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OpenGL Translate, Rotate and mouse coordinates

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Hello.
I have problem with my application. When I click left mouse button and move with mouse, it change translation. When I click right mouse button and move with mouse, it change rotation. When I press 'a' and click, gluSphere will be draw at mouse coordinates in openGL. Drawing , rotation and translation work fine, but mouse coordinates that I calculate are wrong. So spheres will draw at a strange places. I read a lot of tutorials and forums, but I still dont know where I do mistake. I make it in C#.

Here is a part of my code:
Mouse and Keyboard events:
[CODE]
private void openGL_MouseWheel(object sender, MouseEventArgs e)
{
if (e.Delta > 0)
zoom += 1;
else
zoom -= 1f;

Invalidate();
glDraw();
}

private void openGL_MouseMove(object sender, MouseEventArgs e)
{
if (MouseD == 2)
{
yrot -= (mouX - e.Location.X)/5;
if ((yrot > 360) || (yrot < -360)) yrot = 0;
xrot -= (mouY - e.Location.Y)/5;
if ((xrot > 360) || (xrot < -360)) xrot = 0;
}

if (MouseD == 1)
{
xpos -= (mouX - e.Location.X) / 100;
ypos += (mouY - e.Location.Y) / 100;
}

if ((MouseD == 1) | (MouseD == 2))
{
Invalidate();
glDraw();
}

mouX = e.Location.X;
mouY = e.Location.Y;

}

private void openGL_MouseUp(object sender, MouseEventArgs e)
{
BodGL bod;

if ((AtrBod == true) & (MouseD == 0))
{
pocetAtrBodov++;

bod = new BodGL();
bod.Quad = GLU.gluNewQuadric();
bod.bod = new Bod();
bod.bod.Pozicia = openGLPos(e.Location.X, e.Location.Y);
bod.bod.Typ = 1;
bod.bod.Farba = new Vektor(0.5, 0.5, 0.5);

poleBodov.Add(bod);

Invalidate();
glDraw();
}

MouseD = 0;

}

private void openGL_MouseDown(object sender, MouseEventArgs e)
{
if (e.Button == System.Windows.Forms.MouseButtons.Right)
MouseD = 2;
else
if (AtrBod) MouseD = 0; else MouseD = 1;
}

private void openGL_KeyDown(object sender, KeyEventArgs e)
{
if (e.KeyCode == Keys.A) AtrBod = true;
}

private void openGL_KeyUp(object sender, KeyEventArgs e)
{
AtrBod = false;
}
[/CODE]

Calculate openGL coordinates from mouse window coordinates(I thing, here is mistake):
[CODE]
private Vektor openGLPos(int x, int y)
{
int[] viewport = new int[4];
double[] modelview = new double[16];
double[] projection = new double[16];
double outX, outY, outZ;

GL.glGetDoublev( GL.GL_MODELVIEW_MATRIX, modelview );
GL.glGetDoublev( GL.GL_PROJECTION_MATRIX, projection );
GL.glGetIntegerv( GL.GL_VIEWPORT, viewport );

Vektor win = new Vektor((float)x, (float)viewport[3] - y, 0f);

unsafe
{
GL.glReadPixels(x, (int)win.Y, 1, 1, GL.GL_DEPTH_COMPONENT, GL.GL_FLOAT, (&outZ));
}

GL.gluUnProject((float)win.X, (float)win.Y, (float)win.Z, modelview, projection, viewport, out outX, out outY, out outZ);

Vektor temp = new Vektor(outX, outY, outZ - 10);

return temp;
}
[/CODE]

And draw method:
[CODE]
public override void glDraw()
{

GL.glClear(GL.GL_COLOR_BUFFER_BIT | GL.GL_DEPTH_BUFFER_BIT);

GL.glPushMatrix();
GL.glLoadIdentity();

GL.glTranslatef(xpos, ypos, zoom);
GL.glRotatef(xrot, 1.0f, 0.0f, 0.0f);
GL.glRotatef(yrot, 0.0f, 1.0f, 0.0f);


if (pocetAtrBodov > 0)
{
foreach (BodGL B in poleBodov)
{
VykresliAtrBod(B.Quad, B.bod.Priemer, B.bod.Farba);
}
}

GL.glPopMatrix();
}


private void VykresliAtrBod(GLUquadric Q, double r , Vektor farba)
{
unsafe
{
GL.glColor3f((float)farba.X, (float)farba.Y, (float)farba.Z);

GL.gluQuadricDrawStyle(Q, GL.GLU_SILHOUETTE); /* smooth shaded */
GL.gluQuadricNormals(Q, GL.GLU_SMOOTH);


GL.gluSphere(Q, r, 10, 10);

}
}
[/CODE]

Please is here somebody, who can help me?

Thank you very much and please sorry about my english.

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