path: root/chromium/device/vr/public/mojom/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/public/mojom/base/time.mojom";
import "gpu/ipc/common/mailbox_holder.mojom";
import "gpu/ipc/common/sync_token.mojom";
import "ui/display/mojo/display.mojom";
import "ui/gfx/geometry/mojo/geometry.mojom";
import "ui/gfx/mojo/gpu_fence_handle.mojom";
import "ui/gfx/mojo/transform.mojom";

//
// WebXR interfaces
//

enum XRHandedness {
  NONE = 0,
  LEFT = 1,
  RIGHT = 2
};

enum XRTargetRayMode {
  GAZING = 1,
  POINTING = 2,
  TAPPING = 3
};

struct XRSessionOptions {
  bool immersive;
  bool provide_passthrough_camera;

  // A flag to indicate if there has been a user activation when the request
  // session is made.
  bool has_user_activation;

  // This flag ensures that render paths that are only supported in WebXR are
  // not used for WebVR 1.1.
  bool use_legacy_webvr_render_path;
};

// TODO(offenwanger) Rearrange these two interfaces to merge duplicate
// functionality.
struct XRSession {
  VRMagicWindowProvider? magic_window_provider;
  XRPresentationConnection? connection;
};

struct XRPresentationConnection {
  VRSubmitFrameClient& client_request;
  VRPresentationProvider provider;
  VRDisplayFrameTransportOptions transport_options;
};

struct XRInputSourceDescription {
  XRTargetRayMode target_ray_mode;
  XRHandedness handedness;
  bool emulated_position;

  // Transform from the grip matrix to the pointer's origin and orientation.
  gfx.mojom.Transform? pointer_offset;
};

struct XRInputSourceState {
  uint32 source_id;

  // Description of this input source's behavior. Should be mostly static, only
  // need periodic updates.
  XRInputSourceDescription? description;

  // Transform to the controllers grip (users palm) from start space origin.
  gfx.mojom.Transform? grip;

  // Describes the current state of the primary input.
  bool primary_input_pressed;

  // Indicates if the input's primary input has been released (clicked) since
  // the last report. May indicate that the button was pressed and released in
  // the space of a single frame, so it may not have been preceeded by a
  // primary_input_pressed = true;
  bool primary_input_clicked;
};

//
// WebVR/WebXR shared interfaces
//

// 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;

  // For WebXR sessions only, reports the state of all active input devices
  // synced with the head pose.
  array<XRInputSourceState>? input_state;

  // Indicates that a reset pose event was triggered, either by device specific
  // UI or by some other method, and handled on the browser side, and the
  // renderer should now bubble up an event to the WebXR Device API.
  bool pose_reset;
};

struct XRRay {
  // TODO(https://crbug.com/845293): use Point3F and Vector3F from
  // ui/gfx/geometry and inline directly in requestHitTest().
  array<float, 3> origin;
  array<float, 3> direction;
};

struct XRHitResult {
  // A 4x4 transformation matrix representing the position of the object hit
  // and the orientation of the normal of the object at the hit location.
  // TODO(https://crbug.com/845293): use gfx.mojom.Transform.
  array<float, 16> hit_matrix;
};

struct VRDisplayCapabilities {
  bool hasPosition;
  bool hasExternalDisplay;

  // Indicates whether the display can actively show imagery on a headset.
  bool canPresent;

  // If true, this is an AR display that can provide a background image along
  // with each pose. Clients who want them should send a frame image request
  // via getFrameData instead of getPose.
  // TODO(https://crbug.com/836349): this may need to change.
  bool can_provide_pass_through_images;
};

// 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;
  // Parameters required to distort a scene for viewing in a VR headset. Only
  // required for devices which have the canPresent capability.
  VREyeParameters? leftEye;
  VREyeParameters? rightEye;
  float webvr_default_framebuffer_scale = 1.0;
  float webxr_default_framebuffer_scale = 1.0;
};

// Frame transport method from the Renderer's point of view.
enum VRDisplayFrameTransportMethod {
  NONE = 0,

  // Renderer should create a new texture handle (Windows) or
  // texture mailbox (Android Surface path) containing the
  // frame's image and supply that as a submitFrame argument.
  SUBMIT_AS_TEXTURE_HANDLE = 1,
  SUBMIT_AS_MAILBOX_HOLDER = 2,

  // Renderer should draw directly into a texture mailbox
  // provided for each frame in OnVSync.
  DRAW_INTO_TEXTURE_MAILBOX = 3,
};

struct VRDisplayFrameTransportOptions {
  VRDisplayFrameTransportMethod transport_method;

  // Booleans indicating which of the VRSubmitFrameClient callbacks
  // are in use. Default is false, the device implementation should set
  // the ones to true that it needs and can ignore the rest.
  bool wait_for_transfer_notification;
  bool wait_for_render_notification;
  bool wait_for_gpu_fence;
};

// The data needed for each animation frame of an XRSession.
struct XRFrameData {
  // General XRSession value

  // The pose may be null if the device lost tracking. The XRFrameData can still
  // have other data, such as pass through camera image.
  VRPose? pose;
  // TODO(https://crbug.com/838515): Is this delta since the last
  // frame? OR an unspecified origin? Something else?
  mojo_base.mojom.TimeDelta time_delta;
  // The buffer_holder is used for sending data imagery back and forth across
  // the process boundary. For application with pass through camera, it holds
  // the camera image to be passed to the renderer. For immersive sessions, it
  // is the place for the renderer to draw into to pass imagery to the device
  // for rendering.
  gpu.mojom.MailboxHolder? buffer_holder;

  // Exclusive session values

  // The frame_id maps frame data to a frame arriving from the compositor. IDs
  // will be reused after the frame arrives from the compositor. Negative IDs
  // imply no mapping.
  int16 frame_id;

  // Pass through camera values
  gfx.mojom.Size? buffer_size;
  array<float, 16>? projection_matrix;
};

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, https://crbug.com/701027): Use a factory
  // function which takes a VRServiceClient so we will never have a
  // half-initialized VRService.
  SetClient(VRServiceClient client) => ();
  // Inform the service that the page is listening for vrdisplayactivate events.
  // TODO(mthiesse): Move SetListeningForActivate onto VRDisplay.
  SetListeningForActivate(bool listening);
};

interface VRServiceClient {
  OnDisplayConnected(VRDisplayHost display, VRDisplayClient& request,
                     VRDisplayInfo display_info);
};

// After submitting a frame, the VRPresentationProvider will notify the client
// about several stages of the render pipeline.  This allows pipelining
// efficiency.  Following VRPresentationProvider::Submit*, the submitted frame
// will be transferred (read from, perhaps copied to another texture), and then
// rendered (submitted to the underlying VR API).
// The client lives in the render process, implemented by VRDisplay.
//
// See VRDisplayFrameTransportConfiguration which configures which of these
// callbacks are in use.
interface VRSubmitFrameClient {
  // The VRPresentationProvider calls this to indicate that the submitted frame
  // has been transferred, so the backing data (mailbox or GpuMemoryBuffer) can
  // be reused or discarded.  Note that this is a convenience/optimization
  // feature, not a security feature - if a site discards the data early we may
  // drop a frame, but nothing will otherwise misbehave.
  // When the frame wasn't successfully transferred, the client should create a
  // new mailbox/GpuMemoryBuffer rather than reusing an existing one to recover
  // for subsequent frames.
  OnSubmitFrameTransferred(bool success);

  // The VRPresentationProvider calls this after the frame was handed off to the
  // underlying VR API. This allows some pipelining of CPU/GPU work, while
  // delaying expensive tasks for a subsequent frame until the current frame has
  // completed.
  OnSubmitFrameRendered();

  // This callback provides a GpuFence corresponding to the previous frame's
  // rendering completion, intended for use with a server wait issued before
  // the following wait to prevent its rendering work from competing with
  // the previous frame.
  OnSubmitFrameGpuFence(gfx.mojom.GpuFenceHandle gpu_fence_handle);
};


// Provides a communication channel from the renderer to the browser-side host
// of a (device/) VrDisplayImpl.
interface VRDisplayHost {
  // Request to initialize a session in the browser process. The return value
  // indicates if the session was successfully initialized or not.
  // TODO(https://crbug.com/842025): Refactor VR device interfaces to better
  // reflect WebXR.
  RequestSession(
    XRSessionOptions options,
    bool triggered_by_displayactive) => (XRSession? session);
  SupportsSession(XRSessionOptions options) => (bool supports_session);

  ExitPresent();
};

// Provides the necessary functionality for a non-presenting WebXR session to
// draw magic window content.
// This interface is hosted in the Browser process, but will move to a sandboxed
// utility process on Windows.  The render process communicates with it.
// For AR displays (VRDisplayCapabilities.can_provide_pass_through_images
// is true), clients can use GetFrameData to get images.
// TODO(836478): rename VRMagicWindowProvider to NonImmersiveWindowProvider or
// similar.
interface VRMagicWindowProvider {
  // frame_data is optional and will not be set if and only if the call fails
  // for some reason, such as device disconnection.
  GetFrameData() => (XRFrameData? frame_data);

  // Different devices can have different native orientations - 0
  // is the native orientation, and then increments of 90 degrees
  // from there.
  UpdateSessionGeometry(
      gfx.mojom.Size frame_size,
      display.mojom.Rotation display_rotation);

  // Performs a raycast into the magic window scene and returns a list of
  // XRHitResults sorted from closest to furthest hit from the ray. Each
  // hit result contains a hit_matrix containing the transform of the hit
  // where the rotation represents the normal of the surface hit.
  // An empty result list means there were no hits. If a nullopt is returned,
  // there was an error.
  // TODO(https://crbug.com/842025): have one "session" type, merging
  // VRMagicWindowProvider and VRPresentationProvider because RequestHitTest
  // makes sense for both types of sessions.
  RequestHitTest(XRRay ray) => (array<XRHitResult>? results);
};

// Provides the necessary functionality for a presenting WebVR page to draw
// frames for a VrDisplay.
// This interface is hosted in the Browser process, but will move to a sandboxed
// utility process on Windows.  The render process communicates with it.
interface VRPresentationProvider {
  // frame_data is optional and will not be set if and only if the call fails
  // for some reason, such as device disconnection.
  GetFrameData() => (XRFrameData? frame_data);

  UpdateLayerBounds(int16 frame_id, gfx.mojom.RectF left_bounds,
                    gfx.mojom.RectF right_bounds, gfx.mojom.Size source_size);

  // Call this if the animation loop exited without submitting a frame to
  // ensure that every GetFrameData has a matching Submit call. This happens for
  // WebXR if there were no drawing operations to the opaque framebuffer, and
  // for WebVR 1.1 if the application didn't call SubmitFrame. Usable with any
  // VRDisplayFrameTransportMethod. This path does *not* call the
  // SubmitFrameClient methods such as OnSubmitFrameTransferred. This is
  // intended to help separate frames while presenting, it may or may not
  // be called for the last animating frame when presentation ends.
  SubmitFrameMissing(int16 frame_id, gpu.mojom.SyncToken sync_token);

  // VRDisplayFrameTransportMethod SUBMIT_AS_MAILBOX_HOLDER
  SubmitFrame(int16 frame_id, gpu.mojom.MailboxHolder mailbox_holder,
              mojo_base.mojom.TimeDelta time_waited);

  // VRDisplayFrameTransportMethod SUBMIT_AS_TEXTURE_HANDLE
  // TODO(https://crbug.com/676224): Support preprocessing of mojom files, since
  // this is Windows only.
  SubmitFrameWithTextureHandle(int16 frameId, handle texture);

  // VRDisplayFrameTransportMethod DRAW_INTO_TEXTURE_MAILBOX
  SubmitFrameDrawnIntoTexture(int16 frameId, gpu.mojom.SyncToken sync_token,
                              mojo_base.mojom.TimeDelta time_waited);
};

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