;
};

struct VRDisplayCapabilities {
  bool hasOrientation;
  bool hasPosition;
  bool hasExternalDisplay;
  bool canPresent;
};

// Information about the optical properties for an eye in a VRDisplay.
struct VREyeParameters {
  VRFieldOfView fieldOfView;
  array<float, 3> offset;
  uint32 renderWidth;
  uint32 renderHeight;
};

struct VRStageParameters {
  array<float, 16> standingTransform;
  float sizeX;
  float sizeZ;
};

struct VRDisplayInfo {
  uint32 index;
  string displayName;
  VRDisplayCapabilities capabilities;
  VRStageParameters? stageParameters;
  VREyeParameters leftEye;
  VREyeParameters rightEye;
};

struct VRLayerBounds {
  float left;
  float top;
  float width;
  float height;
};

enum VRDisplayEventReason {
  NONE = 0,
  NAVIGATION = 1,
  MOUNTED = 2,
  UNMOUNTED = 3
};

// TODO(shaobo.yan@intel.com) : Add comments to describe these interfaces about how to use and where they live.
interface VRService {
  // TODO(shaobo.yan@intel.com) : Use a factory function which took a VRServiceClient
  // so we would never have a half-initialized VRService.
  SetClient(VRServiceClient client) => (uint32 numberOfConnectedDevices);
  // Inform the service that the page is listening for vrdisplayactivate events.
  SetListeningForActivate(bool listening);
};

interface VRServiceClient {
  OnDisplayConnected(VRDisplay display, VRDisplayClient& request, VRDisplayInfo displayInfo);
};

interface VRDisplay {
  [Sync]
  GetPose() => (VRPose? pose);
  ResetPose();

  RequestPresent(bool secureOrigin) => (bool success);
  ExitPresent();
  SubmitFrame(VRPose? pose);
  UpdateLayerBounds(VRLayerBounds leftBounds, VRLayerBounds rightBounds);
};

interface VRDisplayClient {
  OnChanged(VRDisplayInfo display);
  OnExitPresent();
  OnBlur();
  OnFocus();
  OnActivate(VRDisplayEventReason reason);
  OnDeactivate(VRDisplayEventReason reason);
};