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// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkPointSource.h"
#include "vtkCellArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMath.h"
#include "vtkObjectFactory.h"
#include "vtkPoints.h"
#include "vtkPolyData.h"
#include "vtkRandomSequence.h"
#include <cfloat>
#include <cmath>
VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkPointSource);
//------------------------------------------------------------------------------
// Specify a random sequence, or use the non-threadsafe one in vtkMath by
// default.
vtkCxxSetObjectMacro(vtkPointSource, RandomSequence, vtkRandomSequence);
//------------------------------------------------------------------------------
vtkPointSource::vtkPointSource(vtkIdType numPts)
{
this->NumberOfPoints = (numPts > 0 ? numPts : 10);
this->Center[0] = 0.0;
this->Center[1] = 0.0;
this->Center[2] = 0.0;
this->Radius = 0.5;
this->Distribution = VTK_POINT_UNIFORM;
this->OutputPointsPrecision = SINGLE_PRECISION;
this->RandomSequence = nullptr;
this->SetNumberOfInputPorts(0);
}
//------------------------------------------------------------------------------
vtkPointSource::~vtkPointSource()
{
this->SetRandomSequence(nullptr);
}
//------------------------------------------------------------------------------
int vtkPointSource::RequestData(vtkInformation* vtkNotUsed(request),
vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
// get the info object
vtkInformation* outInfo = outputVector->GetInformationObject(0);
// get the output
vtkPolyData* output = vtkPolyData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));
vtkIdType i;
double theta, rho, cosphi, sinphi, radius;
double x[3];
// Create the output points.
// Set the desired precision for the points in the output.
vtkNew<vtkPoints> newPoints;
if (this->OutputPointsPrecision == vtkAlgorithm::DOUBLE_PRECISION)
{
newPoints->SetDataType(VTK_DOUBLE);
}
else
{
newPoints->SetDataType(VTK_FLOAT);
}
newPoints->Allocate(this->NumberOfPoints);
// Create the output poly vertices. These are needed for rendering and
// some filters only operate on vertex cells.
vtkNew<vtkCellArray> newVerts;
newVerts->AllocateEstimate(1, this->NumberOfPoints);
newVerts->InsertNextCell(this->NumberOfPoints);
// TODO: This could be threaded if the number of points
// became large enough to warrant the effort.
// Randomly compute spherical coordinates satisfying the
// distribution constraints.
if (this->Distribution == VTK_POINT_SHELL)
{ // only produce points on the surface of the sphere
for (i = 0; i < this->NumberOfPoints; i++)
{
cosphi = 1 - 2 * this->Random();
sinphi = sqrt(1 - cosphi * cosphi);
radius = this->Radius * sinphi;
theta = 2.0 * vtkMath::Pi() * this->Random();
x[0] = this->Center[0] + radius * cos(theta);
x[1] = this->Center[1] + radius * sin(theta);
x[2] = this->Center[2] + this->Radius * cosphi;
newVerts->InsertCellPoint(newPoints->InsertNextPoint(x));
}
}
else if (this->Distribution == VTK_POINT_EXPONENTIAL && this->Lambda != 0)
{ // exponential distribution throughout the sphere volume if lambda!=0
for (i = 0; i < this->NumberOfPoints; i++)
{
cosphi = 1 - 2 * this->Random();
sinphi = sqrt(1 - cosphi * cosphi);
// Compute radius with exponential distribution between [0,this->Radius]
double u = this->Random(); // uniformally distributed random number
rho = log(1 - u * (1 - exp(-this->Lambda * this->Radius))) /
this->Lambda; // exp distribution [0,Radius]
radius = rho * sinphi;
theta = 2.0 * vtkMath::Pi() * this->Random();
x[0] = this->Center[0] + radius * cos(theta);
x[1] = this->Center[1] + radius * sin(theta);
x[2] = this->Center[2] + rho * cosphi;
newVerts->InsertCellPoint(newPoints->InsertNextPoint(x));
}
}
else // Uniform distribution
{
for (i = 0; i < this->NumberOfPoints; i++)
{
cosphi = 1 - 2 * this->Random();
sinphi = sqrt(1 - cosphi * cosphi);
rho = this->Radius * pow(this->Random(), 0.33333333);
radius = rho * sinphi;
theta = 2.0 * vtkMath::Pi() * this->Random();
x[0] = this->Center[0] + radius * cos(theta);
x[1] = this->Center[1] + radius * sin(theta);
x[2] = this->Center[2] + rho * cosphi;
newVerts->InsertCellPoint(newPoints->InsertNextPoint(x));
}
}
// Update ourselves and release memory
//
output->SetPoints(newPoints);
output->SetVerts(newVerts);
return 1;
}
//------------------------------------------------------------------------------
double vtkPointSource::Random()
{
if (!this->RandomSequence)
{
return vtkMath::Random();
}
this->RandomSequence->Next();
return this->RandomSequence->GetValue();
}
//------------------------------------------------------------------------------
void vtkPointSource::PrintSelf(ostream& os, vtkIndent indent)
{
this->Superclass::PrintSelf(os, indent);
os << indent << "Number Of Points: " << this->NumberOfPoints << "\n";
os << indent << "Radius: " << this->Radius << "\n";
os << indent << "Center: (" << this->Center[0] << ", " << this->Center[1] << ", "
<< this->Center[2] << ")\n";
os << indent << "Distribution: ";
switch (this->Distribution)
{
case VTK_POINT_UNIFORM:
os << "Uniform\n";
break;
case VTK_POINT_SHELL:
os << "Shell\n";
break;
case VTK_POINT_EXPONENTIAL:
os << "Exponential\n";
break;
}
os << indent << "Lambda: " << this->Lambda << "\n";
os << indent << "Output Points Precision: " << this->OutputPointsPrecision << "\n";
}
VTK_ABI_NAMESPACE_END
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