QT FBO

QOenGLFrameBufferObject这个要在initializeOpenGLFunctions()这之后才行

framebuffer=new QOpenGLFramebufferObject(w,h, QOpenGLFramebufferObject::Depth);

这个framebuffer->bind();release();

void MainWidget::paintGL()

{

    texture->bind();

    bool result=framebuffer->bind();

    if(result)

    // Clear color and depth buffer

   {

        glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

//! [6]

    // Calculate model view transformation

    QMatrix4x4 matrix;

    QMatrix4x4 view;

    view.lookAt(QVector3D(0,0,1.0),QVector3D(0,0.0,0.0),QVector3D(0,1.0,0.0));

   QVector3D lightPos(3.0f,0.0f,0.0f);

   { // Draw cube geometry

       {

           // Bind shader pipeline for use

           if (!program.bind())

              {close();}

        matrix.translate(-1.0,0.0, -5.0);

        matrix.rotate(rotation);

        QMatrix4x4 model=matrix;

        QMatrix4x4 transpose_inverse_model=model.inverted().transposed();

        program.setUniformValue("model",model);

        program.setUniformValue("transpose_inverse_model",transpose_inverse_model);

        program.setUniformValue("mvp_matrix", projection *view* matrix);

   // Use texture unit 0 which contains cube.png

       program.setUniformValue("texture", 0);

       //program.setUniformValue("objectColor", 1.0f, 0.5f, 0.31f);

       program.setUniformValue("lightColor", 1.0f, 0.5f, 1.0f);

       program.setUniformValue("lightPos",lightPos);

       program.setUniformValue("viewPos",QVector3D(0,0,1.0));

       geometries->drawCubeGeometry(&program);

       }

       {           

            if (!program2.bind())

               {close();}

            //texture->bind();

            QMatrix4x4 m2;

            m2.translate(3.0, 0.0, -0.0);

            m2.scale(QVector3D(0.5,0.5,0.5));

            program2.setUniformValue("mvp_matrix", projection* m2);

            geometries->drawCubeGeometry(&program2);

       }

   }

  GLuint tid=framebuffer->texture();

  framebuffer->release();

  glBindTexture(GL_TEXTURE_2D, tid);

  view.lookAt(QVector3D(0,0,1.0),QVector3D(0,0.0,0.0),QVector3D(0,1.0,0.0));

 { 

     {

         // Bind shader pipeline for use

         if (!program.bind())

            {close();}

      matrix.translate(-1.0,0.0, -5.0);

      matrix.rotate(rotation);

      QMatrix4x4 model=matrix;

      QMatrix4x4 transpose_inverse_model=model.inverted().transposed();

      program.setUniformValue("model",model);

      program.setUniformValue("transpose_inverse_model",transpose_inverse_model);

      program.setUniformValue("mvp_matrix", projection *view* matrix);

 // Use texture unit 0 which contains cube.png

     program.setUniformValue("texture", 0);

     //program.setUniformValue("objectColor", 1.0f, 0.5f, 0.31f);

     program.setUniformValue("lightColor", 1.0f, 0.5f, 1.0f);

     program.setUniformValue("lightPos",lightPos);

     program.setUniformValue("viewPos",QVector3D(0,0,1.0));

     geometries->drawCubeGeometry(&program);

     }

     {

         // program.release();

           //Link shader pipeline

         //program.destroyed();

          if (!program2.bind())

             {close();}

          //texture->bind();

          QMatrix4x4 m2;

          m2.translate(3.0, 0.0, -0.0);

          m2.scale(QVector3D(0.5,0.5,0.5));

          //matrix.rotate(rotation);

          program2.setUniformValue("mvp_matrix", projection* m2);

          geometries->drawCubeGeometry(&program2);

     }

 }

    }

    glBindTexture(GL_TEXTURE_2D,0);

}