Using QOpenGLWidget

inefarius

Hello,
I'm trying to use OpenGL inside of Qt using QOpenGLWidget, but I am having a hard time finding any relevant examples. I am new to OpenGL, so I am trying to learn how to use it, but the tutorials that I find don't seem to apply particularly well in QOpenGLWidget. Right now, all I want to do is render a triangle to start with.

Here's what I have so far.

Header:

namespace Ui {
class Widget;
}

class Widget : public QOpenGLWidget, protected QOpenGLFunctions
{
public:
    explicit Widget(QWidget *parent = 0);
    ~Widget();

protected:
    void initializeGL();
    void resizeGL(int, int);
    void paintGL();

private:
    Ui::Widget *ui;
};

Class:

Widget::Widget(QWidget *parent) :
    QOpenGLWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
}

void Widget::initializeGL()
{
    // Set up the rendering context, load shaders and other resources, etc.:
    initializeOpenGLFunctions();
    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
}

void Widget::resizeGL(int w, int h)
{
    // Update projection matrix and other size-related settings:
}

void Widget::paintGL()
{
    // Draw the scene:
    glClear(GL_COLOR_BUFFER_BIT);
}

Widget::~Widget()
{
    delete ui;
}

Is there any example I could use to just render a basic triangle? I tried the one from here: https://www.khronos.org/assets/uploads/books/openglr_es_20_programming_guide_sample.pdf, but it threw a lot of errors that I couldn't work out.

I also don't know how OpenGL contexts work in QOpenGLWidget.

djvi

http://www.trentreed.net/blog/qt5-opengl-part-0-creating-a-window/

Follow thoose tutorials or at least the part 0, 1 ,2 ,3a, 3b and you will have decent basis to start.

In the tutorial he use QOpenGLWindow which isn't really far from QOpenGLWidget so I think you should be able to adapt his code a bit to suit your need but if you didn't succed to do it ask here again.

Do you look for opengl ressources to ?