Rotate opengl view with mouse position?

Hi, I struggled a lot to load OBJ files, then I found GLM library and Im amazed how easy,
then I took my old QT OpenGL code,
and Ive started making a new FPS view game.
Problem is, I have no experience in how to rotate the view.

Here's how I rotate (xRot = 0, yRot = 0)

Code:

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glRotatef(xRot+speedX, 0, 0.01f, 0);
    glRotatef(yRot+speedY, 0.01f, 0, 0);

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and here's how I make rotation with speedX and speedY:

Code:

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void GLWidget::mouseMoveEvent(QMouseEvent *event) {
    if(event->x() != this->width()/2 && event->y() != this->height()/2) {
        speedX += (float)event->x()/500;
        speedY +=  (float)event->y()/500;
    }
 
//Mouse mouse to Center in Linux
    dpy = XOpenDisplay(0);
    root_window = XRootWindow(dpy, 0);
    XSelectInput(dpy, root_window, KeyReleaseMask);
    XWarpPointer(dpy, None, root_window, 0, 0, 0, 0, this->width()/2, this->height()/2);
    XFlush(dpy); // Flushes the output buffer, therefore updates the cursor's position. Thanks to Achernar.
    XCloseDisplay(dpy);
}

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And here's full Code, if it interests anybody (its in one file):

Code:

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#include <QtGui/QApplication>
#include <QtOpenGL/QGLWidget>
#include <QtGui/QMouseEvent>
#include <GL/glu.h>
#include <QTimer>
#include <QThread>
#include <QCursor>
#include <X11/Xlib.h>
#include <math.h>
#include <GL/glfw.h>
#include "glm.h"
#define screenWidth 800
#define screenHeight 600
 
#define PI 3.14159265358979
float cameraX, cameraY, cameraZ;
float xMove, yMove, zMove;
float angleX = 0;
float angleY = 0;
float angleZ = 0;
float xRot = 0;
float yRot = 0;
float zRot = 0;
float z = 1.0f;
float speedX = 0.0f;
float speedY = 0.0f;
GLMmodel *model = 0;
Display *dpy;
Window root_window;
 
class GLWidget : public QGLWidget{
public:
    GLWidget();
    void initializeGL();
    void resizeGL(int w, int h);
    void paintGL();
    void mousePressEvent(QMouseEvent *event);
    void mouseMoveEvent(QMouseEvent *event);
    void keyPressEvent(QKeyEvent *event);
private slots:
    void updateGL();
private:
    QTimer glUpdateTime;
};
 
GLWidget::GLWidget() {
    connect(&glUpdateTime, SIGNAL(timeout()), this, SLOT(updateGL()));
    glUpdateTime.start(1);
    setMouseTracking(true);
}
 
void GLWidget::updateGL() {
    this->update();
}
 
void GLWidget::initializeGL() {
    glDisable(GL_TEXTURE_2D);
    glDisable(GL_DEPTH_TEST);
    glDisable(GL_COLOR_MATERIAL);
    glEnable(GL_BLEND);
    glEnable(GL_POLYGON_SMOOTH);
    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
    glClearColor(0, 0, 0, 0);
    cameraX = 0;
    cameraY = 0;
    cameraZ = -10;
}
 
void GLWidget::resizeGL(int w, int h) {
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluPerspective(40.0,(GLdouble)w/(GLdouble)h,0.5,20.0);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();
    glViewport(0, 0, w, h);
}
 
void GLWidget::paintGL() {
    if(!model) {
        model = glmReadOBJ("/home/marcus/untitled/untitled.obj");
        glmUnitize(model);
        glmFacetNormals(model);
        glmVertexNormals(model, 90.0);
    }
 
    glClear(GL_COLOR_BUFFER_BIT);
    glLoadIdentity();
    glTranslatef(0, 0, -z);
    glRotatef(xRot+speedX, 0, 0.01f, 0);
    glRotatef(yRot+speedY, 0.01f, 0, 0);
    glTranslatef(cameraX + xMove, cameraY + yMove, cameraZ + zMove);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL);
    glTranslatef(-2.0f, 0.0f, 0.0f);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL);
    glTranslatef(-2.0f, 0.0f, 0.0f);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL);
    glTranslatef(-2.0f, 0.0f, 0.0f);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL);
    glTranslatef(-2.0f, 0.0f, 0.0f);
    glmDraw(model, GLM_SMOOTH | GLM_MATERIAL);
}
void GLWidget::mousePressEvent(QMouseEvent *event) {
 
}
void GLWidget::mouseMoveEvent(QMouseEvent *event) {
    if(event->x() != this->width()/2 && event->y() != this->height()/2) {
        speedX += (float)event->x()/500;
        speedY +=  (float)event->y()/500;
    }
    dpy = XOpenDisplay(0);
    root_window = XRootWindow(dpy, 0);
    XSelectInput(dpy, root_window, KeyReleaseMask);
    XWarpPointer(dpy, None, root_window, 0, 0, 0, 0, this->width()/2, this->height()/2);
    XFlush(dpy); // Flushes the output buffer, therefore updates the cursor's position. Thanks to Achernar.
    XCloseDisplay(dpy);
}
void GLWidget::keyPressEvent(QKeyEvent* event) {
    switch(event->key()) {
    case Qt::Key_Escape:
        close();
        break;
    case Qt::Key_W:
        zMove += 0.35f;
        break;
    case Qt::Key_S:
        zMove -= 0.35f;
        break;
    case Qt::Key_A:
        xMove += 0.35f;
        break;
    case Qt::Key_D:
        xMove -= 0.35f;
        break;
    default:
        event->ignore();
break;
}
}
int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    GLWidget window;
    window.resizeGL(screenWidth, screenHeight);
    window.showFullScreen();
    a.exec();
}

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Thanks in advance.