private void OnRender(object sender, double delta)
{
GLDraw.Fill(ref backgroundColor);
var root = (PBTTaskTreeControl <DataType>)TreeContainer.Controls.First().Controls.FirstOrDefault(c => c is PBTTaskTreeControl <DataType>);
if (root != null)
{
lines.Clear();
float scale = Math.Min(InnerWidth / (float)root.Width, InnerHeight / (float)root.Height);
RenderSubtree(root, 0, 0, scale);
GLDraw.PrepareCustomDrawing();
var sr = GLDraw.CurrentScreenRect;
GL.Color3(Color.White);
GL.LineWidth(scale);
GL.Enable(EnableCap.LineSmooth);
GL.Begin(PrimitiveType.Lines);
for (int i = 0; i < lines.Count; i++)
{
GL.Vertex2(sr.X + lines[i].Item1.X, sr.Y + lines[i].Item1.Y);
GL.Vertex2(sr.X + lines[i].Item2.X, sr.Y + lines[i].Item2.Y);
}
GL.End();
GL.LineWidth(2.0f);
GL.Begin(PrimitiveType.LineLoop);
GL.Vertex2(sr.X + TreeContainer.ScrollPosition.X * scale, sr.Y + TreeContainer.ScrollPosition.Y * scale);
GL.Vertex2(sr.X + (TreeContainer.ScrollPosition.X + TreeContainer.InnerWidth) * scale, sr.Y + TreeContainer.ScrollPosition.Y * scale);
GL.Vertex2(sr.X + (TreeContainer.ScrollPosition.X + TreeContainer.InnerWidth) * scale, sr.Y + (TreeContainer.ScrollPosition.Y + TreeContainer.InnerHeight) * scale);
GL.Vertex2(sr.X + TreeContainer.ScrollPosition.X * scale, sr.Y + (TreeContainer.ScrollPosition.Y + TreeContainer.InnerHeight) * scale);
GL.End();
}
}