T:/Eigene Dateien/Visual Studio 2008/Projects/VisLuFramework/src/HistogramDraw.cpp

#include "HistogramDraw.h"

#include "TransferFunctionGUI.h"
#include "Volume.h"

HistogramDraw* HistogramDraw::_instance = NULL;
bool HistogramDraw::initialized = false;

HistogramDraw::~HistogramDraw()
{
        if(m_HistogramData)
                delete m_HistogramData;
        if(m_HistogramDataLogarithmic)
                delete m_HistogramData;
}

HistogramDraw::HistogramDraw()
{
        m_HistogramData = NULL;
        m_HistogramDataLogarithmic = NULL;
        m_HistogramDataSize = 0;
        m_HistogramDrawType = HISTOGRAM_DRAW_LOG;
}

HistogramDraw *HistogramDraw::getInstance()
{
        if(!initialized)
        {
                _instance = new HistogramDraw();
                initialized = true;
        }

        return _instance;
}




void HistogramDraw::refreshHistogramDrawData(Volume& volume)
{
        if(m_HistogramData)
                delete m_HistogramData;
        if(m_HistogramDataLogarithmic)
                delete m_HistogramDataLogarithmic;

        std::vector<double> normalizedHistogramData = volume.GetNormHistogram();

        m_HistogramDataSize = normalizedHistogramData.size();
        m_HistogramData = new float[m_HistogramDataSize];
        m_HistogramDataLogarithmic = new float[m_HistogramDataSize];

        rescaleHistogramDataToHighestValue(normalizedHistogramData);
        calculateLogarithmicHistogramData();
}


void HistogramDraw::draw()
{
        if(!m_HistogramDrawType == HISTOGRAM_DRAW_NONE)
        {
                int histogramDrawWidth = TransferFunctionGUI::g_iTransferFuncPickerWidth;

                glLineWidth(1.0f);
                glEnable(GL_LINE_SMOOTH);
                glHint(GL_LINE_SMOOTH_HINT, GL_NICEST);


                glBegin(GL_LINES);
                glColor4f(0.3f,0.4f,0.4f,0.3f);

                for(int i = 0; i < m_HistogramDataSize; ++i)
                {
                        float yFactor;

                        if(m_HistogramDrawType == HISTOGRAM_DRAW_LINEAR)
                                yFactor = m_HistogramData[i];
                        else if(m_HistogramDrawType == HISTOGRAM_DRAW_LOG)
                                yFactor = m_HistogramDataLogarithmic[i];

                        float y = TransferFunctionGUI::g_iTransferFuncPickerHeight * yFactor;
                        float x = histogramDrawWidth *  i / (float) m_HistogramDataSize;

                        glVertex2f(x, - y);
                        glVertex2f(x, 0.f);
                }


                glEnd();

                glDisable(GL_LINE_SMOOTH);
        }
}


void HistogramDraw::setDrawType(HistogramDrawType drawType)
{
        m_HistogramDrawType = drawType;
}

void HistogramDraw::rescaleHistogramDataToHighestValue( std::vector<double> &normalizedHistogramData )
{
        float histoMax = 0.f;
        for(unsigned int i = 0; i < normalizedHistogramData.size(); ++i)
        {
                if(normalizedHistogramData.at(i) > histoMax)
                        histoMax = (float)normalizedHistogramData.at(i);
        }


        for(unsigned int i = 0; i < normalizedHistogramData.size(); ++i)
        {
                m_HistogramData[i] = (float)normalizedHistogramData.at(i) / histoMax;
        }
}

void HistogramDraw::calculateLogarithmicHistogramData()
{
        for(int i = 0; i < m_HistogramDataSize; ++i)
        {
                m_HistogramDataLogarithmic[i] = 1.f - pow(10, ( - m_HistogramData[i] * 2.f));
        }
}