ResInsight/Fwk/AppFwk/CommonCode/cafContourLines.cpp
2020-11-06 06:18:34 -05:00

309 lines
14 KiB
C++

/////////////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2018- Equinor ASA
// Copyright (C) 2018- Ceetron Solutions AS
//
// Adapted from work by Paul D. Bourke named "conrec"
//
// http://paulbourke.net/papers/conrec/.
//
// ResInsight is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// ResInsight is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE.
//
// See the GNU General Public License at <http://www.gnu.org/licenses/gpl.html>
// for more details.
//
/////////////////////////////////////////////////////////////////////////////////
#include "cafContourLines.h"
#include <algorithm>
#include <cmath>
#include <list>
const int caf::ContourLines::s_castab[3][3][3] = { { { 0, 0, 8 }, { 0, 2, 5 }, { 7, 6, 9 } },
{ { 0, 3, 4 }, { 1, 3, 1 }, { 4, 3, 0 } },
{ { 9, 6, 7 }, { 5, 2, 0 }, { 8, 0, 0 } } };
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
void caf::ContourLines::create( const std::vector<double>& dataXY,
const std::vector<double>& xCoords,
const std::vector<double>& yCoords,
const std::vector<double>& contourLevels,
std::vector<std::vector<cvf::Vec2d>>* polygons )
{
CVF_ASSERT( !contourLevels.empty() );
int nContourLevels = static_cast<int>( contourLevels.size() );
std::vector<int> sh( 5, 0 );
std::vector<double> h( 5, 0.0 ), xh( 5, 0.0 ), yh( 5, 0.0 );
int nx = static_cast<int>( xCoords.size() );
int ny = static_cast<int>( yCoords.size() );
CVF_ASSERT( static_cast<int>( dataXY.size() ) == nx * ny );
polygons->resize( nContourLevels );
int im[4] = { 0, 1, 1, 0 }, jm[4] = { 0, 0, 1, 1 };
for ( int j = ( ny - 2 ); j >= 0; j-- )
{
for ( int i = 0; i < nx - 1; i++ )
{
double temp1, temp2;
temp1 = std::min( saneValue( gridIndex1d( i, j, nx ), dataXY, contourLevels ),
saneValue( gridIndex1d( i, j + 1, nx ), dataXY, contourLevels ) );
temp2 = std::min( saneValue( gridIndex1d( i + 1, j, nx ), dataXY, contourLevels ),
saneValue( gridIndex1d( i + 1, j + 1, nx ), dataXY, contourLevels ) );
double dmin = std::min( temp1, temp2 );
temp1 = std::max( saneValue( gridIndex1d( i, j, nx ), dataXY, contourLevels ),
saneValue( gridIndex1d( i, j + 1, nx ), dataXY, contourLevels ) );
temp2 = std::max( saneValue( gridIndex1d( i + 1, j, nx ), dataXY, contourLevels ),
saneValue( gridIndex1d( i + 1, j + 1, nx ), dataXY, contourLevels ) );
double dmax = std::max( temp1, temp2 );
// Using dmax <= contourLevels[0] as a deviation from Bourke because it empirically
// Reduces gridding artifacts in our code.
if ( dmax <= contourLevels[0] || dmin > contourLevels[nContourLevels - 1] ) continue;
for ( int k = 0; k < nContourLevels; k++ )
{
if ( contourLevels[k] < dmin || contourLevels[k] > dmax ) continue;
for ( int m = 4; m >= 0; m-- )
{
if ( m > 0 )
{
double value = saneValue( gridIndex1d( i + im[m - 1], j + jm[m - 1], nx ), dataXY, contourLevels );
if ( value == invalidValue( contourLevels ) )
{
h[m] = invalidValue( contourLevels );
}
else
{
h[m] = value - contourLevels[k];
}
xh[m] = xCoords[i + im[m - 1]];
yh[m] = yCoords[j + jm[m - 1]];
}
else
{
h[0] = 0.25 * ( h[1] + h[2] + h[3] + h[4] );
xh[0] = 0.5 * ( xCoords[i] + xCoords[i + 1] );
yh[0] = 0.5 * ( yCoords[j] + yCoords[j + 1] );
}
if ( h[m] > 0.0 )
sh[m] = 1;
else if ( h[m] < 0.0 )
sh[m] = -1;
else
sh[m] = 0;
}
/*
Note: at this stage the relative heights of the corners and the
centre are in the h array, and the corresponding coordinates are
in the xh and yh arrays. The centre of the box is indexed by 0
and the 4 corners by 1 to 4 as shown below.
Each triangle is then indexed by the parameter m, and the 3
vertices of each triangle are indexed by parameters m1,m2,and m3.
It is assumed that the centre of the box is always vertex 2
though this isimportant only when all 3 vertices lie exactly on
the same contour level, in which case only the side of the box
is drawn.
vertex 4 +-------------------+ vertex 3
| \ / |
| \ m-3 / |
| \ / |
| \ / |
| m=2 X m=2 | the centre is vertex 0
| / \ |
| / \ |
| / m=1 \ |
| / \ |
vertex 1 +-------------------+ vertex 2
*/
/* Scan each triangle in the box */
for ( int m = 1; m <= 4; m++ )
{
int m1 = m;
int m2 = 0;
int m3 = ( m != 4 ) ? m + 1 : 1;
double x1 = 0.0, x2 = 0.0, y1 = 0.0, y2 = 0.0;
int case_value = s_castab[sh[m1] + 1][sh[m2] + 1][sh[m3] + 1];
if ( case_value == 0 ) continue;
switch ( case_value )
{
case 1: /* Line between vertices 1 and 2 */
x1 = xh[m1];
y1 = yh[m1];
x2 = xh[m2];
y2 = yh[m2];
break;
case 2: /* Line between vertices 2 and 3 */
x1 = xh[m2];
y1 = yh[m2];
x2 = xh[m3];
y2 = yh[m3];
break;
case 3: /* Line between vertices 3 and 1 */
x1 = xh[m3];
y1 = yh[m3];
x2 = xh[m1];
y2 = yh[m1];
break;
case 4: /* Line between vertex 1 and side 2-3 */
x1 = xh[m1];
y1 = yh[m1];
x2 = xsect( m2, m3, h, xh, yh );
y2 = ysect( m2, m3, h, xh, yh );
break;
case 5: /* Line between vertex 2 and side 3-1 */
x1 = xh[m2];
y1 = yh[m2];
x2 = xsect( m3, m1, h, xh, yh );
y2 = ysect( m3, m1, h, xh, yh );
break;
case 6: /* Line between vertex 3 and side 1-2 */
x1 = xh[m3];
y1 = yh[m3];
x2 = xsect( m1, m2, h, xh, yh );
y2 = ysect( m1, m2, h, xh, yh );
break;
case 7: /* Line between sides 1-2 and 2-3 */
x1 = xsect( m1, m2, h, xh, yh );
y1 = ysect( m1, m2, h, xh, yh );
x2 = xsect( m2, m3, h, xh, yh );
y2 = ysect( m2, m3, h, xh, yh );
break;
case 8: /* Line between sides 2-3 and 3-1 */
x1 = xsect( m2, m3, h, xh, yh );
y1 = ysect( m2, m3, h, xh, yh );
x2 = xsect( m3, m1, h, xh, yh );
y2 = ysect( m3, m1, h, xh, yh );
break;
case 9: /* Line between sides 3-1 and 1-2 */
x1 = xsect( m3, m1, h, xh, yh );
y1 = ysect( m3, m1, h, xh, yh );
x2 = xsect( m1, m2, h, xh, yh );
y2 = ysect( m1, m2, h, xh, yh );
break;
default:
break;
}
/* Finally draw the line */
polygons->at( k ).push_back( cvf::Vec2d( x1, y1 ) );
polygons->at( k ).push_back( cvf::Vec2d( x2, y2 ) );
} /* m */
} /* k - contour */
} /* i */
} /* j */
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
std::vector<caf::ContourLines::ListOfLineSegments> caf::ContourLines::create( const std::vector<double>& dataXY,
const std::vector<double>& xPositions,
const std::vector<double>& yPositions,
const std::vector<double>& contourLevels )
{
const double eps = 1.0e-4;
std::vector<std::vector<cvf::Vec2d>> contourLineSegments;
caf::ContourLines::create( dataXY, xPositions, yPositions, contourLevels, &contourLineSegments );
std::vector<ListOfLineSegments> listOfSegmentsPerLevel( contourLevels.size() );
for ( size_t i = 0; i < contourLevels.size(); ++i )
{
size_t nPoints = contourLineSegments[i].size();
size_t nSegments = nPoints / 2;
if ( nSegments >= 3u ) // Need at least three segments for a closed polygon
{
ListOfLineSegments unorderedSegments;
for ( size_t j = 0; j < contourLineSegments[i].size(); j += 2 )
{
unorderedSegments.push_back( std::make_pair( cvf::Vec3d( contourLineSegments[i][j] ),
cvf::Vec3d( contourLineSegments[i][j + 1] ) ) );
}
listOfSegmentsPerLevel[i] = unorderedSegments;
}
}
return listOfSegmentsPerLevel;
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double caf::ContourLines::contourRange( const std::vector<double>& contourLevels )
{
CVF_ASSERT( !contourLevels.empty() );
return std::max( 1.0e-6, contourLevels.back() - contourLevels.front() );
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double caf::ContourLines::invalidValue( const std::vector<double>& contourLevels )
{
return contourLevels.front() - 1000.0 * contourRange( contourLevels );
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double caf::ContourLines::saneValue( int index, const std::vector<double>& dataXY, const std::vector<double>& contourLevels )
{
CVF_ASSERT( index >= 0 && index < static_cast<int>( dataXY.size() ) );
// Place all invalid values below the bottom contour level.
if ( dataXY[index] == -std::numeric_limits<double>::infinity() ||
dataXY[index] == std::numeric_limits<double>::infinity() )
{
return invalidValue( contourLevels );
}
return dataXY[index];
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double caf::ContourLines::xsect( int p1,
int p2,
const std::vector<double>& h,
const std::vector<double>& xh,
const std::vector<double>& yh )
{
return ( h[p2] * xh[p1] - h[p1] * xh[p2] ) / ( h[p2] - h[p1] );
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
double caf::ContourLines::ysect( int p1,
int p2,
const std::vector<double>& h,
const std::vector<double>& xh,
const std::vector<double>& yh )
{
return ( h[p2] * yh[p1] - h[p1] * yh[p2] ) / ( h[p2] - h[p1] );
}
//--------------------------------------------------------------------------------------------------
///
//--------------------------------------------------------------------------------------------------
int caf::ContourLines::gridIndex1d( int i, int j, int nx )
{
return j * nx + i;
}