/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include <math.h>

#include "gfxVR.h"

#include "mozilla/dom/GamepadEventTypes.h"

#include "mozilla/dom/GamepadBinding.h"

#include "VRDisplayHost.h"

#ifndef M_PI

# define M_PI 3.14159265358979323846

#endif

using namespace mozilla;

using namespace mozilla::gfx;

Atomic<uint32_t> VRSystemManager::sDisplayBase(0);

Atomic<uint32_t> VRSystemManager::sControllerBase(0);

/* static */ uint32_t

VRSystemManager::AllocateDisplayID()

{

  return ++sDisplayBase;

}

/* static */ uint32_t

VRSystemManager::AllocateControllerID()

{

  return ++sControllerBase;

}

/**

 * VRSystemManager::NotifyVsync must be called even when a WebVR site is

 * not active, in order to poll for respond to VR Platform API requests.

 * This should be called very often, ideally once per frame.

 * VRSystemManager::Refresh will not activate VR hardware or

 * initialize VR runtimes that have not already been activated.

 */

void

VRSystemManager::NotifyVSync()

{

  // VRDisplayHost::NotifyVSync may modify mVRDisplays, so we iterate

  // through a local copy here.

  nsTArray<RefPtr<VRDisplayHost>> displays;

  GetHMDs(displays);

  for (const auto& display : displays) {

    display->NotifyVSync();

  }

  // Ensure that the controller state is updated at least

  // on every 2d display VSync when not in a VR presentation.

  if (!GetIsPresenting()) {

    HandleInput();

  }

}

/**

 * VRSystemManager::GetHMDs must not be called unless

 * VRSystemManager::ShouldInhibitEnumeration is called

 * on all VRSystemManager instances and they all return

 * false.

 *

 * This is used to ensure that VR devices that can be

 * enumerated by multiple API's are only enumerated by

 * one API.

 *

 * GetHMDs is called for the most specific API

 * (ie. Oculus SDK) first before calling GetHMDs on

 * more generic api's (ie. OpenVR) to ensure that a device

 * is accessed using the API most optimized for it.

 *

 * ShouldInhibitEnumeration may also be used to prevent

 * devices from jumping to other API's when they are

 * intentionally ignored, such as when responding to

 * requests by the VR platform to unload the libraries

 * for runtime software updates.

 */

bool

VRSystemManager::ShouldInhibitEnumeration()

{

  return false;

}

Matrix4x4

VRFieldOfView::ConstructProjectionMatrix(float zNear, float zFar,

                                         bool rightHanded) const

{

  float upTan = tan(upDegrees * M_PI / 180.0);

  float downTan = tan(downDegrees * M_PI / 180.0);

  float leftTan = tan(leftDegrees * M_PI / 180.0);

  float rightTan = tan(rightDegrees * M_PI / 180.0);

  float handednessScale = rightHanded ? -1.0 : 1.0;

  float pxscale = 2.0f / (leftTan + rightTan);

  float pxoffset = (leftTan - rightTan) * pxscale * 0.5;

  float pyscale = 2.0f / (upTan + downTan);

  float pyoffset = (upTan - downTan) * pyscale * 0.5;

  Matrix4x4 mobj;

  float *m = &mobj._11;

  m[0*4+0] = pxscale;

  m[2*4+0] = pxoffset * handednessScale;

  m[1*4+1] = pyscale;

  m[2*4+1] = -pyoffset * handednessScale;

  m[2*4+2] = zFar / (zNear - zFar) * -handednessScale;

  m[3*4+2] = (zFar * zNear) / (zNear - zFar);

  m[2*4+3] = handednessScale;

  m[3*4+3] = 0.0f;

  return mobj;

}

void

VRSystemManager::AddGamepad(const VRControllerInfo& controllerInfo)

{

  dom::GamepadAdded a(NS_ConvertUTF8toUTF16(controllerInfo.GetControllerName()),

                      controllerInfo.GetMappingType(),

                      controllerInfo.GetHand(),

                      controllerInfo.GetDisplayID(),

                      controllerInfo.GetNumButtons(),

                      controllerInfo.GetNumAxes(),

                      controllerInfo.GetNumHaptics());

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadAdded>(mControllerCount, a);

}

void

VRSystemManager::RemoveGamepad(uint32_t aIndex)

{

  dom::GamepadRemoved a;

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadRemoved>(aIndex, a);

}

void

VRSystemManager::NewButtonEvent(uint32_t aIndex, uint32_t aButton,

                                bool aPressed, bool aTouched, double aValue)

{

  dom::GamepadButtonInformation a(aButton, aValue, aPressed, aTouched);

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadButtonInformation>(aIndex, a);

}

void

VRSystemManager::NewAxisMove(uint32_t aIndex, uint32_t aAxis,

                             double aValue)

{

  dom::GamepadAxisInformation a(aAxis, aValue);

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadAxisInformation>(aIndex, a);

}

void

VRSystemManager::NewPoseState(uint32_t aIndex,

                              const dom::GamepadPoseState& aPose)

{

  dom::GamepadPoseInformation a(aPose);

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadPoseInformation>(aIndex, a);

}

void

VRSystemManager::NewHandChangeEvent(uint32_t aIndex,

                                    const dom::GamepadHand aHand)

{

  dom::GamepadHandInformation a(aHand);

  VRManager* vm = VRManager::Get();

  vm->NotifyGamepadChange<dom::GamepadHandInformation>(aIndex, a);

}

void

VRHMDSensorState::CalcViewMatrices(const gfx::Matrix4x4* aHeadToEyeTransforms)

{

  gfx::Matrix4x4 matHead;

  if (flags & VRDisplayCapabilityFlags::Cap_Orientation) {

    matHead.SetRotationFromQuaternion(gfx::Quaternion(pose.orientation[0], pose.orientation[1],

                                                      pose.orientation[2], pose.orientation[3]));

  }

  matHead.PreTranslate(-pose.position[0], -pose.position[1], -pose.position[2]);

  gfx::Matrix4x4 matView = matHead * aHeadToEyeTransforms[VRDisplayState::Eye_Left];

  matView.Normalize();

  memcpy(leftViewMatrix, matView.components, sizeof(matView.components));

  matView = matHead * aHeadToEyeTransforms[VRDisplayState::Eye_Right];

  matView.Normalize();

  memcpy(rightViewMatrix, matView.components, sizeof(matView.components));

}

const IntSize

VRDisplayInfo::SuggestedEyeResolution() const

{

  return IntSize(mDisplayState.mEyeResolution.width,

                 mDisplayState.mEyeResolution.height);

}

const Point3D

VRDisplayInfo::GetEyeTranslation(uint32_t whichEye) const

{

  return Point3D(mDisplayState.mEyeTranslation[whichEye].x,

                 mDisplayState.mEyeTranslation[whichEye].y,

                 mDisplayState.mEyeTranslation[whichEye].z);

}

const Size

VRDisplayInfo::GetStageSize() const

{

  return Size(mDisplayState.mStageSize.width,

              mDisplayState.mStageSize.height);

}

const Matrix4x4

VRDisplayInfo::GetSittingToStandingTransform() const

{

  Matrix4x4 m;

  // If we could replace Matrix4x4 with a pod type, we could

  // use it directly from the VRDisplayInfo struct.

  memcpy(m.components, mDisplayState.mSittingToStandingTransform, sizeof(float) * 16);

  return m;

}