// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkImageMandelbrotSource.h"

#include "vtkDataArray.h"
#include "vtkImageData.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include "vtkStreamingDemandDrivenPipeline.h"

VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkImageMandelbrotSource);

//------------------------------------------------------------------------------
vtkImageMandelbrotSource::vtkImageMandelbrotSource()
{
  this->MaximumNumberOfIterations = 100;
  this->WholeExtent[0] = 0;
  this->WholeExtent[1] = 250;
  this->WholeExtent[2] = 0;
  this->WholeExtent[3] = 250;
  this->WholeExtent[4] = 0;
  this->WholeExtent[5] = 0;

  this->SampleCX[0] = 0.01;
  this->SampleCX[1] = 0.01;
  this->SampleCX[2] = 0.01;
  this->SampleCX[3] = 0.01;

  this->SizeCX[0] = 2.5;
  this->SizeCX[1] = 2.5;
  this->SizeCX[2] = 2.0;
  this->SizeCX[3] = 1.5;

  this->ConstantSize = 1;

  this->OriginCX[0] = -1.75;
  this->OriginCX[1] = -1.25;
  this->OriginCX[2] = 0.0;
  this->OriginCX[3] = 0.0;

  this->ProjectionAxes[0] = 0;
  this->ProjectionAxes[1] = 1;
  this->ProjectionAxes[2] = 2;

  this->SubsampleRate = 1;

  this->SetNumberOfInputPorts(0);
}

//------------------------------------------------------------------------------
vtkImageMandelbrotSource::~vtkImageMandelbrotSource() = default;

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);

  os << indent << "OriginC: (" << this->OriginCX[0] << ", " << this->OriginCX[1] << ")\n";
  os << indent << "OriginX: (" << this->OriginCX[2] << ", " << this->OriginCX[3] << ")\n";

  os << indent << "SampleC: (" << this->SampleCX[0] << ", " << this->SampleCX[1] << ")\n";
  os << indent << "SampleX: (" << this->SampleCX[2] << ", " << this->SampleCX[3] << ")\n";

  double* size = this->GetSizeCX();
  os << indent << "SizeC: (" << size[0] << ", " << size[1] << ")\n";
  os << indent << "SizeX: (" << size[2] << ", " << size[3] << ")\n";

  if (this->ConstantSize)
  {
    os << indent << "ConstantSize\n";
  }
  else
  {
    os << indent << "ConstantSpacing\n";
  }

  os << indent << "WholeExtent: (" << this->WholeExtent[0] << ", " << this->WholeExtent[1] << ", "
     << this->WholeExtent[2] << ", " << this->WholeExtent[3] << ", " << this->WholeExtent[4] << ", "
     << this->WholeExtent[5] << ")\n";
  os << "MaximumNumberOfIterations: " << this->MaximumNumberOfIterations << endl;

  os << indent << "ProjectionAxes: (" << this->ProjectionAxes[0] << ", " << this->ProjectionAxes[1]
     << this->ProjectionAxes[2] << ")\n";

  os << indent << "SubsampleRate: " << this->SubsampleRate << endl;
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::SetWholeExtent(int extent[6])
{
  int idx, modified = 0;
  double saveSize[4];

  this->GetSizeCX(saveSize);

  for (idx = 0; idx < 6; ++idx)
  {
    if (this->WholeExtent[idx] != extent[idx])
    {
      this->WholeExtent[idx] = extent[idx];
      modified = 1;
    }
  }

  if (modified)
  {
    this->Modified();
    if (this->ConstantSize)
    {
      this->SetSizeCX(saveSize[0], saveSize[1], saveSize[2], saveSize[3]);
    }
  }
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::SetProjectionAxes(int x, int y, int z)
{
  double saveSize[4];

  if (this->ProjectionAxes[0] == x && this->ProjectionAxes[1] == y && this->ProjectionAxes[2] == z)
  {
    return;
  }

  this->Modified();
  this->GetSizeCX(saveSize);
  this->ProjectionAxes[0] = x;
  this->ProjectionAxes[1] = y;
  this->ProjectionAxes[2] = z;
  if (this->ConstantSize)
  {
    this->SetSizeCX(saveSize[0], saveSize[1], saveSize[2], saveSize[3]);
  }
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::SetWholeExtent(
  int minX, int maxX, int minY, int maxY, int minZ, int maxZ)
{
  int extent[6];

  extent[0] = minX;
  extent[1] = maxX;
  extent[2] = minY;
  extent[3] = maxY;
  extent[4] = minZ;
  extent[5] = maxZ;
  this->SetWholeExtent(extent);
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::SetSizeCX(double cReal, double cImag, double xReal, double xImag)
{
  int axis;
  int idx;
  int d;

  double* s = this->GetSizeCX();
  if (s[0] == cReal && s[1] == cImag && s[2] == xReal && s[3] == xImag)
  {
    return;
  }
  this->Modified();

  // Set this because information can be carried over for collapsed axes.
  this->SizeCX[0] = cReal;
  this->SizeCX[1] = cImag;
  this->SizeCX[2] = xReal;
  this->SizeCX[3] = xImag;

  // Now compute the gold standard (for non collapsed axes.
  for (idx = 0; idx < 3; ++idx)
  {
    d = this->WholeExtent[idx * 2 + 1] - this->WholeExtent[idx * 2];
    if (d > 0)
    {
      axis = this->ProjectionAxes[idx];
      this->SampleCX[axis] = this->SizeCX[axis] / static_cast<double>(d);
    }
  }
}

//------------------------------------------------------------------------------
double* vtkImageMandelbrotSource::GetSizeCX()
{
  int axis;
  int idx;
  int d;

  // Recompute the size for the spacing (gold standard).
  for (idx = 0; idx < 3; ++idx)
  {
    d = this->WholeExtent[idx * 2 + 1] - this->WholeExtent[idx * 2];
    if (d > 0)
    {
      axis = this->ProjectionAxes[idx];
      this->SizeCX[axis] = this->SampleCX[axis] * static_cast<double>(d);
    }
  }

  return this->SizeCX;
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::GetSizeCX(double s[4])
{
  double* p = this->GetSizeCX();

  s[0] = p[0];
  s[1] = p[1];
  s[2] = p[2];
  s[3] = p[3];
}

//------------------------------------------------------------------------------
int vtkImageMandelbrotSource::RequestInformation(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  // get the info objects
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  int idx, axis;
  double origin[3];
  double spacing[3];

  int ext[6];
  for (int i = 0; i < 6; i++)
  {
    ext[i] = this->WholeExtent[i] / this->SubsampleRate;
  }

  outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), ext, 6);
  for (idx = 0; idx < 3; ++idx)
  {
    axis = this->ProjectionAxes[idx];
    if (axis >= 0 && axis < 4)
    {
      origin[idx] = this->OriginCX[axis];
      spacing[idx] = this->SampleCX[axis] * this->SubsampleRate;
    }
    else
    {
      vtkErrorMacro("Bad projection axis.");
      origin[idx] = 0.0;
      spacing[idx] = 1.0;
    }
  }

  outInfo->Set(vtkDataObject::SPACING(), spacing, 3);
  outInfo->Set(vtkDataObject::ORIGIN(), origin, 3);
  vtkDataObject::SetPointDataActiveScalarInfo(outInfo, VTK_FLOAT, 1);
  return 1;
}

//------------------------------------------------------------------------------
// We may want separate zooms for mandelbrot and julia.
void vtkImageMandelbrotSource::Zoom(double factor)
{
  if (factor == 1.0)
  {
    return;
  }
  this->Modified();
  this->SampleCX[0] *= factor;
  this->SampleCX[1] *= factor;
  this->SampleCX[2] *= factor;
  this->SampleCX[3] *= factor;
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::Pan(double x, double y, double z)
{
  int idx, axis;
  double pan[3];

  if (x == 0.0 && y == 0.0 && z == 0.0)
  {
    return;
  }

  this->Modified();
  pan[0] = x;
  pan[1] = y;
  pan[2] = z;
  for (idx = 0; idx < 3; ++idx)
  {
    axis = this->ProjectionAxes[idx];
    if (axis >= 0 && axis < 4)
    {
      this->OriginCX[axis] += this->SampleCX[axis] * pan[idx];
    }
  }
}

//------------------------------------------------------------------------------
void vtkImageMandelbrotSource::CopyOriginAndSample(vtkImageMandelbrotSource* source)
{
  int idx;

  for (idx = 0; idx < 4; ++idx)
  {
    this->OriginCX[idx] = source->OriginCX[idx];
    this->SampleCX[idx] = source->SampleCX[idx];
  }

  this->Modified();
}
//------------------------------------------------------------------------------
int vtkImageMandelbrotSource::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** vtkNotUsed(inputVector), vtkInformationVector* outputVector)
{
  // get the output
  vtkInformation* outInfo = outputVector->GetInformationObject(0);
  vtkImageData* data = vtkImageData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  // We need to allocate our own scalars since we are overriding
  // the superclasses "Execute()" method.
  int* ext = outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT());
  data->SetExtent(ext);
  data->AllocateScalars(outInfo);

  int a0, a1, a2;
  float* ptr;
  int min0, max0;
  int idx0, idx1, idx2;
  vtkIdType inc0, inc1, inc2;
  double *origin, *sample;
  double p[4];
  unsigned long count = 0;
  unsigned long target;

  // Name the array appropriately.
  data->GetPointData()->GetScalars()->SetName("Iterations");

  if (data->GetNumberOfPoints() <= 0)
  {
    return 1;
  }

  // Copy origin into pixel
  for (idx0 = 0; idx0 < 4; ++idx0)
  {
    p[idx0] = this->OriginCX[idx0];
  }

  ptr = static_cast<float*>(data->GetScalarPointerForExtent(ext));

  vtkDebugMacro(
    "Generating Extent: " << ext[0] << " -> " << ext[1] << ", " << ext[2] << " -> " << ext[3]);

  // Get min and max of axis 0 because it is the innermost loop.
  min0 = ext[0];
  max0 = ext[1];
  data->GetContinuousIncrements(ext, inc0, inc1, inc2);

  target = static_cast<unsigned long>((ext[5] - ext[4] + 1) * (ext[3] - ext[2] + 1) / 50.0);
  target++;

  a0 = this->ProjectionAxes[0];
  a1 = this->ProjectionAxes[1];
  a2 = this->ProjectionAxes[2];
  origin = this->OriginCX;
  sample = this->SampleCX;

  if (a0 < 0 || a1 < 0 || a2 < 0 || a0 > 3 || a1 > 3 || a2 > 3)
  {
    vtkErrorMacro("Bad projection axis");
    return 0;
  }
  for (idx2 = ext[4]; idx2 <= ext[5]; ++idx2)
  {
    p[a2] = static_cast<double>(origin[a2]) +
      static_cast<double>(idx2) * (sample[a2] * this->SubsampleRate);
    for (idx1 = ext[2]; !this->AbortExecute && idx1 <= ext[3]; ++idx1)
    {
      if (!(count % target))
      {
        this->UpdateProgress(static_cast<double>(count) / (50.0 * static_cast<double>(target)));
      }
      count++;
      p[a1] = static_cast<double>(origin[a1]) +
        static_cast<double>(idx1) * (sample[a1] * this->SubsampleRate);
      for (idx0 = min0; idx0 <= max0; ++idx0)
      {
        p[a0] = static_cast<double>(origin[a0]) +
          static_cast<double>(idx0) * (sample[a0] * this->SubsampleRate);

        *ptr = static_cast<float>(this->EvaluateSet(p));

        ++ptr;
        // inc0 is 0
      }
      ptr += inc1;
    }
    ptr += inc2;
  }

  return 1;
}

//------------------------------------------------------------------------------
double vtkImageMandelbrotSource::EvaluateSet(double p[4])
{
  unsigned short count = 0;
  double v0, v1;
  double cReal, cImag, zReal, zImag;
  double zReal2, zImag2;

  cReal = p[0];
  cImag = p[1];
  zReal = p[2];
  zImag = p[3];

  zReal2 = zReal * zReal;
  zImag2 = zImag * zImag;
  v0 = 0.0;
  v1 = (zReal2 + zImag2);
  while (v1 < 4.0 && count < this->MaximumNumberOfIterations)
  {
    zImag = 2.0 * zReal * zImag + cImag;
    zReal = zReal2 - zImag2 + cReal;
    zReal2 = zReal * zReal;
    zImag2 = zImag * zImag;
    ++count;
    v0 = v1;
    v1 = (zReal2 + zImag2);
  }

  if (count == this->MaximumNumberOfIterations)
  {
    return static_cast<double>(count);
  }

  return static_cast<double>(count) + (4.0 - v0) / (v1 - v0);
}
VTK_ABI_NAMESPACE_END
