MetroFramework.Controls.MetroProgressSpinner.OnPaintForeground C# (CSharp) 메소드

        protected virtual void OnPaintForeground(PaintEventArgs e)
        {
            Color foreColor;

            if (useCustomBackground)
            {
                foreColor = MetroPaint.GetStyleColor(Style);
            }
            else
            {
                if (Parent is MetroTile)
                {
                    foreColor = MetroPaint.ForeColor.Tile.Normal(Theme);
                }
                else
                {
                    foreColor = MetroPaint.GetStyleColor(Style);
                }
            }

            using (Pen forePen = new Pen(foreColor, (float)Width / 5))
            {
                int padding = (int)Math.Ceiling((float)Width / 10);

                e.Graphics.SmoothingMode = System.Drawing.Drawing2D.SmoothingMode.HighQuality;

                if (progress != -1)
                {
                    float sweepAngle;
                    float progFrac = (float)(progress - minimum) / (float)(maximum - minimum);

                    if (ensureVisible)
                    {
                        sweepAngle = 30 + 300f * progFrac;
                    }
                    else
                    {
                        sweepAngle = 360f * progFrac;
                    }

                    if (backwards)
                    {
                        sweepAngle = -sweepAngle;
                    }

                    e.Graphics.DrawArc(forePen, padding, padding, Width - 2 * padding - 1, Height - 2 * padding - 1, angle, sweepAngle);
                }
                else
                {
                    const int maxOffset = 180;
                    for (int offset = 0; offset <= maxOffset; offset += 15)
                    {
                        int alpha = 290 - (offset * 290 / maxOffset);

                        if (alpha > 255)
                        {
                            alpha = 255;
                        }
                        if (alpha < 0)
                        {
                            alpha = 0;
                        }

                        Color col = Color.FromArgb(alpha, forePen.Color);
                        using (Pen gradPen = new Pen(col, forePen.Width))
                        {
                            float startAngle = angle + (offset - (ensureVisible ? 30 : 0)) * (backwards ? 1 : -1);
                            float sweepAngle = 15 * (backwards ? 1 : -1);
                            e.Graphics.DrawArc(gradPen, padding, padding, Width - 2 * padding - 1, Height - 2 * padding - 1, startAngle, sweepAngle);
                        }
                    }
                }
            }

            OnCustomPaintForeground(new MetroPaintEventArgs(Color.Empty, foreColor, e.Graphics));
        }