vtkTextureMapToPlane.cxx

/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkTextureMapToPlane.cxx

  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 "vtkTextureMapToPlane.h"

#include "vtkCellData.h"
#include "vtkDataSet.h"
#include "vtkFloatArray.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkMath.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"

vtkStandardNewMacro(vtkTextureMapToPlane);

// Construct with s,t range=(0,1) and automatic plane generation turned on.
vtkTextureMapToPlane::vtkTextureMapToPlane()
{
  // all zero - indicates that using normal is preferred and automatic is off
  this->Origin[0] = this->Origin[1] = this->Origin[2] = 0.0;
  this->Point1[0] = this->Point1[1] = this->Point1[2] = 0.0;
  this->Point2[0] = this->Point2[1] = this->Point2[2] = 0.0;

  this->Normal[0] = 0.0;
  this->Normal[1] = 0.0;
  this->Normal[2] = 1.0;

  this->SRange[0] = 0.0;
  this->SRange[1] = 1.0;

  this->TRange[0] = 0.0;
  this->TRange[1] = 1.0;

  this->AutomaticPlaneGeneration = 1;
}

int vtkTextureMapToPlane::RequestData(vtkInformation* vtkNotUsed(request),
  vtkInformationVector** inputVector, vtkInformationVector* outputVector)
{
  // get the info objects
  vtkInformation* inInfo = inputVector[0]->GetInformationObject(0);
  vtkInformation* outInfo = outputVector->GetInformationObject(0);

  // get the input and output
  vtkDataSet* input = vtkDataSet::SafeDownCast(inInfo->Get(vtkDataObject::DATA_OBJECT()));
  vtkDataSet* output = vtkDataSet::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));

  double tcoords[2];
  vtkIdType numPts;
  vtkFloatArray* newTCoords;
  vtkIdType i;
  int j;
  double proj, minProj, axis[3], sAxis[3], tAxis[3];
  int dir = 0;
  double s, t, sSf, tSf, p[3];
  int abort = 0;
  vtkIdType progressInterval;

  vtkDebugMacro(<< "Generating texture coordinates!");

  // First, copy the input to the output as a starting point
  output->CopyStructure(input);

  if ((numPts = input->GetNumberOfPoints()) < 3 && this->AutomaticPlaneGeneration)
  {
    vtkErrorMacro(<< "Not enough points for automatic plane mapping\n");
    return 1;
  }

  //  Allocate texture data
  //
  newTCoords = vtkFloatArray::New();
  newTCoords->SetName("Texture Coordinates");
  newTCoords->SetNumberOfComponents(2);
  newTCoords->SetNumberOfTuples(numPts);
  progressInterval = numPts / 20 + 1;

  //  Compute least squares plane if on automatic mode; otherwise use
  //  normal specified or plane specified
  //
  if (this->AutomaticPlaneGeneration &&
    (this->Origin[0] == 0.0 && this->Origin[1] == 0.0 && this->Origin[2] == 0.0 &&
      this->Point1[0] == 0.0 && this->Point1[1] == 0.0 && this->Point1[2] == 0.0))
  {
    this->ComputeNormal(output);

    vtkMath::Normalize(this->Normal);

    //  Now project each point onto plane generating s,t texture coordinates
    //
    //  Create local s-t coordinate system.  Need to find the two axes on
    //  the plane and encompassing all the points.  Hence use the bounding
    //  box as a reference.
    //
    for (minProj = 1.0, i = 0; i < 3; i++)
    {
      axis[0] = axis[1] = axis[2] = 0.0;
      axis[i] = 1.0;
      if ((proj = fabs(vtkMath::Dot(this->Normal, axis))) < minProj)
      {
        minProj = proj;
        dir = i;
      }
    }
    axis[0] = axis[1] = axis[2] = 0.0;
    axis[dir] = 1.0;

    vtkMath::Cross(this->Normal, axis, tAxis);
    vtkMath::Normalize(tAxis);

    vtkMath::Cross(tAxis, this->Normal, sAxis);

    //  Construct projection matrices
    //
    //  Arrange s-t axes so that parametric location of points will fall
    //  between s_range and t_range.  Simplest to do by projecting maximum
    //  corner of bounding box unto plane and backing out scale factors.
    //
    const double* bounds = output->GetBounds();
    for (i = 0; i < 3; i++)
    {
      axis[i] = bounds[2 * i + 1] - bounds[2 * i];
    }

    s = vtkMath::Dot(sAxis, axis);
    t = vtkMath::Dot(tAxis, axis);

    sSf = (this->SRange[1] - this->SRange[0]) / s;
    tSf = (this->TRange[1] - this->TRange[0]) / t;

    //  Now can loop over all points, computing parametric coordinates.
    //
    for (i = 0; i < numPts && !abort; i++)
    {
      if (!(i % progressInterval))
      {
        this->UpdateProgress((double)i / numPts);
        abort = this->GetAbortExecute();
      }

      output->GetPoint(i, p);
      for (j = 0; j < 3; j++)
      {
        axis[j] = p[j] - bounds[2 * j];
      }

      tcoords[0] = this->SRange[0] + vtkMath::Dot(sAxis, axis) * sSf;
      tcoords[1] = this->TRange[0] + vtkMath::Dot(tAxis, axis) * tSf;

      newTCoords->SetTuple(i, tcoords);
    }
  } // compute plane and/or parametric range

  else // use the axes specified
  {
    double num, sDenom, tDenom;

    for (i = 0; i < 3; i++) // compute axes
    {
      sAxis[i] = this->Point1[i] - this->Origin[i];
      tAxis[i] = this->Point2[i] - this->Origin[i];
    }

    sDenom = vtkMath::Dot(sAxis, sAxis);
    tDenom = vtkMath::Dot(tAxis, tAxis);

    if (sDenom == 0.0 || tDenom == 0.0)
    {
      vtkErrorMacro("Bad plane definition");
      sDenom = tDenom = 1.0;
    }

    // compute s-t coordinates
    for (i = 0; i < numPts && !abort; i++)
    {
      if (!(i % progressInterval))
      {
        this->UpdateProgress((double)i / numPts);
        abort = this->GetAbortExecute();
      }
      output->GetPoint(i, p);
      for (j = 0; j < 3; j++)
      {
        axis[j] = p[j] - this->Origin[j];
      }

      // s-coordinate
      num = sAxis[0] * axis[0] + sAxis[1] * axis[1] + sAxis[2] * axis[2];
      tcoords[0] = num / sDenom;

      // t-coordinate
      num = tAxis[0] * axis[0] + tAxis[1] * axis[1] + tAxis[2] * axis[2];
      tcoords[1] = num / tDenom;

      newTCoords->SetTuple(i, tcoords);
    }
  }

  // Update ourselves
  //
  output->GetPointData()->CopyTCoordsOff();
  output->GetPointData()->PassData(input->GetPointData());
  output->GetCellData()->PassData(input->GetCellData());

  output->GetPointData()->SetTCoords(newTCoords);
  newTCoords->Delete();

  return 1;
}

#define VTK_TOLERANCE 1.0e-03

void vtkTextureMapToPlane::ComputeNormal(vtkDataSet* output)
{
  vtkIdType numPts = output->GetNumberOfPoints();
  double m[9], v[3], x[3];
  vtkIdType ptId;
  int dir = 0, i;
  double length, w, *c1, *c2, *c3, det;

  //  First thing to do is to get an initial normal and point to define
  //  the plane.  Then, use this information to construct better
  //  matrices.  If problem occurs, then the point and plane becomes the
  //  fallback value.
  //
  //  Get minimum width of bounding box.
  const double* bounds = output->GetBounds();
  length = output->GetLength();

  for (w = length, i = 0; i < 3; i++)
  {
    this->Normal[i] = 0.0;
    if ((bounds[2 * i + 1] - bounds[2 * i]) < w)
    {
      dir = i;
      w = bounds[2 * i + 1] - bounds[2 * i];
    }
  }

  //  If the bounds is perpendicular to one of the axes, then can
  //  quickly compute normal.
  //
  this->Normal[dir] = 1.0;
  if (w <= (length * VTK_TOLERANCE))
  {
    return;
  }

  //  Need to compute least squares approximation.  Depending on major
  //  normal direction (dir), construct matrices appropriately.
  //
  //  Compute 3x3 least squares matrix
  v[0] = v[1] = v[2] = 0.0;
  for (i = 0; i < 9; i++)
  {
    m[i] = 0.0;
  }

  for (ptId = 0; ptId < numPts; ptId++)
  {
    output->GetPoint(ptId, x);

    v[0] += x[0] * x[2];
    v[1] += x[1] * x[2];
    v[2] += x[2];

    m[0] += x[0] * x[0];
    m[1] += x[0] * x[1];
    m[2] += x[0];

    m[3] += x[0] * x[1];
    m[4] += x[1] * x[1];
    m[5] += x[1];

    m[6] += x[0];
    m[7] += x[1];
  }
  m[8] = numPts;

  //  Solve linear system using Kramers rule
  //
  c1 = m;
  c2 = m + 3;
  c3 = m + 6;
  if ((det = vtkMath::Determinant3x3(c1, c2, c3)) <= VTK_TOLERANCE)
  {
    return;
  }

  this->Normal[0] = vtkMath::Determinant3x3(v, c2, c3) / det;
  this->Normal[1] = vtkMath::Determinant3x3(c1, v, c3) / det;
  this->Normal[2] = -1.0; // because of the formulation
}

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

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

  os << indent << "Axis Point 1: (" << this->Point1[0] << ", " << this->Point1[1] << ", "
     << this->Point1[2] << " )\n";

  os << indent << "Axis Point 2: (" << this->Point2[0] << ", " << this->Point2[1] << ", "
     << this->Point2[2] << " )\n";

  os << indent << "S Range: (" << this->SRange[0] << ", " << this->SRange[1] << ")\n";
  os << indent << "T Range: (" << this->TRange[0] << ", " << this->TRange[1] << ")\n";
  os << indent
     << "Automatic Normal Generation: " << (this->AutomaticPlaneGeneration ? "On\n" : "Off\n");
  os << indent << "Normal: (" << this->Normal[0] << ", " << this->Normal[1] << ", "
     << this->Normal[2] << ")\n";
}