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694 lines
19 KiB
694 lines
19 KiB
/*=========================================================================
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Program: Visualization Toolkit
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Module: $RCSfile: vtkPixel.cxx,v $
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Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
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All rights reserved.
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See Copyright.txt or http://www.kitware.com/Copyright.htm for details.
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This software is distributed WITHOUT ANY WARRANTY; without even
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the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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PURPOSE. See the above copyright notice for more information.
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=========================================================================*/
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#include "vtkPixel.h"
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#include "vtkObjectFactory.h"
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#include "vtkQuad.h"
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#include "vtkTriangle.h"
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#include "vtkPlane.h"
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#include "vtkMath.h"
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#include "vtkCellArray.h"
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#include "vtkLine.h"
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#include "vtkPointLocator.h"
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#include "vtkPointData.h"
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#include "vtkCellData.h"
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#include "vtkPoints.h"
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vtkCxxRevisionMacro(vtkPixel, "$Revision: 1.2 $");
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vtkStandardNewMacro(vtkPixel);
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//----------------------------------------------------------------------------
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// Construct the pixel with four points.
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vtkPixel::vtkPixel()
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{
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int i;
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this->Points->SetNumberOfPoints(4);
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this->PointIds->SetNumberOfIds(4);
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for (i = 0; i < 4; i++)
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{
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this->Points->SetPoint(i, 0.0, 0.0, 0.0);
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}
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for (i = 0; i < 4; i++)
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{
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this->PointIds->SetId(i,0);
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}
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this->Line = vtkLine::New();
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}
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//----------------------------------------------------------------------------
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vtkPixel::~vtkPixel()
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{
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this->Line->Delete();
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}
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//----------------------------------------------------------------------------
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int vtkPixel::EvaluatePosition(double x[3], double* closestPoint,
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int& subId, double pcoords[3],
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double& dist2, double *weights)
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{
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double pt1[3], pt2[3], pt3[3];
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int i;
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double p[3], p21[3], p31[3], cp[3];
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double l21, l31, n[3];
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subId = 0;
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pcoords[2] = 0.0;
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// Get normal for pixel
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//
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this->Points->GetPoint(0, pt1);
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this->Points->GetPoint(1, pt2);
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this->Points->GetPoint(2, pt3);
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vtkTriangle::ComputeNormal (pt1, pt2, pt3, n);
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// Project point to plane
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//
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vtkPlane::ProjectPoint(x,pt1,n,cp);
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for (i=0; i<3; i++)
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{
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p21[i] = pt2[i] - pt1[i];
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p31[i] = pt3[i] - pt1[i];
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p[i] = x[i] - pt1[i];
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}
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if ( (l21=vtkMath::Norm(p21)) == 0.0 )
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{
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l21 = 1.0;
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}
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if ( (l31=vtkMath::Norm(p31)) == 0.0 )
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{
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l31 = 1.0;
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}
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pcoords[0] = vtkMath::Dot(p21,p) / (l21*l21);
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pcoords[1] = vtkMath::Dot(p31,p) / (l31*l31);
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this->InterpolationFunctions(pcoords, weights);
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if ( pcoords[0] >= 0.0 && pcoords[0] <= 1.0 &&
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pcoords[1] >= 0.0 && pcoords[1] <= 1.0 )
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{
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if (closestPoint)
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{
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closestPoint[0] = cp[0];
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closestPoint[1] = cp[1];
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closestPoint[2] = cp[2];
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dist2 =
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vtkMath::Distance2BetweenPoints(closestPoint,x); //projection distance
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}
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return 1;
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}
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else
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{
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double pc[3], w[4];
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if (closestPoint)
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{
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for (i=0; i<2; i++)
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{
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if (pcoords[i] < 0.0)
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{
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pc[i] = 0.0;
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}
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else if (pcoords[i] > 1.0)
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{
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pc[i] = 1.0;
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}
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else
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{
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pc[i] = pcoords[i];
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}
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}
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this->EvaluateLocation(subId, pc, closestPoint, (double *)w);
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dist2 = vtkMath::Distance2BetweenPoints(closestPoint,x);
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}
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return 0;
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}
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}
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//----------------------------------------------------------------------------
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void vtkPixel::EvaluateLocation(int& subId, double pcoords[3], double x[3],
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double *weights)
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{
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double pt1[3], pt2[3], pt3[3];
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int i;
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subId = 0;
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this->Points->GetPoint(0, pt1);
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this->Points->GetPoint(1, pt2);
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this->Points->GetPoint(2, pt3);
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for (i=0; i<3; i++)
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{
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x[i] = pt1[i] + pcoords[0]*(pt2[i] - pt1[i]) +
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pcoords[1]*(pt3[i] - pt1[i]);
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}
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this->InterpolationFunctions(pcoords, weights);
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}
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//----------------------------------------------------------------------------
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int vtkPixel::CellBoundary(int vtkNotUsed(subId), double pcoords[3], vtkIdList *pts)
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{
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double t1=pcoords[0]-pcoords[1];
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double t2=1.0-pcoords[0]-pcoords[1];
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pts->SetNumberOfIds(2);
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// compare against two lines in parametric space that divide element
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// into four pieces.
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if ( t1 >= 0.0 && t2 >= 0.0 )
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{
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pts->SetId(0,this->PointIds->GetId(0));
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pts->SetId(1,this->PointIds->GetId(1));
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}
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else if ( t1 >= 0.0 && t2 < 0.0 )
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{
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pts->SetId(0,this->PointIds->GetId(1));
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pts->SetId(1,this->PointIds->GetId(3));
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}
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else if ( t1 < 0.0 && t2 < 0.0 )
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{
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pts->SetId(0,this->PointIds->GetId(3));
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pts->SetId(1,this->PointIds->GetId(2));
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}
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else //( t1 < 0.0 && t2 >= 0.0 )
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{
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pts->SetId(0,this->PointIds->GetId(2));
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pts->SetId(1,this->PointIds->GetId(0));
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}
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if ( pcoords[0] < 0.0 || pcoords[0] > 1.0 ||
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pcoords[1] < 0.0 || pcoords[1] > 1.0 )
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{
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return 0;
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}
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else
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{
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return 1;
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}
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}
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//----------------------------------------------------------------------------
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//
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// Marching squares
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//
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#include "vtkMarchingSquaresCases.h"
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static int edges[4][2] = { {0,1}, {1,3}, {2,3}, {0,2} };
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void vtkPixel::Contour(double value, vtkDataArray *cellScalars,
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vtkPointLocator *locator,
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vtkCellArray *vtkNotUsed(verts),
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vtkCellArray *lines,
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vtkCellArray *vtkNotUsed(polys),
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vtkPointData *inPd, vtkPointData *outPd,
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vtkCellData *inCd, vtkIdType cellId, vtkCellData *outCd)
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{
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static int CASE_MASK[4] = {1,2,8,4}; //note differenceom quad!
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vtkMarchingSquaresLineCases *lineCase;
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EDGE_LIST *edge;
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int i, j, index, *vert;
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int newCellId;
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vtkIdType pts[2];
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double t, x1[3], x2[3], x[3];
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// Build the case table
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for ( i=0, index = 0; i < 4; i++)
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{
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if (cellScalars->GetComponent(i,0) >= value)
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{
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index |= CASE_MASK[i];
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}
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}
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lineCase = vtkMarchingSquaresLineCases::GetCases() + index;
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edge = lineCase->edges;
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for ( ; edge[0] > -1; edge += 2 )
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{
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for (i=0; i<2; i++) // insert line
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{
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vert = edges[edge[i]];
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t = (value - cellScalars->GetComponent(vert[0],0)) /
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(cellScalars->GetComponent(vert[1],0) -
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cellScalars->GetComponent(vert[0],0));
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this->Points->GetPoint(vert[0], x1);
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this->Points->GetPoint(vert[1], x2);
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for (j=0; j<3; j++)
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{
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x[j] = x1[j] + t * (x2[j] - x1[j]);
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}
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if ( locator->InsertUniquePoint(x, pts[i]) )
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{
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if ( outPd )
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{
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int p1 = this->PointIds->GetId(vert[0]);
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int p2 = this->PointIds->GetId(vert[1]);
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outPd->InterpolateEdge(inPd,pts[i],p1,p2,t);
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}
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}
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}
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// check for degenerate line
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if ( pts[0] != pts[1] )
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{
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newCellId = lines->InsertNextCell(2,pts);
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outCd->CopyData(inCd,cellId,newCellId);
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}
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}
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}
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//----------------------------------------------------------------------------
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vtkCell *vtkPixel::GetEdge(int edgeId)
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{
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int *verts;
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verts = edges[edgeId];
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// load point id's
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this->Line->PointIds->SetId(0,this->PointIds->GetId(verts[0]));
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this->Line->PointIds->SetId(1,this->PointIds->GetId(verts[1]));
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// load coordinates
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this->Line->Points->SetPoint(0,this->Points->GetPoint(verts[0]));
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this->Line->Points->SetPoint(1,this->Points->GetPoint(verts[1]));
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return this->Line;
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}
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//----------------------------------------------------------------------------
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//
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// Compute interpolation functions (similar but different than Quad interpolation
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// functions)
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//
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void vtkPixel::InterpolationFunctions(double pcoords[3], double sf[4])
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{
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double rm, sm;
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rm = 1. - pcoords[0];
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sm = 1. - pcoords[1];
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sf[0] = rm * sm;
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sf[1] = pcoords[0] * sm;
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sf[2] = rm * pcoords[1];
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sf[3] = pcoords[0] * pcoords[1];
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}
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//----------------------------------------------------------------------------
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//
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// Compute derivatives of interpolation functions.
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//
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void vtkPixel::InterpolationDerivs(double pcoords[3], double derivs[8])
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{
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double rm, sm;
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rm = 1. - pcoords[0];
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sm = 1. - pcoords[1];
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// r derivatives
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derivs[0] = -sm;
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derivs[1] = sm;
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derivs[2] = -pcoords[1];
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derivs[3] = pcoords[1];
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// s derivatives
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derivs[4] = -rm;
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derivs[5] = -pcoords[0];
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derivs[6] = rm;
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derivs[7] = pcoords[0];
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}
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//----------------------------------------------------------------------------
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//
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// Intersect plane; see whether point is inside.
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//
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int vtkPixel::IntersectWithLine(double p1[3], double p2[3], double tol, double& t,
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double x[3], double pcoords[3], int& subId)
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{
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double pt1[3], pt4[3], n[3];
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double tol2 = tol*tol;
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double closestPoint[3];
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double dist2, weights[4];
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int i;
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subId = 0;
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pcoords[0] = pcoords[1] = pcoords[2] = 0.0;
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//
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// Get normal for triangle
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//
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this->Points->GetPoint(0, pt1);
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this->Points->GetPoint(3, pt4);
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n[0] = n[1] = n[2] = 0.0;
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for (i=0; i<3; i++)
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{
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if ( (pt4[i] - pt1[i]) <= 0.0 )
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{
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n[i] = 1.0;
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break;
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}
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}
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//
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// Intersect plane of pixel with line
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//
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if ( ! vtkPlane::IntersectWithLine(p1,p2,n,pt1,t,x) )
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{
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return 0;
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}
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//
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// Use evaluate position
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//
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if (this->EvaluatePosition(x, closestPoint, subId, pcoords, dist2, weights) )
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{
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if ( dist2 <= tol2 )
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{
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return 1;
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}
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}
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return 0;
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}
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//----------------------------------------------------------------------------
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int vtkPixel::Triangulate(int index, vtkIdList *ptIds, vtkPoints *pts)
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{
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pts->Reset();
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ptIds->Reset();
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if ( (index % 2) )
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{
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ptIds->InsertId(0,this->PointIds->GetId(0));
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pts->InsertPoint(0,this->Points->GetPoint(0));
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ptIds->InsertId(1,this->PointIds->GetId(1));
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pts->InsertPoint(1,this->Points->GetPoint(1));
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ptIds->InsertId(2,this->PointIds->GetId(2));
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pts->InsertPoint(2,this->Points->GetPoint(2));
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ptIds->InsertId(3,this->PointIds->GetId(1));
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pts->InsertPoint(3,this->Points->GetPoint(1));
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ptIds->InsertId(4,this->PointIds->GetId(3));
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pts->InsertPoint(4,this->Points->GetPoint(3));
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ptIds->InsertId(5,this->PointIds->GetId(2));
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pts->InsertPoint(5,this->Points->GetPoint(2));
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}
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else
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{
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ptIds->InsertId(0,this->PointIds->GetId(0));
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pts->InsertPoint(0,this->Points->GetPoint(0));
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ptIds->InsertId(1,this->PointIds->GetId(1));
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pts->InsertPoint(1,this->Points->GetPoint(1));
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ptIds->InsertId(2,this->PointIds->GetId(3));
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pts->InsertPoint(2,this->Points->GetPoint(3));
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ptIds->InsertId(3,this->PointIds->GetId(0));
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pts->InsertPoint(3,this->Points->GetPoint(0));
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ptIds->InsertId(4,this->PointIds->GetId(3));
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pts->InsertPoint(4,this->Points->GetPoint(3));
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ptIds->InsertId(5,this->PointIds->GetId(2));
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pts->InsertPoint(5,this->Points->GetPoint(2));
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}
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return 1;
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}
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//----------------------------------------------------------------------------
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void vtkPixel::Derivatives(int vtkNotUsed(subId),
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double pcoords[3],
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double *values,
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int dim, double *derivs)
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{
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double functionDerivs[8], sum;
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int i, j, k, plane, idx[2], jj;
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double x0[3], x1[3], x2[3], x3[3], spacing[3];
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this->Points->GetPoint(0, x0);
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this->Points->GetPoint(1, x1);
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this->Points->GetPoint(2, x2);
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this->Points->GetPoint(3, x3);
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//figure which plane this pixel is in
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for (i=0; i < 3; i++)
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{
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spacing[i] = x3[i] - x0[i];
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}
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if ( spacing[0] > spacing[2] && spacing[1] > spacing[2] ) // z-plane
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{
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plane = 2;
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idx[0] = 0; idx[1] = 1;
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}
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else if ( spacing[0] > spacing[1] && spacing[2] > spacing[1] ) // y-plane
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{
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plane = 1;
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idx[0] = 0; idx[1] = 2;
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}
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else // x-plane
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{
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plane = 0;
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idx[0] = 1; idx[1] = 2;
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}
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spacing[0] = x1[idx[0]] - x0[idx[0]];
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spacing[1] = x2[idx[1]] - x0[idx[1]];
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// get derivatives in r-s directions
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this->InterpolationDerivs(pcoords, functionDerivs);
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// since two of the x-y-z axes are aligned with r-s axes, only need to scale
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// the derivative values by the data spacing.
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for (k=0; k < dim; k++) //loop over values per vertex
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{
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for (jj=j=0; j < 3; j++) //loop over derivative directions
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{
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if ( j == plane ) // 0-derivate values in this direction
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{
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sum = 0.0;
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}
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else //compute derivatives
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{
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for (sum=0.0, i=0; i < 4; i++) //loop over interp. function derivatives
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{
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sum += functionDerivs[4*jj + i] * values[dim*i + k];
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}
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sum /= spacing[idx[jj++]];
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}
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derivs[3*k + j] = sum;
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}
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}
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}
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//----------------------------------------------------------------------------
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// support pixel clipping
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typedef int PIXEL_EDGE_LIST;
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typedef struct {
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PIXEL_EDGE_LIST edges[14];
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} PIXEL_CASES;
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static PIXEL_CASES pixelCases[] = {
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{{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 0
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{{ 3, 100, 0, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 1
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{{ 3, 101, 1, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 2
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{{ 4, 100, 101, 1, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 3
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{{ 3, 103, 2, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 4
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{{ 3, 100, 0, 3, 3, 103, 2, 1, 4, 0, 1, 2, 3, -1}}, // 5
|
|
{{ 4, 101, 103, 2, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 6
|
|
{{ 3, 100, 101, 3, 3, 101, 2, 3, 3, 101, 103, 2, -1, -1}}, // 7
|
|
{{ 3, 102, 3, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 8
|
|
{{ 4, 100, 0, 2, 102, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 9
|
|
{{ 3, 101, 1, 0, 3, 102, 3, 2, 4, 0, 1, 2, 3, -1}}, // 10
|
|
{{ 3, 100, 101, 1, 3, 100, 1, 2, 3, 100, 2, 102, -1, -1}}, // 11
|
|
{{ 4, 103, 102, 3, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 12
|
|
{{ 3, 100, 0, 102, 3, 0, 1, 102, 3, 1, 103, 102, -1, -1}}, // 13
|
|
{{ 3, 0, 101, 103, 3, 0, 103, 3, 3, 103, 102, 3, -1, -1}}, // 14
|
|
{{ 4, 100, 101, 103, 102, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 15
|
|
};
|
|
|
|
static PIXEL_CASES pixelCasesComplement[] = {
|
|
{{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 0
|
|
{{ 3, 100, 0, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 1
|
|
{{ 3, 101, 1, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 2
|
|
{{ 4, 100, 101, 1, 3, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 3
|
|
{{ 3, 103, 2, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 4
|
|
{{ 3, 100, 0, 3, 3, 103, 2, 1, -1, -1, -1, -1, -1, -1}}, // 5
|
|
{{ 4, 101, 103, 2, 0, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 6
|
|
{{ 3, 100, 101, 3, 3, 101, 2, 3, 3, 101, 103, 2, -1, -1}}, // 7
|
|
{{ 3, 102, 3, 2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 8
|
|
{{ 4, 100, 0, 2, 102, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 9
|
|
{{ 3, 101, 1, 0, 3, 102, 3, 2, -1, -1, -1, -1, -1, -1}}, // 10
|
|
{{ 3, 100, 101, 1, 3, 100, 1, 2, 3, 100, 2, 102, -1, -1}}, // 11
|
|
{{ 4, 103, 102, 3, 1, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 12
|
|
{{ 3, 100, 0, 102, 3, 0, 1, 102, 3, 1, 103, 102, -1, -1}}, // 13
|
|
{{ 3, 0, 101, 103, 3, 0, 103, 3, 3, 103, 102, 3, -1, -1}}, // 14
|
|
{{ 4, 100, 101, 103, 102, -1, -1, -1, -1, -1, -1, -1, -1, -1}}, // 15
|
|
};
|
|
|
|
|
|
//----------------------------------------------------------------------------
|
|
// Clip this pixel using scalar value provided. Like contouring, except
|
|
// that it cuts the pixel to produce quads and/or triangles.
|
|
void vtkPixel::Clip(double value, vtkDataArray *cellScalars,
|
|
vtkPointLocator *locator, vtkCellArray *polys,
|
|
vtkPointData *inPd, vtkPointData *outPd,
|
|
vtkCellData *inCd, vtkIdType cellId, vtkCellData *outCd,
|
|
int insideOut)
|
|
{
|
|
static int CASE_MASK[4] = {1,2,8,4}; //note difference from quad!
|
|
PIXEL_CASES *pixelCase;
|
|
PIXEL_EDGE_LIST *edge;
|
|
int i, j, index, *vert;
|
|
int e1, e2;
|
|
int newCellId;
|
|
vtkIdType pts[4];
|
|
int vertexId;
|
|
double t, x1[3], x2[3], x[3], deltaScalar;
|
|
double scalar0, scalar1, e1Scalar;
|
|
|
|
// Build the index into the case table
|
|
if ( insideOut )
|
|
{
|
|
for ( i=0, index = 0; i < 4; i++)
|
|
{
|
|
if (cellScalars->GetComponent(i,0) <= value)
|
|
{
|
|
index |= CASE_MASK[i];
|
|
}
|
|
}
|
|
// Select case based on the index and get the list of edges for this case
|
|
pixelCase = pixelCases + index;
|
|
}
|
|
else
|
|
{
|
|
for ( i=0, index = 0; i < 4; i++)
|
|
{
|
|
if (cellScalars->GetComponent(i,0) > value)
|
|
{
|
|
index |= CASE_MASK[i];
|
|
}
|
|
}
|
|
// Select case based on the index and get the list of edges for this case
|
|
pixelCase = pixelCasesComplement + index;
|
|
}
|
|
|
|
edge = pixelCase->edges;
|
|
|
|
// generate each pixel
|
|
for ( ; edge[0] > -1; edge += edge[0]+1 )
|
|
{
|
|
for (i=0; i < edge[0]; i++) // insert pixel or triangle
|
|
{
|
|
// vertex exists, and need not be interpolated
|
|
if (edge[i+1] >= 100)
|
|
{
|
|
vertexId = edge[i+1] - 100;
|
|
this->Points->GetPoint(vertexId, x);
|
|
if ( locator->InsertUniquePoint(x, pts[i]) )
|
|
{
|
|
outPd->CopyData(inPd,this->PointIds->GetId(vertexId),pts[i]);
|
|
}
|
|
}
|
|
|
|
else //new vertex, interpolate
|
|
{
|
|
vert = edges[edge[i+1]];
|
|
|
|
// calculate a preferred interpolation direction
|
|
scalar0 = cellScalars->GetComponent(vert[0],0);
|
|
scalar1 = cellScalars->GetComponent(vert[1],0);
|
|
deltaScalar = scalar1 - scalar0;
|
|
|
|
if (deltaScalar > 0)
|
|
{
|
|
e1 = vert[0]; e2 = vert[1];
|
|
e1Scalar = scalar0;
|
|
}
|
|
else
|
|
{
|
|
e1 = vert[1]; e2 = vert[0];
|
|
e1Scalar = scalar1;
|
|
deltaScalar = -deltaScalar;
|
|
}
|
|
|
|
// linear interpolation
|
|
if (deltaScalar == 0.0)
|
|
{
|
|
t = 0.0;
|
|
}
|
|
else
|
|
{
|
|
t = (value - e1Scalar) / deltaScalar;
|
|
}
|
|
|
|
this->Points->GetPoint(e1, x1);
|
|
this->Points->GetPoint(e2, x2);
|
|
|
|
for (j=0; j<3; j++)
|
|
{
|
|
x[j] = x1[j] + t * (x2[j] - x1[j]);
|
|
}
|
|
|
|
if ( locator->InsertUniquePoint(x, pts[i]) )
|
|
{
|
|
int p1 = this->PointIds->GetId(e1);
|
|
int p2 = this->PointIds->GetId(e2);
|
|
outPd->InterpolateEdge(inPd,pts[i],p1,p2,t);
|
|
}
|
|
}
|
|
}
|
|
// check for degenerate output
|
|
if ( edge[0] == 3 ) //i.e., a triangle
|
|
{
|
|
if (pts[0] == pts[1] || pts[0] == pts[2] || pts[1] == pts[2] )
|
|
{
|
|
continue;
|
|
}
|
|
}
|
|
else // a pixel
|
|
{
|
|
if ((pts[0] == pts[3] && pts[1] == pts[2]) ||
|
|
(pts[0] == pts[1] && pts[3] == pts[2]) )
|
|
{
|
|
continue;
|
|
}
|
|
}
|
|
|
|
newCellId = polys->InsertNextCell(edge[0],pts);
|
|
outCd->CopyData(inCd,cellId,newCellId);
|
|
}
|
|
}
|
|
|
|
//----------------------------------------------------------------------------
|
|
static double vtkPixelCellPCoords[12] = {0.0,0.0,0.0, 1.0,0.0,0.0,
|
|
0.0,1.0,0.0, 1.0,1.0,0.0};
|
|
|
|
double *vtkPixel::GetParametricCoords()
|
|
{
|
|
return vtkPixelCellPCoords;
|
|
}
|
|
|
|
//----------------------------------------------------------------------------
|
|
void vtkPixel::PrintSelf(ostream& os, vtkIndent indent)
|
|
{
|
|
this->Superclass::PrintSelf(os,indent);
|
|
|
|
os << indent << "Line:\n";
|
|
this->Line->PrintSelf(os,indent.GetNextIndent());
|
|
}
|
|
|
|
|