device/vr/vr_service.mojom

// 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;

import "mojo/common/time.mojom";
import "gpu/ipc/common/mailbox_holder.mojom";
import "gpu/ipc/common/sync_token.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 {
  array<float, 4>? orientation;
  array<float, 3>? position;
  array<float, 3>? angularVelocity;
  array<float, 3>? linearVelocity;
  array<float, 3>? angularAcceleration;
  array<float, 3>? linearAcceleration;
};

struct VRDisplayCapabilities {
  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, crbug/701027): Use a factory function which
  // takes a VRServiceClient so we will 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 VRSubmitFrameClient {
  OnSubmitFrameTransferred();
  OnSubmitFrameRendered();
};

interface VRDisplay {
  RequestPresent(bool secureOrigin, VRSubmitFrameClient client) => (bool success);
  ExitPresent();
  SubmitFrame(int16 frameId, gpu.mojom.MailboxHolder mailboxHolder);
  UpdateLayerBounds(int16 frameId, VRLayerBounds leftBounds,
                    VRLayerBounds rightBounds, int16 sourceWidth,
                    int16 sourceHeight);
  GetVRVSyncProvider(VRVSyncProvider& request);
};

interface VRVSyncProvider {
  enum Status { SUCCESS, CLOSING };

  // The frameId maps a VSync to a frame arriving from the compositor. IDs will
  // be reused after the frame arrives from the compositor. Negative IDs imply
  // no mapping.
  GetVSync() => (VRPose? pose, mojo.common.mojom.TimeDelta time, int16 frameId,
                 Status status);
};

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