imstkVTKTetrahedralMeshRenderDelegate.cpp

/*
** This file is part of the Interactive Medical Simulation Toolkit (iMSTK)
** iMSTK is distributed under the Apache License, Version 2.0.
** See accompanying NOTICE for details.
*/

#include "imstkVTKTetrahedralMeshRenderDelegate.h"
#include "imstkTetrahedralMesh.h"
#include "imstkVisualModel.h"
#include "imstkRenderMaterial.h"
#include "imstkGeometryUtilities.h"

#include <vtkActor.h>
#include <vtkDataSetMapper.h>
#include <vtkDoubleArray.h>
#include <vtkUnstructuredGrid.h>
#include <vtkPointData.h>
#include <vtkTransform.h>

namespace imstk
{
VTKTetrahedralMeshRenderDelegate::VTKTetrahedralMeshRenderDelegate() :
    m_mesh(vtkSmartPointer<vtkUnstructuredGrid>::New()),
    m_mappedVertexArray(vtkSmartPointer<vtkDoubleArray>::New()),
    m_cellArray(vtkSmartPointer<vtkCellArray>::New())
{
}

void
VTKTetrahedralMeshRenderDelegate::init()
{
    auto geometry = std::dynamic_pointer_cast<TetrahedralMesh>(m_visualModel->getGeometry());
    CHECK(geometry != nullptr) << "VTKTetrahedralMeshRenderDelegate only works with TetrahedralMesh geometry";

    // Create vtkUnstructuredGrid vtkPoints
    m_mappedVertexArray->SetNumberOfComponents(3);
    auto points = vtkSmartPointer<vtkPoints>::New();
    points->SetNumberOfPoints(0);
    points->SetData(m_mappedVertexArray);
    m_mesh->SetPoints(points);

    setVertexBuffer(geometry->getVertexPositions());

    setIndexBuffer(geometry->getCells());
    m_mesh->SetCells(VTK_TETRA, m_cellArray);

    // Map vertex scalars if it has them
    if (geometry->getVertexScalars() != nullptr)
    {
        m_mappedVertexScalarArray = GeometryUtils::coupleVtkDataArray(geometry->getVertexScalars());
        m_mesh->GetPointData()->SetScalars(m_mappedVertexScalarArray);
    }

    // When geometry is modified, update data source, mostly for when an entirely new array/buffer was set
    queueConnect<Event>(geometry, &Geometry::modified,
        std::static_pointer_cast<VTKTetrahedralMeshRenderDelegate>(shared_from_this()),
        &VTKTetrahedralMeshRenderDelegate::geometryModified);

    // Setup the mapper
    {
        vtkNew<vtkDataSetMapper> mapper;
        mapper->SetInputData(m_mesh);
        vtkNew<vtkActor> actor;
        actor->SetMapper(mapper);
        actor->SetUserTransform(m_transform);
        m_actor  = actor;
        m_mapper = mapper;
    }

    update();
    updateRenderProperties();
}

void
VTKTetrahedralMeshRenderDelegate::processEvents()
{
    // Custom handling of events
    std::shared_ptr<TetrahedralMesh>         geom     = std::dynamic_pointer_cast<TetrahedralMesh>(m_visualModel->getGeometry());
    std::shared_ptr<VecDataArray<double, 3>> vertices = geom->getVertexPositions();
    std::shared_ptr<VecDataArray<int, 4>>    indices  = geom->getCells();

    // Only use the most recent event from respective sender
    std::array<Command, 5> cmds;
    std::array<bool, 5>    contains = { false, false, false, false, false };
    rforeachEvent([&](Command cmd)
        {
            if (cmd.m_event->m_sender == m_visualModel.get() && !contains[0])
            {
                cmds[0]     = cmd;
                contains[0] = true;
            }
            else if (cmd.m_event->m_sender == m_material.get() && !contains[1])
            {
                cmds[1]     = cmd;
                contains[1] = true;
            }
            else if (cmd.m_event->m_sender == geom.get() && !contains[2])
            {
                cmds[2]     = cmd;
                contains[2] = true;
            }
            else if (cmd.m_event->m_sender == vertices.get() && !contains[3])
            {
                cmds[3]     = cmd;
                contains[3] = true;
            }
            else if (cmd.m_event->m_sender == indices.get() && !contains[4])
            {
                cmds[4]     = cmd;
                contains[4] = true;
            }
        });

    cmds[0].invoke();
    cmds[1].invoke();
    cmds[3].invoke();
    cmds[4].invoke();
    cmds[2].invoke(); // Process geometry changes last
}

void
VTKTetrahedralMeshRenderDelegate::vertexDataModified(Event* imstkNotUsed(e))
{
    auto geometry = std::static_pointer_cast<TetrahedralMesh>(m_visualModel->getGeometry());
    setVertexBuffer(geometry->getVertexPositions());
}

void
VTKTetrahedralMeshRenderDelegate::indexDataModified(Event* imstkNotUsed(e))
{
    auto geometry = std::static_pointer_cast<TetrahedralMesh>(m_visualModel->getGeometry());
    setIndexBuffer(geometry->getCells());
}

void
VTKTetrahedralMeshRenderDelegate::geometryModified(Event* imstkNotUsed(e))
{
    auto geometry = std::static_pointer_cast<TetrahedralMesh>(m_visualModel->getGeometry());

    // If the vertices were reallocated
    if (m_vertices != geometry->getVertexPositions())
    {
        setVertexBuffer(geometry->getVertexPositions());
    }

    // Assume vertices are always changed
    m_mappedVertexArray->Modified();

    // Only update index buffer when reallocated
    if (m_indices != geometry->getCells())
    {
        setIndexBuffer(geometry->getCells());
    }
}

void
VTKTetrahedralMeshRenderDelegate::setVertexBuffer(std::shared_ptr<VecDataArray<double, 3>> vertices)
{
    // If the buffer changed
    if (m_vertices != vertices)
    {
        // If previous buffer exist
        if (m_vertices != nullptr)
        {
            // stop observing its changes
            disconnect(m_vertices,
                std::static_pointer_cast<VTKTetrahedralMeshRenderDelegate>(shared_from_this()),
                &VecDataArray<double, 3>::modified);
        }
        // Set new buffer and observe
        m_vertices = vertices;
        queueConnect<Event>(m_vertices, &VecDataArray<double, 3>::modified,
            std::static_pointer_cast<VTKTetrahedralMeshRenderDelegate>(shared_from_this()),
            &VTKTetrahedralMeshRenderDelegate::vertexDataModified);
    }

    // Couple the buffer
    m_mappedVertexArray->SetNumberOfComponents(3);
    m_mappedVertexArray->SetArray(reinterpret_cast<double*>(m_vertices->getPointer()), m_vertices->size() * 3, 1);
    m_mappedVertexArray->Modified();
    m_mesh->GetPoints()->SetNumberOfPoints(m_vertices->size());
}

void
VTKTetrahedralMeshRenderDelegate::setIndexBuffer(std::shared_ptr<VecDataArray<int, 4>> indices)
{
    // If the buffer changed
    if (m_indices != indices)
    {
        // If previous buffer exist
        if (m_indices != nullptr)
        {
            // stop observing its changes
            disconnect(m_indices,
                std::static_pointer_cast<VTKTetrahedralMeshRenderDelegate>(shared_from_this()),
                &VecDataArray<int, 4>::modified);
        }
        // Set new buffer and observe
        m_indices = indices;
        queueConnect<Event>(m_indices, &VecDataArray<int, 4>::modified,
            std::static_pointer_cast<VTKTetrahedralMeshRenderDelegate>(shared_from_this()),
            &VTKTetrahedralMeshRenderDelegate::indexDataModified);
    }

    // Copy the buffer
    m_cellArray->Reset();
    vtkIdType cell[4];
    for (const auto& t : *m_indices)
    {
        for (size_t i = 0; i < 4; i++)
        {
            cell[i] = t[i];
        }
        m_cellArray->InsertNextCell(4, cell);
    }
    m_mesh->SetCells(VTK_TETRA, m_cellArray);
    m_cellArray->Modified();
    m_mesh->Modified();
}
} // namespace imstk