/********************************************************************
* Height map
* _heightmap_form
********************************************************************/
        private void heightMapToolStripMenuItem_Click(object sender, EventArgs e)
        {
            if (_heightmap_form == null)
            {
                _heightmap_form             = new ControlHeightMapForm();
                _heightmap_form.FormClosed += formClosed_HeightmapForm;
                _heightmap_form.btnStartHeightScan.Click             += getGCodeScanHeightMap; // in MainFormGetCodeTransform
                _heightmap_form.loadHeightMapToolStripMenuItem.Click += loadHeightMap;         // in MainFormGetCodeTransform
                _heightmap_form.btnApply.Click += applyHeightMap;                              // in MainFormGetCodeTransform
                _heightmap_form.RaiseXYZEvent  += OnRaisePositionClickEvent;                   // in MainForm
                _heightmap_form.btnGCode.Click += getGCodeFromHeightMap;                       // in MainFormGetCodeTransform
            }
            else
            {
                _heightmap_form.Visible = false;
            }
            _heightmap_form.Show(this);
            _heightmap_form.WindowState = FormWindowState.Normal;
        }
 private void formClosed_HeightmapForm(object sender, FormClosedEventArgs e)
 {
     _heightmap_form = null;
     VisuGCode.clearHeightMap();
     _serial_form.stopStreaming();
 }