cqtopencvviewergl.cxx

/*=========================================================================

  Program:   OpenCVDisparityTuner

  Copyright (c) Julien Jomier
  All rights reserved.

   This software is distributed WITHOUT ANY WARRANTY; without even
   the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
   PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "cqtopencvviewergl.h"
#include <QOpenGLFunctions>

CQtOpenCVViewerGl::CQtOpenCVViewerGl(QWidget *parent) : QOpenGLWidget(parent)
{
  mSceneChanged = false;
  mBgColor = QColor::fromRgb(150, 150, 150);

  mOutH = 0;
  mOutW = 0;
  mImgRatio = 4.0f/3.0f;

  mPosX = 0;
  mPosY = 0;
}

void CQtOpenCVViewerGl::initializeGL()
{
  makeCurrent();

  QOpenGLFunctions *f = QOpenGLContext::currentContext()->functions();
  float r = ((float)mBgColor.darker().red())/255.0f;
  float g = ((float)mBgColor.darker().green())/255.0f;
  float b = ((float)mBgColor.darker().blue())/255.0f;
  f->glClearColor(r,g,b,1.0f);
}

void CQtOpenCVViewerGl::resizeGL(int width, int height)
{
  makeCurrent();
  glViewport(0, 0, (GLint)width, (GLint)height);

  glMatrixMode(GL_PROJECTION);
  glLoadIdentity();

  glOrtho(0, width, 0, height, 0, 1);	// To Draw image in the center of the area

  glMatrixMode(GL_MODELVIEW);

  // ---> Scaled Image Sizes
  mOutH = width/mImgRatio;
  mOutW = width;

  if(mOutH>height)
  {
  mOutW = height*mImgRatio;
  mOutH = height;
  }

  emit imageSizeChanged( mOutW, mOutH );

  mPosX = (width-mOutW)/2;
  mPosY = (height-mOutH)/2;

  mSceneChanged = true;

  updateScene();
}

void CQtOpenCVViewerGl::updateScene()
{
  if( mSceneChanged && this->isVisible() )
  {
  update();
  }
}

void CQtOpenCVViewerGl::paintGL()
{
  makeCurrent();

  if( !mSceneChanged )
  {
  return;
  }
  glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

  renderImage();

  mSceneChanged = false;
}

void CQtOpenCVViewerGl::renderImage()
{
  makeCurrent();

  glClear(GL_COLOR_BUFFER_BIT);
  if (!mRenderQtImg.isNull())
  {
  glLoadIdentity();

  QImage image; // the image rendered

  glPushMatrix();
    {
   int imW = mRenderQtImg.width();
   int imH = mRenderQtImg.height();

      // The image is to be resized to fit the widget?
      if( imW != this->size().width() &&
          imH != this->size().height() )
      {

        image = mRenderQtImg.scaled( //this->size(),
                       QSize(mOutW,mOutH),
                       Qt::IgnoreAspectRatio,
                       Qt::SmoothTransformation
                       );

        //qDebug( QString( "Image size: (%1x%2)").arg(imW).arg(imH).toAscii() );
      }
      else
        image = mRenderQtImg;

      // ---> Centering image in draw area

      glRasterPos2i( mPosX, mPosY );
      // <--- Centering image in draw area

      imW = image.width();
      imH = image.height();

      glDrawPixels( imW, imH, GL_RGBA, GL_UNSIGNED_BYTE, image.bits());
    }
    glPopMatrix();

    // end
    glFlush();
  }
}

bool CQtOpenCVViewerGl::showImage(cv::Mat image)
{
  image.copyTo(mOrigImage);

  mImgRatio = (float)image.cols/(float)image.rows;

  if( mOrigImage.channels() == 3)
    mRenderQtImg = QImage((const unsigned char*)(mOrigImage.data),
                mOrigImage.cols, mOrigImage.rows,
                mOrigImage.step, QImage::Format_RGB888)/*.rgbSwapped()*/;
  else if( mOrigImage.channels() == 1)
    mRenderQtImg = QImage((const unsigned char*)(mOrigImage.data),
                mOrigImage.cols, mOrigImage.rows,
                mOrigImage.step, QImage::Format_Indexed8);
  else
    return false;

  this->resizeGL(this->width(),this->height());

  mSceneChanged = true;

  updateScene();

  return true;
}