BiomePainter.BitmapSelector.BitmapSelector.Redraw C# (CSharp) Method

        public void Redraw()
        {
            if (g == null)
                return;

            g.Clear(Color.White);
            g.InterpolationMode = InterpolationMode.NearestNeighbor;

            ColorMatrix cm = new ColorMatrix();
            ImageAttributes ia = new ImageAttributes();
            Rectangle dest = new Rectangle(0, 0, this.Width, this.Height);
            Rectangle source = new Rectangle(OffsetX, OffsetY, (int)Math.Round(((double)this.Width) / ((double)Magnification)), (int)Math.Round(((double)this.Height) / ((double)Magnification)));
            for (int i = Layers.Count - 1; i >= 0; i--)
            {
                if (!Layers[i].Visible)
                    continue;
                cm.Matrix33 = Layers[i].Opacity;
                ia.SetColorMatrix(cm);
                g.DrawImage(Layers[i].Image, dest, source.X, source.Y, source.Width, source.Height, GraphicsUnit.Pixel, ia);
            }

            if (scrollHorizontal.Visible && scrollVertical.Visible)
            {
                //draw over the corner between the scrollbars
                dest = new Rectangle(scrollVertical.Location.X, scrollHorizontal.Location.Y, scrollVertical.Width, scrollHorizontal.Height);
                Brush b = new SolidBrush(SystemColors.Control);
                g.FillRectangle(b, dest);
                b.Dispose();
            }

            this.Refresh();
        }