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Thread: QGLWidget don't draw in its place in the layout

  1. 14th October 2011, 16:57 #1
    entee
    entee is offline Beginner
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    Question QGLWidget don't draw in its place in the layout

    Hi,

    I have a reimplemented QGLWidget, which I added to a Layout. But it draw from the top-left corner of the window, not in its place in the layout.
    My code:
    glwidget.h
    Qt Code: 
    1. #ifndef GLWIDGET_H
    2. #define GLWIDGET_H
    3.  
    4. #include <QGLWidget>
    5. #include <QtOpenGL>
    6. #include <opencv2/opencv.hpp>
    7. #include <QMutex>
    8. using namespace cv;
    9.  
    10. class GLWidget : public QGLWidget
    11. {
    12.     Q_OBJECT
    13. public:
    14.     GLWidget();
    15.     void sendImage(Mat *img);
    16. protected:
    17.     void initializeGL();
    18.     void paintGL();
    19.     void resizeGL(int width, int height);
    20. private:
    21.     QImage qframe;
    22.     QMutex mutex;
    23.  
    24. };
    25.  
    26. #endif // GLWIDGET_H
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    glwidget.cpp
    Qt Code: 
    1. #include "glwidget.h"
    2. #include <QMutexLocker>
    3.  
    4. GLWidget::GLWidget() : QGLWidget(QGLFormat(QGL::SampleBuffers)) {
    5.     setMinimumSize(320,240);
    6. }
    7.  
    8. void GLWidget::initializeGL() {
    9.     glClearColor(0.0f,0.0f,0.0f,1.0f);
    10. }
    11. void GLWidget::paintGL() {
    12.     glClear (GL_COLOR_BUFFER_BIT);
    13.     glClearColor (0.0,0.0,0.0,1.0);
    14.     if (!qframe.isNull()) {
    15.         qframe = qframe.scaled(this->size(), Qt::KeepAspectRatio,Qt::SmoothTransformation);
    16.         glDisable(GL_DEPTH_TEST);
    17.         glMatrixMode(GL_PROJECTION);
    18.         glLoadIdentity();
    19.         gluOrtho2D(0,qframe.width(),qframe.height(),0);
    20.         glMatrixMode(GL_MODELVIEW);
    21.         glLoadIdentity();
    22.         glEnable(GL_TEXTURE_2D);
    23.         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    24.         glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
    25.         glTexImage2D( GL_TEXTURE_2D, 0, 4, qframe.width(), qframe.height(), 0, GL_RGBA, GL_UNSIGNED_BYTE, qframe.bits() );
    26.         glBegin(GL_QUADS);
    27.         glTexCoord2f(0,0); glVertex2f(0,qframe.height());
    28.         glTexCoord2f(0,1); glVertex2f(0,0);
    29.         glTexCoord2f(1,1); glVertex2f(qframe.width(),0);
    30.         glTexCoord2f(1,0); glVertex2f(qframe.width(),qframe.height());
    31.         glEnd();
    32.         glDisable(GL_TEXTURE_2D);
    33.         glFlush();
    34.     }
    35.     // qDebug() << "Drawing...";
    36. }
    37.  
    38. void GLWidget::resizeGL(int w, int h) {
    39.     glViewport (0, 0, (GLsizei)w, (GLsizei)h);
    40.     glMatrixMode (GL_PROJECTION);
    41.     glLoadIdentity ();
    42.     gluPerspective (60, (GLfloat)w / (GLfloat)h, 1.0, 100.0);
    43.     glMatrixMode (GL_MODELVIEW);
    44.     // qDebug() << "Resizing...";
    45. }
    46.  
    47. void GLWidget::sendImage(Mat* img) {
    48.     QMutexLocker l(&mutex);
    49.     cvtColor(*img, *img, CV_GRAY2RGB);
    50.     imwrite("ki.png", *img);
    51.     qframe = QImage((const unsigned char*)(img->data), img->cols, img->rows, img->step, QImage::Format_RGB888).rgbSwapped();
    52.     qframe = QGLWidget::convertToGLFormat(qframe);
    53.     this->updateGL();
    54. }
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    mainwindow.h
    Qt Code: 
    1. #ifndef MAINWINDOW_H
    2. #define MAINWINDOW_H
    3.  
    4. #include <QMainWindow>
    5. #include "borderlayout.h"
    6. #include "glwidget.h"
    7. #include "voxel.h"
    8. #include <QToolBar>
    9.  
    10. namespace Ui {
    11.     class MainWindow;
    12. }
    13.  
    14. class MainWindow : public QMainWindow
    15. {
    16.     Q_OBJECT
    17.  
    18. public:
    19.     explicit MainWindow(QWidget *parent = 0);
    20.     ~MainWindow();
    21.  
    22. public slots:
    23.     void refresh(int num);
    24.  
    25. private:
    26.     Ui::MainWindow *ui;
    27.     BorderLayout *layout;
    28.     QToolBar *leftToolbar;
    29.     QToolBar *rightToolbar;
    30.     QHBoxLayout *centralLayout;
    31.     BorderLayout *leftImage;
    32.     BorderLayout *rightImage;
    33.     GLWidget *rgl;
    34.     GLWidget *lgl;
    35.     QSlider *lslider;
    36.     QSlider *rslider;
    37.     QHBoxLayout *box1;
    38.     QHBoxLayout *box2;
    39.     Voxel left;
    40.     Voxel right;
    41. };
    42.  
    43. #endif // MAINWINDOW_H
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    mainwindow.cpp
    Qt Code: 
    1. #include "mainwindow.h"
    2. #include "ui_mainwindow.h"
    3. #include <QDebug>
    4.  
    5. using namespace cv;
    6.  
    7. MainWindow::MainWindow(QWidget *parent) :
    8.     QMainWindow(parent),
    9.     ui(new Ui::MainWindow)
    10. {
    11.     ui->setupUi(this);
    12.     layout = new BorderLayout;
    13.     leftToolbar = new QToolBar;
    14.     leftToolbar->setOrientation(Qt::Vertical);
    15.     leftToolbar->addAction("Hello");
    16.     rightToolbar = new QToolBar;
    17.     rightToolbar->setOrientation(Qt::Vertical);
    18.     rightToolbar->addAction("Hello");
    19.     rightToolbar->addAction("Heo");
    20.     layout->addWidget(leftToolbar, BorderLayout::West);
    21.     layout->addWidget(rightToolbar, BorderLayout::East);
    22.     centralLayout = new QHBoxLayout();
    23.     rightImage = new BorderLayout();
    24.     leftImage = new BorderLayout();
    25.     lgl = new GLWidget();
    26.     rgl = new GLWidget();
    27.     box1 = new QHBoxLayout();
    28.     box2 = new QHBoxLayout();
    29.     box1->addWidget(lgl);
    30.     box2->addWidget(rgl);
    31.     leftImage->add(box1, BorderLayout::Center);
    32.     rightImage->add(box2, BorderLayout::Center);
    33.     lslider = new QSlider(Qt::Horizontal);
    34.     rslider = new QSlider(Qt::Horizontal);
    35.  
    36.     connect(lslider,SIGNAL(valueChanged(int)),this, SLOT(refresh(int)));
    37.     leftImage->addWidget(lslider,BorderLayout::South);
    38.     rightImage->addWidget(rslider, BorderLayout::South);
    39.     centralLayout->addLayout(leftImage);
    40.     centralLayout->addLayout(rightImage);
    41.     layout->add(centralLayout, BorderLayout::Center);
    42.     ui->centralWidget->setLayout(layout);
    43.     left.beolvas("airjet.hdr");
    44.     lslider->setRange(0,left.numReteg()-1);
    45.     /*for(int i = 0; i<59; i++){
    46.         qDebug() << sum(left[i]).val[0];
    47.     }
    48.     imshow("kep",left[20]);*/
    49. }
    50.  
    51. MainWindow::~MainWindow()
    52. {
    53.     delete ui;
    54.     delete layout;
    55.     delete centralLayout;
    56.     delete leftToolbar;
    57.     delete rightToolbar;
    58.     delete rightImage;
    59.     delete leftImage;
    60.     delete box1;
    61.     delete box2;
    62.     delete lgl;
    63.     delete rgl;
    64.     delete lslider;
    65.     delete rslider;
    66. }
    67.  
    68. void MainWindow::refresh(int n){
    69.     if(sender()==lslider){
    70.         Mat a = left[n];
    71.         lgl->sendImage(&a);
    72.         Mat b = left[n];
    73.         rgl->sendImage(&b);
    74.     }else{
    75.         Mat a = right[n];
    76.         rgl->sendImage(&a);
    77.     }
    78. }
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    BorderLayout is come from qt example.

    I think these are the relevant code.


    I made a screenshot from my window.
    The GLWidgets should be above the sliders.
    window.png

    What's wrong?
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  2. 15th October 2011, 19:01 #2
    finetjul
    finetjul is offline Beginner
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    Default Re: QGLWidget don't draw in its place in the layout

    Try with a QGridLayout, you should get the same result.
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