void Histogram::insertZeroBoundaryValues(float xMin, float xMax)
{
if (_valueMap.empty())
{
if (xMin<xMax)
{
_valueMap[xMin] = 0.0;
_valueMap[xMax] = 0.0;
}
return;
}
float interval = 1.0f;
float min_gap_for_single_insertion = interval*1.5;
float min_gap_for_double_insertion = interval*2.5;
if (xMin<_valueMap.begin()->first)
{
_valueMap[xMin] = 0.0;
}
if (xMax>_valueMap.rbegin()->first)
{
_valueMap[xMax] = 0.0;
}
ValueMap::iterator itr = _valueMap.begin();
float previous_x = itr->first;
for(;
itr != _valueMap.end();
++itr)
{
float current_x = itr->first;
float gap = current_x-previous_x;
if (gap>min_gap_for_double_insertion)
{
_valueMap[previous_x+interval] = 0.0f;
_valueMap[current_x-interval] = 0.0f;
}
else if (gap>min_gap_for_single_insertion)
{
_valueMap[(previous_x+current_x)*0.5]=0.0f;
}
previous_x = current_x;
}
}
osg::Node* Histogram::createGraphicalRepresentation()
{
if (_valueMap.empty()) return 0;
osg::ref_ptr<osg::MatrixTransform> transform = new osg::MatrixTransform;
float xMin = _valueMap.begin()->first;
float xMax = _valueMap.rbegin()->first;
float depth = 0.0f;
float yMax = 0.0f;
// find yMax
for(ValueMap::iterator itr = _valueMap.begin();
itr != _valueMap.end();
++itr)
{
float y = itr->second;
if (y>yMax) yMax = y;
}
float xScale = 1.0f/(xMax-xMin);
float yScale = 1.0f/yMax;
{
osg::ref_ptr<osg::Geode> geode = new osg::Geode;
transform->addChild(geode.get());
osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry;
geode->addDrawable(geometry.get());
geode->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
geode->getOrCreateStateSet()->setMode(GL_BLEND, osg::StateAttribute::ON);
osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;
geometry->setVertexArray(vertices.get());
osg::ref_ptr<osg::Vec4Array> colours = new osg::Vec4Array;
geometry->setColorArray(colours.get(), osg::Array::BIND_PER_PRIMITIVE_SET);
colours->push_back(osg::Vec4(1.0,1.0,1.0,1.0));
colours->push_back(osg::Vec4(1.0,1.0,1.0,1.0));
colours->push_back(osg::Vec4(1.0,1.0,1.0,0.1));
unsigned numColumnsRequired = _valueMap.size();
vertices->reserve(numColumnsRequired*3);
for(ValueMap::iterator itr = _valueMap.begin();
itr != _valueMap.end();
++itr)
{
float x = itr->first;
float y = itr->second;
vertices->push_back(osg::Vec3(x*xScale, 0.0f, depth));
vertices->push_back(osg::Vec3(x*xScale, y*yScale, depth));
vertices->push_back(osg::Vec3(x*xScale, yMax*yScale, depth));
}
osg::ref_ptr<osg::DrawElementsUShort> background_primitives = new osg::DrawElementsUShort(GL_TRIANGLE_STRIP);
osg::ref_ptr<osg::DrawElementsUShort> historgram_primitives = new osg::DrawElementsUShort(GL_TRIANGLE_STRIP);
osg::ref_ptr<osg::DrawElementsUShort> outline_primitives = new osg::DrawElementsUShort(GL_LINE_STRIP);
for(unsigned int i=0; i<numColumnsRequired; ++i)
{
int iv = i*3;
background_primitives->push_back(iv+2);
background_primitives->push_back(iv+1);
historgram_primitives->push_back(iv+1);
historgram_primitives->push_back(iv+0);
outline_primitives->push_back(iv+1);
}
geometry->addPrimitiveSet(outline_primitives.get());
geometry->addPrimitiveSet(historgram_primitives.get());
geometry->addPrimitiveSet(background_primitives.get());
}
//transform->setMatrix(osg::Matrix::scale(xScale/(maxX-minY), yScale/(yMax), 1.0f));
transform->setMatrix(osg::Matrix::scale(2.0,1.0,1.0)*osg::Matrix::rotate(osg::DegreesToRadians(90.0), osg::Vec3d(1.0,0.0,0.0)));
return transform.release();
}
