the qt class is not getting registered in qtquick

**sajis997** · 17th December 2014, 19:16

Hello forum,

i am registering a quickitem subclass object will the following command:

Qt Code:

Switch view

qmlRegisterType<TessellationSceneItem>("TeapotTessellation",1,0,"TessellationSceneItem");

qmlRegisterType<TessellationSceneItem>("TeapotTessellation",1,0,"TessellationSceneItem");

To copy to clipboard, switch view to plain text mode

I should be seeing a rectangle with spring animation with mouse event and opengl scene as an underlay. I am only seeing the qml scene.

I tried to set the breakpoint to the constructor of the qquickitem subclass that initiate the opengl rendering and i found out that the constructor is never executed.

Any idea ?

**wysota** · 17th December 2014, 19:31

So is it that the class doesn't get registered or that it doesn't do what you thought it would? Do you get an error about an unexisting module when trying to import "TeapotTessellation" in your QML document? How about when you declare a TessellationSceneItem element (assuming the import worked).

**sajis997** · 17th December 2014, 19:54

Both , i guess. No i am not getting any error about an unexisting module when trying to import.

OOps, my bad, now it is fine, the constructor is running. I have to decleare an element of the qquickitem type. Now i have something new. The application crashes with the following:

Qt Code:

Switch view

QObject: Cannot create children for a parent that is in a different thread.
(Parent is TessellationSceneItem(0x8153ea8), parent's thread is QThread(0x8080e08), current thread is QSGRenderThread(0x81d5db0)

QObject: Cannot create children for a parent that is in a different thread.
(Parent is TessellationSceneItem(0x8153ea8), parent's thread is QThread(0x8080e08), current thread is QSGRenderThread(0x81d5db0)

To copy to clipboard, switch view to plain text mode

And at the following point (glviewport(......)):

Qt Code:

Switch view

void TeapotTessellation::resize(int w,int h)
{
    if(h < 1)
         h = 1;
 
     //set the viewport matrix
     ViewportMatrix = glm::mat4(glm::vec4((GLfloat)w/2.0f,0.0f,0.0f,0.0f),
                                glm::vec4(0.0f,(GLfloat)h/2.0f,0.0f,0.0f),
                                glm::vec4(0.0f,0.0f,1.0f,0.0f),
                                glm::vec4((GLfloat)w/2.0f,(GLfloat)h/2.0f,0.0f,1.0f));
 
     GLfloat aspect = w/(GLfloat)h;
 
     //setup the projection matrix
     ProjectionMatrix = glm::perspective(50.0f,aspect,0.1f,1000.0f);
 
     glViewport(0,0,w,h);
}

void TeapotTessellation::resize(int w,int h)
{
    if(h < 1)
         h = 1;

     //set the viewport matrix
     ViewportMatrix = glm::mat4(glm::vec4((GLfloat)w/2.0f,0.0f,0.0f,0.0f),
                                glm::vec4(0.0f,(GLfloat)h/2.0f,0.0f,0.0f),
                                glm::vec4(0.0f,0.0f,1.0f,0.0f),
                                glm::vec4((GLfloat)w/2.0f,(GLfloat)h/2.0f,0.0f,1.0f));

     GLfloat aspect = w/(GLfloat)h;

     //setup the projection matrix
     ProjectionMatrix = glm::perspective(50.0f,aspect,0.1f,1000.0f);

     glViewport(0,0,w,h);
}

To copy to clipboard, switch view to plain text mode

Let me give you more code snippet:

Qt Code:

Switch view

class TeapotTessellation;
 
class TessellationSceneItem : public QQuickItem
{
    Q_OBJECT
 
    Q_PROPERTY(float t READ t WRITE setT NOTIFY tChanged)
 
public:
    TessellationSceneItem();
 
    qreal t() const { return m_t; }
    void setT(qreal t);
 
signals:
    void tChanged();
 
public slots:
    void sync();
    void cleanup();
 
private slots:
    void handleWindowChanged(QQuickWindow *);
 
private:
 
    TeapotTessellation* mTessScene;
 
    qreal m_t;
 
};
 
.......................
.......................
 
#ifndef TEAPOTTESSELLATION_H
#define TEAPOTTESSELLATION_H
 
#include <QOpenGLFunctions_4_3_Compatibility>
 
#include "defines.h"
#include "AbstractScene.h"
 
class GLSLShader;
class TeapotVboPatch;
 
class TeapotTessellation : public AbstractScene, protected QOpenGLFunctions_4_3_Compatibility
{
    Q_OBJECT
 
public:
 
    explicit TeapotTessellation(QObject *parent = 0);
    ~TeapotTessellation();
 
    //scene related functions
    virtual void initialise();
    virtual void update(float t);
    virtual void render();
    virtual void resize(int w,int h);
 
public slots:
 
    void paint();
 
private:
 
    void loadShaders();
 
    GLSLShader *mTessellationShader;
 
    TeapotVboPatch *mTeapotPatch;
 
    GLint mMaxPatchVertices;
 
    GLfloat mInnerTessellationFactor;
 
    GLfloat mOuterTessellationFactor;
 
    glm::mat4 ModelViewMatrix;
    glm::mat4 ProjectionMatrix;
    glm::mat4 ViewportMatrix;
 
    glm::mat4 ModelMatrix;
    glm::mat4 ViewMatrix;
 
    glm::mat3 NormalMatrix;
 
    float mTime;
 
    float mZoom;
 
    bool mInitialized;
};
 
#endif // TEAPOTTESSELLATION_H

class TeapotTessellation;

class TessellationSceneItem : public QQuickItem
{
    Q_OBJECT

    Q_PROPERTY(float t READ t WRITE setT NOTIFY tChanged)

public:
    TessellationSceneItem();

    qreal t() const { return m_t; }
    void setT(qreal t);

signals:
    void tChanged();

public slots:
    void sync();
    void cleanup();

private slots:
    void handleWindowChanged(QQuickWindow *);

private:

    TeapotTessellation* mTessScene;

    qreal m_t;

};

.......................
.......................

#ifndef TEAPOTTESSELLATION_H
#define TEAPOTTESSELLATION_H

#include <QOpenGLFunctions_4_3_Compatibility>

#include "defines.h"
#include "AbstractScene.h"

class GLSLShader;
class TeapotVboPatch;

class TeapotTessellation : public AbstractScene, protected QOpenGLFunctions_4_3_Compatibility
{
    Q_OBJECT

public:

    explicit TeapotTessellation(QObject *parent = 0);
    ~TeapotTessellation();

    //scene related functions
    virtual void initialise();
    virtual void update(float t);
    virtual void render();
    virtual void resize(int w,int h);

public slots:

    void paint();

private:

    void loadShaders();

    GLSLShader *mTessellationShader;

    TeapotVboPatch *mTeapotPatch;

    GLint mMaxPatchVertices;

    GLfloat mInnerTessellationFactor;

    GLfloat mOuterTessellationFactor;

    glm::mat4 ModelViewMatrix;
    glm::mat4 ProjectionMatrix;
    glm::mat4 ViewportMatrix;

    glm::mat4 ModelMatrix;
    glm::mat4 ViewMatrix;

    glm::mat3 NormalMatrix;

    float mTime;

    float mZoom;

    bool mInitialized;
};

#endif // TEAPOTTESSELLATION_H

To copy to clipboard, switch view to plain text mode

Let me know if you need more

**wysota** · 17th December 2014, 20:29

When do you instantiate TeapotTessellation? How exactly do you use it? What does your updatePaintNode() look like? You really have to provide more information, my crystal ball is broken.

**sajis997** · 18th December 2014, 02:13

Hi ,

I have uploaded the source to the following repository:

https://sajis997@bitbucket.org/sajis...negraphqml.git

Please make some time to go through it.

Thanks

Hi ,

I have uploaded the source to the following repository:

https://sajis997@bitbucket.org/sajis...negraphqml.git

Please make some time to go through it.

Thanks

Added after 1:

Hi

I managed to run the application. It does not crash anymore. But i still have following console output as before:

Qt Code:

Switch view

QObject: Cannot create children for a parent that is in a different thread.
(Parent is TessellationSceneItem(0x8153138), parent's thread is QThread(0x807fe08), current thread is QSGRenderThread(0x81d54f8)

QObject: Cannot create children for a parent that is in a different thread.
(Parent is TessellationSceneItem(0x8153138), parent's thread is QThread(0x807fe08), current thread is QSGRenderThread(0x81d54f8)

To copy to clipboard, switch view to plain text mode

While debuggin i found that i get the above console output with following connection snippet inside sync():

Qt Code:

Switch view

void TessellationSceneItem::sync()
{
    if(!mTessScene)
    {
        mTessScene = new TeapotTessellation(this);
 
        connect(window(),SIGNAL(beforeRendering()),mTessScene,SLOT(paint()),Qt::DirectConnection);
    }
 
    mTessScene->setViewportSize(window()->width() * window()->devicePixelRatio(),
                                window()->height() * window()->devicePixelRatio());
 
    //set  the timer value from the qml to the mTessScene
}

void TessellationSceneItem::sync()
{
    if(!mTessScene)
    {
        mTessScene = new TeapotTessellation(this);

        connect(window(),SIGNAL(beforeRendering()),mTessScene,SLOT(paint()),Qt::DirectConnection);
    }

    mTessScene->setViewportSize(window()->width() * window()->devicePixelRatio(),
                                window()->height() * window()->devicePixelRatio());

    //set  the timer value from the qml to the mTessScene
}

To copy to clipboard, switch view to plain text mode

Any more thoughts ?

Thanks

**wysota** · 18th December 2014, 09:13

Line #5 of the snippet is certainly invalid. Assuming sync() is called from the rendering thread, you are creating a QObject instance and passing it a parent that lives in a different thread. To make the warning go away it is enough to not pass this as a parent. However you still access window's properties from the rendering thread which is what you shouldn't do.

**sajis997** · 18th December 2014, 14:57

Originally Posted by wysota

Line #5 of the snippet is certainly invalid. Assuming sync() is called from the rendering thread, you are creating a QObject instance and passing it a parent that lives in a different thread. To make the warning go away it is enough to not pass this as a parent.

Thanks the issue is resolved

Originally Posted by wysota

However you still access window's properties from the rendering thread which is what you shouldn't do.

Did you mean the following snippet:

Qt Code:

Switch view

mTessScene->setViewportSize(window()->width() * window()->devicePixelRatio(),
                                window()->height() * window()->devicePixelRatio());

mTessScene->setViewportSize(window()->width() * window()->devicePixelRatio(),
                                window()->height() * window()->devicePixelRatio());

To copy to clipboard, switch view to plain text mode

inside the sync() function . Let me tell you.... i followed the procedure narrated in the following qt documnentation :

http://doc-snapshot.qt-project.org/q...l-example.html

And it explained as follows:

Note: The QQuickWindow::beforeSynchronizing() signal is emitted on the rendering thread while the GUI thread is blocked, so it is safe to simply copy the value without any additional protection.

If you have some better suggestion get around with this issue, you are most welcome to refer me to any example/reference.

I guess that issues never ends. Now i am having a white background color even after i am explicitly setting the background color to :

Qt Code:

Switch view

//set the clearing color for the background
    glClearColor(0.5f,0.5f,0.5f,1.0f);

//set the clearing color for the background
    glClearColor(0.5f,0.5f,0.5f,1.0f);

To copy to clipboard, switch view to plain text mode

What could be the reason ? Since you have the reference to the repository , you will see that the rendering thread is functioning as follows:

Qt Code:

Switch view

TeapotTessellation::TeapotTessellation(QObject *parent)
    : AbstractScene(parent),
      mTessellationShader(0),
      mTeapotPatch(0),
      mMaxPatchVertices(0),
      mInnerTessellationFactor(1.0f),
      mOuterTessellationFactor(1.0f),
      mZoom(22.0f),
      mInitialized(false)
{
 
}
 
TeapotTessellation::~TeapotTessellation()
{
    if(mTessellationShader)
    {
        mTessellationShader->DeleteShaderProgram();
        delete mTessellationShader;
        mTessellationShader = 0;
    }
 
    if(mTeapotPatch)
    {
        delete mTeapotPatch;
        mTeapotPatch = 0;
    }
}
 
void TeapotTessellation::initialise()
{
 
    //initialize the opengl functions
    initializeOpenGLFunctions();
 
    loadShaders();
 
    //initialize the teapot patch
    mTeapotPatch = new TeapotVboPatch(mTessellationShader);
 
    //set the clearing color for the background
    glClearColor(0.5f,0.5f,0.5f,1.0f);
 
    glGetIntegerv(GL_MAX_PATCH_VERTICES,&mMaxPatchVertices);
 
    ModelViewMatrix = glm::mat4(1.0f);
    ProjectionMatrix = glm::mat4(1.0f);
    ViewportMatrix = glm::mat4(1.0f);
 
    ViewMatrix = glm::mat4(1.0f);
    ModelMatrix = glm::mat4(1.0f);
 
    NormalMatrix = glm::mat3(1.0f);
 
    //enable depth testing
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_CULL_FACE);
 
    mInitialized = true;
 
}
 
void TeapotTessellation::loadShaders()
{
    mTessellationShader = new GLSLShader();
 
    mTessellationShader->LoadFromFile(GL_VERTEX_SHADER,"shaders/teapottessellation.vert");
    mTessellationShader->LoadFromFile(GL_TESS_CONTROL_SHADER,"shaders/teapottessellation.tcs");
    mTessellationShader->LoadFromFile(GL_TESS_EVALUATION_SHADER,"shaders/teapottessellation.tes");
    mTessellationShader->LoadFromFile(GL_GEOMETRY_SHADER,"shaders/teapottessellation.geom");
    mTessellationShader->LoadFromFile(GL_FRAGMENT_SHADER,"shaders/teapottessellation.frag");
 
    mTessellationShader->CreateAndLinkProgram();
 
    mTessellationShader->Use();
 
    mTessellationShader->AddUniform("inner");
    mTessellationShader->AddUniform("outer");
    mTessellationShader->AddUniform("ModelviewMatrix");
    mTessellationShader->AddUniform("ProjectionMatrix");
    mTessellationShader->AddUniform("NormalMatrix");
    mTessellationShader->AddUniform("ViewportMatrix");
    mTessellationShader->AddUniform("Line.Width");
    mTessellationShader->AddUniform("Line.Color");
    mTessellationShader->AddUniform("Light.Position");
    mTessellationShader->AddUniform("Light.Intensity");
    mTessellationShader->AddUniform("Material.Kd");
    mTessellationShader->AddUniform("Material.Ka");
    mTessellationShader->AddUniform("Material.Ks");
    mTessellationShader->AddUniform("Material.Shininess");
 
    //send the width of the line
    glUniform1f((*mTessellationShader)("Line.Width"),0.8f);
 
    //define the color of the line
    glm::vec4 lineColor = glm::vec4(0.05f,0.0f,0.05f,1.0f);
 
    //send the line color to the shader
    glUniform4fv((*mTessellationShader)("Line.Color"),1,glm::value_ptr(lineColor));
 
    //define the light position
    glm::vec4 lightPosition = glm::vec4(0.25f,0.25f,1.0f,1.0f);
 
    //send the light position to the shader
    glUniform4fv((*mTessellationShader)("Light.Position"),1,glm::value_ptr(lightPosition));
 
    //define the light intensity
    glm::vec3 lightIntensity = glm::vec3(1.f,1.f,1.f);
 
    //send the light intensity to the shader
    glUniform3fv((*mTessellationShader)("Light.Intensity"),1,glm::value_ptr(lightIntensity));
 
    //now set and send the material property
 
    glm::vec3 materialAmbientReflectivity = glm::vec3(0.2f,0.2f,0.2f);
 
    glUniform3fv((*mTessellationShader)("Material.Ka"),1,glm::value_ptr(materialAmbientReflectivity));
 
    glm::vec3 materialDiffuseReflectivity = glm::vec3(0.7f,0.7f,0.7f);
 
    glUniform3fv((*mTessellationShader)("Material.Kd"),1,glm::value_ptr(materialDiffuseReflectivity));
 
    glm::vec3 materialSpecularReflectivity = glm::vec3(0.8f,0.8f,0.8f);
 
    glUniform3fv((*mTessellationShader)("Material.Ks"),1,glm::value_ptr(materialSpecularReflectivity));
 
 
    float materialShininess = 100.0f;
 
    glUniform1f((*mTessellationShader)("Material.Shininess"),materialShininess);
 
    mTessellationShader->UnUse();
}
 
void TeapotTessellation::update(float t)
{
    mTime = t;
}
 
void TeapotTessellation::render()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
    glm::mat4 Ty = glm::translate(glm::mat4(1.0f),glm::vec3(0.0f,1.5f,0.0f));
    glm::mat4 Tz = glm::translate(glm::mat4(1.0f),glm::vec3(0.0f,0.0f,-mZoom));
    glm::mat4 Ry = glm::rotate(glm::mat4(1.0),mTime,glm::vec3(0.0f,1.0f,0.0f));
    glm::mat4 Rx = glm::rotate(glm::mat4(1.0f),20.0f,glm::vec3(1.0f,0.0f,0.0f));
 
    ModelMatrix = Tz * Ty * Ry * Rx;
 
    ModelViewMatrix = ViewMatrix * ModelMatrix;
 
    NormalMatrix = glm::inverseTranspose(glm::mat3(ModelViewMatrix));
 
    mTessellationShader->Use();
 
    glUniformMatrix4fv((*mTessellationShader)("ModelviewMatrix"),1,GL_FALSE,glm::value_ptr(ModelViewMatrix));
    glUniformMatrix4fv((*mTessellationShader)("ProjectionMatrix"),1,GL_FALSE,glm::value_ptr(ProjectionMatrix));
    glUniformMatrix4fv((*mTessellationShader)("ViewportMatrix"),1,GL_FALSE,glm::value_ptr(ViewportMatrix));
    glUniformMatrix3fv((*mTessellationShader)("NormalMatrix"),1,GL_FALSE,glm::value_ptr(NormalMatrix));
    glUniform1f((*mTessellationShader)("outer"),mOuterTessellationFactor);
    glUniform1f((*mTessellationShader)("inner"),mInnerTessellationFactor);
 
    mTeapotPatch->render();
 
    mTessellationShader->UnUse();
 
}
 
void TeapotTessellation::resize(int w,int h)
{
    if(h < 1)
         mViewportHeight = 1;
 
    mViewportWidth = w;
 
     //set the viewport matrix
     ViewportMatrix = glm::mat4(glm::vec4((GLfloat)mViewportWidth/2.0f,0.0f,0.0f,0.0f),
                                glm::vec4(0.0f,(GLfloat)mViewportHeight/2.0f,0.0f,0.0f),
                                glm::vec4(0.0f,0.0f,1.0f,0.0f),
                                glm::vec4((GLfloat)mViewportWidth/2.0f,(GLfloat)mViewportHeight/2.0f,0.0f,1.0f));
 
     GLfloat aspect = w/(GLfloat)h;
 
     //setup the projection matrix
     ProjectionMatrix = glm::perspective(50.0f,aspect,0.1f,1000.0f);
 
     glViewport(0,0,mViewportWidth,mViewportHeight);
}
 
void TeapotTessellation::setViewportSize(int width,int height)
{
    mViewportWidth = width;
    mViewportHeight = height;
}
 
void TeapotTessellation::paint()
{
    if(!mInitialized)
        initialise();
 
    resize(mViewportWidth,mViewportHeight);
    render();
}

TeapotTessellation::TeapotTessellation(QObject *parent)
    : AbstractScene(parent),
      mTessellationShader(0),
      mTeapotPatch(0),
      mMaxPatchVertices(0),
      mInnerTessellationFactor(1.0f),
      mOuterTessellationFactor(1.0f),
      mZoom(22.0f),
      mInitialized(false)
{

}

TeapotTessellation::~TeapotTessellation()
{
    if(mTessellationShader)
    {
        mTessellationShader->DeleteShaderProgram();
        delete mTessellationShader;
        mTessellationShader = 0;
    }

    if(mTeapotPatch)
    {
        delete mTeapotPatch;
        mTeapotPatch = 0;
    }
}

void TeapotTessellation::initialise()
{

    //initialize the opengl functions
    initializeOpenGLFunctions();

    loadShaders();

    //initialize the teapot patch
    mTeapotPatch = new TeapotVboPatch(mTessellationShader);

    //set the clearing color for the background
    glClearColor(0.5f,0.5f,0.5f,1.0f);

    glGetIntegerv(GL_MAX_PATCH_VERTICES,&mMaxPatchVertices);

    ModelViewMatrix = glm::mat4(1.0f);
    ProjectionMatrix = glm::mat4(1.0f);
    ViewportMatrix = glm::mat4(1.0f);

    ViewMatrix = glm::mat4(1.0f);
    ModelMatrix = glm::mat4(1.0f);

    NormalMatrix = glm::mat3(1.0f);

    //enable depth testing
    glEnable(GL_DEPTH_TEST);
    glEnable(GL_CULL_FACE);

    mInitialized = true;

}

void TeapotTessellation::loadShaders()
{
    mTessellationShader = new GLSLShader();

    mTessellationShader->LoadFromFile(GL_VERTEX_SHADER,"shaders/teapottessellation.vert");
    mTessellationShader->LoadFromFile(GL_TESS_CONTROL_SHADER,"shaders/teapottessellation.tcs");
    mTessellationShader->LoadFromFile(GL_TESS_EVALUATION_SHADER,"shaders/teapottessellation.tes");
    mTessellationShader->LoadFromFile(GL_GEOMETRY_SHADER,"shaders/teapottessellation.geom");
    mTessellationShader->LoadFromFile(GL_FRAGMENT_SHADER,"shaders/teapottessellation.frag");

    mTessellationShader->CreateAndLinkProgram();

    mTessellationShader->Use();

    mTessellationShader->AddUniform("inner");
    mTessellationShader->AddUniform("outer");
    mTessellationShader->AddUniform("ModelviewMatrix");
    mTessellationShader->AddUniform("ProjectionMatrix");
    mTessellationShader->AddUniform("NormalMatrix");
    mTessellationShader->AddUniform("ViewportMatrix");
    mTessellationShader->AddUniform("Line.Width");
    mTessellationShader->AddUniform("Line.Color");
    mTessellationShader->AddUniform("Light.Position");
    mTessellationShader->AddUniform("Light.Intensity");
    mTessellationShader->AddUniform("Material.Kd");
    mTessellationShader->AddUniform("Material.Ka");
    mTessellationShader->AddUniform("Material.Ks");
    mTessellationShader->AddUniform("Material.Shininess");

    //send the width of the line
    glUniform1f((*mTessellationShader)("Line.Width"),0.8f);

    //define the color of the line
    glm::vec4 lineColor = glm::vec4(0.05f,0.0f,0.05f,1.0f);

    //send the line color to the shader
    glUniform4fv((*mTessellationShader)("Line.Color"),1,glm::value_ptr(lineColor));

    //define the light position
    glm::vec4 lightPosition = glm::vec4(0.25f,0.25f,1.0f,1.0f);

    //send the light position to the shader
    glUniform4fv((*mTessellationShader)("Light.Position"),1,glm::value_ptr(lightPosition));

    //define the light intensity
    glm::vec3 lightIntensity = glm::vec3(1.f,1.f,1.f);

    //send the light intensity to the shader
    glUniform3fv((*mTessellationShader)("Light.Intensity"),1,glm::value_ptr(lightIntensity));

    //now set and send the material property

    glm::vec3 materialAmbientReflectivity = glm::vec3(0.2f,0.2f,0.2f);

    glUniform3fv((*mTessellationShader)("Material.Ka"),1,glm::value_ptr(materialAmbientReflectivity));

    glm::vec3 materialDiffuseReflectivity = glm::vec3(0.7f,0.7f,0.7f);

    glUniform3fv((*mTessellationShader)("Material.Kd"),1,glm::value_ptr(materialDiffuseReflectivity));

    glm::vec3 materialSpecularReflectivity = glm::vec3(0.8f,0.8f,0.8f);

    glUniform3fv((*mTessellationShader)("Material.Ks"),1,glm::value_ptr(materialSpecularReflectivity));


    float materialShininess = 100.0f;

    glUniform1f((*mTessellationShader)("Material.Shininess"),materialShininess);

    mTessellationShader->UnUse();
}

void TeapotTessellation::update(float t)
{
    mTime = t;
}

void TeapotTessellation::render()
{
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    glm::mat4 Ty = glm::translate(glm::mat4(1.0f),glm::vec3(0.0f,1.5f,0.0f));
    glm::mat4 Tz = glm::translate(glm::mat4(1.0f),glm::vec3(0.0f,0.0f,-mZoom));
    glm::mat4 Ry = glm::rotate(glm::mat4(1.0),mTime,glm::vec3(0.0f,1.0f,0.0f));
    glm::mat4 Rx = glm::rotate(glm::mat4(1.0f),20.0f,glm::vec3(1.0f,0.0f,0.0f));

    ModelMatrix = Tz * Ty * Ry * Rx;

    ModelViewMatrix = ViewMatrix * ModelMatrix;

    NormalMatrix = glm::inverseTranspose(glm::mat3(ModelViewMatrix));

    mTessellationShader->Use();

    glUniformMatrix4fv((*mTessellationShader)("ModelviewMatrix"),1,GL_FALSE,glm::value_ptr(ModelViewMatrix));
    glUniformMatrix4fv((*mTessellationShader)("ProjectionMatrix"),1,GL_FALSE,glm::value_ptr(ProjectionMatrix));
    glUniformMatrix4fv((*mTessellationShader)("ViewportMatrix"),1,GL_FALSE,glm::value_ptr(ViewportMatrix));
    glUniformMatrix3fv((*mTessellationShader)("NormalMatrix"),1,GL_FALSE,glm::value_ptr(NormalMatrix));
    glUniform1f((*mTessellationShader)("outer"),mOuterTessellationFactor);
    glUniform1f((*mTessellationShader)("inner"),mInnerTessellationFactor);

    mTeapotPatch->render();

    mTessellationShader->UnUse();

}

void TeapotTessellation::resize(int w,int h)
{
    if(h < 1)
         mViewportHeight = 1;

    mViewportWidth = w;

     //set the viewport matrix
     ViewportMatrix = glm::mat4(glm::vec4((GLfloat)mViewportWidth/2.0f,0.0f,0.0f,0.0f),
                                glm::vec4(0.0f,(GLfloat)mViewportHeight/2.0f,0.0f,0.0f),
                                glm::vec4(0.0f,0.0f,1.0f,0.0f),
                                glm::vec4((GLfloat)mViewportWidth/2.0f,(GLfloat)mViewportHeight/2.0f,0.0f,1.0f));

     GLfloat aspect = w/(GLfloat)h;

     //setup the projection matrix
     ProjectionMatrix = glm::perspective(50.0f,aspect,0.1f,1000.0f);

     glViewport(0,0,mViewportWidth,mViewportHeight);
}

void TeapotTessellation::setViewportSize(int width,int height)
{
    mViewportWidth = width;
    mViewportHeight = height;
}

void TeapotTessellation::paint()
{
    if(!mInitialized)
        initialise();

    resize(mViewportWidth,mViewportHeight);
    render();
}

To copy to clipboard, switch view to plain text mode

Thanks