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/*=========================================================================
Program: Visualization Toolkit
Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
All rights reserved.
See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
#include "vtkOpenVRCamera.h"
#include "vtkMatrix3x3.h"
#include "vtkMatrix4x4.h"
#include "vtkObjectFactory.h"
#include "vtkOpenGLError.h"
#include "vtkOpenGLState.h"
#include "vtkOpenVRRenderWindow.h"
#include "vtkPerspectiveTransform.h"
#include "vtkRenderer.h"
#include "vtkTimerLog.h"
#include <cmath>
VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkOpenVRCamera);
vtkOpenVRCamera::vtkOpenVRCamera() = default;
vtkOpenVRCamera::~vtkOpenVRCamera() = default;
// a reminder, with vtk order matrices multiplcation goes right to left
// e.g. vtkMatrix4x4::Multiply(BtoC, AtoB, AtoC);
namespace
{
void setMatrixFromOpenVRMatrix(vtkMatrix4x4* result, const vr::HmdMatrix34_t& vrMat)
{
// because openvr is in left handed coords we
// have to invert z, apply the transform, then invert z again
for (vtkIdType i = 0; i < 3; ++i)
{
for (vtkIdType j = 0; j < 4; ++j)
{
result->SetElement(i, j, ((i == 2) != (j == 2) ? -1 : 1) * vrMat.m[i][j]);
}
}
// Add last row
result->SetElement(3, 0, 0.0);
result->SetElement(3, 1, 0.0);
result->SetElement(3, 2, 0.0);
result->SetElement(3, 3, 1.0);
result->Invert();
}
}
//------------------------------------------------------------------------------
// we could try to do some smart caching here where we only
// check the eyetohead transform when the ipd changes etc
void vtkOpenVRCamera::UpdateHMDToEyeMatrices(vtkRenderer* ren)
{
vtkOpenVRRenderWindow* win = vtkOpenVRRenderWindow::SafeDownCast(ren->GetRenderWindow());
vr::IVRSystem* hMD = win->GetHMD();
vr::HmdMatrix34_t matEye = hMD->GetEyeToHeadTransform(vr::Eye_Left);
setMatrixFromOpenVRMatrix(this->HMDToLeftEyeMatrix, matEye);
matEye = hMD->GetEyeToHeadTransform(vr::Eye_Right);
setMatrixFromOpenVRMatrix(this->HMDToRightEyeMatrix, matEye);
}
//------------------------------------------------------------------------------
void vtkOpenVRCamera::UpdateWorldToEyeMatrices(vtkRenderer* ren)
{
// could do this next call only every now and then as these matrices
// rarely change typically only when the user is changing the ipd
this->UpdateHMDToEyeMatrices(ren);
vtkOpenVRRenderWindow* win = vtkOpenVRRenderWindow::SafeDownCast(ren->GetRenderWindow());
auto hmdHandle = win->GetDeviceHandleForOpenVRHandle(vr::k_unTrackedDeviceIndex_Hmd);
// first we get the physicalToHMDMatrix (by inverting deviceToPhysical for the HMD)
auto* deviceToPhysical = win->GetDeviceToPhysicalMatrixForDeviceHandle(hmdHandle);
if (!deviceToPhysical)
{
return;
}
this->PhysicalToHMDMatrix->DeepCopy(deviceToPhysical);
this->PhysicalToHMDMatrix->Invert();
// compute the physicalToEye matrices
vtkMatrix4x4::Multiply4x4(
this->HMDToLeftEyeMatrix, this->PhysicalToHMDMatrix, this->PhysicalToLeftEyeMatrix);
vtkMatrix4x4::Multiply4x4(
this->HMDToRightEyeMatrix, this->PhysicalToHMDMatrix, this->PhysicalToRightEyeMatrix);
// get the world to physical matrix by inverting phsycialToWorld
win->GetPhysicalToWorldMatrix(this->WorldToPhysicalMatrix);
this->WorldToPhysicalMatrix->Invert();
// compute the world to eye matrices
vtkMatrix4x4::Multiply4x4(
this->PhysicalToLeftEyeMatrix, this->WorldToPhysicalMatrix, this->WorldToLeftEyeMatrix);
vtkMatrix4x4::Multiply4x4(
this->PhysicalToRightEyeMatrix, this->WorldToPhysicalMatrix, this->WorldToRightEyeMatrix);
}
//------------------------------------------------------------------------------
void vtkOpenVRCamera::UpdateEyeToProjectionMatrices(vtkRenderer* ren)
{
vtkOpenVRRenderWindow* win = vtkOpenVRRenderWindow::SafeDownCast(ren->GetRenderWindow());
vr::IVRSystem* hMD = win->GetHMD();
double scale = win->GetPhysicalScale();
double znear = this->ClippingRange[0] / scale;
double zfar = this->ClippingRange[1] / scale;
float fxmin, fxmax, fymin, fymax;
double xmin, xmax, ymin, ymax;
// note docs are probably wrong in OpenVR arg list for this func
hMD->GetProjectionRaw(vr::Eye_Left, &fxmin, &fxmax, &fymin, &fymax);
xmin = fxmin * znear;
xmax = fxmax * znear;
ymin = fymin * znear;
ymax = fymax * znear;
this->LeftEyeToProjectionMatrix->Zero();
this->LeftEyeToProjectionMatrix->SetElement(0, 0, 2 * znear / (xmax - xmin));
this->LeftEyeToProjectionMatrix->SetElement(1, 1, 2 * znear / (ymax - ymin));
this->LeftEyeToProjectionMatrix->SetElement(0, 2, (xmin + xmax) / (xmax - xmin));
this->LeftEyeToProjectionMatrix->SetElement(1, 2, (ymin + ymax) / (ymax - ymin));
this->LeftEyeToProjectionMatrix->SetElement(2, 2, -(znear + zfar) / (zfar - znear));
this->LeftEyeToProjectionMatrix->SetElement(3, 2, -1);
this->LeftEyeToProjectionMatrix->SetElement(2, 3, -2 * znear * zfar / (zfar - znear));
hMD->GetProjectionRaw(vr::Eye_Right, &fxmin, &fxmax, &fymin, &fymax);
xmin = fxmin * znear;
xmax = fxmax * znear;
ymin = fymin * znear;
ymax = fymax * znear;
this->RightEyeToProjectionMatrix->Zero();
this->RightEyeToProjectionMatrix->SetElement(0, 0, 2 * znear / (xmax - xmin));
this->RightEyeToProjectionMatrix->SetElement(1, 1, 2 * znear / (ymax - ymin));
this->RightEyeToProjectionMatrix->SetElement(0, 2, (xmin + xmax) / (xmax - xmin));
this->RightEyeToProjectionMatrix->SetElement(1, 2, (ymin + ymax) / (ymax - ymin));
this->RightEyeToProjectionMatrix->SetElement(2, 2, -(znear + zfar) / (zfar - znear));
this->RightEyeToProjectionMatrix->SetElement(3, 2, -1);
this->RightEyeToProjectionMatrix->SetElement(2, 3, -2 * znear * zfar / (zfar - znear));
}
//------------------------------------------------------------------------------
void vtkOpenVRCamera::Render(vtkRenderer* ren)
{
vtkOpenGLClearErrorMacro();
vtkVRRenderWindow* win = vtkVRRenderWindow::SafeDownCast(ren->GetRenderWindow());
vtkOpenGLState* ostate = win->GetState();
int renSize[2];
win->GetRenderBufferSize(renSize[0], renSize[1]);
// if were on a stereo renderer draw to special parts of screen
if (this->LeftEye)
{
// Left Eye
if (win->GetMultiSamples() && !ren->GetSelector())
{
ostate->vtkglEnable(GL_MULTISAMPLE);
}
}
else
{
// right eye
if (win->GetMultiSamples() && !ren->GetSelector())
{
ostate->vtkglEnable(GL_MULTISAMPLE);
}
}
ostate->vtkglViewport(0, 0, renSize[0], renSize[1]);
ostate->vtkglScissor(0, 0, renSize[0], renSize[1]);
ren->Clear();
if ((ren->GetRenderWindow())->GetErase() && ren->GetErase())
{
ren->Clear();
}
vtkOpenGLCheckErrorMacro("failed after Render");
}
VTK_ABI_NAMESPACE_END
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