edit: .NET ScrollBar code

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{{
/* We want the final ratio of LargeChange to Maximum to
 * represent the ratio of panInner visible to total panInner.
 * However, if we only adjust LargeChange, then the range of values
 * available is Maximum - LargeChange, so we must adjust Maximum as well
 * (by adding LargeChange to it).  Doing this changes the ratio, so
 * we use algebra (yay!) to figure out what the initial ratio should be
 * in order to get the desired ratio.
 * 
 * L = LargeChange
 * r = ratio of panOuter.Width / panInner.Width (inital ratio)
 * m = Original maximum
 * M = new maximum after adjusted with LargeChange (adjusted maximum)
 * R = new ratio with new maximum (desired ratio)
 *
 * L = m * r
 * M = m + L
 * R = L / M
 *   = m * r / (m + m * r)
 *   = r / (1 + r)
 * R + r * R = r
 * r = R / (1 - R)
 * */

int iLarge;
int iMax;
float fRatio;

iMax = panInner.Width - panOuter.Width - 1;

if (bShowHSC)
{
    fRatio = (float)panOuter.Width / panInner.Width;
    fRatio /= (1 - fRatio);
    iLarge = (int)(fRatio * iMax);

hsc.Maximum = iMax + iLarge;
    hsc.LargeChange = iLarge;
    hsc.SmallChange = 4;

// if panInner is scrolled further than the new maximum, move it back
    if (-panInner.Left > iMax)
        panInner.Left = -iMax;

hsc.Top = this.Height - hsc.Height - miOffset;
    hsc.Width = panOuter.Width - miOffset + 1 + (hsc.Visible ? 0 : 1);
    hsc.Visible = true;
}

iMax = panInner.Height - panOuter.Height - 1;

if (bShowVSC)
{
    fRatio = (float)panOuter.Height / panInner.Height;
    fRatio /= 1 - fRatio;
    iLarge = (int)(fRatio * iMax);

vsc.Maximum = iMax + iLarge;
    vsc.LargeChange = iLarge;
    vsc.SmallChange = 4;

if (-panInner.Top > iMax)
        panInner.Top = -iMax;

vsc.Left = this.Width - vsc.Width - miOffset;
    vsc.Height = panOuter.Height - miOffset + 1 + (vsc.Visible ? 0 : 1);
    vsc.Visible = true;
}

if (bHSC != bShowHSC || bVSC != bShowVSC)
    this.OnScrollVisibleChanged(new EventArgs());
}}

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