opengl 鼠标拾取

 

 

void GLWidget::HitGet(QPoint pos)
{
    GLuint NameBuffer[27];
    GLint viewport[4];
    GLint hits;

    glGetIntegerv (GL_VIEWPORT, viewport);
    glSelectBuffer(27,NameBuffer);
    glRenderMode(GL_SELECT);

    glInitNames();
    glPushName(0);

    glMatrixMode(GL_PROJECTION);
    glPushMatrix();
    glLoadIdentity();

    gluPickMatrix((GLdouble)pos.x(),(GLdouble)(viewport[3]-pos.y()),5,5,viewport);
    glOrtho(0, 600, 0, 600, 4.0, 15.0);
    qDebug()<<"viewport"<<viewport[0]<<" "<<pos<<(GLdouble)pos.x()<<viewport[3]-(GLdouble)(pos.y());
    glMatrixMode(GL_MODELVIEW);
    for(int i=0;i<10;i++){
        glLoadName(i);
        Data::nodes[i].Draw();
    }

    
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    hits=glRenderMode(GL_RENDER);
    qDebug()<<hits;
    if(hits>0)
    {
        qDebug()<<NameBuffer[0]<<NameBuffer[1]<<NameBuffer[3];
    }
}

 

 

 

void GLWidget::MousePick(QPoint pos)
{
#ifndef SIZE
#define SIZE 30
    GLuint NameBuffer[SIZE];    //名称缓存
    GLint viewport[4];        //视点
    GLint hits;

    //设置选择模式参数
    glSelectBuffer(SIZE,NameBuffer);
    glGetIntegerv (GL_VIEWPORT, viewport);
    glMatrixMode(GL_PROJECTION);
    glRenderMode(GL_SELECT);

    //保存矩阵
    glPushMatrix();
    glLoadIdentity();

    //拾取对象
    gluPickMatrix((GLdouble)pos.x(),(GLdouble)(viewport[3]-pos.y()),5,5,viewport);
    glOrtho(0, 600, 0, 600, 4.0, 15.0);
    glMatrixMode(GL_MODELVIEW);
    glInitNames();
    glPushName(0);
    Paint(GL_SELECT);
    glMatrixMode(GL_PROJECTION);
    glPopMatrix();
    glFlush();
    hits=glRenderMode(GL_RENDER);
    qDebug()<<hits;
    if(hits>0)
    {
        qDebug()<<NameBuffer[0]<<NameBuffer[1]<<NameBuffer[2]<<NameBuffer[3]<<NameBuffer[4]<<NameBuffer[5];
    }

#endif
}