how to bind a bitmap to texture in QT?

[saman_artorious]

Stampede, thanks for your comment, Yes, I shoudav generated the texture name before binding it to the current texture GL_TEXTURE_2D.
This is the main code, I simply receive a bitmap from socket and then try to create a texture out of it.

void GlWidget::initializeGL()
{
    initCommon();
 
    shaderProgram.addShaderFromSourceFile(QGLShader::Vertex, ":/vertexShader.vsh");
 
    shaderProgram.addShaderFromSourceFile(QGLShader::Fragment, ":/fragmentShader.fsh");
 
    if(!shaderProgram.link())
    {
        exit(1);
    }
 
    vertices << QVector3D(-1, -1,  1) << QVector3D( 1, -1,  1) << QVector3D( 1,  1,  1) // Front
             << QVector3D( 1,  1,  1) << QVector3D(-1,  1,  1) << QVector3D(-1, -1,  1);
 
    textureCoordinates
            << QVector2D(1, 0) << QVector2D(1, 1) << QVector2D(0, 1) // Front
            << QVector2D(0, 1) << QVector2D(0, 0) << QVector2D(1, 0);
 
    updateGL();
}
//! [1]
 
//############################
 
void GlWidget::createTextureFromBitmap(QByteArray bytes)
{
  /* create a 800 bye 600 texture from bitmap */
 
    tex.buf = new unsigned char[bytes.size()];
 
    memcpy(tex.buf, bytes.constData(), bytes.size());
 
    glGenTextures( 1, &tex.id);
    glBindTexture(GL_TEXTURE_2D, tex.id);
 
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 
    glTexImage2D(     GL_TEXTURE_2D, 0, GL_RGB, 0, 0, 0, GL_RGB, GL_UNSIGNED_BYTE, tex.buf);
 
    gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, 800, 600, GL_RGB, GL_UNSIGNED_BYTE, tex.buf);
 
    delete [] tex.buf;
 
    tex.buf = NULL;
 
    updateGL();
}
 
 
 
void GlWidget::paintGL()
{
    //! [5]
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 
    QMatrix4x4 mMatrix;
    QMatrix4x4 vMatrix;
 
    QMatrix4x4 cameraTransformation;
    //    cameraTransformation.rotate(alpha, 0, 1, 0);
    //    cameraTransformation.rotate(beta, 1, 0, 0);
 
    QVector3D cameraPosition = cameraTransformation * QVector3D(0, 0, distance);
    QVector3D cameraUpDirection = cameraTransformation * QVector3D(0, 1, 0);
 
    vMatrix.lookAt(cameraPosition, QVector3D(0, 0, 0), cameraUpDirection);
 
    //! [6]
    shaderProgram.bind();
    shaderProgram.setUniformValue("mvpMatrix", pMatrix * vMatrix * mMatrix);
    shaderProgram.setUniformValue("texture", 0);
 
 
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, tex.id);
    glActiveTexture(0);
 
 
    shaderProgram.setAttributeArray("vertex", vertices.constData());
    shaderProgram.enableAttributeArray("vertex");
    shaderProgram.setAttributeArray("textureCoordinate", textureCoordinates.constData());
    shaderProgram.enableAttributeArray("textureCoordinate");
 
    glDrawArrays(GL_TRIANGLES, 0, vertices.size());
 
    shaderProgram.disableAttributeArray("vertex");
    shaderProgram.disableAttributeArray("textureCoordinate");
    shaderProgram.release();
}

void GlWidget::initializeGL()
{
    initCommon();

    shaderProgram.addShaderFromSourceFile(QGLShader::Vertex, ":/vertexShader.vsh");

    shaderProgram.addShaderFromSourceFile(QGLShader::Fragment, ":/fragmentShader.fsh");

    if(!shaderProgram.link())
    {
        exit(1);
    }

    vertices << QVector3D(-1, -1,  1) << QVector3D( 1, -1,  1) << QVector3D( 1,  1,  1) // Front
             << QVector3D( 1,  1,  1) << QVector3D(-1,  1,  1) << QVector3D(-1, -1,  1);

    textureCoordinates
            << QVector2D(1, 0) << QVector2D(1, 1) << QVector2D(0, 1) // Front
            << QVector2D(0, 1) << QVector2D(0, 0) << QVector2D(1, 0);

    updateGL();
}
//! [1]

//############################

void GlWidget::createTextureFromBitmap(QByteArray bytes)
{
  /* create a 800 bye 600 texture from bitmap */

    tex.buf = new unsigned char[bytes.size()];

    memcpy(tex.buf, bytes.constData(), bytes.size());

    glGenTextures( 1, &tex.id);
    glBindTexture(GL_TEXTURE_2D, tex.id);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR_MIPMAP_LINEAR);
    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);

    glTexImage2D(     GL_TEXTURE_2D, 0, GL_RGB, 0, 0, 0, GL_RGB, GL_UNSIGNED_BYTE, tex.buf);

    gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, 800, 600, GL_RGB, GL_UNSIGNED_BYTE, tex.buf);

    delete [] tex.buf;

    tex.buf = NULL;

    updateGL();
}



void GlWidget::paintGL()
{
    //! [5]
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

    QMatrix4x4 mMatrix;
    QMatrix4x4 vMatrix;

    QMatrix4x4 cameraTransformation;
    //    cameraTransformation.rotate(alpha, 0, 1, 0);
    //    cameraTransformation.rotate(beta, 1, 0, 0);

    QVector3D cameraPosition = cameraTransformation * QVector3D(0, 0, distance);
    QVector3D cameraUpDirection = cameraTransformation * QVector3D(0, 1, 0);

    vMatrix.lookAt(cameraPosition, QVector3D(0, 0, 0), cameraUpDirection);

    //! [6]
    shaderProgram.bind();
    shaderProgram.setUniformValue("mvpMatrix", pMatrix * vMatrix * mMatrix);
    shaderProgram.setUniformValue("texture", 0);


    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, tex.id);
    glActiveTexture(0);


    shaderProgram.setAttributeArray("vertex", vertices.constData());
    shaderProgram.enableAttributeArray("vertex");
    shaderProgram.setAttributeArray("textureCoordinate", textureCoordinates.constData());
    shaderProgram.enableAttributeArray("textureCoordinate");

    glDrawArrays(GL_TRIANGLES, 0, vertices.size());

    shaderProgram.disableAttributeArray("vertex");
    shaderProgram.disableAttributeArray("textureCoordinate");
    shaderProgram.release();
}

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I tested the program again, it receives a few packets and then gives segmentation fault at line:

gluBuild2DMipmaps(GL_TEXTURE_2D, GL_RGB, 800, 600, GL_RGB, GL_UNSIGNED_BYTE, tex.buf);

before this error, the widget looks some garbage colors.