Azmyth.Editor.GridControl.PaintGrid C# (CSharp) Method

        private void PaintGrid(Graphics g)
        {
            RectangleF bounds = g.VisibleClipBounds;

            int startCol = (int)(bounds.Left / m_cellWidth);
            int endCol = (int)(bounds.Right / m_cellWidth);
            for (int col = startCol; col <= endCol; col++)
            {
                float x = col * m_cellWidth;
                g.DrawLine(m_gridPen, x, bounds.Top, x, bounds.Bottom);
            }

            int startRow = (int)(bounds.Top / m_cellHeight);
            int endRow = (int)(bounds.Bottom / m_cellHeight);
            for (int row = startRow; row <= endRow; row++)
            {
                float y = row * m_cellHeight;
                g.DrawLine(m_gridPen, bounds.Left, y, bounds.Right, y);
            }

            Matrix viewportMatrix = g.Transform.Clone();
            Point[] points = new Point[] { new Point(0, 0) };
            viewportMatrix.Invert();
            viewportMatrix.TransformPoints(points);
            Point transformedOrigin = points[0];

            int viewportX = (int)System.Math.Floor(transformedOrigin.X / m_cellWidth);
            int viewportY = (int)System.Math.Floor(transformedOrigin.Y / m_cellHeight);

            m_viewport = new Rectangle(viewportX, viewportY, (int)(bounds.Width / m_cellWidth) + 1, (int)(bounds.Height / m_cellHeight) + 1);
        }