140 lines
3.6 KiB
C++
140 lines
3.6 KiB
C++
/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
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*
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* This library is open source and may be redistributed and/or modified under
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* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
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* (at your option) any later version. The full license is in LICENSE file
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* included with this distribution, and on the openscenegraph.org website.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* OpenSceneGraph Public License for more details.
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*/
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#include <osg/TransferFunction>
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#include <osg/Notify>
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#include <osg/io_utils>
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using namespace osg;
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///////////////////////////////////////////////////////////////////////
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//
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// TransferFunction base class
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//
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TransferFunction::TransferFunction()
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{
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}
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TransferFunction::~TransferFunction()
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{
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}
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///////////////////////////////////////////////////////////////////////
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//
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// TransferFunction1D class
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//
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TransferFunction1D::TransferFunction1D()
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{
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_minimum = 0.0;
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_maximum = 1.0;
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}
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void TransferFunction1D::setInputRange(float minimum, float maximum)
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{
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_minimum = minimum;
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_maximum = maximum;
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}
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void TransferFunction1D::allocate(unsigned int numX)
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{
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_colors.resize(numX);
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_image = new osg::Image;
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_image->setImage(numX,1,1,GL_RGBA, GL_RGBA, GL_FLOAT, (unsigned char*)&_colors[0], osg::Image::NO_DELETE);
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}
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void TransferFunction1D::clear(const osg::Vec4& color)
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{
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for(Colors::iterator itr = _colors.begin();
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itr != _colors.end();
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++itr)
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{
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*itr = color;
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}
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}
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void TransferFunction1D::assign(const ValueMap& vcm, bool updateMinMaxRange)
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{
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if (vcm.empty()) return;
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if (updateMinMaxRange)
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{
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_minimum = vcm.begin()->first;
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_maximum = vcm.rbegin()->first;
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}
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if (_colors.empty()) allocate(1024);
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float multiplier = float(_colors.size()-1)/(_maximum - _minimum);
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if (vcm.size()==1)
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{
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osg::Vec4 color = vcm.begin()->second;
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if (_minimum == _maximum)
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{
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clear(color);
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}
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else
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{
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float iPos = (vcm.begin()->first - _minimum)*multiplier;
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if (iPos>=0.0f || iPos<float(_colors.size()))
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{
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float iFloor = floorf(iPos);
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unsigned int i = (unsigned int)(iFloor);
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_colors[i] = color;
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}
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}
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return;
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}
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ValueMap::const_iterator lower_itr = vcm.begin();
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ValueMap::const_iterator upper_itr = lower_itr;
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++upper_itr;
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for(;
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upper_itr != vcm.end();
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++upper_itr)
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{
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float lower_v = lower_itr->first;
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const osg::Vec4& lower_c = lower_itr->second;
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float upper_v = upper_itr->first;
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const osg::Vec4& upper_c = upper_itr->second;
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float lower_iPos = (lower_v - _minimum)*multiplier;
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float upper_iPos = (upper_v - _minimum)*multiplier;
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float start_iPos = ceilf(lower_iPos);
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if (start_iPos<0.0f) start_iPos=0.0f;
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if (start_iPos>float(_colors.size()-1)) break;
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float end_iPos = floorf(upper_iPos);
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if (end_iPos<0.0f) continue;
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if (end_iPos>float(_colors.size()-1)) end_iPos=_colors.size()-1;
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Vec4 delta_c = (upper_c-lower_c)/(upper_iPos-lower_iPos);
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unsigned int i=static_cast<unsigned int>(start_iPos);
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for(float iPos=start_iPos;
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iPos<=end_iPos;
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++iPos, ++i)
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{
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_colors[i] = lower_c + delta_c*(iPos-lower_v);
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}
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lower_itr = upper_itr;
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}
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}
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