cxTransferFunctionAlphaWidget.cpp

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/*=========================================================================
This file is part of CustusX, an Image Guided Therapy Application.

Copyright (c) 2008-2014, SINTEF Department of Medical Technology
All rights reserved.

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modification, are permitted provided that the following conditions are met:

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   this list of conditions and the following disclaimer.

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   and/or other materials provided with the distribution.

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   may be used to endorse or promote products derived from this software 
   without specific prior written permission.

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
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#include "cxTransferFunctionAlphaWidget.h"

#include <limits.h>
#include <vtkImageData.h>
#include <vtkPointData.h>
#include <vtkImageAccumulate.h>
#include <QPainter>
#include <QPen>
#include <QColor>
#include <QBrush>
#include <QMouseEvent>
#include "cxImageTF3D.h"
#include "cxImageTFData.h"
#include "cxLogger.h"
#include "cxUtilHelpers.h"
#include "cxTypeConversions.h"
#include "vtkDataArray.h"
#include "cxReporter.h"
#include "cxMathUtils.h"


namespace cx
{
TransferFunctionAlphaWidget::TransferFunctionAlphaWidget(ActiveDataPtr activeData, QWidget* parent) :
  BaseWidget(parent, "TransferFunctionAlphaWidget", "Alpha Transfer Function"),
  mBorder(5),
  mReadOnly(false)
{
        this->setToolTip("Set the alpha part of a transfer function");
        this->setFocusPolicy(Qt::StrongFocus);

        mActiveImageProxy = ActiveImageProxy::New(activeData);
  connect(mActiveImageProxy.get(), SIGNAL(transferFunctionsChanged()), this, SLOT(activeImageTransferFunctionsChangedSlot()));

  mSelectedAlphaPoint.reset();
}
TransferFunctionAlphaWidget::~TransferFunctionAlphaWidget()
{}

void TransferFunctionAlphaWidget::setData(ImagePtr image, ImageTFDataPtr tfData)
{
  if (( mImage == image )&&( mImageTF==tfData ))
    return;

  mImage = image;
  mImageTF = tfData;
  this->update();
}

void TransferFunctionAlphaWidget::setReadOnly(bool readOnly)
{
  mReadOnly = readOnly;
}

void TransferFunctionAlphaWidget::activeImageTransferFunctionsChangedSlot()
{
  this->update();
}
  
void TransferFunctionAlphaWidget::enterEvent(QEvent* event)
{
  this->setMouseTracking(true);
}

void TransferFunctionAlphaWidget::leaveEvent(QEvent* event)
{
  this->setMouseTracking(false);
}

void TransferFunctionAlphaWidget::mousePressEvent(QMouseEvent* event)
{
  if(mReadOnly)
    return;
  QWidget::mousePressEvent(event);

  if(event->button() == Qt::LeftButton)
  {
          mSelectedAlphaPoint = this->selectPoint(event->pos());
  }
  else if(event->button() == Qt::RightButton)
  {
          this->toggleSelectedPoint(event->pos());
  }

  this->update();
}

void TransferFunctionAlphaWidget::mouseReleaseEvent(QMouseEvent* event)
{
  if(mReadOnly)
    return;
  QWidget::mouseReleaseEvent(event);
//  mCurrentAlphaPoint.reset();
}

void TransferFunctionAlphaWidget::mouseMoveEvent(QMouseEvent* event)
{
  if (!mImage)
    return;

  this->updateTooltip(event->pos());
  if(mReadOnly) //Only show tool tip if readOnly
    return;

  QWidget::mouseMoveEvent(event);

  if(event->buttons() == Qt::LeftButton)
  {
        this->moveCurrentAlphaPoint(this->getCurrentAlphaPoint(event->pos()));
          this->update();
  }
}

void TransferFunctionAlphaWidget::keyPressEvent(QKeyEvent* event)
{
        if (mSelectedAlphaPoint.isValid())
        {
                int shift = 0;
                int alphaShift = 0;
                if (event->key()==Qt::Key_Left)
                        shift = -1;
                if (event->key()==Qt::Key_Right)
                        shift = +1;
                if (event->key()==Qt::Key_Down)
                        alphaShift = -1;
                if (event->key()==Qt::Key_Up)
                        alphaShift = +1;

                if ((shift!=0) || (alphaShift!=0))
                {
                        AlphaPoint newPoint = mSelectedAlphaPoint;
                        newPoint.position += shift;
                        newPoint.value += alphaShift;
                        this->moveCurrentAlphaPoint(newPoint);
                        this->updateTooltip(mSelectedAlphaPoint);
                        this->update();
                        return;
                }
        }

        QWidget::keyPressEvent(event);
}

void TransferFunctionAlphaWidget::updateTooltip(QPoint pos)
{
        AlphaPoint selected = this->selectPoint(pos);
        if (!selected.isValid())
                selected = this->getCurrentAlphaPoint(pos);
        this->updateTooltip(selected);
        this->update();
}

void TransferFunctionAlphaWidget::updateTooltip(AlphaPoint point)
{
        QString tip = QString("alpha(%1)=%2").arg(point.position).arg(double(point.value)/255, 0, 'f', 2);
        this->setToolTip(tip);
        reporter()->sendVolatile(tip);
}


void TransferFunctionAlphaWidget::paintEvent(QPaintEvent* event)
{
  QWidget::paintEvent(event);
  QPainter painter(this);
  this->clearBackground(painter);

  if (!mImage)
          return;

  this->paintHistogram(painter);
  this->paintOpacityGraph(painter);
}

void TransferFunctionAlphaWidget::clearBackground(QPainter& painter)
{
        // Fill with white global background color and grey plot area background color
        const QBrush frameBrush = QBrush(QColor(170, 170, 170));
        const QBrush backgroundBrush = QBrush(QColor(200, 200, 200));
        painter.fillRect(this->mFullArea, frameBrush);
        painter.fillRect(this->mPlotArea, backgroundBrush);

}

void TransferFunctionAlphaWidget::paintOpacityGraph(QPainter& painter)
{
        QPen pointPen, pointLinePen;
        pointPen.setColor(QColor(0, 0, 150));
        pointLinePen.setColor(QColor(150, 100, 100));

        // Go through each point and draw squares and lines
        IntIntMap opacityMap = mImageTF->getOpacityMap();

        QPoint lastScreenPoint;
        this->mPointRects.clear();
        for (IntIntMap::iterator opPoint = opacityMap.begin();
                 opPoint != opacityMap.end();
                 ++opPoint)
        {
          // Get the screen (plot) position of this point
                AlphaPoint pt(opPoint->first, opPoint->second);
                QPoint screenPoint = this->alpha2screen(pt);

                // draw line from left edge to first point:
                if (opPoint==opacityMap.begin())
                {
                        lastScreenPoint = QPoint(mPlotArea.left(), screenPoint.y());
                }

          // Draw line from previous point
                painter.setPen(pointLinePen);
                painter.drawLine(lastScreenPoint, screenPoint);

          // Draw the rectangle
          QRect pointRect(screenPoint.x() - mBorder, screenPoint.y() - mBorder,
                                          mBorder*2, mBorder*2);
          if (opPoint->first==mSelectedAlphaPoint.position)
          {
                  pointPen.setWidth(2);
                  painter.setPen(pointPen);
          }
          else
          {
                  pointPen.setWidth(1);
                  painter.setPen(pointPen);
          }
          painter.drawRect(pointRect);
          this->mPointRects[opPoint->first] = pointRect;

          // Store the point
          lastScreenPoint = screenPoint;
        }

        // draw a line from the last point to the right end
        QPoint screenPoint(mPlotArea.right(), lastScreenPoint.y());
        painter.setPen(pointLinePen);
        painter.drawLine(lastScreenPoint, screenPoint);

}

QPoint TransferFunctionAlphaWidget::alpha2screen(AlphaPoint pt) const
{
        QPoint screenPoint = QPoint(
                                static_cast<int>(mPlotArea.left() + mPlotArea.width() *
                                                                 (pt.position - mImage->getMin()) /
                                                                 static_cast<double>(mImage->getRange())),
                                static_cast<int>(mPlotArea.bottom() - mPlotArea.height() *
                                                                 pt.value /
                                                                 static_cast<double>(mImage->getMaxAlphaValue())) );
        return screenPoint;
}

void TransferFunctionAlphaWidget::paintHistogram(QPainter& painter)
{
        // Draw histogram
        // with log compression

        vtkImageAccumulatePtr histogram = mImage->getHistogram();
        int histogramSize = histogram->GetComponentExtent()[1] -
                                                histogram->GetComponentExtent()[0];

        painter.setPen(QColor(140, 140, 210));

        double numElementsInBinWithMostElements = log(histogram->GetOutput()->GetPointData()->GetScalars()->GetRange()[1]+1);
        double barHeightMult = (this->height() - mBorder*2) / numElementsInBinWithMostElements;

        double posMult = (this->width() - mBorder*2) / double(histogramSize);
        for (int i = mImage->getMin(); i <= mImage->getMax(); i++)
        {
          int x = ((i- mImage->getMin()) * posMult); //Offset with min value
          int y = log(double(static_cast<int*>(histogram->GetOutput()->GetScalarPointer(i - mImage->getMin(), 0, 0))[0]+1)) * barHeightMult;
          if (y > 0)
          {
                painter.drawLine(x + mBorder, height() - mBorder,
                                                 x + mBorder, height() - mBorder - y);
          }
        }
}


void TransferFunctionAlphaWidget::resizeEvent(QResizeEvent* evt)
{
  QWidget::resizeEvent(evt);

  // Calculate areas
  this->mFullArea = QRect(0, 0, width(), height());
  this->mPlotArea = QRect(mBorder, mBorder, 
                          width() - mBorder*2, height() - mBorder*2);
}

TransferFunctionAlphaWidget::AlphaPoint TransferFunctionAlphaWidget::selectPoint(QPoint pos)
{
        std::map<int, QRect>::iterator it = mPointRects.begin();
        for(;it != mPointRects.end(); ++it)
        {
                if (it->second.contains(pos))
                {
                        AlphaPoint retval;
                        retval.position = it->first;
                        IntIntMap opactiyMap = mImageTF->getOpacityMap();
                        if (opactiyMap.find(retval.position) != opactiyMap.end())
                                retval.value = opactiyMap.find(retval.position)->second;
                        return retval;
                }
        }

        return AlphaPoint();
}

bool TransferFunctionAlphaWidget::isEndpoint(int intensity) const
{
        if (mPointRects.begin()->first == intensity)
                return true;
        if (mPointRects.rbegin()->first == intensity)
                return true;
        return false;
}

TransferFunctionAlphaWidget::AlphaPoint TransferFunctionAlphaWidget::getCurrentAlphaPoint(QPoint pos)
{
  AlphaPoint point;

  double dposition = mImage->getMin() + mImage->getRange() * double(pos.x() - mPlotArea.left()) / mPlotArea.width();
  double dvalue = mImage->getMaxAlphaValue() * double(mPlotArea.bottom() - pos.y())/mPlotArea.height();
  point.position = roundAwayFromZero(dposition);
  point.value = roundAwayFromZero(dvalue);

  point.position = constrainValue(point.position, mImage->getMin(), mImage->getMax());
  point.value = constrainValue(point.value, 0, mImage->getMaxAlphaValue());

  return point;
}

void TransferFunctionAlphaWidget::toggleSelectedPoint(QPoint pos)
{
  if(!mImage)
    return;
  mSelectedAlphaPoint = this->selectPoint(pos);
  if(!mSelectedAlphaPoint.isValid())
  {
    // Outside any of the rectangles
        AlphaPoint point = getCurrentAlphaPoint(pos);
    mImageTF->addAlphaPoint(point.position,point.value);
        mSelectedAlphaPoint = this->selectPoint(pos);
  }
  else if(!this->isEndpoint(mSelectedAlphaPoint.position))
  {
    // Inside one of the rectangles
        if(mSelectedAlphaPoint.isValid())
          mImageTF->removeAlphaPoint(mSelectedAlphaPoint.position);
        mSelectedAlphaPoint.reset();
  }

  this->update();
}

void TransferFunctionAlphaWidget::moveCurrentAlphaPoint(AlphaPoint newAlphaPoint)
{
        if(!mSelectedAlphaPoint.isValid())
                return;

        newAlphaPoint.value = constrainValue(newAlphaPoint.value, 0, 255);

        std::pair<int,int> range = this->findAllowedMoveRangeAroundAlphaPoint(mSelectedAlphaPoint.position);
        newAlphaPoint.position = constrainValue(newAlphaPoint.position, range.first, range.second);

        mImageTF->moveAlphaPoint(mSelectedAlphaPoint.position, newAlphaPoint.position, newAlphaPoint.value);

        mSelectedAlphaPoint = newAlphaPoint;
        this->update();
}

std::pair<int,int> TransferFunctionAlphaWidget::findAllowedMoveRangeAroundAlphaPoint(int selectedPointIntensity)
{
        // constrain new point intensity between the two neigbours
        IntIntMap opacityMap = mImageTF->getOpacityMap();
        IntIntMap::iterator pointIterator = opacityMap.find(selectedPointIntensity);

        std::pair<int,int> range(mImage->getMin(), mImage->getMax());
        if (pointIterator!=opacityMap.begin())
        {
                IntIntMap::iterator prevPointIterator = pointIterator;
                --prevPointIterator;
                range.first = std::max(range.first, prevPointIterator->first + 1);
        }

        IntIntMap::iterator nextPointIterator = pointIterator;
        ++nextPointIterator;
        if (nextPointIterator!=opacityMap.end())
        {
                range.second = std::min(range.second, nextPointIterator->first - 1);
        }

        return range;
}


}//namespace cx