Loading files into drawBackground(QPainter *painter, const QRectF &)

basil_fawlty

Hello everybody,

currently i am trying to laod *.obj-files into my programm. My code is based on this example:

"Accelerate your widgets with opengl (new link)":http://qt.gitorious.org/qt-labs/modelviewer

The only differeence in my code, is that i have a glwidget-class, in which all the drawing is defined. In the class OpenGLScene only my Gui is defined. In the function drawBackground(QPainter *painter, const QRectF &) i call the function paintGL.

@
void OpenGLScene::drawBackground(QPainter *painter, const QRectF &)
{
if (painter->paintEngine()->type() != QPaintEngine::OpenGL
&& painter->paintEngine()->type() != QPaintEngine::OpenGL2)
{
qWarning("OpenGLScene: drawBackground needs a QGLWidget to be set as viewport on the graphics view");
return;
}

painter->beginNativePainting();

glClearColor(m_backgroundColor.redF(), m_backgroundColor.greenF(), m_backgroundColor.blueF(), 1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

if (m_model) {

    m_model->paintGL();
}

painter->endNativePainting();

}

@

Simple drawing and stuff works fine. I only get problems until i try to load *.obj-Files. I have tried several things, which didnt work.
Now I ended up with the solution to define all the functions from the model-class(which you can find in the example) in my glWidget-Class and then calling the render-function in paintGL. Afterwards calling the paintGL in OpenGLScene.

Here you can see my header-files: OpenGLScene.h and GLWidget.h:

@
class GLWidget : public QGLWidget
{
Q_OBJECT
public:
float m_distance;
GLWidget(const QString &filePath);
GLWidget(QWidget *parent = 0);
~GLWidget();
QSize minimumSizeHint() const;
QSize sizeHint() const;
void initializeGL();
void paintGL();
void resizeGL(int width, int height);
void render() const;
QString fileName() const { return m_fileName; }
int faces() const { return m_pointIndices.size() / 3; }
int edges() const { return m_edgeIndices.size() / 2; }
int points() const { return m_points.size(); }
QString m_fileName;
QVector<Point3d> m_points;
QVector<Point3d> m_normals;
QVector<int> m_edgeIndices;
QVector<int> m_pointIndices;
};

#ifndef QT_NO_CONCURRENT
#include <QFutureWatcher>
#endif

class GLWidget;

class OpenGLScene : public QGraphicsScene
{
Q_OBJECT

public:
OpenGLScene();
void drawBackground(QPainter *painter, const QRectF &rect);
QDialog *createDialog(const QString &windowTitle) const;

void setModel(GLWidget *model);

//Model       *m_model;
GLWidget    *m_model;
QColor      m_backgroundColor;
float       m_distance;
QLabel      *m_labels[4];
QWidget     *m_modelButton;

#ifndef QT_NO_CONCURRENT
QFutureWatcher<GLWidget *> m_modelLoader;
#endif
public slots:
void loadModel();
void loadModel(const QString &filePath);
void modelLoaded();
};
@

Unfortunately this idea isnt working, because i get this error:

"It is not safe to use pixmaps outside the GUI thread"

But I really dont understand whats that supposed to mean.
Thanks in Advance

EDIT: I have changed the upper link. The old link referred to an old version of the code which was not correct.

basil_fawlty

Hm...maybe i've asked too much. Maybe I should specify it more.

My first question would be why it is a problem to define the modelfunctions in glwidget?
GLWidget's content is the same as the model-class content plus some extras.
Therefore I dont understand the error: “It is not safe to use pixmaps outside the GUI thread”

Because in the OpenGLScene-Class I have nothing changed except the datatype-names. I've replaced Model-datatype to GLWidget-datatype.

Maybe someone would be able to help me? Or is it so obvious that it is to easy to answer. If so I would be happy if you could share your ideas with me.

Thank you