gfx/vr/gfxVR.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include <math.h>
   8
   9 #include "gfxVR.h"
  10
  11 #ifndef M_PI
  12 #  define M_PI 3.14159265358979323846
  13 #endif
  14
  15 using namespace mozilla;
  16 using namespace mozilla::gfx;
  17
  18 Matrix4x4 VRFieldOfView::ConstructProjectionMatrix(float zNear, float zFar,
  19                                                    bool rightHanded) const {
  20   float upTan = tan(upDegrees * M_PI / 180.0);
  21   float downTan = tan(downDegrees * M_PI / 180.0);
  22   float leftTan = tan(leftDegrees * M_PI / 180.0);
  23   float rightTan = tan(rightDegrees * M_PI / 180.0);
  24
  25   float handednessScale = rightHanded ? -1.0 : 1.0;
  26
  27   float pxscale = 2.0f / (leftTan + rightTan);
  28   float pxoffset = (leftTan - rightTan) * pxscale * 0.5;
  29   float pyscale = 2.0f / (upTan + downTan);
  30   float pyoffset = (upTan - downTan) * pyscale * 0.5;
  31
  32   Matrix4x4 mobj;
  33   float* m = &mobj._11;
  34
  35   m[0 * 4 + 0] = pxscale;
  36   m[2 * 4 + 0] = pxoffset * handednessScale;
  37
  38   m[1 * 4 + 1] = pyscale;
  39   m[2 * 4 + 1] = -pyoffset * handednessScale;
  40
  41   m[2 * 4 + 2] = zFar / (zNear - zFar) * -handednessScale;
  42   m[3 * 4 + 2] = (zFar * zNear) / (zNear - zFar);
  43
  44   m[2 * 4 + 3] = handednessScale;
  45   m[3 * 4 + 3] = 0.0f;
  46
  47   return mobj;
  48 }
  49
  50 void VRHMDSensorState::CalcViewMatrices(
  51     const gfx::Matrix4x4* aHeadToEyeTransforms) {
  52   gfx::Matrix4x4 matHead;
  53   if (flags & VRDisplayCapabilityFlags::Cap_Orientation) {
  54     matHead.SetRotationFromQuaternion(
  55         gfx::Quaternion(-pose.orientation[0], -pose.orientation[1],
  56                         -pose.orientation[2], pose.orientation[3]));
  57   }
  58   matHead.PreTranslate(-pose.position[0], -pose.position[1], -pose.position[2]);
  59
  60   gfx::Matrix4x4 matView =
  61       matHead * aHeadToEyeTransforms[VRDisplayState::Eye_Left];
  62   matView.Normalize();
  63   memcpy(leftViewMatrix, matView.components, sizeof(matView.components));
  64   matView = matHead * aHeadToEyeTransforms[VRDisplayState::Eye_Right];
  65   matView.Normalize();
  66   memcpy(rightViewMatrix, matView.components, sizeof(matView.components));
  67 }
  68
  69 const IntSize VRDisplayInfo::SuggestedEyeResolution() const {
  70   return IntSize(mDisplayState.eyeResolution.width,
  71                  mDisplayState.eyeResolution.height);
  72 }
  73
  74 const Point3D VRDisplayInfo::GetEyeTranslation(uint32_t whichEye) const {
  75   return Point3D(mDisplayState.eyeTranslation[whichEye].x,
  76                  mDisplayState.eyeTranslation[whichEye].y,
  77                  mDisplayState.eyeTranslation[whichEye].z);
  78 }
  79
  80 const Size VRDisplayInfo::GetStageSize() const {
  81   return Size(mDisplayState.stageSize.width, mDisplayState.stageSize.height);
  82 }
  83
  84 const Matrix4x4 VRDisplayInfo::GetSittingToStandingTransform() const {
  85   Matrix4x4 m;
  86   // If we could replace Matrix4x4 with a pod type, we could
  87   // use it directly from the VRDisplayInfo struct.
  88   memcpy(m.components, mDisplayState.sittingToStandingTransform,
  89          sizeof(float) * 16);
  90   return m;
  91 }